S-8323/8327 Series. Rev. 7.1 SMALL PACKAGE PWM CONTROL STEP-UP SWITCHING REGULATOR

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1 Rev. 7.1 SMALL PACKAGE PWM CONTROL STEPUP SWITCHING REGULATOR S8323/8327 Series The S8323/8327 Series is a CMOS PWMcontrol stepup switching regulator which mainly consists of a reference voltage source, an oscillation circuit, a power MOS FET (for S8323 Series), and an error amplifier. Equipped with bestdesigned control circuits, the products maintain high efficiency over a wide range of conditions with the capability of automatically controlling the duty ratio from % to 83% (78% for 25kHz model) according to each applied load. A stepup switching regulator is constructed by externally connecting only a coil, a capacitor and a diode to the S8323 Series. This feature, along with its small package and low current consumption, makes the S8323 Series ideal for the power supply of portable equipment. For applications requiring a high output current, products used with an external transistor (S8327 Series) are also available. Features Low voltage operation:.9v(i OUT =1mA, 5kHz and khz models) Low current consumption : During operation: 17.2µA (typ.) ( = 3 V, 5 khz) During shutdown:.5µa (max.) Duty ratio: Builtin PWM control circuit External parts: coil, diode, and capacitor only (a transistor is needed for the S8327 Series.) voltage: accuracy of ±2.4% Applications Oscillation frequency: 3kHz, 5kHz, khz, and 25kHz Software start function is builtin Shutdown function External transistor type is available (S8327 Series) SOT235 small plastic package SOT233 small plastic package SOT893 miniature power molded plastic package Stepdown and voltageinverting type are available. Power supplies for portable equipment such as pagers, handy calculators, and remote controllers Constant voltage power supplies for cameras, video equipment, and communications equipment Power supply for microcomputers Block Diagram (1) S8323 Series (Types A, C, H) (2) S8327 Series (Types B, H) CONT PWM control circuit VREF EXT PWM control circuit VREF Soft start circuit V SS Soft start circuit V SS ON/ OFF (3) S8323 Series (Types D, J) ON/ OFF (4) S8327 Series (Types E, J) CONT V DD PWM control circuit VREF V DD EXT PWM control circuit VREF Soft start circuit V SS Soft start circuit V SS Figure 1 Block Diagram Seiko Instruments Inc. 1

2 SMALL PACKAGE PWM CONTROL STEPUP SWITCHING REGULATOR S8323/8327 Series Rev. 7.1 Selection Guide 1. Product Name S832 X X XX XX XXX T2 Tape Specification Product name (abbreviation) Package name (abbreviation) MA : SOT233 (without shutdown function) MC : SOT235 (with shutdown function, V DD / separate product) UA : SOT893 (without shutdown function) voltage x 1 Product category A : Normal product, fosc=5 khz (S8323 only) B : Normal product, fosc= khz (S8327 only) C : For pagers, fosc=3 khz (S8323 only) D : V DD / separate product, fosc=5 khz (S8323 only) E : V DD / separate product, fosc= khz (S8327 only) H : Normal product, fosc=25 khz (S8323/7) J : V DD / separate product, fosc=25 khz (S8323/7) 2. Function List Power transistor 3: Builtin switch. 7: External transistor. Product Name Built In power transistor with external power transistor Switching frequency (khz) shutdown function V DD/ separate type Package Application Reference page S8323AXXMC Yes 5 Yes SOT235 With shutdown function S8323AXXMA Yes 5 SOT233 Without shutdown function S8323AXXUA Yes 5 SOT893 Without shutdown function S8323DXXMC Yes 5 Yes SOT235 For variable output voltage by stepup DC/DC converter and stepdown, inverted output DC/DC converter with an external resistor Page 2 S8323CXXMA Yes 3 SOT233 For pagers S8323HXXMC Yes 25 Yes SOT235 With shutdown function S8323JXXMC Yes 25 Yes SOT235 For variable output voltage by stepup DC/DC converter and Page 2 stepdown, inverted output DC/DC converter with an external resistor S8327BXXMC Yes Yes For large load current with SOT235 shutdown function Pages 19 S8327BXXMA Yes For large load current without SOT233 shutdown function Pages 19 S8327BXXUA Yes For large load current without SOT893 shutdown function Pages 19 S8327EXXMC Yes Yes For variable output voltage by Pages 19 and SOT235 stepup DC/DC converter with an 2 external resistor S8327HXXMC Yes 25 Yes SOT235 For large load current without shutdown function Pages 19 S8327JXXMC Yes 25 Yes SOT235 For variable output voltage by stepup DC/DC converter with an external resistor Pages 19 and 2 2 Seiko Instruments Inc.

3 Rev. 7.1 SMALL PACKAGE PWM CONTROL STEPUP SWITCHING REGULATOR S8323/8327 Series 3. Product list voltage S8323AXXMC Series S8323AXXMA Series S8323AXXUA Series S8323CXXMA Series S8323DXXMC Series 2. S8323D2MCEZAT2 2.5 S8323A25MCELFT2 S8323A25MAELFT2 S8323A25UAELFT2 S8323C25MAENFT2 2.7 S8323A27MCELHT2 S8323A27MAELHT2 S8323A27UAELHT2 S8323C27MAENHT2 3. S8323A3MCELKT2 S8323A3MAELKT2 S8323A3UAELKT2 S8323C3MAENKT2 S8323D3MCEZKT2 3.3 S8323A33MCELNT2 S8323A33MAELNT2 S8323A33UAELNT2 5. S8323A5MCEMET2 S8323A5MAEMET2 S8323A5UAEMET2 S8323D5MCE3ET2 5.2 S8323A52MCEMGT2 voltage S8323HXXMC Series S8323JXXMA Series 2.5 S8323J25MCFQFT S8323H33MCF4NT2 5. S8323H5MCF5ET2 S8323J5MCFRET2 voltage S8327BXXMC Series S8327BXXMA Series S8327BXXUA Series S8327EXXMC Series 2. S8327E2MCEVAT2 2.5 S8327B25MCERFT2 S8327B25MAERFT2 S8327B25UAERFT2 2.7 S8327B27MCERHT2 S8327B27MAERHT2 S8327B27UAERHT2 2.8 S8327B28MCERIT2 3. S8327B3MCERKT2 S8327B3MAERKT2 S8327B3UAERKT2 3.3 S8327B33MCERNT2 S8327B33MAERNT2 S8327B33UAERNT2 3.6 S8327B36MCERQT2 5. S8327B5MCESET2 S8327B5MAESET2 S8327B5UAESET2 S8327E5MCEKET2 5.4 S8327B54MCESIT2 voltage S8327HXXMC Series S8327JXXMA Series 2.5 S8327J25MCF8FT2 3. S8327H3MCFWKT2 3.3 S8327H33MCFWNT2 5. S8327H5MCFXET2 S8327J5MCF9ET2 Consult our sales person for products with an output voltage other than specified above. Seiko Instruments Inc. 3

4 SMALL PACKAGE PWM CONTROL STEPUP SWITCHING REGULATOR S8323/8327 Series Rev. 7.1 Pin Assignment SOT235 Top view SOT233 Top view SOT893 Top view Figure 2 S8323AXXMC, S8327BXXMC S8323HXXMC/S8327HXXMC SOT235 Pin No. Pin name Functions Shutdown pin H : 1 ON / OFF normal operation (stepping up operation) L : stop stepping up (whole circuit stop) 2 voltage pin and power supply pin 3 N.C. (Non Connection) 4 V SS GND pin 5 CONT External inductor connection pin (for S8323 Series) EXT External transistor connection pin (for S8327 Series) S8323DXXMC, S8327EXXMC S8323JXXMC/S8327JXXMC SOT235 Pin No. Pin name Functions 1 voltage pin 2 V DD Power supply pin 3 N.C. (Non Connection) 4 V SS GND pin 5 CONT External inductor connection pin (for S8323 Series) EXT External transistor connection pin (for S8327 Series) S8323AXXMA, S8323AXXUA, S8323CXXMA S8327BXXMA, S8327BXXUA SOT233, SOT893 Pin No. Pin name Functions 1 V SS GND pin 2 pin and power voltage supply pin 3 CONT External inductor connection pin (for S8323 Series) EXT External transistor connection pin (for S8327 Series) Absolute Maximum Ratings Note: A protect circuit for static electricity is built into this IC chip. However, prevent a charge of static electricity which exceeds the capacity of the protect circuit. Parameter Symbol Ratings Unit, V DD pin voltage, V DD 11 V ON/OFF pin voltage ON/OFF V ss.3 to 11 V CONT pin voltage V CONT 11 V CONT pin current I CONT 3 ma EXT pin voltage V EXT V ss.3 to.3 V EXT pin current I EXT ±5 ma Power dissipation PD SOT893 5 mw SOT235, SOT ( Unless otherwise specified: Ta=25 C) Operating temperature T OPR 4 to 85 C Storage temperature T STG 4 to 125 C 4 Seiko Instruments Inc.

5 Rev. 7.1 SMALL PACKAGE PWM CONTROL STEPUP SWITCHING REGULATOR S8323/8327 Series Electrical Characteristics 11. S8323AXXMC (Unless otherwise specified: Ta=25 C) Parameter Symbol Conditions Min. Typ. Max. Unit Test circuit S8323A52MC S8323A5MC voltage S8323A33MC S8323A3MC S8323A27MC V 1 S8323A25MC Input voltage V IN 9 Operation start voltage V ST1 I OUT=1mA.9 Oscillation start voltage V ST2 No external parts, voltage applied to.8 2 CONT pulled up to 5 V by 1kΩ Operation holding voltage V HLD I OUT=1mA, Measured by decreasing V IN voltage.7 1 graduelly S8323A52MC S8323A5MC Current consumption 1 I SS1 =output voltage.95 S8323A33MC S8323A3MC S8323A27MC S8323A25MC S8323A52MC µa 2 S8323A5MC Current consumption 2 I SS2 =output voltage.5 S8323A33MC S8323A3MC S8323A27MC S8323A25MC Current consumption during I SSS shutdown pin=v.5 shutdown S8323A52MC S8323A5MC Switching current I SW VCONT=.4V S8323A33MC ma S8323A3MC S8323A27MC S8323A25MC Switchin transistor leak I SWQ = VCONT=1V 1. µa current Line regulation 1 V IN=output voltage.4 to mv Load regulation 2 I OUT=1µA to I OUT(below) S8323A52MC ±.26 voltage S8323A5MC ±.25 1 temperature / Ta Ta=4 C to 85 C S8323A33MC ±.17 mv/ C coefficient S8323A3MC ±.15 S8323A27MC ±.14 S8323A25MC ±.13 Oscillation frequency fosc =output voltage khz 2 Measured waveform at CONT pin Max. duty ratio MaxDuty =output voltage % Measured waveform at CONT pin Shutdown pin V SH =output voltage.95 Judged the oscillation at CONT pin.75 Input voltage V SL1 =output voltage.95 When.3 V (ON/OFF type) 1.5V V SL2 Judged the stop of oscillation at CONT pin When <1.5V.2 Soft start time T SS ms S8323A52MC 87 S8323A5MC 87 EFFI S8323A33MC 83 % 1 S8323A3MC 83 S8323A27MC 79 S8323A25MC 79 External parts used: Coil: CD54 (µh) of Sumida Electric Co., Ltd. Diode: MA72 (Schottky type) of Matsushita Electronic Components Co., Ltd. Capacitor: F93 (16V, 22µF, tantalum type) of Nichicon Corporation Applied V IN=output voltage.6, applied, I OUT=output voltage/25ω The shutdown pin is connected to pin. Note 1: The output voltage specified above is the typical value. Seiko Instruments Inc. 5

6 SMALL PACKAGE PWM CONTROL STEPUP SWITCHING REGULATOR S8323/8327 Series Rev S8323AXXMA, S8323AXXUA, S8323DXXMC (Unless otherwise specified: Ta=25 C) Parameter Symbol Conditions Min. Typ. Max. Unit Test circuit S8323X5XX S8323X33XX voltage S8323X3XX S8323X27XX V 1 S8323X25XX S8323X2XX Input voltage V IN 9 Operation start voltage V ST1 I OUT=1mA.9 Oscillation start voltage V ST2 No external parts, voltage applied to.8 2 CONT pulled up to 5 V by 1Ω Operation holding voltage V HLD I OUT=1mA, Measured by decreasing V IN.7 1 voltage gradually. S8323X5XX S8323X33XX Current consumption 1 I SS1 =output voltage.95 S8323X3XX S8323X27XX S8323X25XX S8323X2XX µa 2 S8323X5XX S8323X33XX Current consumption 2 I SS2 =output voltage.5 S8323X3XX S8323X27XX S8323X25XX S8323X2XX S8323X5XX S8323X33XX Switching current I SW VCONT=.4V S8323X3XX ma S8323X27XX S8323X25XX S8323X2XX Switchin transistor leak I SWQ = VCONT=9V 1. µa current Line regulation 1 V IN= output voltage.4 to mv Load regulation 2 I OUT=1µA to I OUT (below) S8323X5XX ±.25 voltage S8323X33XX ±.17 temperature / Ta Ta=4 C to 85 C S8323X3XX ±.15 mv/ C 1 coefficient S8323X27XX ±.14 S8323X25XX ±.13 S8323X2XX ±.1 Oscillation frequency fosc =output voltage khz Measured waveform at CONT pin 2 Max.duty ratio MaxDuty =output voltage.95 Measured waveform at CONT pin % Soft start time T SS ms S8323X5XX 87 S8323X33XX 83 EFFI S8323X3XX 83 % 2 S8323X27XX 79 S8323X25XX 79 S8323X2XX 75 External parts used: Coil: CD54 (µh) of Sumida Electric Co., Ltd. Diode: MA72 (Schottky type) of Matsushita Electronic Components Co., Ltd. Capacitor: F93 (16V, 22µF, tantalum type) of Nichicon Corporation Applied V IN=output voltage.6, I OUT=output voltage/25ω The V DD pin is connected to pin for V DD/ separate product. Note 1: Note 2: The output voltage specified above is the typical value. V DD/ Separate products: Boot operation is performed from V DD=.8V. However, 2. V or more for V DD is recommended to stabilize the output voltage and oscilation frequency. 6 Seiko Instruments Inc.

7 Rev. 7.1 SMALL PACKAGE PWM CONTROL STEPUP SWITCHING REGULATOR S8323/8327 Series 13. S8323CXXMA (Unless otherwise specified: Ta=25 C) Parameter Symbol Conditions Min. Typ. Max. Unit Test circuit S8323C3MA voltage S8323C27MA S8323C25MA V 1 Input voltage V IN 9 Operation start voltage V ST1 I OUT=1mA.9 Oscillation start voltage V ST2 No external parts, voltage applied to.8 2 CONT pulled up to 5 V by 1kΩ Operation holding voltage V HLD I OUT=1mA, Measured by decreasing V IN voltage.7 1 gradually. S8323C3MA Current consumption 1 I SS1 =output voltage.95 S8323C27MA S8323C25MA S8323C3MA µa 2 Current consumption 2 I SS2 =output voltage.5 S8323C27MA S8323C25MA S8323C3MA Switching current I SW VCONT=.4V S8323C27MA ma S8323C25MA Switching transistor leak I SWQ = VCONT=9V 1. µa current Line regulation 1 V IN= output voltage.4 to mv Load regulation 2 I OUT=1µA to I OUT (below) voltage S8323C3MA ±.15 1 temperature / Ta Ta=4 C to 85 C S8323C27MA ±.14 mv/ C coefficient S8323C25MA ±.13 Oscillation frequency fosc =output voltage khz Measured waveform at CONT pin 2 Max. duty ratio MaxDuty =output voltage.95 Measured waveform at CONT pin % Soft start time T SS ms S8323C3MA 81 EFFI S8323C27MA 77 % 2 S8323C25MA 77 External parts used: Coil: CD54 (µh) of Sumida Electric Co., Ltd. Diode: MA72 (Schottky type) of Matsushita Electronic Components Co., Ltd. Capacitor: F93 (16V, 22µF, tantalum type) of Nichicon Corporation Applied V IN=output voltage.6, I OUT=output voltage/25ω Note 1: The output voltage specified above is the typical value of the output voltage. Seiko Instruments Inc. 7

8 SMALL PACKAGE PWM CONTROL STEPUP SWITCHING REGULATOR S8323/8327 Series Rev S8323HXXMC (Unless otherwise specified: Ta=25 C) Parameter Symbol Conditions Min. Typ. Max. Unit Test circuit voltage S8323H33MC S8323H5MC Input voltage V IN 9 V 1 Operation start voltage V ST1 I OUT=1mA 1.4 Oscillation start voltage V ST2 No external parts, voltage applied to CONT pulled up to 5 V by 1kΩ Operation holding voltage V HLD I OUT=1mA, Measured by decreasing V IN voltage graduelly.7 1 Current consumption 1 =output voltage.95 S8323H33MC µa S8323H5MC Current consumption 2 I SS2 =output voltage.5 S8323H33MC S8323H5MC Current consumption during shutdown I SSS shutdown pin=v.5 Switching current I SW VCONT=.4V S8323H33MC ma S8323H5MC Switchin transistor leak I SWQ = VCONT=1V 1. µa current Line regulation 1 V IN=output voltage.4 to mv Load regulation 2 I OUT=1µA to I OUT(below) voltage / Ta Ta=4 C to 85 C S8323H33MC ±.17 mv/ C 1 temperature coefficient S8323H5MC ±.25 Oscillation frequency fosc =output voltage khz Measured waveform at CONT pin Max. duty ratio MaxDuty =output voltage.95 Measured waveform at CONT pin % V SH =output voltage Shutdown pin Judged the oscillation at CONT pin Input voltage V SL1 =output voltage.95 When.3 V (ON/OFF type) 1.5V V SL2 Judged the stop of oscillation at CONT pin When <1.5V.2 Soft start time T SS ms EFFI S8323H33MC 83 % 1 S8323H5MC 87 External parts used: Coil: CD54 (22µH) of Sumida Electric Co., Ltd. Diode: MA72 (Schottky type) of Matsushita Electronic Components Co., Ltd. Capacitor: F93 (16V, 22µF, tantalum type) of Nichicon Corporation Applied V IN=output voltage.6, applied, I OUT=output voltage/25ω The shutdown pin is connected to pin. Note 1: The output voltage specified above is the typical value. 8 Seiko Instruments Inc.

9 Rev. 7.1 SMALL PACKAGE PWM CONTROL STEPUP SWITCHING REGULATOR S8323/8327 Series 15. S8323JXXMC (Unless otherwise specified: Ta=25 C) Parameter Symbol Conditions Min. Typ. Max. Unit Test circuit voltage S8323J25MC S8323J5MC Input voltage V IN 9 V 1 Operation start voltage V ST1 I OUT=1mA 1.4 Oscillation start voltage V ST2 No external parts, voltage applied to CONT pulled up to 5 V by 1Ω Operation holding voltage V HLD I OUT=1mA, Measured by decreasing V IN voltage gradually..7 1 Current consumption 1 I SS1 =output voltage.95 S8323J25MC S8323J5MC µa 2 Current consumption 2 I SS2 =output voltage.5 S8323J25MC S8323J5MC Switching current I SW VCONT=.4V S8323J25MC ma S8323J5MC Switchin transistor leak I SWQ = VCONT=9V 1. µa current Line regulation 1 V IN= output voltage.4 to mv Load regulation 2 I OUT=1µA to I OUT (below) voltage / Ta Ta=4 C to 85 C S8323J25MC ±.13 mv/ C 1 temperature coefficient S8323J5MC ±.25 Oscillation frequency fosc =output voltage khz Measured waveform at CONT pin 2 Max.duty ratio MaxDuty =output voltage.95 Measured waveform at CONT pin % Soft start time T SS ms EFFI S8323J25MC 79 % 2 S8323J5MC 87 External parts used: Coil: CD54 (22µH) of Sumida Electric Co., Ltd. Diode: MA72 (Schottky type) of Matsushita Electronic Components Co., Ltd. Capacitor: F93 (16V, 22µF, tantalum type) of Nichicon Corporation Applied V IN=output voltage.6, I OUT=output voltage/25ω The V DD pin is connected to pin for V DD/ separate product. Note 1: Note 2: The output voltage specified above is the typical value. V DD/ Separate products: Boot operation is performed from V DD=.8V. However, 2. V or more for V DD is recommended to stabilize the output voltage and oscilation frequency. However,accuuracy of output volutage is degraded to ±4% under the V DD volltage between 2.V to 2.35V. Seiko Instruments Inc. 9

10 SMALL PACKAGE PWM CONTROL STEPUP SWITCHING REGULATOR S8323/8327 Series Rev S8327BXXMC (Unless otherwise specified: Ta=25 C) Parameter Symbol Conditions Min. Typ. Max. Unit Test circuit S8327B54MC S8327B5MC S8327B36MC voltage S8327B33MC S8327B3MC S8327B28MC V 3 S8327B27MC S8327B25MC Input voltage V IN 9 Operation start voltage V ST1 I OUT=1mA.9 Oscillation start voltage V ST2 No external parts, voltage applied to.8 4 Operation holding voltage V HLD I OUT=1mA, Measured by decreasing V IN voltage.7 3 gradually. S8327B54MC S8327B5MC S8327B36MC Current consumption 1 I SS1 =output voltage.95 S8327B33MC S8327B3MC S8327B28MC S8327B27MC S8327B25MC µa 4 S8327B54MC S8327B5MC S8327B36MC Current consumption 2 I SS2 =output voltage.5 S8327B33MC S8327B3MC S8327B28MC S8327B27MC S8327B25MC Current consumption while shutdown I SSS shutdown pin=v.5 S8327B54MC S8327B5MC S8327B36MC I EXTH VEXT=.4V S8327B33MC S8327B3MC S8327B28MC S8327B27MC EXT pin output current S8327B25MC ma S8327B54MC S8327B5MC S8327B36MC I EXTL VEXT=.4V S8327B33MC S8327B3MC S8327B28MC S8327B27MC S8327B25MC Line regulation 1 V IN=output voltage.4 to mv Load regulation 2 I OUT=1µA to I OUT(below) S8327B54MC ±.27 S8327B5MC ±.25 voltage S8327B36MC ±.18 3 temperature / Ta Ta=4 C to 85 C S8327B33MC ±.17 mv/ C coefficient S8327B3MC ±.15 S8327B28MC ±.14 S8327B27MC ±.14 S8327B25MC ±.13 Oscillation frequency fosc =output voltage khz Measure waveform at EXT pin Max. duty ratio MaxDuty =output voltage % Measure waveform at EXT pin Shutdown pin V SH =output voltage.95 Measure the oscillation at EXT pin.75 Input voltage V SL1 =output voltage.95 When.3 V 4 1.5V V SL2 Judged the stop of oscillation When.2 at EXT pin <1.5V Soft start time T SS ms S8327B54MC 88 S8327B5MC 88 S8327B36MC 84 EFFI S8327B33MC 84 % 3 S8327B3MC 84 S8327B28MC 8 S8327B27MC 8 S8327B25MC 8 External parts used: Coil: CD54 (47µH) of Sumida Electric Co., Ltd. Diode: MA72 (Schottky type) of Matsushita Electronic Components Co., Ltd. Capacitor: F93 (16V, 47µF, tantalum type) of Nichicon Corporation Transistor: 2SD1628G of Sanyo Electronics Base Resistance (Rb): 1.kΩ Base Capacitor (Cb): 22 pf (ceramic) Applied V IN=output voltage.6, I OUT=output voltage/5ω The shutdown pin is connected to pin. Note 1: The output voltage specified above is the typical value. 1 Seiko Instruments Inc.

11 Rev. 7.1 SMALL PACKAGE PWM CONTROL STEPUP SWITCHING REGULATOR S8323/8327 Series 22. S8327BXXMA, S8327BXXUA, S8327EXXMC (Unless otherwise specified: Ta=25 C) Parameter Symbol Conditions Min. Typ. Max. Unit Test circuit S8327X5XX S8327X33XX voltage S8327X3XX S8327X27XX V 3 S8327X25XX S8327X2XX Input voltage V IN 9 Operation start voltage V ST1 I OUT=1mA.9 Oscillation start voltage V ST2 No external parts, voltage applied to.8 4 Operation holding voltage V HLD I OUT=1mA, Measured by decreasing V IN.7 3 voltage gradually B. S8327X5XX S8327X33XX Current consumption 1 I SS1 =output voltage.95 S8327X3XX S8327X27XX S8327X25XX S8327X2XX µa 4 S8327X5XX S8327X33XX Current consumption 2 I SS2 =output voltage.5 S8327X3XX S8327X27XX S8327X25XX S8327X2XX S8327X5XX S8327X33XX I EXTH VEXT=.4V S8327X3XX S8327X27XX S8327X25XX EXT pin output current S8327X2XX ma S8327X5XX S8327X33XX I EXTL VEXT=.4V S8327X3XX S8327X27XX S8327X25XX S8327X2XX Line regulation 1 V IN=output voltage.4 to Load regulation 2 I OUT=1µA to I OUT(below) mv S8327X5XX ±.25 voltage S8327X33XX ±.17 temperature / Ta Ta=4 C to 85 C S8327X3XX ±.15 mv/ C 3 coefficient S8327X27XX ±.14 S8327X25XX ±.13 S8327X2XX ±.1 Oscillation frequency fosc =output voltage khz Measured waveform at EXT pin Max. duty ratio MaxDuty =output voltage % 4 Measured waveform at EXT pin Soft start time T SS ms S8327X5XX 88 S8327X33XX 84 EFFI S8327X3XX 84 % 3 S8327X27XX 8 S8327X25XX 8 S8327X2XX 76 External parts used: Coil: CD54 (47µH) of Sumida Electric Co., Ltd. Diode: MA72 (Schottky type) of Matsushita Electronic Components Co., Ltd. Capacitor: F93 (16V, 47µF, tantalum type) of Nichicon Corporation Transistor: 2SD1628G of Sanyo Electronics Base resistor (Rb): 1.KΩ Base capacitor (Cb): 22pF (ceramic) Applied V IN=output voltage.6, I OUT=output voltage/5ω The V DD pin is connected to pin for V DD/ separate product. Note 1: Note 2: The output voltage specified above is the typical value. V DD/ Separate products: Boot operation is performed from V DD=.8V. However, 2. V or more for V DD is recommended to stabilize the output voltage and oscilation frequency. Seiko Instruments Inc. 11

12 SMALL PACKAGE PWM CONTROL STEPUP SWITCHING REGULATOR S8323/8327 Series Rev S8327HXXMC (Unless otherwise specified: Ta=25 C) Parameter Symbol Conditions Min. Typ. Max. Unit Test circuit S8327H3MC voltage S8327H33MC S8327H5MC V 3 Input voltage V IN 9 Operation start voltage V ST1 I OUT=1mA 1.4 Oscillation start voltage V ST2 No external parts, voltage applied to Operation holding voltage V HLD I OUT=1mA, Measured by decreasing V IN voltage.7 3 gradually. S8327H3MC Current consumption 1 I SS1 =output voltage.95 S8327H33MC S8327H5MC S8327H3MC µa 4 Current consumption 2 I SS2 =output voltage.5 S8327H33MC S8327H5MC Current consumption while shutdown I SSS shutdown pin=v.5 S8327H3MC I EXTH VEXT=.4V S8327H33MC EXT pin output current S8327H5MC S8327H3MC ma I EXTL VEXT=.4V S8327H33MC S8327H5MC Line regulation 1 V IN=output voltage.4 to mv Load regulation 2 I OUT=1µA to I OUT(below) voltage temperature S8327H3MC ±.15 coefficient / Ta Ta=4 C to 85 C S8327H33MC ±.17 mv/ C S8327H5MC ±.25 Oscillation frequency fosc =output voltage khz Measure waveform at EXT pin Max. duty ratio MaxDuty =output voltage.95 Measure waveform at EXT pin % V SH =output voltage Shutdown pin Input voltage (ON/OFF type) V SL1 =output voltage.95 When 1.5V.3 V V SL2 When <1.5V.2 Soft start time T SS ms S8327H3MC 81 EFFI S8327H33MC 81 % 3 S8327H5MC 85 External parts used: Coil: CD54 (22µH) of Sumida Electric Co., Ltd. Diode: MA72 (Schottky type) of Matsushita Electronic Components Co., Ltd. Capacitor: F93 (16V, 47µF, tantalum type) of Nichicon Corporation Transistor: NDS355AN of National Semiconductor Applied V IN=output voltage.6, I OUT=output voltage/5ω The shutdown pin is connected to pin. Note 1: The output voltage specified above is the typical value. 12 Seiko Instruments Inc.

13 Rev. 7.1 SMALL PACKAGE PWM CONTROL STEPUP SWITCHING REGULATOR S8323/8327 Series 24. S8327JXXMC (Unless otherwise specified: Ta=25 C) Parameter Symbol Conditions Min. Typ. Max. Unit Test circuit voltage S8327H25MC S8327H5MC V 3 Input voltage V IN 9 Operation start voltage V ST1 I OUT=1mA 1.4 Oscillation start voltage V ST2 No external parts, voltage applied to Operation holding voltage V HLD I OUT=1mA, Measured by decreasing V IN voltage gradually B..7 3 Current consumption 1 I SS1 =output voltage.95 S8327H25MC S8327H5MC µa 4 Current consumption 2 I SS2 =output voltage.5 S8327H25MC S8327H5MC I EXTH VEXT=.4V S8327H25MC EXT pin output current S8327H5MC ma I EXTL VEXT=.4V S8327H25MC S8327H5MC Line regulation 1 V IN=output voltage.4 to Load regulation 2 I OUT=1µA to I OUT(below) mv voltage / Ta Ta=4 C to 85 C S8327H25MC ±.13 mv/ C 3 temperature coefficient S8327H5MC ±.25 Oscillation frequency fosc =output voltage khz Measured waveform at EXT pin Max. duty ratio MaxDuty =output voltage % 4 Measured waveform at EXT pin Soft start time T SS ms EFFI S8327H25MC 77 % 3 S8327H5MC 85 External parts used: Coil: CD54 (22µH) of Sumida Electric Co., Ltd. Diode: MA72 (Schottky type) of Matsushita Electronic Components Co., Ltd. Capacitor: F93 (16V, 47µF, tantalum type) of Nichicon Corporation Transistor: NDS355AN of National Semiconductor Applied V IN=output voltage.6, I OUT=output voltage/5ω The V DD pin is connected to pin for V DD/ separate product. Note 1: Note 2: The output voltage specified above is the typical value. V DD/ Separate products: Boot operation is performed from V DD=.8V. However, 2. V or more for V DD is recommended to stabilize the output voltage and oscilation frequency. However,accuuracy of output volutage is degraded to ±4% under the V DD volltage between 2.V to 2.35V. Seiko Instruments Inc. 13

14 SMALL PACKAGE PWM CONTROL STEPUP SWITCHING REGULATOR S8323/8327 Series Rev. 7.1 Test Circuits Cb CONT V SS (V DD ) (ON/OFF) V Rb EXT V SS (V DD ) (ON/OFF) V 2. 1k 4. CONT (ON/OFF) V SS (V DD ) A Oscilloscope Oscilloscope EXT (ON/OFF) V SS (V DD ) A Figure 3 Operation 1. StepUp DC/DC Converter The S8323/8327 Series is a stepup switching regulator using a pulse width modulation method (PWM) and DC/DC converter and features a low current consumption. In conventional PFM DC/DC converters, pulses are skipped at low output load current, causing fluctuation in ripple frequency of the output voltage, with the result of increase in ripple voltage. In S8323/27 series the switching frequency does not change, although the pulse width changes from % to 83%(78% for H, J types) corresponding to each load current. The ripple voltage generated from switching can be removed easily through the filter because the switching frequency is constant. The builtin soft start circuit controls a rush current and overshoot of the output voltage when powering on or the ON/OFF terminal turns to H level. Shutdown pin: Stops or starts stepup operation. (Only for SOT235 package products of A, B, and H Series.) Turning the shutdown pin low stops operation of all the internal circuits and reduces current consumption significantly. DO NOT use the shutdown pin in floating state because it has a structure shown in Figure 4 and is not pulled up or pulled down internally. DO NOT apply voltage of between.3 V and.75 V to the shutdown pin because applying such voltage increases the current consumption. If the shutdown pin is not used, connect it to (V DD for D, E, J types) pin. The shutdown pin doesn t have hysteresis. Shutdown pin CR oscillation circuit voltage H Operation Fixed L Stop V IN * ON/OFF (V DD for D, E, J types) * obtained by extracting the voltage drop due to DC resistance of the inductor and the diode forward voltage from V IN. V SS Figure 4 14 Seiko Instruments Inc.

15 Rev. 7.1 SMALL PACKAGE PWM CONTROL STEPUP SWITCHING REGULATOR S8323/8327 Series L VA Di VIN ON/OFF CONT C OUT OSC M1 Figure 5 The following are basic equations [(1) through (7)] of the stepup switching regulator (see Figure 5.) at CONT pin the moment M1 is turned ON (current I L flowing through L is zero): V A =V S... (1) (V S : Nonsaturated voltage of M1) The change in I L over time: di L V L V INV S = =... (2) d L L Integration of the above equation (I L ): V IN V S I L = t... (3) L I L flows while M1 is ON (t ON ). The time of t ON is determined by the oscillation frequency of the OSC. The peak current (I PK ) after t ON : V IN V S I PK = t ON... (4) L The energy stored in L is represented with 1/2 L (I PK ) 2. When M1 is turned OFF (t OFF ), the energy stored in L is transmitted through a diode to the output capacitor. Then reverse voltage (V L ) is generated. V L = ( V D ) V IN... (5) (V D : Diode forward voltage) The voltage at CONT pin rises only by the voltage corresponding to V D. The change in the current flowing through the diode into during t OFF : di L V L V DV IN = =... (6) d L L Integration of the above equation is as follows: V DV IN I L=I PK t... (7) L Seiko Instruments Inc. 15

16 SMALL PACKAGE PWM CONTROL STEPUP SWITCHING REGULATOR S8323/8327 Series Rev. 7.1 During t ON, the energy is stored in L and is not transmitted to. When receiving output current (I OUT ) from, the energy of the capacitor (C OUT ) is consumed. As a result, the pin voltage of C OUT is reduced, and goes to the lowest level after M1 is turned ON (t ON ). When M1 is turned OFF, the energy stored in L is transmitted through the diode to C OUT, and the voltage of C OUT rises drastically. is a time function that indicates the maximum value (ripple voltage: V PP ) when the current flowing through the diode into and load current (I OUT ) match. Next, the ripple voltage is found out as follows: I OUT vs t 1 (time) from when M1 is turned OFF (after t ON ) to when reaches the maximum level: I OUT=I PK V DV IN L t 1... (8) L t 1=(I PKI OUT)... (9) V DV IN When M1 is turned ON (after t OFF ), I L = (when the energy of the inductor is completely transmitted). Based on equation (7), L t OFF =...(1) V DV IN I PK When substituting equation (1) for equation (9), I OUT t 1=t OFF t OFF...(11) I PK Electric charge Q 1 which is charged in C OUT during t1: t 1 Q 1 = V t OUTV DV IN 1 I Ldt= I PK dt t 1 tdt L V DV IN 1 =I PK t 1 t (12) L 2 When substituting equation (12) for equation (9): 1 I PKI OUT Q 1=I PK (I PK I OUT) t 1 = t 1...(13) 2 2 A rise in voltage (V PP ) due to Q 1 : Q 1 1 I PK I OUT V PP = = t 1...(14) C OUT C OUT 2 When taking into consideration I OUT to be consumed during t1 and ESR (Equivalent Series Resistance) of C OUT, namely R ESR : Q 1 1 I PK I OUT I PK I OUT I OUT t 1 V PP = = t 1 R ESR...(15) C OUT C OUT 2 2 C OUT When substituting equation (11) for equation (15): (I PKI OUT) 2 t OFF I PKI OUT V PP = R ESR...(16) 2I PK C OUT 2 Therefore to reduce the ripple voltage, it is important that the capacitor connected to the output pin has a large capacity and a small ESR. 16 Seiko Instruments Inc.

17 Rev. 7.1 SMALL PACKAGE PWM CONTROL STEPUP SWITCHING REGULATOR S8323/8327 Series External parts selection for DCDC converter The relationship between majorcharacteristics of the stepup circuit and characteristics parameters of the external parts are shown in Figure 6. for large output current? for high efficiency? for small ripple voltage operation efficiency standby efficiency small inductance large inductance small DC resistance of inductor large output capacitance external switching transistor (small ON resistance) builtin switching transistor small resistance of external resistor Rb when an external switching transistor is used large resistance of external resistor Rb when an external switching transistor is used. Figure 6 Relationship between major character stics of the stepup circuit and external parts Seiko Instruments Inc. 17

18 SMALL PACKAGE PWM CONTROL STEPUP SWITCHING REGULATOR S8323/8327 Series Rev Inductor An inductance has strong influence on max. output current I OUT and efficiency η. Figure 7 shows I OUT η characteristics for inductance of S8323 and S8327. S8323 A/B/C/D/E D75C =5.V, V IN=3.V S8327 A/B/C/D/E CD15 =5.V, V IN=3.V I OUT I OUT η η I OUT I OUT η η L (µh) 22 L (µh) recommended range recommended range Figure 7 The peak current I PK increases by decreasing L and I OUT is at max. value at L value. Further decreasing L decreases I OUT due to the lack of the current driving capacity of the switching transistor. The loss of I PK by the switching transistor decreases by increasing L and the efficiency becomes max. at L value. Further increasing L decreases efficiency due to the loss of DC resistance of the coil. 47 to 22µH inductor for S8323 A/B/C/D/E, 22 to µh inductor for S8327 A/B/C/D/E, 1 to 22µH inductor for S8323 H/J, and 4.7 to 1µH inductor for S8327 H/J are recommended. Choose a value for L by refering to the reference data because the maximum output current is due to the input voltage in an actual case. Choose an inductor so that the peak current I PK does not exceed the allowable current. Exceeding the allowable current of the inductor causes magnetic saturation, remarkable low efficiency and destruction of the IC chip due to a large current. The peak current I PK in uncontinuous mode is caluculated from the following formula: I PK = 2 I OUT ( V D V IN ) f OSC L (A) (17) fosc: oscillation frequency VD.4V For instance, when you choose µh at fosc=5 khz for L using the S8323A5MC at the following conditions, I PK is caluculated to 17 ma from the (17) formula. Input voltage V IN =3 V voltage =5 V Load current I OUT =3 ma The switching current limit circuit is not built into this IC chip. I PK current must be 5 ma or less. 18 Seiko Instruments Inc.

19 Rev. 7.1 SMALL PACKAGE PWM CONTROL STEPUP SWITCHING REGULATOR S8323/8327 Series 2. Diode Use an external diode that meets the following requirements: Low forward voltage: (V F <.) High switching speed: (5 ns max.) Reverse voltage: V F or more Rated current: I PK or more 3. Capacitors (C IN, C OUT ) A capacitor at the input side (C IN ) improves the efficiency by reducing the power impedance and stabilizing the input current. Select a C IN value according to the impedance of the power supply used. The capacitor value should be around 1 µf. A capacitor at the output side (C OUT ) is used for smoothing the ripple voltage. Therefore select a capacitor with a small ESR (Equivalent Series Resistance) and a large capacitance. The capacitor value should be 1 µf min. A tantalum electrolytic capacitor and an organic semiconductor capacitor are especially recommended because of their superior lowtemperature characteristic and leakage current characteristic. 4. External transistor (S8327 Series) For the S8327 Series, connecting an external transistor increases the output current. A bipolar (NPN) transistor or an enhancement (Nchannel) MOS FET transistor can be used as external transistor Bipolar (NPN) transistor A circuit example using a bipolar transistor (NPN), Sanyo 2SD1628G (h FE =28 to 56) is shown in Figure 11. The h FE value and the Rb value determine the driving capacity to increase the output current using a bipolar transistor. A peripheral circuit example of the transistor is shown in Figure 8. (V DD for D, E, J types) Cb Pch 22pF Nch S8327 EXT Rb 1K I PK Figure 8 External transistor peripheral 1 kω is recommended for Rb. Rb is caluculated from the following formula:.7.4 V DD.7.4 Rb= (Rb= for D, E, J types) Ib I EXTH Ib I EXTH Ib : I PK /h FE A small Rb increases output current, however, the efficiency decreases. The current flows pulsating and there is voltage drop due to wiring resistance in an actual circuit, therefore optimum Rb value should be determined by experiment. A speedup capacitor connected in parallel with Rb resistance as shown in Figure 9 decreases the switching loss and improves the efficiency. Cb is caluculated from the following formula: 1 Cb 2π Rb f OSC.7 However, in practice, the optimum Cb value also varies with the characteristics of the bipolar transistor to be employed. Therefore, determine the optimum value through experiments. Seiko Instruments Inc. 19

20 SMALL PACKAGE PWM CONTROL STEPUP SWITCHING REGULATOR S8323/8327 Series Rev Enhancement MOS FET type Figure 9 is a circuit example using NEC 2SK1959 MOS FET transistor (Nchannel). For a MOS FET, an Nchannel power MOS FET should be used. Because the gate voltage and current of the external power MOS FET are supplied from the stepped up output voltage, the MOS FET is driven more effectively. Depending on which MOS FET you use in your device, there is a chance of a current overrun at power ON. Thoroughly test all settings with your device before deciding on which one to use. Also, try to use a MOS FET with the gate capacitance of 3 pf or less. Since the ON resistor of the MOS FET might affect the output amperage as well as the efficiency, the threshold voltage should be low. When the output voltage is as low as 2.V the same as in the S8327E2, the circuit operates only when the MOS FET has the threshold voltage lower than 2.V. EXT (ON / OFF) (V DD ) V SS Figure 9 Circuit example using 2SK Others (S8323D/J and S8327E/J only) The S8323D/J and S8327E/J are applicable to the following uses because the power pin for IC chip and Vout pin for output voltage are separated: 1 When changing the output voltage with an external resistance. 2 When outputing the high voltage such as 12 V or 15 V. 3 When making the stepdown DC/DC converter 4 When making the voltage inverting type DC/DC converter. Choose the products in the following table according to applications for 1 to 3. Use Stepup Stepdown voltage V CC 2V V CC< V CC<5V 5V V CC<9V 9V V CC Ref. circuit 2V V CC< V CC<5V 5V V CC<9V Ref. circuit S8323D2 Std. circuit (5) Appl. circuit 3 S8323D3 Std. circuit (5) Appl. circuit 3 S8323D5 Std. circuit (5) Appl. circuit 3 S8323J25 Std. circuit (5) S8323J5 Std. circuit (5) S8327E2 Std. circuit (6) S8327E5 Std. circuit (6) S8327J25 Std. circuit (6) S8327J5 Std. circuit (6) Connection to V DD pin V IN or V CC V IN or V CC V IN or V CC V IN V IN V IN V IN The operational precautions are follows: I. This IC starts to oscillate and step up operation at V DD =.8V(1. for Jtype) but frequency of the oscillator does not stabilize. Input the voltage from 2 V to 9 V for V DD pin to get the stabilized output voltage and oscilation frequency. The input voltage from 2 V to 9 V for V DD pin allows the connection of V DD pin to both input power pin V IN and output power pin Vout. II. Choose external resistors R A and R B not to affect to the output voltage with the consideration of the impedance between and V SS pins in the IC chip. Internal resistance between and V SS pins are as follows: 1 S8323D2, S8323J2 and S8327E2: 3. MΩ to 19.6 MΩ 2 S8323J25, S8327J25:3.9 MΩ to 22.5MΩ 3 S8323D3: 3.3 MΩ to 22.6 MΩ 4 S8323D5,S8323J5, S8327E5 and S8327J5: 2.1 MΩ to 19.1 MΩ III. Attach the capacitor C C in parallel to R A resistance when the oscilation of the output voltage occurs. Caluculate C C from the following formula: 2 Seiko Instruments Inc.

21 Rev. 7.1 SMALL PACKAGE PWM CONTROL STEPUP SWITCHING REGULATOR S8323/8327 Series C C (F)= 1 2 π R A 2 khz IV. When the device is used with an external resistance in the output voltagesvariable mode, a large ripple voltage having a frequency lower than that of the switching frequency may appear as an output, if the load current is large, depending on the circuit patterns on the evaluation board and other factors (the interval is several times or a few tens times as large as the switching interval (4µS), see waves in Figure 1). Be sure to check the circuit patterns on your board in advance for practical use. 2 1 CONT Pin 8 6 CONT Pin 1 2 Coil Current (A) 4 2 Coil Current (A) TIME (µsec) Figure 1 Seiko Instruments Inc. 21

22 SMALL PACKAGE PWM CONTROL STEPUP SWITCHING REGULATOR S8323/8327 Series Rev. 7.1 Standard Circuits (1) S8323AXXMC L CONT SD V IN VREF C IN PWM control circuit C OUT Note: The power supply for IC chip is supplied from pin. Soft start circuit V SS ON / OFF Figure 11 (2) S8327BXXMC S8327HXXMC L SD V IN 22pF VREF C IN 1 kω EXT PWM control circuit C OUT Note: The power supply for IC chip is supplied from pin. Soft start circuit V SS ON / OFF Figure 12 (3) S8323AXXMA S8323AXXUA S8323CXXMA L CONT SD V IN VREF C IN PWM control circuit C OUT Note: The power supply for IC chip is supplied from pin. Soft start circuit V SS Figure Seiko Instruments Inc.

23 Rev. 7.1 SMALL PACKAGE PWM CONTROL STEPUP SWITCHING REGULATOR S8323/8327 Series (4) S8327BXXMA S8327BXXUA L SD V IN C IN 22pF 1KΩ EXT PWM control circuit VREF C OUT Note: The power supply for IC chip is supplied from pin. Soft start circuit V SS Figure 14 (5) S8323DXXMC ( voltage adjustment circuit with external resistors) S8323JXXMC L CONT SD V DD C C V CC V IN C IN PWM control circuit VREF R 1 R 2 V SS R A R B C OUT Note: The power supply for IC chip is supplied from V DD pin. Soft start circuit Figure 15 (6) S8327EXXMC ( voltage adjustment circuit with external resistors) L SD V DD C C V CC V IN C IN 22pF 1KΩ EXT PWM control circuit VREF R 1 R 2 V SS R A R B C OUT Note: The power supply for IC chip is supplied from V DD pin. Soft start circuit Figure 16 Seiko Instruments Inc. 23

24 SMALL PACKAGE PWM CONTROL STEPUP SWITCHING REGULATOR S8323/8327 Series Rev. 7.1 (7) S8327JXXMC L SD V DD V IN VREF C IN EXT PWM control circuit R 1 R 2 C OUT Note: The power supply for IC chip is supplied from V DD pin. Soft start circuit V SS (8) S8327HXXMC Figure 17 L SD VREF V IN C IN EXT PWM control circuit C OUT Note: The power supply for IC chip is supplied from pin. Soft start circuit V SS ON / OFF Precautions Figure 18 Mount external capacitors, a diode, and a coil as near as possible to the IC. Ripple voltage and spike noise occur in switching regulators. Because they largely depend on the coil and the capacitor used, check them using an actually mounted model. The performance of this IC varies depending on the PCB patterns, peripheral circuits or external parts. Thoroughly test all settings with your device. Also, try to use recommended external parts. If not, contact your local SII Sales Office. Seiko Instruments shall not be responsible for any patent infringement by products including S8323/8327 Series in connection with the method of using S8323/8327 Series in such products, the specification of such products, or the country of destination thereof. Make sure dissipation of the switching transistor (especially at a high temperatures) does not exceed the allowable power dissipation of the package. 6 Power dissipation P D (mw) 4 2 SOT893 SOT235, SOT Amb. Temperature Ta ( C) Figure 19 Power dissipation of the package (before mounting) 24 Seiko Instruments Inc.

25 Rev. 7.1 SMALL PACKAGE PWM CONTROL STEPUP SWITCHING REGULATOR S8323/8327 Series Application Circuits 1. Backup Circuit Reduces the backup battery voltage from 3 V to 1.5 V (from 2 cells to 1 cell). 1.5V CONT Main Power ON/OFFS8323A VOUT V SS SRAM 2. 5V/Backup Change Figure 2 For the products with shutdown function builtin, becomes about V IN.6V at shutdown. This characteristic allows the backup voltage of the microcomputer to be supplied with low current consumption. V IN Detector ON/OF CONT S8323A V SS CPU CE 3. Stepdown DC/DC converter Figure 21 R E Tr C C R A V CC V IN C OUT R b C IN V DD CONT S8323D R B V SS The start circuit is not needed because the power supply is supplied from V DD to the IC. The maximum input voltage for V DD is 9 V. Figure 22 DO NOT mount R A and R B resistors when V CC is 2V for S8323D2MC, for S8323D3MC and 5V for S8323D5MC. The external resistor Rb must be 6Ω or more and R E must be 6kΩ or less. A large value for R E raises efficiency due to the reduction of reactive current for R E and R b. Too large value of R E lowers efficiency due to the large switching loss of the external transistor (Tr). Choose a suitable value of R E under the operating conditions. Seiko Instruments Inc. 25

26 SMALL PACKAGE PWM CONTROL STEPUP SWITCHING REGULATOR S8323/8327 Series Rev PDA/Digital Camera Power Supply The following are a circuit example and its characteristics showing a system drive (/2mA) powered by 4 secondary Nicd batteries (3.6 to 4.8V), 2 lithiumion batteries (4.8 to 8.8V) or 4 alkalinemanganese batteries (3.6 to 6.V). V IN C IN R E 2SA1213/TOSHIBA 5.1kΩ R b A 75Ω SD CONT V DD S8324D3 L CD54/µH MA72 C OUT F93 22µF V SS Figure (a) Current (b) Current V out 8 η (%) VIN=3. VIN=3.6V VIN=4.8V VIN=7.2V Current I OUT (ma) 4 VIN=3. VIN=3.6V 2 VIN=4.8V VIN=7.2V Current I OUT (ma) (1mV/div) (c) Ripple Characteristics Figure 24 VIN=3.6V IOUT=3mA Point A (1V/div) V t (1 µsec/div) Figure Seiko Instruments Inc.

27 Rev. 7.1 SMALL PACKAGE PWM CONTROL STEPUP SWITCHING REGULATOR S8323/8327 Series 5. Inverting Type DC/DC Converter Tr V CC R E V IN C IN V DD R b CONT S8323D V SS R A C OUT R B Figure 26 The Start circuit is not needed because the power is supplied from V DD to the IC. Set V IN to 9V V CC or less. When V CC is 2 V, 3 V and 5 V, use the S8323D2MC, the S8323D3MC and the S8323D5MC respectively. Always connect to GND without attaching R A, R B. Set R b to 6Ω or more and R E to 6 kω or less. The larger R E, the smaller the reactive current through R E and R b, allowing the efficiency to be improved. On the other hand, the switching loss of the Tr becomes large and consequently the efficiency will be worsend. Select R E to ensure high efficiency under operating conditions. 6. Power Supply for GaAs and MR Head The following are an application negative power supply circuit for GaAs and MR head, and its characteristics when (±1%) and 5V (5V±1%) are used for the applied power. Set V IN to 9V V CC or less. 2SA1362/Toshiba SD V CC V IN R E 75Ω R b A 2kΩ MA72 CD54/µH C OUT F93 47µF C IN CONT V DD S8323D3 V SS V CC (a) Current Figure 27 VIN=2.7V VIN=3.V VIN=4.5V VIN=5.V (b) Current VIN=2.7V VIN=3.V 8 VIN=4.5V VIN=5.V η (%) Current I OUT (ma) Current I OUT (ma) Figure 28 Seiko Instruments Inc. 27

28 SMALL PACKAGE PWM CONTROL STEPUP SWITCHING REGULATOR S8323/8327 Series Rev. 7.1 (c) Ripple Characteristics (1mV/div) V Point A (2V/div) t (1 µsec/div) Figure 29 When output current I OUT exceeds 5 ma, the current capacitance in the external transistor 2SA1362 becomes in short supply and the IC may be broken. Select a large current capacitance transistor. The start circuit is not needed because the power supply is supplied from V DD to the IC. Set Vin to 9 V V CC or less. The output voltage cannot be changed with external resistors. Set R b to 6Ω or more and R E to 6 kω or less. The larger R E, the smaller the reactive current through R E and R b, allowing the efficiency to be improved. On the other hand, the switching loss of the Tr becomes large and consequently the efficiency will be worsened. Select R E to ensure high efficiency under operating conditions. 7. LCD Power Supply (Standard circuit (6)) The following are an application power supply circuit (/5mA) for intermidiate and large size LCD, and its characteristics when (±1%) and 5V (5V±1%) are used for the applied power. V IN C IN 482kΩ L SD CD54/µH MA72 R A 15pF C C C OUT F93 to 4.7µF/5V 2 Cb.22µF V DD S8327E5 R B kω 2SD1624T R b 1kΩ EXT V SS Figure 3 28 Seiko Instruments Inc.

29 Rev. 7.1 SMALL PACKAGE PWM CONTROL STEPUP SWITCHING REGULATOR S8323/8327 Series (a) Current V out VIN=2.7V VIN=3.V VIN=4.5V VIN=5.V 8 η (%) (b) Current VIN=2.7V VIN=3.V VIN=4.5V VIN=5.V Current I OUT (ma) Current I OUT (ma) 8. Flash Memory Power Supply Figure 31 The following are a circuit example and its characteristics for a 5 V Flash Memory, 16 Mbit (5V/12mA) on a single lithium battery (2.4 V to 4.4 V). L CD54/47µH SD MA72 5V V IN C IN 2SD1628G.22µF Cb R b 1 kω Control Signal C OUT F93 47µF EXT S8327B5 ON/OFF V SS Figure 32 (a) Current (b) Current V out 5.2 VIN=2.V VIN=2.4V VIN=3.6V VIN=4.4V 8 η (%) 6 VIN=2.V VIN=2.4V VIN=3.6V VIN=4.4V Current I OUT (ma) Current I OUT (ma) Figure 33 Seiko Instruments Inc. 29

30 SMALL PACKAGE PWM CONTROL STEPUP SWITCHING REGULATOR S8323/8327 Series Rev Power Supply for CCD The follows are a circuit example and its characteristics for CCD power supply (15, 5.5V/1mA) powered by 4 alkalinemanganese batteries (3.66.V), used for digital still cameras and others. VIN CIN u Cc RA MA p k uh Co1 V DD 1 /F93 3 RB 1u S8327J5 14 k CEE93 Vss EXT TR1 11 Co2 /F93 1u MA72 VOUT 15V VOUT 5.5V NDS335N Figure 34 (a) Current (positive output) VIN=3. V VIN=3.6 V VIN=6. V Current I OUT (ma) (b) Current (negative output) VIN=3. V VIN=3.6 V VIN=6. V Current I OUT (ma) 8 η (%) 6 (c) Current 4 VIN=3.V VIN=3.6V VIN=6.V Current I OUT (ma) Figure 35 3 Seiko Instruments Inc.