SG3527A PULSE WIDTH MODULATOR CONTROL CIRCUITS

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1 Order this document by SG55A/D The SG55A, SG5A pulse width modulator control circuits offer improved performance and lower external parts count when implemented for controlling all types of switching power supplies. The onchip 5. V reference is trimmed to ±% and the error amplifier has an input commonmode voltage range that includes the reference voltage, thus eliminating the need for external divider resistors. A sync input to the oscillator enables multiple units to be slaved or a single unit to be synchronized to an external system clock. A wide range of deadtime can be programmed by a single resistor connected between the CT and Discharge pins. These devices also feature builtin softstart circuitry, requiring only an external timing capacitor. A shutdown pin controls both the softstart circuitry and the output stages, providing instantaneous turn off through the PWM latch with pulsed shutdown, as well as softstart recycle with longer shutdown commands. The under voltage lockout inhibits the outputs and the changing of the softstart capacitor when C is below nominal. The output stages are totempole design capable of sinking and sourcing in excess of ma. The output stage of the SG55A features NOR logic resulting in a low output for an offstate while the SG5A utilized OR logic which gives a high output when off. 8. V to 5 V Operation 5. V ±.% Trimmed Reference Hz to 4 khz Oscillator Range Separate Oscillator Sync Pin Adjustable Deadtime Control Input Undervoltage Lockout Latching PWM to Prevent Multiple Pulses PulsebyPulse Shutdown Dual Source/Sink Outputs: ±4 ma Peak PULSE WIDTH MODULATOR CONTROL CIRCUITS 6 6 Inv. Input Noninv. Input SEMICONDUCTOR TECHNICAL DATA N SUFFIX PLASTIC PACKAGE CASE 648 DW SUFFIX PLASTIC PACKAGE CASE 5B (SO6L) PIN CONNECTIONS Sync C Output B 6 V ref 5 V CC Ground 4 OSC Output Sync 6 RT 5 CT Discharge 9 Compensation INV. Input Noninv. Input 8 C SoftStart Shutdown Reference Regulator Error Amp Oscillator Representative Block Diagram To Internal Circuitry PWM 5µA S V REF Under Voltage Lockout F/F Latch S R Q Q NOR NOR Output A 4 Output B SG55A Output Stage Output A OR OR Output B 4 SG5A Output Stage OSC. Output Device CT RT Discharge SoftStart SG55AN SG55ADW SG5AN (Top View) Operating Temperature Range Ground Output A Shutdown ORDERING INFORMATION TA = to C Compensation Package Plastic DIP SO6L Plastic DIP MOTOROLA ANALOG IC DEVICE DATA Motorola, Inc. 996 Rev

2 SG55A SG5A MAXIMUM RATINGS (Note ) Rating Symbol Value Unit Supply Voltage C 4 Vdc Collector Supply Voltage 4 Vdc Logic Inputs. to 5.5 V Analog Inputs. to C V Output Current, Source or Sink IO ±5 ma Reference Output Current Iref 5 ma Oscillator Charging Current 5. ma Power Dissipation (Plastic & Ceramic Package) TA = 5 C (Note ) TC = 5 C (Note ) PD Thermal Resistance JunctiontoAir RθJA C/W Thermal Resistance JunctiontoCase RθJC 6 C/W Operating Junction Temperature TJ 5 C Storage Temperature Range Tstg 55 to 5 C Lead Temperature (Soldering, seconds) TSolder C NOTES:. Values beyond which damage may occur.. Derate at mw/ C for ambient temperatures above 5 C.. Derate at 6 mw/ C for case temperatures above 5 C. mw RECOMMENDED OPERATING CONDITIONS Characteristics Symbol Min Max Unit Supply Voltage C 8. 5 Vdc Collector Supply Voltage Vdc Output Sink/Source Current (Steady State) (Peak) Reference Load Current Iref ma Oscillator Frequency Range fosc. 4 khz Oscillator Timing Resistor RT. 5 kω Oscillator Timing Capacitor CT.. µf Deadtime Resistor Range RD 5 Ω Operating Ambient Temperature Range TA C IO ± ±4 ma APPLICATION INFORMATION Shutdown Options (See Block diagram, front page) Since both the compensation and softstart terminals (Pins 9 and 8) have current source pullups, either can readily accept a pulldown signal which only has to sink a maximum of µa to turn off the outputs. This is subject to the added requirement of discharging whatever external capacitance may be attached to these pins. An alternate approach is the use of the shutdown circuitry of Pin which has been improved to enhance the available shutdown options. Activating this circuit by applying a positive signal on Pin performs two functions: the PWM latch is immediately set providing the fastest turnoff signal to the outputs; and a 5 µa current sink begins to discharge the external softstart capacitor. If the shutdown command is short, the PWM signal is terminated without significant discharge of the softstart capacitor, thus, allowing, for example, a convenient implementation of pulsebypulse current limiting. Holding Pin high for a longer duration, however, will ultimately discharge this external capacitor, recycling slow turnon upon release. Pin should not be left floating as noise pickup could conceivably interrupt normal operation. MOTOROLA ANALOG IC DEVICE DATA

3 SG55A SG5A ELECTRICAL CHARACTERISTICS (C = Vdc, TA = Tlow to Thigh [Note 4], unless otherwise noted.) Characteristics Symbol Min Typ Max Unit REFERENCE SECTION Reference Output Voltage (TJ = 5 C) Vdc Line Regulation (8. V C 5 V) Regline mv Load Regulation ( ma IL ma) Regload 5 mv Temperature Stability / T mv Total Output Variation Includes Line and Load Regulation over Temperature Vdc Short Circuit Current ( = V, TJ = 5 C) ISC 8 ma Output Noise Voltage ( Hz f khz, TJ = 5 C) Vn 4 µvrms Long Term Stability (TJ = 5 C) (Note 5) S 5 mv/khr OSCILLATOR SECTION (Note 6, unless otherwise noted.) Initial Accuracy (TJ = 5 C) ±. ±6. % Frequency Stability with Voltage (8. V C 5 V) fosc ±. ±. % D C Frequency Stability with Temperature fosc D T ±. % Minimum Frequency (RT = 5 kω, CT =. µf) fmin 5 Hz Maximum Frequency (RT =. kω, CT =. nf) fmax 4 khz Current Mirror (IRT =. ma)... ma Clock Amplitude..5 V Clock Width (TJ = 5 C)..5. µs Sync Threshold...8 V Sync Input Current (Sync Voltage =.5 V)..5 ma ERROR AMPLIFIER SECTION (M = 5. V) Input Offset Voltage VIO. mv Input Bias Current IIB. µa Input Offset Current IIO. µa DC Open Loop Gain (RL MΩ) AVOL 6 5 db Low Level Output Voltage VOL..5 V High Level Output Voltage VOH V Common Mode Rejection Ratio (.5 V M 5. V) CMRR 6 5 db Power Supply Rejection Ratio (8. V C 5 V) PSRR 5 6 db PWM COMPARATOR SECTION Minimum Duty Cycle DCmin % Maximum Duty Cycle DCmax % Input Threshold, Zero Duty Cycle (Note 6) Vth.6.9 V Input Threshold, Maximum Duty Cycle (Note 6) Vth..6 V Input Bias Current IIB.5. µa NOTES: 4. T low = for SG55A, 5A T high = C for SG55A, 5A 5. Since long term stability cannot be measured on each device before shipment, this specification is an engineering estimate of average stability from lot to lot. 6. Tested at f osc = 4 khz (R T =.6 kω, C T =. µf, R D = Ω). MOTOROLA ANALOG IC DEVICE DATA

4 ELECTRICAL CHARACTERISTICS (Continued) SOFTSTART SECTION SG55A SG5A Characteristics Symbol Min Typ Max Unit SoftStart Current (Vshutdown = V) µa SoftStart Voltage (Vshutdown =. V).4.6 V Shutdown Input Current (Vshutdown =.5 V).4. ma OUTPUT DRIVERS (Each Output, C = V) Output Low Level (Isink = ma) (Isink = ma) Output High Level (Isource = ma) (Isource = ma) Under Voltage Lockout (V8 and V9 = High) VUL V Collector Leakage, = 5 V (Note ) IC(leak) µa Rise Time (CL =. nf, TJ = 5 C) tr 6 ns Fall Time (CL =. nf, TJ = 5 C) tf 5 ns Shutdown Delay (VDS =. V, CS =, TJ = 5 C) tds..5 µs Supply Current (C = 5 V) ICC 4 ma VOL VOH V V NOTE:. Applies to SG55A only, due to polarity of output pulses. Lab Test Fixture PWM ADJ..k.k.5k.9. 6 Clock. 4 Sync RT 6 Deadtime Ramp Ω 5. Comp O s c i l l a t o r Reference Regulator Flip/ Flop A B Out A.k,.W () Out B C V/I Meter = VIO = () = () k 9. E/A DUT PWM 5µA Gnd 8 Softstart 5.µF.k Shutdown 4 MOTOROLA ANALOG IC DEVICE DATA

5 SG55A SG5A Figure. Oscillator Charge Time versus RT Figure. Oscillator Discharge Time versus RD 5 RT, TIMING RESISTOR (k Ω ) 5 * R D = Ω R D * R T C T , CHARGE TIME (µs), DEAD TIME RESISTOR ( ) R D Ω DISCHARGE TIME (µs) Figure. Error Amplifier Open Loop Frequency Response Figure 4. Output Saturation Characteristics (SG55A) VOL, VOLTAGE GAIN (db) A RZ = k 9 C P R Z Vsat, SATURATION VOLTAGE (V) C = V TJ = 5 C Sink Sat, (VOL) Source Sat, (VOH).. k k k. M M f, FREQUENCY (Hz) IO, OUTPUT SOURCE OR SINK CURRENT (A) Figure 5. Oscillator Schematic (SG55A) Figure 6. Error Amplifier Schematic (SG55A) 6 Q Q5 Q8.4k 5 C Q RT 6 CT 5 Sync Discharge Q Gnd Q Q6 Q9.k 4k.k Q Q 5.pF Q4 4µA k Q.k Q.k 5k Q4 Ramp To PWM Blanking To Output Q.k 5 4 OSC Output Inverting Q Input Noninverting Input µa Q µa Q4 5.8V 9 To PWM Comparator Compensation MOTOROLA ANALOG IC DEVICE DATA 5

6 SG55A SG5A Figure. SG55A Output Circuit (/ Circuit Shown) Q4 Q5 C Q Q9 Q Q6 Q8 Q.k, 4 Output Q Q Q Q6 Omitted in SG5A k k Clock F/F PWM Figure 8. SingleEnded Supply Figure 9. PushPull Configuration Vsupply Q To Output Filter R R SG55A A 4 B Gnd Vsupply R A SG55A B Gnd 4 C R C R Q Q T For singleended supplies, the driver outputs are grounded. The terminal is switched to ground by the totempole source transistors on alternate oscillator cycles. In conventional pushpull bipolar designs, forward base drive is controlled by RR. Rapid turnoff times for the power devices are achieved with speedup capacitors C and C. Figure. Driving Power FETS Figure. Driving Transformers in a HalfBridge Configuration Vsupply R A Q T Vsupply A T Q R T C SG55A Gnd B 4 Q SG55A Gnd B 4 Q R C The low source impedance of the output drivers provides rapid charging of power FET input capacitance while minimizing external components. Low power transformers can be driven directly by the SG55A. Automatic reset occurs during deadtime, when both ends of the primary winding are switched to ground. 6 MOTOROLA ANALOG IC DEVICE DATA

7 SG55A SG5A OUTLINE DIMENSIONS 6 H A 8 G F 9 D 6 PL B S C K.5 (.) M T N SUFFIX PLASTIC PACKAGE CASE 6488 ISSUE R SEATING T PLANE A M J L M NOTES:. DIMENSIONING AND TOLERANCING PER ANSI Y4.5M, 98.. CONTROLLING DIMENSION: INCH.. DIMENSION L TO CENTER OF LEADS WHEN FORMED PARALLEL. 4. DIMENSION B DOES NOT INCLUDE MOLD FLASH. 5. ROUNDED CORNERS OPTIONAL. INCHES MILLIMETERS DIM MIN MAX MIN MAX A B C D F.4... G. BSC.54 BSC H.5 BSC. BSC J K...8. L M S T SEATING PLANE G A K B D 6 PL.5 (.) M T B S A S DW SUFFIX PLASTIC PACKAGE CASE 5B5 (SO6L) ISSUE J P 8 PL.5 (.) M B S C M R X 45 J F NOTES:. DIMENSIONING AND TOLERANCING PER ANSI Y4.5M, 98.. CONTROLLING DIMENSION: MILLIMETER.. DIMENSIONS A AND B DO NOT INCLUDE MOLD PROTRUSION. 4. MAXIMUM MOLD PROTRUSION.5 (.6) PER SIDE. 5. DIMENSION D DOES NOT INCLUDE DAMBAR PROTRUSION. ALLOWABLE DAMBAR PROTRUSION SHALL BE. (.5) TOTAL IN EXCESS OF THE D DIMENSION AT MAXIMUM MATERIAL CONDITION. MILLIMETERS INCHES DIM MIN MAX MIN MAX A B C D F G. BSC.5 BSC J K M P R MOTOROLA ANALOG IC DEVICE DATA

8 SG55A SG5A Motorola reserves the right to make changes without further notice to any products herein. Motorola makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does Motorola assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation consequential or incidental damages. Typical parameters which may be provided in Motorola data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. All operating parameters, including Typicals must be validated for each customer application by customer s technical experts. Motorola does not convey any license under its patent rights nor the rights of others. Motorola products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications intended to support or sustain life, or for any other application in which the failure of the Motorola product could create a situation where personal injury or death may occur. Should Buyer purchase or use Motorola products for any such unintended or unauthorized application, Buyer shall indemnify and hold Motorola and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that Motorola was negligent regarding the design or manufacture of the part. Motorola and are registered trademarks of Motorola, Inc. Motorola, Inc. is an Equal Opportunity/Affirmative Action Employer. How to reach us: USA / EUROPE / Locations Not Listed: Motorola Literature Distribution; JAPAN: Nippon Motorola Ltd.; TatsumiSPDJLDC, 6F SeibuButsuryuCenter, P.O. Box 9; Phoenix, Arizona or Tatsumi KotoKu, Tokyo 5, Japan MFAX: RMFAX@ .sps.mot.com TOUCHTONE ASIA/PACIFIC: Motorola Semiconductors H.K. Ltd.; 8B Tai Ping Industrial Park, INTERNET: 5 Ting Kok Road, Tai Po, N.T., Hong Kong MOTOROLA ANALOG IC DEVICE SG55A/D DATA

LM337MT MEDIUM CURRENT THREE TERMINAL ADJUSTABLE NEGATIVE VOLTAGE REGULATOR

LM337MT MEDIUM CURRENT THREE TERMINAL ADJUSTABLE NEGATIVE VOLTAGE REGULATOR Order this document by /D The is an adjustable threeterminal negative voltage regulator capable of supplying in excess of 5 ma over an output voltage range of 1.2 V to 37 V. This voltage regulator is exceptionally