LDO with Reverse Current Protection / Soft Start / Discharge Function. Exposed PAD on backside connected to GND. Reverse Current Protection

Transcription

1 LDO with Reverse Current Protection / Soft Start / Discharge Function GENERAL DESCRIPTION The NJM877 is a low dropout regulator which achieves high ripple rejection, low noise and high speed response with the bipolar technology. Adjustable soft-start function is useful for reducing inrush current and controlling power-on sequence. Moreover the discharge function makes effective sequence control with the soft-start function. In addition, the reverse current protection makes external SBD unnecessary. PACKAGE OUTLINE NJM877KG NJM877F FEATURES Operating Voltage Range.3V to 6.5V Output Voltage Accuracy V O.% Output Current I O (min.)=ma Reverse Current Protection Adjustable soft-start Function Discharge Function ON/OFF Control Correspond to Low ESR capacitor (MLCC) Thermal Shutdown Circuit Over Current Protection Circuit Package Outline DFN6-G(ESON6-G), SOT-3-5 PIN CONFIGRATION (Top View) (Bottom View) Cs 6 6 GND 5 NC 5 CONTROL 3 V IN NJM877KG 3 Exposed PAD on backside connected to GND. V IN GND CONTROL 3 NJM877F 5 Cs BLOCK DIAGRAM V IN CONTROL Reverse Current Protection Thermal Protection Bandgap Reference C S Over Current Protection GND Ver

2 OUTPUT VOLTAGE RANK LIST DFN6-G(ESON6-G) SOT-3-5 Device Name Output Output Device Name Voltage Voltage NJM877KG-5.5V NJM877F5.5V NJM877KG-8.8V NJM877F8.8V NJM877KG-5.5V NJM877F5.5V NJM877KG V NJM877F33 3.3V NJM877KG-5 5.V NJM877F5 5.V ABSOLUTE MAXIMUM RATINGS (Ta=5 C) PARAMETER SYMBOL MAXIMUM RATING UNIT Input Voltage V IN -.3 ~ +7 V Control Pin Voltage V CONT -.3 ~ +7 V Output Voltage Vo.8V -.3 ~ +5.5 V Vo.8V -.3 ~ +7 V Soft start Pin Voltage V CS -.3 ~ + V Power Dissipation P D ESON6-G (*) (*) SOT-3-5 8(*3) 65(*) mw Junction Temperature Range Tj - +5 C Operating Temperature Range Topr - +5 C Storage Temperature Range Tstg C (*): Mounted on glass epoxy board. (.5.5.6mm: based on EIA/JEDEC standard, Layers FR-, with Exposed Pad) (*): Mounted on glass epoxy board. (.5.5.6mm: based on EIA/JEDEC standard, Layers FR-, with Exposed Pad) (For Layers: Applying mm inner Cu area and a thermal via hole to a board based on JEDEC standard JESD5-5) (*3): Mounted on glass epoxy board. ( mm:based on EIA/JDEC standard, Layers) (*): Mounted on glass epoxy board. ( mm:based on EIA/JDEC standard, Layers), internal Cu area: 7.x7.mm Operating Voltage Range :V IN =.3V ~ 6.5V - - Ver.5-8-6

3 ELECTRICAL CHARACTERISTICS Unless other noted, V IN = V O + V, C IN =.µf, C O =.µf :.V Vo 5.V, C O =.µf :.9V Vo.V, C O =.7µF :.3V Vo.9V, C O =.µf :Vo.3V Cs=.µF, T a = 5 C) PARAMETER SYMBOL TEST CONDITION MIN. TYP. MAX. UNIT Output Voltage V O I O =3mA -.% - +.% V Quiescent Current I Q I O = ma, except I CONT - 6 μa Quiescent Current at OFF-state I Q(OFF) V CONT = V - - μa Output Current I O V O ma Line Regulation V O / V IN V IN = V O + V ~ 6.5V, Io=3mA - -. %/V Vo=.5V Vo=.8V -.6 Load Regulation V O / I O I O = ~ ma Vo=.5V -. %/ma Vo=3.3V -. Vo=5.V -. Dropout Voltage (*5) V IO I O = ma -.. V Average Temperature Coefficient of Output Voltage Ripple Rejection Output Noise Voltage V O / Ta Ta = - +5 C, I O =3mA ppm/ C RR V NO ein=mvrms, f=khz, Io=mA f=hz ~ 8kHz, Io=mA Vo=.5V Vo=.8V Vo=.5V Vo=3.3V Vo=5.V Vo=.5V Vo=.8V - - Vo=.5V Vo=3.3V Vo=5.V - - Control Current I CONT V CONT =.6V - 3 μa Control Voltage at ON-state Control Voltage at OFF-state V CONT(ON) V V CONT(OFF) V Soft Start Time t S(ON) V CONT =L H, Io=3mA, Cs=.μF -. - msec Discharge Current at OFF-state I DIS V IN =.3V, V CONT =V, V O =.5V 9 - V IN =6.5V, V CONT =V, V O =.5V (*5): Except Output Voltage Rank less than.v The above specification is a common specification for all output voltages. Therefore, it may be different from the individual specification for a specific output voltage. db μvrms ma Ver

4 THERMAL CHARACTERISTICS PARAMETER SYMBOL VALUE UNIT DFN6-G 98 (*6) Junction-to-ambient (ESON6-G) (*7) ja C/W thermal resistance 6 (*8) SOT (*9) DFN6-G 5 (*6) Junction-to-Top of package (ESON6-G) 6 (*7) jt C/W characterization parameter 7 (*8) SOT (*9) (*6): Mounted on glass epoxy board. (.5.5.6mm: based on EIA/JEDEC standard, Layers FR-, with Exposed Pad) (*7): Mounted on glass epoxy board. (.5.5.6mm: based on EIA/JEDEC standard, Layers FR-, with Exposed Pad) (For Layers: Applying mm inner Cu area and a thermal via hole to a board based on JEDEC standard JESD5-5) (*8): Mounted on glass epoxy board. ( mm:based on EIA/JDEC standard, Layers) (*9): Mounted on glass epoxy board. ( mm:based on EIA/JDEC standard, Layers), internal Cu area: 7.x7.mm POWER DISSIPATION vs. AMBIENT TEMPERATURE Power Dissipation P D (mw) 6 8 NJM888KG NJM877KG PowerDissipation (Topr=-~+5 C,Tj=5 C) Tj=5 C) on layers board on layers board Temperature : Ta( C) Power Dissipation P D (mw) on layers board on layers board NJM877F PowerDissipation (Topr=-~+5 C,Tj=5 C) Temperature : Ta( C) - - Ver.5-8-6

5 TEST CIRCUIT A I IN V IN V IN.μF (ceramic) NJM877 (*).μf (ceramic) I OUT V A I CONT CONTROL Cs V V CONT GND.μF (ceramic) *:.9V<Vo.V version :Co=. F(Ceramic).3V<Vo.9V version :Co=.7 F(Ceramic) Vo.3V version :Co=. F(Ceramic) TYPICAL APPLICATION. In the case where ON/OFF Control is not required V IN V IN (*). F. F NJM877 CONTROL Cs Connect CONTROL pin to V IN pin *:.9V<Vo.V version :Co=. F.3V<Vo.9V version :Co=.7 F Vo.3V version :Co=. F GND. F *Connected when soft start is Required.. In use of ON/OFF CONTROL V IN V IN (*) NJM877. F. F CONTROL Cs GND. F *Connected when soft start is Required. *:.9V<Vo.V version :Co=. F.3V<Vo.9V version :Co=.7 F Vo.3Vversion :Co=. F State of CONTROL pin: H output is enabled. L or open output is disabled Ver

6 *Reverse Current Protection The NJM877 has built-in Reverse Current Protection circuit. This circuit prevents the large reverse current when output voltage is higher than input voltage. Therefore external schottky-barrier diode(sbd) is not required. *Soft Start capacitor Cs The Soft Start function can control the rise time of Output Voltage and reduce the inrush current by connecting the Cs capacitor. The Soft Start time is defined as % to 9% of the Output Voltage. The Cs capacitor is not essential, but it used for noise bypass of bandgap reference either. Therefore Output Noise Voltage increases when the capacitor isn't connected. If the Cs capacitor is not used, the Cs pin should be OPEN. Soft Start Time: t S(ON) (ms).. NJM877 Soft Start Time vs Cs Pin o C Vo_rise=%-9%.... Cs Pin Capacitor : Cs (nf) Soft-Start Time vs. Cs Pin Capacitor Soft Start Time : t S(ON) (ms) NJM877 Soft Start Time vs Vo_rise=%-9% Soft-Start Time (.μf) vs. Temperature Output Noise Voltage :V NO (μvrms) Output Noise Voltage vs Cs Pin Io=mA Cin=.μF(Ceramic) Co=.μF(Ceramic) Inrush Current :I RUSH (ma) Inrush Current vs Cs pin Io=3mA C IN =.μf(ceramic) Co=.μF(Ceramic)... Soft Start Capacitor :Cs (nf) Output Noise Voltage vs. Cs Pin Capacitor... Cs pin Capacitor : Cs (nf) Inrush Current vs. Cs Pin Capacitor Ver.5-8-6

7 *Discharge Function The NJM877 has a built-in discharge circuit to discharge the charged output capacitors. Discharge circuit operates when the CONTROL pin is set in LOW level. The circuit discharges the charged output capacitors rapidly. 6 ON/OFF Transient Response without Load Control Voltage:VCONT (V) Control Voltage Output C Io=mA C IN =.μf(ceramic) Co=.μF(Ceramic) Cs=.μF(Ceramic) 3 Output Voltage:Vo (V) 8 6 Time:t (ms) Output Voltage sweep down characteristics by Discharge function *Transient response characteristic of Output Voltage In general, overshoot or undershoot of output voltage may occur due to the transient response characteristic of an internal error amplifier. Especially, low current consumption regulator may have overshoot or undershoot due to slow feedback caused by current saving design. Therefore, design validation is important in the following cases:. Input voltage or output current change sharply. Output capacitors is small 3. Output load is light. A regulator starts up with very low dropout voltage operation. Increasing the value of input and/or output capacitor is a common countermeasure for improving a transient response characteristic. A transient response characteristic may vary with operating conditions and external components value. Please check it with the actual environment. Ver

8 *Input Capacitor C IN The input capacitor C IN is required to prevent oscillation and reduce power supply ripple for applications when high power supply impedance or a long power supply line. Therefore, use the recommended C IN value (refer to conditions of ELECTRIC CHARACTERISTIC) or larger and should connect between GND and V IN as shortest path as possible to avoid the problem. *Output Capacitor C O The output capacitor C O will be required for a phase compensation of the internal error amplifier. The capacitance and the equivalent series resistance (ESR) influence to stable operation of the regulator. Use of a smaller C O may cause excess an output noise or an oscillation of the regulator due to lack of the phase compensation. On the other hand, use of a larger C O reduces an output noise and a ripple output, and also improves an output transient response when a load rapidly changes. Therefore, use the recommended C O value (refer to conditions of ELECTRIC CHARACTERISTIC) or larger and should connect between GND and as shortest path as possible for stable operation The recommended capacitance depends on the output voltage rank. Especially, a low voltage regulator requires larger C O value. In addition, you should consider varied characteristics of capacitor (a frequency characteristic, a temperature characteristic, a DC bias characteristic and so on) and unevenness peculiar to a capacitor supplier enough. When selecting C O, recommend that have withstand voltage margin against an output voltage and superior temperature characteristics though this product is designed stability works with wide range ESR of capacitor including low ESR products Ver.5-8-6

9 TYPICAL CHARACTERISTICS Output Voltage : V O (V) Output Voltage vs Input C IN =.µf(ceramic) Co=.µF(Ceramic) Cs=.µF(Ceramic) Io=mA Io=3mA Io=mA Output Voltage : Vo (V) C 5 C 5 C Output Voltage vs Output C IN =.µf(ceramic) Co=.µF(Ceramic) Cs=.µF(Ceramic) Input Voltage : V IN (V) Output Current : Io (ma) GND Current : I GND (ma) GND Current vs Output C IN =.µf(ceramic) Co=.µF(Ceramic) Cs=.µF(Ceramic) 5 5 Output Current : Io (ma) Dropout Voltage : ΔV IO (V) Dropout Voltage vs Output C IN =.µf(ceramic) Co=.µF(Ceramic) Cs=.µF(Ceramic) 5 5 Output Current : Io (ma) Control Current : I CONT (μa) 5 3 Control Current vs Control C IN =.µf(ceramic) Co=.µF(Ceramic) Cs=.µF(Ceramic) Output Voltage : V O (V) Output Voltage vs Control C IN =.µf(ceramic) Co=.µF(Ceramic) Cs=.µF(Ceramic) Control Voltage : V CONT (V) Control Voltage : V CONT (V) Ver

10 Load Regulation : ΔVo/ΔIo (mv) Load Regulation vs Output C IN =.µf(ceramic) Co=.µF(Ceramic) Cs=.µF(Ceramic) Output Current : Io (ma) Quiescent Current:I Q (μa) Quiescent Current vs Input Output is Open except I CONT C IN =.µf(ceramic) Co=.µF(Ceramic) Cs=.µF(Ceramic) Input Voltage : V IN (V) Peak Output Current : I OPEAK (ma) Peak Output Current vs Input Vo=.97V C IN =.µf(ceramic) Co=.µF(Ceramic) Cs=.µF(Ceramic) Input Voltage : V IN (V) Short Circuit Current : I SC (ma) Short Circuit Current vs Input V O =V C IN =.µf(ceramic) Co=.µF(Ceramic) Cs=.µF(Ceramic) Input Voltage : V IN (V) Discharge Current : I DIS (ma) Discharge Current vs Output V CONT =V C IN =.µf(ceramic) Co=.µF(Ceramic) Cs=.µF(Ceramic) VIN=7.V VIN=.3V Reverse Current : IRV (ma) Discharge Current vs Input V IN =V CONT V O =3.3-7.V C IN =.µf(ceramic) Co=.µF(Ceramic) Cs=.µF(Ceramic) Reverse Current Quiescent Current Output Voltage : V O (V) Input Voltage : V IN (V) - - Ver.5-8-6

11 Output Noise Voltage :V NO (μvrms) Output Noise Voltage vs Output C IN =.µf(ceramic) Co=.µF(Ceramic) Cs=.µF(Ceramic)... Output Current :Io (ma) Equivalent Serise Resistance : ESR (Ω). Equivalent Serise Resistance vs Output IN =.µf(ceramic) Co=.µF(Ceramic) Cs=.µF(Ceramic) STABLE REGION.... Output Current : Io (ma) Ripple Rejection :RR (db) Io=mA Co=.μF Cs=.μF ein=mvrms Ripple Rejection vs Frequency Io=mA Io=mA.. Frequency :f (khz) Ripple Rejection :RR (db) Ripple Rejection vs Output Current f=khz 3 Co=.μF Cs=.μF ein=mvrms.. Output Current :Io (ma) Output Voltage : V O (V) Output Voltage vs C IN =.µf(ceramic) Co=.µF(Ceramic) Cs=.µF(Ceramic) Io=mA Io=3mA Io=mA Dropout Voltage : ΔV IO (V) Dropout Voltage vs IN =.µf(ceramic) Co=.µF(Ceramic) Cs=.µF(Ceramic) Io=3mA Io=mA Io=mA Ver

12 Control Voltage : V CONT (V) Control Voltage vs C IN =.µf(ceramic) Co=.µF(Ceramic) Cs=.µF(Ceramic) Control Current : I CONT (μa) 8 6 Control Current vs CONT =.6V C IN =.µf(ceramic) Co=.µF(Ceramic) Cs=.µF(Ceramic) Quiescent Current : I Q (μa) Quiescent Current vs Output is Open C IN =.µf(ceramic) Co=.µF(Ceramic) Cs=.µF(Ceramic) Discharge Current : I DIS (ma) Discharge Current vs O =.5V C IN =.µf(ceramic) Co=.µF(Ceramic) Cs=.µF(Ceramic) VIN=.3V VIN=6.5V Line Regulation : ΔVo/ΔV IN (%/V) Line Regulation vs IN =.3-6.5V Io=3mA C IN =.µf(ceramic) Co=.µF(Ceramic) Cs=.µF(Ceramic) Load Regulation : ΔVo/ΔIo (%/ma) Load Regulation vs Io=-mA C IN =.µf(ceramic) Co=.µF(Ceramic) Cs=.µF(Ceramic) Ver.5-8-6

13 Peak Output Current : I PEAK (ma) Peak Output Current vs V O =.97V C IN =.µf(ceramic) Co=.µF(Ceramic) Cs=.µF(Ceramic) Short Circuit Current : I SC (ma) Short Circuit Current vs V O =V C IN =.µf(ceramic) Co=.µF(Ceramic) Cs=.µF(Ceramic) Output Voltage vs Temperature 3.5 Output Voltage : V O (V) C IN =.µf(ceramic) Co=.µF(Ceramic) Cs=.µF(Ceramic) Ver

14 Load Transient Response Load Transient Response 3 Output current:io (ma) Output current Output C Io=3-mA C IN =.μf(ceramic) Co=.μF(Ceramic) Cs=.μF(Ceramic) Output Voltage:Vo (V) Output current:io (ma) Output current Output C Io=-mA C IN =.μf(ceramic) Co=.μF(Ceramic) Cs=.μF(Ceramic) Output Voltage:(V) 8 6 Time:t (μs) 8 6 Time:t (μs) 7 Input Transient Response 6 CONTROL_ON Delay Time Input Voltage:VIN (V) 6 5 Input C V IN =.3-5.3V Io=3mA C IN =.μf(ceramic) Co=.μF(ceramic) Cs=.μF(Ceramic) Output Voltage Output Voltage:Vo (V) Control Voltage:VCONT (V) Control Voltage Output C Io=3mA C IN =.μf(ceramic) Co=.μF(Ceramic) Cs=.μF(Ceramic) 3 Output Voltage:Vo (V) 8 6 Time:t (μs) 3 5 Time:t (ms) - - Ver.5-8-6

15 [CAUTION] The specifications on this databook are only given for information, without any guarantee as regards either mistakes or omissions. The application circuits in this databook are described only to show representative usages of the product and not intended for the guarantee or permission of any right including the industrial rights. Ver