NJM2828. Negative Output Low Drop Out voltage regulator

Transcription

1 Negative Output Low Drop Out voltage regulator GENERAL DESCRIPTION The NJM88 is a negative output low dropout regulator. Advanced bipolar technology achieves low noise, high precision voltage and high ripple rejection. It has soft-start and shunt SW function. 1.µF Output capacitor and small package can make NJM88 suitable for portable items. FEATURES Low Current Consumption.13V High Precision Output ±1.5% High Ripple Rejection Vo=-7V Version Output capacitor with.1f ceramic capacitor. Output Current Io(max.)=1mA ON/OFF Control(Positive voltage control from to +5V) Soft-start Function Shunt SW Function Internal Thermal Overload Protection Internal Short Circuit Current Limit Bipolar Technology Package Outline SC88A PIN CONFIGURATION NJM88F3-XX EQUIVALENT CIRCUIT 1.GND.V IN 3.V OUT.CONTROL 5.CS PACKAGE OUTLINE SC88A NJM88F3 GND Thermal Protection Current Limit CS Bandgap Reference CONTROL Output Control V IN V OUT Ver

2 OUTPUT VOLTAGE RANK LIST Device Name V OUT Device Name V OUT NJM88F V NJM88F V NJM88F V NJM88F V NJM88F3- -.V NJM88F V NJM88F V NJM88F V NJM88F3- -.V NJM88F V NJM88F V NJM88F V NJM88F V NJM88F V NJM88F V NJM88F V Output voltage options available : -1.5 ~ -1.V (.1V step) - - Ver

3 ABSOLUTE MAXIMUM RATINGS (Ta=5 C) PARAMETER SYMBOL RATINGS UNIT Input Voltage V IN -1 V Control Voltage V CONT +5 V Power Dissipation P D 5(*1) mw Operating Temperature Topr +85 C Storage Temperature Tstg +15 C Output Sink Current at OFF-state I SINK(OFF) 1 ma (*1): Mounted on glass epoxy board. ( mm : layer,fr-) Operating voltage V IN =-3. -1V (In case of Vo>-3.V version) ELECTRICAL CHARACTERISTICS (Vo<-.V Version: V IN =Vo-1V, V CONT =3V, C IN =.1µF, Co=1.µF, Ta=5 C) (Vo -.V Version: V IN =-3.V, V CONT =3V, C IN =.1µF, Co=.µF(Vo>-.V: Co=.7µF), Ta=5 C) PARAMETER SYMBOL TEST CONDITION MIN. TYP. MAX. UNIT Output Voltage Vo Io=3mA +1.5% % V Quiescent Current I Q Io=mA, except Icont - 13 µa Quiescent Current at OFF-state I Q(OFF) V CONT =V na Output Current Io V O +.3V ma Line Regulation Vo/ V IN V IN =Vo-1V -1V, Io=3mA %/V Load Regulation Vo/ Io Io= 6mA %/ma Dropout Voltage(*) V I_O Io=6mA V Ripple Rejection Average Temperature Coefficient of Output Voltage RR ein=mvrms, f=1khz, Io=1mA Vo=-7V Version db Vo/ Ta Ta= 85 C, Io=1mA - ±5 - ppm/ C Output Noise Voltage1 V NO f=1hz 8kHz, Io=1mA, Vo=-7V Version µvrms CS Terminal Charge Current Ics V CS =V 5 6 µa Output Resistance at OFF-state R O(OFF) V CONT =V, Vo=-7V Version Ω Control Current I CONT V CONT =1.6V - µa Control Voltage for ON-state V CONT(ON) V Control Voltage for OFF-state V CONT(OFF) V Input Voltage V IN V (*):Excludes Vo>-3.V version. 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. Ver

4 TEST CIRCUIT V IN.1µF A GND I Q 1.µF *3 I OUT V OUT (Ceramic) V V IN 88 V OUT.7µF A I CONT CONTROL CS V V CONT *3 -.V Vo< -.V version : Co=.µF(Ceramic) Vo -.V version : Co=.7µ F(Ceramic) - - Ver

5 TYPICAL APPLICATIONS ON/OFF control ON/OFF control can be achieved by applying positive control voltage to CONTROL terminal. Apply positive Vcont ("H") to make chip to be ON (Enabled), and either Vcont is "L" or open (High Z) to make chip to be OFF (Disabled). The relations between Vcont and the state is as follows: Vcont +1.6V Vcont +5V ("H" level): ON state Vcont V Vcont +.6V ("L" level): OFF state Vcont +.6V < Vcont < +1.6V ("L" level): Undefined In case ON/OFF control is not used, keep applying positive Vcont to CONTROL terminal to make chip ON. Note that negative Vcont does not make the chip enabled..1µf 1.µF * (Ceramic V IN GND V OUT V IN V OUT CONTROL R 88 CONTROL CS Cs=.7µF CS * -.V Vo< -.V version : Co=.µF Vo -.V version : Co=.7µ F In the case of using a resistance "R" between V IN and control. The current flow into the control terminal while the IC is ON state (I CONT ) can be reduced when a pull up resistance "R" is inserted between V IN and the control terminal. The minimum control voltage for ON state (V CONT (ON) ) is increased due to the voltage drop caused by I CONT and the resistance "R". The I CONT is temperature dependence as shown in the "Control Current vs. Temperature" characteristics. Therefore, the resistance "R" should be carefully selected to ensure the control voltage exceeds the V CONT (ON) over the required temperature range. Input Capacitance C IN Input capacitance C IN is required to prevent oscillation and reduce power supply ripple for applications with high power supply impedance or a long power supply line. Use the C IN value of.1µf greater to avoid the problem. C IN should connect between GND and V IN as short as possible. Ver

6 Output Capacitance C O Output capacitor (Co) is required for a phase compensation of the internal error amplifier. The capacitance and the equivalent series resistance (ESR) influences stability of the regulator. This product is designed to work with a low ESR capacitor for the Co; however, use of recommended capacitance or greater value is essential for stable operation. Use of a smaller Co may cause excess output noise or oscillation of the regulator due to lack of the phase compensation. Therefore, use Co with the recommended capacitance or greater value and connect between Vo terminal and GND terminal with minimal wiring. The recommended capacitance depends on the output voltage. Low voltage regulator requires greater value of the Co. Thus, check the recommended capacitance for each output voltage. Use of a greater Co reduces output noise and ripple output, and also improves transient response of the output voltage against rapid load change Ver

7 Soft-start function Capacitance Cs connect between CS pin and GND for the following. Control at risetime of output voltage. Reduces inrush current at output ON. When the soft start function is not used, CS pin should be open. 1.Cs capacitance vs risetime of output voltage Calculation : risetime of output voltage t 13 x Cs(µF) 5 Cs capacity vs risetime of output voltage risetime of output voltage : t (ms) VIN=6V CIN=.1µF Co=1µF(Ceramic) Io=mA Cs capacity : Cs(µF).Inrush current at control ON The peak value of the inrush current can be limited according to the capacitance of the Cs. Inrush current wave : Output Voltage Output Voltage Control ON Control ON Inrush current Inrush current Vin=Vo-1V Cin=.1µF(Ceramic) Co=1µF(Ceramic) Io=mA 5mA/div Vin=Vo-1V Cin=.1µF(Ceramic) Co=1µF(Ceramic) Io=mA ma/div Cs=µF(Open) : I PEAK =15µA Cs=.7µF : I PEAK =µa This characteristic is one example. It is necessary to examine the characteristic with an actual circuit because there is an influence by the characteristic such as output voltage/output capacitor. Ver

8 POWER DISSIPATION vs. AMBIENT TEMPERATURE 5 NJM88F3 Power Dissipation (Topr=- +85,Tj=15 ) Power Dissipation P D (mw) 3 1 On Board( mm, FR-) Ambient Temperature Ta( ) Ver

9 ELECTRICAL CHARACTERISTICS Output Voltage : Vo(V) Io=A Output Voltage vs. Input Voltage Io=3mA Io=1mA Co=1.µF(Ceramic) Input Voltage : VIN(V) Output Voltage : Vo(V) Output Voltage vs. Output Current 1 VIN=-8.V Co=1.µF(Ceramic) Output Current : Io(mA) 1 8 Ground Pin Current v.s. Output Current VIN=-8.V Co=1.µF(Ceramic).3.5 Dropout Voltage vs. Output Current Co=1.µF(Ceramic) Vcont=3.V Ground Pin Current : IGND (ma) 6 Dropout Voltage:dVI-O (V) Output Current : IO(mA) Output Current:Io(mA) 3 5 Control Current vs. Control Voltage VIN=-8.V Co=1.µF(Ceramic) Io=3mA 8 7 Output Voltage vs. Control Voltage 6 Rc=Ω Control Current : I Cont (µa) 15 1 Rc=5kΩ Rc=Ω Output Voltage : Vo(V) 5 3 Rc=5kΩ Rc=1kΩ 5 Rc=1kΩ Control Voltage : V (V) Cont 1 VIN=-8.V Co=1.µF(Ceramic) Io=3mA Control Voltage : V Cont (V) Ver

10 ELECTRICAL CHARACTERISTICS Load Regulation vs. Output Current Peak Output Current vs. Input Voltage -1 Load Regulation : dvo/dio(mv) VIN=-8.V Co=1.µF(Ceramic) Output Current : Io(mA) Peak Output Current : IoMAX(mA) Co=1.µF(Ceramic) Vcont=3.V Input Voltage : VIN(V) Quiescent Current : IQ (µa) Quiescent Current v.s. Input Voltage Output is open. Co=1.µF(Ceramic) Vcont=3.V Output Noise Voltage : Vn(µVrms) VIN=-8.V Co=1. µf Output Noise Voltage vs. Output Current LPF:8k FLAT Input Voltage : VIN(V) Output Current : Io(mA) 1 9 Ripple Rejection Ratio v.s. Frequency 1 9 Ripple Rejection vs. Output Current VIN=-8.V ein=mvrms Co=1.µF(Ceramic) Ripple Rejection Ratio : RR (db) Io=3mA Io=1mA Io=mA 3 VIN=-8.V ein=mvrms Co=1. µf(ceramic) k 1k 1k 5 Frequency : f (Hz) Ripple Rejection : RR (db) f=1khz f=1khz Output Current : Io(mA) Ver

11 ELECTRICAL CHARACTERISTICS 1 Equivalent Serise Resistance vs. Output Current Co=1.µF(Ceramic).3 Dropout Voltage v.s. Co=1µF(Ceramic).5 Equivalent Serise Resistance : ESR(Ω) STABLE REGION Dropout Voltage:dVI-O (V) Output Current : Io(mA) Temperature : Ta ( o C) Control Voltage v.s. Temperature 7. Output Voltage v.s. Io=3mA Co=1.µF(Ceramic) Control Voltage : VCONT(ON) (V) Output Voltage Vo (V) Io=3mA Co=1.µF(Ceramic) Temperature : Ta ( o C) Temperature Ta ( o C) 1 CS Charge Current v.s. CS is short to ground. Co=1.µF(Ceramic) 5 Quiescent Current v.s. Temperature 8 CS Charge Current : ICS (µa) 6 Quiescent Current : IQ (µa) Iq+Icont Iq Temperature : Ta ( o Output is open. Co=1. µf(ceramic) Temperature : Ta ( o C) Ver

12 ELECTRICAL CHARACTERISTICS.1 Line Regulation v.s. Io=3mA Co=1.µF(Ceramic).3.5 Load Regulation v.s. Io=-6mA Co=1.µF(Ceramic) Line Regulation : dvo/dio (%/V) Load Regulation : dvo/dio (%/ma) Temperature : Ta ( o C) Temperature : Ta ( o C) 8 Output Voltage v.s. Temperature Short Circuit Current v.s. Output is short to ground. Co=1. µf(ceramic) Output Voltage Vo (V) 6 Short Circuit Current : ISC (ma) 15 1 Io=3mA Co=1.µF(Ceramic) Temperature Ta ( o C) Temperature : Ta ( o C) Ver

13 ELECTRICAL CHARACTERISTICS NJM88_-7.V Line Transient Response NJM88_-7.V Load Transient Response 15 Output Voltage : Vo [V] Input Voltage Output Voltage VDD=-8.V Co=1.µF(Ceramic) Io=3mA Input Voltage : V IN [V] Output Voltage : Vo [V] Output Current Output Voltage VDD=-8.V Co=1.µF(Ceramic) Output Current : Io [ma] Time : t [ms] Time : t [µs] 6 NJM88_-7.V ON/OFF Transient Response without Load Control Voltage Output Voltage : Vo [V] Output Voltage VDD=-8.V Co=1.µF(Ceramic) Cs=.7 µf Io=mA Time : t [ms] Control Voltage : Vo [V] Ver

14 [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