Very Low Output Voltage Series Regulator

Transcription

1 Very Low Output Voltage Series Regulator GENERAL DESCRIPTION The NJM2847 is a series voltage regulator that delivers up to 15mA output current with the output voltage of.8 to 1.4V with ON/OFF control. Advanced Bipolar technology achieves low noise, high ripple rejection, High accuracy and low quiescent current. Small packaging and 2.2µF small decoupling capacitor make the NJM2847 suitable for space conscious applications. PACKAGE OUTLINE NJM2847F3 FEATURES Output Voltage Range.8V to 1.4V Input Voltage Range 2.3V to 9.V High Ripple Rejection 85dB typ. (f=1khz, V O =.8V version) Very Low Output Noise Voltage V NO =2µVrms typ. (Cp=.1µF) Output Current I O (max)=15ma High Precision Output V O ±1.% Output Capacitor with 2.2µF ceramic capacitor ON/OFF Control Built-in Thermal Overload Protection and Short Circuit Current Limit Protection Bipolar Technology Package Outline SC-88A PIN CONNECTION BLOCK DIAGRAM CONTROL 2. GND 3. NOISE BYPASS NJM2847F3 VIN VOUT Control Bandgap Reference Thermal Protection Noise Bypass GND Ver

2 OUTPUT VOLTAGE RANK LIST The WHITE column shows applicable Voltage Rank(s). Device Name V out NJM2847F3-8.8V NJM2847F3-9.9V NJM2847F3-1 1.V NJM2847F V NJM2847F V NJM2847F V NJM2847F V Output Voltage Range:.8V to 1.4V (.1V step) ABSOLUTE MAXIMUM RATINGS (Ta=25 C) PARAMETER SYMBOL RATINGS UNIT Input Voltage +1 V Control Voltage V CONT +1 V Power Dissipation P D 25(*1) mw Operating Temperature Topr C Storage Temperature Tstg C Note1: Mounted on glass epoxy board. ( mm:based on EIA/JDEC standard, 2Layers) INPUT VOLTAGE RANGE = V ELECTRICAL CHARACTERISTICS ( =2.5V, C IN =.1µF, Co=2.2µF, Cp=.1µF, Ta=25 C) PARAMETER SYMBOL TEST CONDITION MIN. TYP. MAV. UNIT Output Voltage Vo Io=3mA -1.% +1.% V Input Voltage V Quiescent Current I Q Io=mA, except Icont 14 2 µa Quiescent Current at Control OFF I Q(OFF) V CONT =V 1 na Output Current Io Vo.9V 15 2 ma Line Regulation Vo/ =2.5V to 9.V, Io=3mA.1 %/V Load Regulation Vo/ Io Io=mA to 1mA.3 %/ma Ripple Rejection RR ein=2mvrms, f=1khz, Io=1mA, Vo=.8V version 85 db Average Temperature Coefficient of Output Voltage Vo/ Ta Ta= C to +85 C, Io=1mA ± 5 ppm/ C Output Noise Voltage V NO f=1hz to 8kHz, Io=1mA, Vo=.8Vversion 2 µvrms Control Current I CONT V CONT =1.6V 3 12 µa Control Current for ON-state V CONT(ON) 1.6 V Control Current for OFF-state V CONT(OFF).6 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 Ver

3 TEST CIRCUIT A I IN.1µF NJM µF (Ceramic) I OUT V A I CONT CONTROL NOISE BYPASS V V CONT GND Cp=.1µF TYPICAL APPLICATION a) In case of where ON/OFF control is not required:.1µf NJM µF R CONTROL GND NOISE BYPASS Cp=.1µF You shall connect control terminal to terminal. Though the I CONT decreases by inserting "R" to between Control terminal and V BIAS terminal, the minimum operating voltage is increased due to the resister "R". Ver

4 b) In use of ON/OFF control:.1µf NJM µF R CONTROL GND NOISE BYPASS Cp=.1µF State of control terminal: H output is enabled. L or open output is disabled. *In the case of using a resistance "R" between and control. If this resistor is inserted, it can reduce the control current when the control voltage is high. The applied voltage to control terminal should set to consider voltage drop through the resistor R and the minimum control voltage for ON-state. The V CONT (ON) and I CONT have temperature dependence as shown in the "Control Current vs. Temperature" and " Control Voltage vs. Temperature" characteristics. Therefore, the resistance "R" should be selected to consider the temperature characteristics Ver

5 *Noise bypass Capacitor Cp Noise bypass capacitor Cp reduces noise generated by band-gap reference circuit. Noise level and ripple rejection will be improved when larger Cp is used. Use of smaller Cp value may cause oscillation. Use the Cp recommended value larger (refer to conditions of ELECTRIC CHARACTERISTIC) to avoid the problem. *Input Capacitor C IN 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 as shortest path as possible to avoid the problem. *Output Capacitor C O 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 output noise or oscillation of the regulator due to lack of the phase compensation. On the other hand, Use of a larger C O reduces output noise and ripple output, and also improves output transient response when rapid load change. 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 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 output voltage and superior temperature characteristic though this product is designed stability works with wide range ESR of capacitor including low ESR products. Ver

6 POWER DISSIPATION vs. AMBIENT TEMPERATURE(SC-88A) 5 NJM2847F3 PowerDissipation (Topr= C,Tj=125 C) Power Dissipation P D (mw) Temperature Ta( C) Ver

7 Typical Characteristics 1.4 Output Voltage vs Input Voltage 1.5 Over Current Protection vs Output Current 1.3 Output Voltage : Vo (V) 1.2 Io=A Io=3mA Io=1mA Input Voltage : VIN (V) Output Voltage : Vo (V) Output Current : Io (ma) Ground Pin Current : I GND (ma) Control Current (ua) Cp=.1uF Io=3mA Ground Current vs Output Current Output Currnet : Io (ma) Control Voltage vs Control Current Rc=Ω Rc=5kΩ Rc=1kΩ Load Regulation : dvo/dio (mv) Output Voltage (V) Cp=.1uF Io=3mA Dropout Voltage VS Output Current Output Current : Io (ma) Control Voltage vs Output Voltage 2 Rc=1kΩ Rc=5kΩ Rc=Ω Control Voltage (V) Control Voltage (V) Ver

8 Typical Characteristics Quiescent Current:IQ (µa) Output is open Inculding Icont Quiescent Current vs Input Voltage Output Noise Voltage :Vn (µvrms) Output Noise Voltage vs Output C Cp=.1uF LPF:8k Input Voltage:VIN (V) Output Current :Io(mA) 1 Ripple Rejection Io=A 1 Output Current vs Ripple Rejection Ripple Rejection :RR(dB) Io=1mA Io=3mA Ripple Rejection :RR(dB) f=1khz f=1khz 4 3 ein=2mvrms Co=2.2uF(Ceramic 4 3 ein=2mvrms Frequency :f(khz) Output Current :Io(mA) Equivalent Serise Resistance:ESR [Ω] NJM2847(mold)_1.2v Equivalent Serise Resistance vs. Output C Cp=.1uF STABLE REGION Output Current : Io[mA] Ver

9 Typical Characteristics 1.3 Output Voltage v s. Temperature 2. Control Voltage(off) vs. Temperature 1.25 Io=3mA Co=2.2µ 1.5 Output Voltage : Vo (V) Control Voltage(OFF) :Vcont-off (V) 1..5 Io=3mA Cp=.1uF Output is open Cp=.1uF Control current vs. Temperature 3 25 Output is open including Icont Quiescent Current vs. Temperature 8 2 Control current : Icnt (ua) Quiescent Current : I Q (ma) Output is short to ground Short Circuit Current vs. Io=3mA Co=2.2µF(Ceramic) Line Regulation vs. Temperature 15.1 Short Circuit Current : Isc (ma) 1 5 Line Regulation : dvo/dvin (%/V) Ver

10 Typical Characteristics.3 Load Regulation vs. Temperature 4 Output Peak Current vs. Temperature.25 Io=-1mA Co=2.2µF(Ceramic) Load Regulation : dvo/dio (%/ma) Output Peak Current : Io_peak (ma) Co=2.2µF(Ceramic) Output Voltage vs. Temperature 1.5 Output Voltage : Vo (V) 1..5 Io=3mA Co=2.2µF(Ceramic) Ver

11 Typical Characteristics NJM2847_1.2v ON/OFF Transient Response without Load CO=2.2µF(Ceramic) 5 Cp=.1mF 7 NJM2847_1.2v ON/OFF Transient Response Output Voltage Vo(V) 5 Control Voltage Output Voltage control Voltage Vcont(V) Output Voltage Vo(V) 5 Control Voltage 4-5 CO=2.2µF(Ceramic) Cp=.1µF 3 IO=3mA -1 2 Output Voltage Control Voltage Vcont(V) Time t(s) Time t(ms) Output Voltage Vo(V) NJM2847_1.2v Load Transient Response CO=2.2µF(Ceramic 1 ) Output Current Output Voltage control Voltage Vcont(V) Output Voltage Vo(V) NJM2847_1.2v Input Transient Response CO=2.2µF(Ceramic) I O=3mA 2 Input Voltage Output Voltage Input Voltage VIN(V) Time t(µs) Time t(µs) 2-4 [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