Very Low Output Negative Voltage Regulator

Transcription

1 Very Low Output Negative Voltage Regulator GENERAL DESCRIPTION The NJM89 is a negative voltage regulator that delivers up to ma output current with the output voltage of -.8 to -.3V with ON/OFF control. Advanced Bipolar technology achieves low noise, high ripple rejection, and high precision voltage. It has soft-start and shunt SW function..µf Output capacitor and small package can make NJM89 suitable for portable items. PACKAGE OUTLINE NJM89F3 FEATURES High Precision Output V O ±.5% High Ripple Rejection 8dB typ. (f=khz, V O =-.V version) Output Capacitor with.µf ceramic capacitor Output Current I O (max)=ma ON/OFF Control (Positive voltage control from V to +5V) Soft-start Function Shunt SW Function Built-in Thermal Overload Protection and Short Circuit Current Limit Protection Bipolar Technology Package Outline SC-88A PIN CONNECTION BLOCK DIAGRAM 5 4. GND. V IN 3. V OUT 4. CONTROL 5. CS 3 NJM89F3 GND CS Bandgap Reference Thermal Protection Current Limit CONTROL Output Control V IN V OUT Ver

2 OUTPUT VOLTAGE RANK LIST Device Name NJM89F V NJM89F V NJM89F3 - -.V NJM89F3 - -.V NJM89F V Output Voltage Range: -.8V to -.3V ABSOLUTE MAXIMUM RATINGS (Ta=5 C) PARAMETER SYMBOL RATINGS UNIT Input Voltage V IN -4 V Control Voltage V CONT +5 V Output Sink Current at OFF-state I SINK(OFF) ma Power Dissipation P D 5(*) mw Operating Temperature Topr C Storage Temperature Tstg C (*): Mounted on glass epoxy board. ( mm : layer,fr-4) OPERATING VOLTAGE RANGE V IN =-3. -V ELECTRICAL CHARACTERISTICS (V IN =-3.V, V CONT =3V, C IN =.µf, Co=.µF(Vo > -.9V :Co=4.7µF), Ta=5 C) PARAMETER SYMBOL TEST CONDITION MIN. TYP. MAX. UNIT Output Voltage Vo Io=3mA -.5% - +.5% V Quiescent Current I Q Io=mA, except Icont - 4 µa Quiescent Current at OFF-state I Q(OFF) V CONT =V - - na Output Current Io V O ma Line Regulation Vo/ V IN V IN =Vo-3.V -V, Io=3mA - -. %/V Load Regulation Vo/ Io Io= 6mA %/ma Ripple Rejection Average Temperature Coefficient of Output Voltage V out RR V IN =-4.V,ein=mVrms,f=kHz, Io=mA,Vo=-.V Version db Vo/ Ta Ta= +85 C, Io=mA - ±5 - ppm/ C Output Noise Voltage V NO f=hz 8kHz, Io=mA, Vo=--.V Version µvrms CS Terminal Charge Current Ics V CS =V µa Output Resistance at OFF-state R O(OFF) V CONT =V Ω Control Current I CONT V CONT =.6V - 4 µa Control Voltage for ON-state V CONT(ON) V Control Voltage for OFF-state V CONT(OFF) V Input Voltage V IN 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.-9-7

3 POWER DISSIPATION vs. AMBIENT TEMPERATURE Power Dissipation PD(mW) NJM89F3 Power Dissipation (Topr=-4~+85 C,Tj=5 C) Layers board( mm, FR-4) Ambient Temperature Ta( C) TEST CIRCUIT V IN.µF A GND I Q.µF* I OUT V OUT (Ceramic)) V V IN NJM89 V OUT.47µF A I CONT CONTROL CS V V CONT *) Vo>-.9V version: Co=4.7µ F(Ceramic) Ver

4 TYPICAL APPLICATION 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 +.6V Vcont +5V ("H" level): ON state Vcont V Vcont +.6V ("L" level): OFF state Vcont +.6V < Vcont < +.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..µf.µf*3 V IN GND V OUT V IN V OUT NJM89.47µF CONTROL R CONTROL CS CS *3) Vo>-.9V version: Co=4.7µ F(Ceramic) *In the case of using a resistance "R" to CONTROL terminal. 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.-9-7

5 *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 V IN 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 V OUT as shortest path as possible for stable operation The recommended capacitance depends on the output voltage rank. Especially, 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 output voltage and superior temperature characteristic. Ver

6 *Soft-start function Capacitance Cs connects 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. Please switch ON/OFF with CONTROL pin by all means because when switch ON/OFF with V IN pin, the electric charge of the CS pin cannot discharge, and normalcy does not work a soft start circuit. Cs capacitance vs. output voltage risetime Calculation: output voltage risetime t (ms) 8 x CS pin Capacitance (µf) 9 NJM89 CS pin Capacitance vs. Output Voltage risetime 8 Output voltage risetime t[ms] C VCONT=+3V Io=A t:~vo Cspin Capacitance CS[uF] Please consider influence such as each temperature characteristic and dispersion enough. Because depend on CS pin charge electric current and CS pin capacitance greatly in an output voltage risetime Ver.-9-7

7 TYPICAL CHARACTERISTICS. Output Voltage vs. Input Voltage Output Voltage vs. Output Current. Io=A.8 Io=3mA Io=mA Input Voltage : V IN(V). 5 5 Output Current : Io(mA) Ground Pin Current vs. Output Ta=5C o Vin=-3.V Vcont=3V Co=.uF - Load Regulation vs. Output Current Output Current : Io(mA) Output Current : Io(mA) 3 5 Control Current vs. Control Voltage Io=3mA. Output Voltage vs. Control Voltage Rc=Ω.8 5 Rc=Ω.6 Rc=5kΩ Rc=5kΩ.4 Rc=kΩ 5 Rc=kΩ Control Voltage : V Cont (V). Io=3mA Control Voltage : V Cont (V) Ver

8 5 4 Quiescent Current vs. Input Voltage Output is open. 3 5 Peak Output Current vs. Input Voltage Input Voltage : V IN(V) Input Voltage : V IN(V) Output Noise Voltage vs. Output Current Co=.uF(Ceramic) 4.7uF(Ceramic) 9 Ripple Rejection Ratio vs. Frequency Io=3mA Io=mA 8 8 FLAT 7 Io=mA LPF:8k 4 3 ein=mvrms u u u m m m Output Current : Io(A) k k k Frequency : f (Hz) 9 Ripple Rejection vs. Output Current f=khz Equivalent Serise Resistance vs. Output Current 8 7 f=khz 6 STABLE REGION ein=mvrms... Output Current : Io(mA).... Output Current : Io(mA) Ver.-9-7

9 Control Voltage v.s. Temperature Io=3mA Co=uF(Ceramic) 8 NJM89_.V Control Current vs. Temperature Output : No Load Co=.uF Vcont=.6V CS Charge Current vs. Temperature CS is short to ground.(vi) 5 Quiescent Current vs. Temperature Output is open. Icont, including Line Regulation vs. Io=3mA.3.5 Load Regulation vs. Temperature Io=-6mA Ver

10 . Output Voltage vs. Temperature Short Circuit Current vs. Temperature Output is short to ground.(vi) Io=3mA Temperature Ta ( o C) Output Voltage vs. Temperature Io=3mA Maximum Output Current vs. Temperature Temperature Ta ( o C) Vo=Vo x Ver.-9-7

11 -.88 Line Transient Response Load Transient Response 5 Output Voltage:Vo(V) Input Voltage C -.96 Vcont=3.V Io=3mA -5 Co=.uF(ceramic) -.98 Cin=uF Output Voltage Input Voltage:Vin(V) Output Voltage:Vo(V) -.9 Output Current Output C Vcont=3.V -5 Io=5-mA -.4 Co=.uF(ceramic) - Cin=.uF Output Current:Io(mA) Time:t(us) Time:t(µs) ON/OFF Transient Response without road 4 ON/OFF Transient Response 4.5 Control Voltage.5 Control Voltage Output C Vcont=3.V.5 Io=mA - Co=.uF(ceramic) Cs=.47uF Output Voltage Control Voltage:Vcont(V) Output C Vcont=3.V.5 Io=3mA - Co=.uF(ceramic) Cs=.47uF Output Voltage Control Voltage:Vcont(V) Time:t(ms) Time:t(ms) [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