LT1020 Micropower Regulator and Comparator U DESCRIPTIO FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ 40µA Supply Current 125mA Output Current 2.5V Reference Voltage Reference Output Sources 1mA and Sinks 0.5mA Dual Output Comparator Comparator Sinks 10mA Dropout Detector 0.2V Dropout Voltage Thermal Limiting Available in SO Package The LT1020 is a combination micropower positive regulator and free collector comparator on a single monolithic chip. With only 40µA supply current, the LT1020 can supply over 125mA of output current. Input voltage range is from 4.5V to 36V and dropout voltage is 0.6V at 125mA. Dropout voltage decreases with lower load currents. Also included on the chip is a class B output 2.5V reference that can either source or sink current. A dropout detector provides an output current to indicate when the regulator is about to drop out of regulation. The dual output comparator can be used as a comparator for system or battery monitoring. For example, the comparator can be used to warn of low system voltage while the dropout detector shuts down the system to prevent abnormal operation. Frequency compensation of the comparator for amplifier applications can be obtained by adding external output capacitance. Dual output or positive and negative regulators can also be made. UO APPLICATI ■ ■ ■ ■ S Battery Systems Battery Backup Systems Portable Terminals Portable Instruments The 2.5V reference will source or sink current. This allows it to be used as a supply splitter or auxiliary output. UO TYPICAL APPLICATI 5V Regulator Dropout Voltage and Supply Current 1 VOUT VIN 2 10µF GND 9 FB 1M 11 + 10µF 1M 1020 TA01 0.1 0.01 0.1 1 10 1 100 OUTPUT CURRENT (mA) SUPPLY CURRENT (mA) + 5V 0.001µF LT1020 DROPOUT VOLTAGE (V) 3 VIN > 5.2V IQ = 40µA 10 0.1 1000 1020 TA02 1 LT1020 W W W AXI U U ABSOLUTE RATI GS Input Voltage .......................................................... 36V NPN Collector Voltage ............................................ 36V PNP Collector Voltage.............................. Supply – 36V Output Short Circuit Duration ......................... Indefinite Power Dissipation.............................. Internally Limited Storage Temperature Range ................ – 65°C to 150°C Operating Temperature Range LT1020C ............................................. 0°C to 100°C LT1020I ........................................ – 40°C to 100 °C LT1020M ....................................... – 55°C to 125°C Lead Temperature (Soldering, 10 sec).................. 300°C U W U PACKAGE/ORDER I FOR ATIO TOP VIEW NC 1 VOUT 2 VIN 3 REF OUT 4 COMP PNP 5 COMP NPN +INPUT 6 7 14 NC DROPOUT 13 DETECTOR 12 SHUTDOWN 11 FEEDBACK CURRENT 10 LIMIT 9 GND 8 –INPUT ORDER PART NUMBER TOP VIEW COMP PNP 5 16 NC 15 DROPOUT DETECTOR 14 SHUTDOWN 13 CURRENT LIMIT 12 FEEDBACK COMP NPN 6 11 GND NC 1 VOUT 2 LT1020CJ LT1020CN LT1020IJ LT1020IN LT1020MJ VIN 3 REF OUT 4 N PACKAGE 14-LEAD PLASTIC DIP 9 TJMAX = 110°C, θJA = 150°C/W ELECTRICAL CHARACTERISTICS Output Current Load Regulation Line Regulation Dropout Voltage Feedback Sense Voltage Dropout Detector Current 2 NC S PACKAGE 16-LEAD PLASTIC SOIC TJMAX = 150°C, θJA = 80°C/W (J) TJMAX = 110°C, θJA = 130°C/W (N) PARAMETER Reference Reference Voltage Line Regulation Load Regulation Output Source Current Output Sink Current Temperature Stability Regulator Supply Current LT1020CS LT1020IS 10 –INPUT +INPUT 7 NC 8 J PACKAGE 14-LEAD CERAMIC DIP ORDER PART NUMBER TJ = 25°C CONDITIONS MIN TYP MAX UNITS 4.5V ≤ VIN ≤ 36V 4.5V ≤ VIN ≤ 36V – 0.5mA ≤ IREF ≤ 1mA, VIN = 12V VIN = 5V VIN = 5V 2.46 2.50 0.01 0.2 4 2 1 2.54 0.015 0.3 V %/V % mA mA % 45 75 11 80 120 20 0.2 0.01 0.02 0.4 2.5 20 0.5 0.015 0.05 0.65 2.56 µA µA mA mA % %/V V V V µA VIN = 6V, IOUT ≤ 100µA VIN = 36V, IOUT ≤ 100µA VIN = 12V, IOUT = 125mA (VIN – VOUT) ≥ 1V, VIN ≥ 6V (VIN – VOUT) ≥ 1V, VIN ≥ 6V 6V ≤ VIN ≤ 36V IOUT = 100µA IOUT = 125mA VIN = 12V ∆VOUT = – 0.05V, IOUT = 500µA 1 0.5 125 2.44 3 LT1020 ELECTRICAL CHARACTERISTICS PARAMETER Regulator Feedback Bias Current Minimum Load Current Short-Circuit Current Comparator Offset Voltage Bias Current Offset Current Gain-NPN Pull-Down Common-Mode Rejection Power Supply Rejection Output Sink Current NPN Saturation Voltage Output Source Current Input Voltage Range Response Time Leakage Current (NPN) TJ = 25°C CONDITIONS VIN = 36V VIN = 36V Pins 9 and 10 Shorted, VIN = 4.5V 0V ≤ VCM ≤ 35V, VIN = 36V 0V ≤ VCM ≤ 35V, VIN = 36V 0V ≤ VCM ≤ 35V, VIN = 36V ∆VOUT = 29V, RL = 20k 0V ≤ VCM ≤ 35V, VIN = 36V 4.5V ≤ VS ≤ 36V VIN = 4.5V IOUT = 1mA MIN TYP MAX UNITS 40 5 400 3 15 1 300 30 nA µA mA mA 3 15 4 10000 94 96 18 0.4 200 7 40 15 mV nA nA V/ V dB dB mA V µA V µs µA 2000 80 80 10 60 0 0.6 VIN – 1 5 2 ELECTRICAL CHARACTERISTICS PARAMETER Reference Reference Voltage Line Regulation Load Regulation Output Source Current Output Sink Current Regulator Supply Current Output Current Load Regulation Line Regulation Dropout Voltage Feedback Sense Voltage Dropout Detector Current Feedback Bias Current Minimum Load Current Short-Circuit Current Comparator Offset Voltage Bias Current Offset Current Gain-NPN Pull-Down CONDITIONS 4.5V ≤ VIN ≤ 36V 4.5V ≤ VIN ≤ 36V – 0.5mA ≤ IREF ≤ 1mA, VIN = 12V VIN = 5V VIN = 5V ● VIN = 6V, IOUT ≤ 100µA VIN = 36V, IOUT ≤ 100µA VIN = 12V, IOUT = 125mA (VIN – VOUT) ≥ 1V, VIN ≥ 6V (VIN – VOUT) ≥ 1V, VIN ≥ 6V 6V ≤ VIN ≤ 36V IOUT = 100µA IOUT = 125mA VIN = 12V ∆VOUT = – 0.05V, IOUT = 500µA ● ● ● MIN TYP MAX UNITS 2.40 2.50 0.01 0.3 2.55 0.02 0.4 V %/V % mA mA 65 85 11 95 120 20 2.5 1 0.02 0.06 0.85 2.57 µA µA mA mA % %/ V V V V µA nA µA mA mA ● ● ● ● ● 1 0.5 125 ● ● ● ● ● ● 2.38 3 ● VIN = 36V VIN = 36V Pins 9 and 10 Shorted, VIN = 4.5V ● 0V ≤ VCM ≤ 35V, VIN = 36V 0V ≤ VCM ≤ 35V, VIN = 36V (Note 1) 0V ≤ VCM ≤ 35V, VIN = 36V ∆VOUT = 29V, RL = 20k ● ● ● 2.5 15 ● ● ● 300 30 1000 50 50 400 10 60 20 mV nA nA V/ V 3 LT1020 ELECTRICAL CHARACTERISTICS PARAMETER Comparator Common-Mode Rejection Power Supply Rejection Output Sink Current Output Source Current Input Voltage Range Leakage Current (NPN) CONDITIONS MIN 0V ≤ VCM ≤ 35V, VIN = 36V 4.5V ≤ VIN ≤ 36V VIN = 4.5V (Note 2) ● ● ● ● ● VIN = 36V TYP 80 80 5 40 0 UNITS dB dB mA µA V µA 10 120 VIN – 1 8 ● The ● denotes specifications which apply over the full operating temperature range. MAX Note 1: For 0V ≤ VCM ≤ 0.1V and T > 85°C IBIAS(MAX) is 100nA. Note 2: For TA ≤ – 40°C output ISINK(MIN) is 2.5mA. U W TYPICAL PERFOR A CE CHARACTERISTICS Regulator Load Regulation Supply Current 0.3 350 TJ = –55°C TO 125°C TJ = –55°C 0.1 TJ = 25°C 0 TJ = 125°C –0.1 SHORT-CIRCUIT CURRENT (mA) 0.2 SUPPLY CURRENT (mA) OUTPUT VOLTAGE CHANGE (%) PRELOAD = 100µA 10 1 0.1 –0.2 –0.3 0.1 1 10 100 OUTPUT CURRENT (mA) 0.01 0.1 1000 200 150 100 1 100 10 1000 REGULATOR OUTPUT CURRENT (mA) 1020 G04 –10 70 110 30 TEMPERATURE (°C) 150 1020 G03 Dropout Voltage 1 1 DROPOUT DETECTOR = 5µA INPUT/OUTPUT DIFFERENTIAL (V) REGULATOR INPUT/OUTPUT DIFFERENTIAL (V) 0.1 CURRENT LIMIT TIED TO GROUND 50 Dropout Voltage ∆VOUT = 100mV 4 250 1020 G02 Dropout Voltage 1 0.01 0.1 300 0 –50 10 100 1000 1 REGULATOR OUTPUT CURRENT (mA) 1020 G01 REGULATOR INPUT/OUTPUT DIFFERENTIAL (V) Regulator Short-Circuit Current 100 0.1 0.01 0.1 I DROPOUT DETECTOR = 0.1% IOUT 0.1 I DROPOUT DETECTOR = 1% IOUT 0.01 1 100 10 1000 REGULATOR OUTPUT CURRENT (mA) 1020 G05 0.1 1 10 100 REGULATOR OUTPUT CURRENT (mA) 1020 G06 LT1020 U W TYPICAL PERFOR A CE CHARACTERISTICS Dropout Detector Current Dropout Detector Current 1 0.1 VDIFF = 1V IOUT = 100mA 100 REGULATOR OUTPUT CURRENT (mA) 10 IOUT = 25mA 100 IOUT = 5mA 10 IOUT = 1mA 1 0.01 100 1000 70 80 90 100 110 120 130 140 TEMPERATURE (°C) Regulator Ripple Rejection 150 1020 G09 1020 G08 Supply Current at Dropout Supply Current 70 10 10 IOUT = 100mA 65 10 1 0 0.2 0.3 0.4 0.5 0.6 0.1 REGULATOR INPUT/OUTPUT DIFFERENTIAL (V) 1020 G07 TJ = –55°C TO 125°C IOUT = 100mA IOUT = 100mA 55 IOUT = 1mA 50 45 40 1 IOUT = 10mA 0.1 VIN = 100VDC, 1VP-P VOUT = 5V COUT = 10µF 35 10k 100 1k RIPPLE FREQUENCY (Hz) 0.01 100k IOUT = 10mA 0.1 0.01 1 10 15 20 25 5 REGULATOR INPUT/OUTPUT DIFFERENTIAL (V) 1020 G10 IOUT = 1mA 1020 G12 Comparator Input Bias Current Reference Regulation 3 90 INPUT BIAS CURRENT (nA) 100 2 1 0 –1 –2 –3 80 70 60 Feedback Pin Current 40 35 TJ = 125°C TJ = 25°C TJ = –55°C 50 40 30 20 1.5 1020 G13 0 –1.0 30 25 TJ = –55°C 20 15 TJ = 25°C 10 TJ = 125°C 5 10 0.5 1.0 –1.0 –0.5 0 REFERENCE OUTPUT CURRENT (mA) 0.2 0.3 0.4 0.5 0.6 0.1 0 REGULATOR INPUT/OUTPUT DIFFERENTIAL (V) 1020 G11 4 –4 –1.5 1 VOUT = 5V TJ = –55°C TO 125°C 30 10 IOUT = 1mA FEEDBACK PIN CURRENT (nA) 60 SUPPLY CURRENT (mA) IOUT = 10mA SUPPLY CURRENT (mA) RIPPLE REJECTION (dB) MINIMUM LOAD CURRENT (µA) DROPOUT DETECTOR CURRENT (µA) DROPOUT DETECTOR CURRENT (µA) VDIFF = 500mV 10 REFERENCE VOLTAGE CHANGE (mV) Regulator Minimum Load Current 1000 100 0 –0.6 0.6 –0.2 GND 0.2 COMMON-MODE VOLTAGE (V) REFERRED TO PIN 9 (GND) 1.0 0.1 100 1000 1 10 REGULATOR OUTPUT CURRENT (mA) 1020 G15 1020 G14 5 LT1020 U W TYPICAL PERFOR A CE CHARACTERISTICS LT1020 Turn-On Characteristic 5.5 VIN = 15V VOUT = 5V 0 –0.1 OUTPUT CURRENT (mA) VOUT = 5V 5.0 OUTPUT VOLTAGE (V) OUTPUT VOLTAGE CHANGE (%) Regulator Thermal Regulation 0.1 50 4.5 4.0 NO LOAD 3.5 RL = 50Ω 3.0 RL = 500Ω 2.5 2.0 0 0 20 40 60 80 100 120 140 160 180 TIME (ms) 0 0 1 1020 G16 2 5 6 3 4 INPUT VOLTAGE (V) 7 8 1020 G17 U U U PI FU CTIO S Pins 1, 14: No internal connection. Pin 9: Ground. Pin 2: Regulator Output. Main output, requires 10µF output capacitor. Can be shorted to VIN or ground without damaging the device. Pin 10: Current Limit. Connecting this pin to ground decreases the regulator current limit to 3mA minimum. Leave open when not used. Pin 3: Input Supply. Bypass with 10µF capacitor. Must always be more positive than ground. Pin 11: Feedback. This is the feedback point of the regulator. When operating, it is nominally at 2.5V. Optimum source resistance is 200k to 500k. The feedback pin should not be driven below ground or more positive than 5V. Pin 4: Reference. 2.5V can source or sink current. May be shorted to ground or up to 5V. Voltages in excess of 5V can damage the device. Pin 5: Comparator PNP Output. Pull-up current source for the comparator. May be connected to any voltage from VIN to 36V more negative than VIN (operates below ground). Short-circuit protected. For example, if VIN is 6V then pin 5 will operate to – 30V. Pin 6: Comparator NPN Output. May be connected to any voltage from ground to 36V more positive than ground (operates above VIN). Short-circuit protected. Pins 7, 8: Comparator Inputs. Operates from ground to VIN – 1V. Comparator inputs will withstand 36V even with VIN of 0V. 6 Pin 12: Shutdown. Turns output off. Pin 13: Dropout Detector. This pin acts like a current source from VIN which turns on when the output transistor goes into saturation. The magnitude of the current depends on the magnitude of the output current and the input/output voltage differential. Pin current ranges from 5µA to about 300µA. LT1020 W BLOCK DIAGRA REF OUT 4 PNP OUT 5 NPN OUT 6 10 – + NONINVERTING 7 INVERTING 8 REF 2.5V CURRENT LIMIT 3 VIN 2 VOUT 13 DROPOUT DETECTOR 11 FB 9 GND 1020 BD U W U UO APPLICATI S I FOR ATIO The LT1020 is especially suited for micropower system applications. For example, the comparator section of the LT1020 may be used as a battery checker to provide an indication of low battery. The dropout detector can shut down the system when the battery voltage becomes too low to regulate. Another type of system application for the LT1020 would be to generate the equivalent of split supplies from a single power input. The regulator section provides regulated output voltage and the reference, which can both source and sink current, is then an artificial system ground providing a split supply for the system. If the PNP output is being used, to maximize the gain a 1µA to 5µA load should be placed upon the NPN output collector. This is easily done by connecting a resistor between the NPN collector and the reference output. (Providing this operating current to the NPN side increases the internal emitter base voltages and maximizes the gain of the PNP stage.) Without this loading on the NPN collector, at temperatures in excess of 75°C, the gain of the PNP collector can decrease by a factor of 2 or 3. For many applications the comparator can be frequency compensated to operate as an amplifier. Compensation values for various gains are given in the data sheet. The comparator gain is purposely low to make it easier to frequency compensate as an amplifier. Two outputs are available on the comparator, the NPN output is capable of sinking 10mA and can drive loads connected to voltages in excess of the positive power supply. This is useful for driving switches or linear regulators from a higher input voltage. The PNP output, which is capable of sourcing 100µA can drive loads below ground. It can be used to make negative regulators with the addition of an external pass transistor. Both outputs can be tied together to provide an output that swings from rail-to-rail for comparator or amplifier applications. Although it is not specified, the gain for the PNP output is about 500 to 1000. Internal to the LT1020 is a 2.5V trimmed class B output reference. The reference was designed to be able to source or sink current so it could be used in supply splitting applications as well as a general purpose reference for external circuitry. The design of the reference allows it to source typically 4mA or 5mA and sink 2mA. The available source and sink current decreases as temperature increases. It is sometimes desirable to decrease the AC output impedance by placing an output capacitor on them. The reference in the LT1020 becomes unstable with large capacitive loads placed directly on it. When using an output capacitor, about 20Ω should be used to isolate the capacitor from the reference pin. This 20Ω resistor can be placed directly in series with the capacitor or alternatively the reference line can have 20Ω placed in series with it and then a capacitor to ground. This is shown in Figure 1. Other than placing large capacitive loads on the reference, no Reference 7 LT1020 W U U UO APPLICATI S I FOR ATIO other precautions are necessary and the reference is stable with nominal stray capacitances. REF 4 REF 4 OUTPUT 20Ω 20Ω OR + OUTPUT + 10µF 10µF 1020 F01 Figure 1. Bypassing Reference Overload Protection The main regulator in the LT1020 is current limited at approximately 350mA. The current limit is stable with both input voltage and temperature. A current limit pin, when strapped to ground, decreases the output current. This allows the output current to be set to a lower value than 250mA. The output current available with the current limit pin strapped to ground is not well controlled so if precise current limiting is desired it should be provided externally as is shown in some of the application circuits. If the device is overloaded for long periods of time, thermal shutdown turns the output off. In thermal shutdown, there may be some oscillations which can disturb external circuitry. A diode connected between the reference and feedback terminal provides hysteresis under thermal shutdown, so that the device turns on and off with about a 5 second period and there are no higher frequency oscillations. This is shown in Figure 2. This diode is recommended for most applications. Thermal shutdown temperature is set at approximately 145°C. VOUT 2 0.001µF LT1020 REF FB 11 + 10µF 4 Like most other IC regulators, a minimum load is required on the output of the LT1020 to maintain regulation. For most standard regulators this is normally specified at 5mA. Of course, for a micropower regulator this would be a tremendously large current. The output current must be large enough to absorb all the leakage current of the pass transistor at the maximum operating temperature. It also affects the transient response; low output currents have long recovery times from load transients. At high operating temperatures the minimum load current increases and having too low of a load current may cause the output to go unregulated. Devices are tested for minimum load current at high temperature. The output voltage setting resistors to the feedback terminal can usually be used to provide the minimum load current. Frequency Compensation The LT1020 is frequency compensated by a dominant pole on the output. An output capacitor of 10µF is usually large enough to provide good stability. Increasing the output capacitor above 10µF further improves stability. In order to insure stability, a feedback capacitor is needed between the output pin and the feedback pin. This is because stray capacitance can form another pole with the large value of feedback resistors used with the LT1020. Also, a feedback capacitor minimizes noise pickup and improves ripple rejection. With the large dynamic operating range of the output current, 10000:1, frequency response changes widely. Low AC impedance capacitors are needed to insure stability. While solid tantalum are best, aluminum electrolytics can be used but larger capacitor values may be needed. The CURRENT LIMIT pin allows one of the internal nodes to be rolled off with a 0.05µF capacitor to ground. With this capacitor, lower values of regulator output capacitance can be used (down to 1µF) for low (<20mA) output currents. Values of capacitance greater than 0.05µF degrade the transient response, so are not recommended. * * DIODE ADDS FEEDBACK 1020 F02 Figure 2. Minimizing Oscillation in Thermal Shutdown 8 If the CURRENT LIMIT pin is connected to GND, the current limit is decreased and only a 1µF output capacitor is needed. When bypassing the reference, a 20Ω resistor must be connected in series with the capacitor. LT1020 UO TYPICAL APPLICATI S Regulator with Output Voltage Monitor 3 VIN – 500k 5 6 LOGIC VOUT 2 5V 0.001µF LT1020 2.5V + LOGIC OUTPUT 8 REF 7 4 100k + 11 10µF FB GND 9 100k 20k 1M LOGIC OUTPUT GOES LOW WHEN VOUT DROPS BY 100mV 1020 TA03 Driving Logic with Dropout Detector 5V Regulator 3 VIN > 5.2V IQ = 40µA VOUT VIN 2 5V 0.001µF LT1020 LT1020 + 10µF DROPOUT FB GND 11 + 10µF 9 500k TO 2M 1M 1M 1020 TA07 3M 1020 TA04 Compensating the Comparator As an Op Amp Regulator with Improved Transient Response 7 + 5 VIN > 5.2V 3 VOUT VIN 2 0.001µF LT1020 GND 9 FB 8 5V 1M 11 + 1M AT AV = 100, SLEW RATE = 0.05V/µs –6V/µs 10µF 0.001µF 22k 6 – R2 1M R1 C2 C1 1020 TA08 AV 1 10 100 R1 33Ω 100Ω 10k C1 C2 0.1µF 0.001µF 0.047µF – 0.002µF – R2 – 100k 10k 1020 TA05 9 LT1020 UO TYPICAL APPLICATI S 1 Amp Low Dropout Regulator Dual Output Regulator VIN VIN > 5.2V 2.2k MJE2955 3 VIN VOUT 2 * LT1020 GND 10k* FB CL 0.001µF 100k 11 10 9 3 VIN 9 GND 8 –INPUT + VOUT 5V VOUT LT1020 5 COMP PNP +INPUT 220µF† * FOR CURRENT LIMIT ≈ 1.5A † MUST HAVE LOW ESR. SEVERAL 100µF CAPACITORS CAN BE PARALLELED. 150Ω* 100k SEE LT1129 DATA SHEET FOR 700mA OUTPUT 0.001µF 1M 0.001µF 500k + 10µF 500k 6 + 100k 500k 5V COMP FB 11 NPN REF OUT 4 7 0.01µF 2 10µF –5V REG 10mA 2N3904 1020 TA06 51k 1020 TA09 –VIN Dual Output 150mA Regulator VIN > 5.2V Maintaining Lowest IQ at Dropout 3 VIN VOUT 2 5V 0.001µF LT1020 GND 9 1M 11 DROPOUT FB VOUT 5 COMP PNP +INPUT + 10µF 13 3 VIN 9 GND 8 –INPUT LT1020 0.001µF 200k 1M 0.001µF 500k 6 + 10µF 500k + 100k 100k 5V COMP FB 11 NPN REF OUT 4 7 2N3904* 2 10µF 1M –5V REG 150mA NC * TRANSISTOR USED BECAUSE OF LOW LEAKAGE CHARACTERISTICS 2N3904 1020 TA11 * FOR TEMPERATURES GREATER THAN 70°C, REDUCE 51k RESISTORS TO 15k. IQ WILL INCREASE. 51k* 2N3904 4.7k 51k* 0.0047µF 1020 TA10 –VIN Dual Output Positive Regulator 3 51k VIN ≥ 12.3V VIN – 2N2907 12VOUT VOUT 6 0.01µF 190k + 10µF 50k 2 0.001µF LT1020 1M + 11 + FB +IN –IN 7 8 REF GND 4 9 10µF 1M 5 10 5V 1020 TA12 LT1020 UO TYPICAL APPLICATI S Battery Backup Regulator VOUT 5V 3 BATTERY INPUT VIN 2 2 VOUT 0.001µF LT1020 10µF 1M 11 FB GND VOUT + FB MAIN POWER INPUT GND 9 50k INTERNAL PARASITIC DIODES OF LT1020 3 LT1020 11 9 VIN 1M 1020 TA13 VOUT VIN 5V Regulator with Shutdown VIN > 5.2V IQ = 40µA 3 VIN VOUT 2 + LT1020 10µF 0.001µF GND 5V NC 1M FB 9 11 500k 100k 2N3904* LOGIC INPUT 1M * TRANSISTOR USED BECAUSE OF LOW LEAKAGE CHARACTERISTICS. TO TURN OFF THE OUTPUT OF THE LT1020, FORCE FB (PIN 11) > 2.5V. 1020 TA14 Turn-Off at Dropout R1 1.5M R2 1M VIN 8 3 – VOUT 2 0.001µF LT1020 + 9 5 6 1M * VOUT TURNS OFF AT DROPOUT. VOUT TURN ON WHEN: VIN × R2 = 2.5V R1 + R2 DROPOUT 13 7 VOUT* FB REF 4 1M + 11 10µF 1M 1.5M 0.047µF 1020 TA15 11 LT1020 UO TYPICAL APPLICATI S Current Limited 1 Amp Regulator 2.2k 0.5Ω* VIN 0.22µF FB 9 + 100k VOUT 2 LT1020 GND 2N3906* MJE2955 3 VIN VOUT 5V, 1A 220µF† 11 270Ω * SETS CURRENT LIMIT BUT INCREASES DROPOUT VOLTAGE BY 0.5V. † MUST HAVE LOW ESR. SEVERAL 100µF CAPACITORS CAN BE PARALLELED. 100k 1020 TA16 1 Amp Regulator with Precision Current Limit VIN 12V 2.2k + 100µF MJE2955 8 – VOUT 5V 1A 3 4 100k + LT1020 0.22µF 100k 220µF† 2 7 1.2k FB + 6 ISC SENSE 0.03Ω † 5 9 11 100k 270Ω 1N4148 RL 1020 TA17 MUST HAVE LOW ESR. SEVERAL 100µF CAPACITORS CAN BE PARALLELED. Logic Output on Dropout VIN 4 8 – 3 LT1020 2 7 VOUT 5V 1M + FB 6 5 9 0.001µF + 11 10µF 1M 13 1M VIN “DROPOUT” 12 0V TTL COMPATIBLE 1020 TA18 LT1020 UO TYPICAL APPLICATI S Charge Pump Negative Voltage Generator VIN 1M 51k 8 3 – 5 0.0033µF 7 2N3904 22k 6 + 9 + 1M 10µF –VOUT 51k VOUT (NL) ≅ – (VIN – 1V) VOUT (5mA) ≅ – (VIN – 3V) IQ ≅ 300µA 20µF + 1N5819 OR EQUIVALENT 1020 TA19 Charge Pump Voltage Doubler VIN 1M 1N5819 OR EQUIVALENT 51k + 8 – 20µF 3 5 0.0033µF 7 + VOUT 6 9 2N3904 22k 10µF + VOUT (NL) ≅ 2VIN – 1V VOUT (5mA) ≅ 2VIN – 3V IQ ≅ 300µA 1M 1020 TA20 51k 13 LT1020 UO TYPICAL APPLICATI S 50mA Battery Charger and Regulator + VIN* + 10µF 51k 10µF 10µF 2N2905 + 20k 220k 8 4 – 3 VIN VOUT 5V + LT1020 6 2 1M 2.5V + FB 0.001µF 6V BATTERY 10µF 11 1M 9 7 3.9Ω * VIN MUST BE GREATER THAN THE BATTERY VOLTAGE PLUS 1.3V 1020 TA21 Switching Preregulator for Wide Input Voltage Range 7.5V TO 30V VIN 100µF 30k 3.3M 2N3906 SWITCHING REGULATOR OUTPUT 2N3904 TO VREF (PIN4) 2N2222 1.8M 2N3904 1M 4mH 10k 1k 3 100k LT1020 COMPARATOR 6 MAINTAINS LOW IQ (< 100µA) FOR ALL INPUT VOLTAGES SWITCHER EFFICIENCY = 85% POST REGULATOR EFFICIENCY = 82% OVERALL EFFICIENCY = 70% SWITCHING REGULATOR OUTPUT = 2.5 × (1 + RA /RB). FOR A CLEAN OUTPUT FROM THE LINEAR REGULATOR SET TO VOUT + 1.2V VIN + 8 30k 7 RA 1.5M VOUT LT1020 VREF 2M – 14 POST REGULATOR 4 2 + FB VOUT 5V 100mA 22µF 11 0.01µF 220k 220k 2M RB 1M 0.001µF + 30k 1020 TA22 100µF 6 Q5 NPN OUTPUT 5 PNP OUTPUT R1 25Ω Q1 Q7 Q6 R36 60k Q8 Q9 Q2 Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights. R2 50k Q12 Q10 R37 110.8k 8 –NPUT R6 3k 7 R5 3k Q17 Q18 Q15 Q16 Q14 R35 42k +INPUT R3 50k Q11 Q13 R4 42k Q21 R7 6.8k C1 10pF Q20 Q19 Q22 Q23 15k C2 25pF 28k Q64 Q62 R38 20k Q61 Q60 R10 75k Q28 Q33 R14 15k Q32 Q34 Q31 Q27 R11 15k Q63 Q30 Q26 Q24 Q25 R8 40k R15 80k Q35 R8 100k 12 60k SHUTDOWN R18 15k 100pF Q65 125k 125k Q42 R23 30k 60k Q41 Q39 Q37 Q40 R22 30k 11 FEEDBACK Q36 C3 10pF R16 6k R17 100Ω Q29 Q38 R19 40k REFERENCE 4 Q45 Q51 R26 15k R27 15k Q46 Q44 C5 100pF Q43 R24 390k R28 2k Q47 C6 100pF R29 5Ω Q48 Q52 Q54 1020 SS 9 GND 10 R32 2k R31 10Ω Q56 CURRENT LIMIT 100pF Q49 R30 2k Q55 R33 138.3k 47k 13 DROPOUT DETECTOR 2 OUTPUT Q58 3 VIN LT1020 SCHE ATIC DIAGRA 15 W W LT1020 U PACKAGE DESCRIPTIO Dimensions in inches (millimeters) unless otherwise noted. J Package 14-Lead Ceramic DIP 0.200 (5.080) MAX 0.290 – 0.320 (7.366 – 8.128) 0.015 – 0.060 (0.381 – 1.524) 0.008 – 0.018 (0.203 – 0.457) 0.785 (19.939) MAX 0.005 (0.127) MIN 14 13 12 11 10 9 8 0° – 15° 0.385 ± 0.025 (9.779 ± 0.635) 0.045 – 0.068 (1.143 – 1.727) 0.100 ± 0.010 (2.540 ± 0.254) 0.125 (3.175) MIN 0.014 – 0.026 (0.360 – 0.660) 0.220 – 0.310 (5.588 – 7.874) 0.025 (0.635) RAD TYP 1 2 3 4 5 6 7 NOTE: LEAD DIMENSIONS APPLY TO SOLDER DIP OR TIN PLATE LEADS. N Package 14-Lead Plastic DIP 0.300 – 0.325 (7.620 – 8.255) 0.045 – 0.065 (1.143 – 1.651) 0.130 ± 0.005 (3.302 ± 0.127) 0.770 (19.558) MAX 0.015 (0.380) MIN 0.065 (1.651) TYP 0.009 – 0.015 (0.229 – 0.381) +0.025 0.325 –0.015 +0.635 8.255 –0.381 ( ) 0.125 (3.175) MIN 0.075 ± 0.015 (1.905 ± 0.381) 14 13 12 11 10 9 8 1 2 3 4 5 6 7 0.260 ± 0.010 (6.604 ± 0.254) 0.018 ± 0.003 (0.457 ± 0.076) 0.100 ± 0.010 (2.540 ± 0.254) S Package 16-Lead Plastic SOIC 0.386 – 0.394* (9.804 – 10.008) 16 15 14 13 12 11 10 9 0.150 – 0.157* (3.810 – 3.988) 0.228 – 0.244 (5.791 – 6.197) 1 0.010 – 0.020 × 45° (0.254 – 0.508) 0.008 – 0.010 (0.203 – 0.254) 2 3 4 5 6 7 8 0.053 – 0.069 (1.346 – 1.752) 0.004 – 0.010 (0.101 – 0.254) 0° – 8° TYP 0.016 – 0.050 0.406 – 1.270 0.014 – 0.019 (0.355 – 0.483) 0.050 (1.270) TYP *THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.006 INCH (0.15mm). 16 Linear Technology Corporation LT/GP 1193 5K REV B • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7487 (408) 432-1900 ● FAX: (408) 434-0507 ● TELEX: 499-3977 LINEAR TECHNOLOGY CORPORATION 1993