ICL7663S S E M I C O N D U C T O R CMOS Programmable Micropower Positive Voltage Regulator April 1994 Features Description * Guaranteed 10A Maximum Quiescent Current Over All Temperature Ranges The ICL7663S Super Programmable Micropower Voltage Regulator is a low power, high efficiency positive voltage regulator which accepts 1.6V to 16V inputs and provides adjustable outputs from 1.3V to 16V at currents up to 40mA. * Wider Operating Voltage Range - 1.6V to 16V * Guaranteed Line and Load Regulation Over Entire Operating Temperature Range Optional * 1% Output Voltage Accuracy (ICL7663SA) * Output Voltage Programmable from 1.3V to 16V * Improved Temperature Coefficient of Output Voltage * 40mA Minimum Output Current with Current Limiting * Output Voltages with Programmable Negative Temperature Coefficients * Output Shutdown via Current-Limit Sensing or External Logic Level * Low Input-to-Output Voltage Differential * Improved Direct Replacement for Industry Standard ICL7663B and Other Second-Source Products Applications * Low-Power Portable Instrumentation * Pagers It is a direct replacement for the industry standard ICL7663B offering wider operating voltage and temperature ranges, improved output accuracy (ICL7663SA), better temperature coefficient, guaranteed maximum supply current, and guaranteed line and load regulation. All improvements are highlighted in the electrical characteristics section. Critical parameters are guaranteed over the entire commercial and industrial temperature ranges. The ICL7663S/SA programmable output voltage is set by two external resistors. The 1% reference accuracy of the ICL7663SA eliminates the need for trimming the output voltage in most applications. The ICL7663S is well suited for battery powered supplies, featuring 4A quiescent current, low VIN to VOUT differential, output current sensing and logic input level shutdown control. In addition, the ICL7663S has a negative temperature coefficient output suitable for generating a temperature compensated display drive voltage for LCD displays. The ICL7663S is available in either an 8 lead Plastic DIP, Ceramic DIP, or SOIC package. * Handheld Instruments * LCD Display Modules * Remote Data Loggers * Battery-Powered Systems Pinout Ordering Information ICL7663S (PDIP, CERDIP, SOIC) TOP VIEW PART NUMBER ICL7663SCBA TEMPERATURE RANGE 0oC to +70oC 8 Lead SOIC (N) SENSE 1 8 VIN+ ICL7663SCPA 8 Lead Plastic DIP VOUT2 2 7 VTC ICL7663SCJA 8 Lead CerDIP VOUT1 3 6 VSET ICL7663SACBA 8 Lead SOIC (N) GND 4 5 SHDN ICL7663SACPA 8 Lead Plastic DIP ICL7663SACJA ICL7663SIBA 8 Lead CerDIP -25oC to +85oC (c) Harris Corporation 1994 8 Lead SOIC (N) ICL7663SIPA 8 Lead Plastic DIP ICL7663SIJA 8 Lead CerDIP ICL7663SAIBA 8 Lead SOIC (N) ICL7663SAIPA 8 Lead Plastic DIP ICL7663SAIJA 8 Lead CerDIP CAUTION: These devices are sensitive to electrostatic discharge. Users should follow proper I.C. Handling Procedures. Copyright PACKAGE 7-138 File Number 3180.2 Specifications ICL7663S Absolute Maximum Ratings Thermal Information Input Supply Voltage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +18V Any Input or Output Voltage (Note 1) Terminals 1, 2, 3, 5, 6, 7 . . . . . . . . . . . . . . VIN+0.3V to GND-0.3V Output Source Current Terminal 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50mA Terminal 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25mA Output Sinking Current Terminal 7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -10mA Thermal Resistance JA JC Ceramic DIP Package . . . . . . . . . . . . . . . 115oC/W 30oC/W Plastic DIP Package . . . . . . . . . . . . . . . . 150oC/W Plastic SOIC Package . . . . . . . . . . . . . . . 180oC/W Maximum Junction Temperature Plastic DIP Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . +150oC CerDIP Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +175oC Storage Temperature Range. . . . . . . . . . . . . . . . . . -65oC to +150oC Lead Temperature (Soldering 10s) . . . . . . . . . . . . . . . . . . . . +300oC (SOIC - Lead Tips Only) CAUTION: Stresses above those listed in "Absolute Maximum Ratings" may cause permanent damage to the device. This is a stress only rating and operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied. Operating Conditions Operating Temperature Range ICL7663SC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0oC to +70oC ICL7663SI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -25oC to +85oC Electrical Specifications PARAMETERS Input Voltage Specifications Below Applicable to Both ICL7663S and ICL7663SA, Unless Otherwise Specified. V+IN = 9V, VOUT = 5V, TA = +25oC, Unless Otherwise Specified. Notes 4, 5. See Test Circuit, Figure 7 SYMBOL V+IN TEST CONDITIONS TA = +25oC ICL7663S 0 oC ICL7663SA < TA < +70oC IQ V+IN = 16V VSET Temperature Coefficient VSET Line Regulation VSET T ISET Shutdown Input Current ISHDN Shutdown Input Voltage VSHDN UNITS 16 V 1.6 - 16 V 1.6 - 16 V 0 oC 1.6 - 16 V 1.6 - 16 V 0oC < TA < +70oC - - 10 A -25oC < TA < +70oC - - 10 A 0oC < TA < +70oC - - 12 A -25oC - - 12 A < TA < < TA < +85oC +85oC IOUT1 = 100A, VOUT = VSET ICL7663S TA = +25oC 1.2 1.3 1.4 V ICL7663SA TA = +25oC 1.275 1.29 1.305 V 0 oC < TA < +70oC -25oC < TA < +85oC 0oC 2V < VIN < 15V < TA < -25oC VSET' VIN VSET Input Current MAX - 1.4V VOUT 8.5V, No Load V+IN = 9V Reference Voltage TYP 1.5 -25oC < TA < +85oC -25oC < TA < +85oC Quiescent Current MIN +70oC 100 - ppm 100 - ppm - 0.03 - %/V - 0.03 0.3 %/V 0oC < TA < +70oC - 0.01 10 nA -25oC - 0.01 10 nA - 0.01 10 nA < TA < +85oC < TA < +85oC - VSHDN HI: Both VOUT Disabled 1.4 - - V VSHDN LO: Both VOUT Enable - - 0.3 V Sense Pin Input Current ISENSE - 0.01 10 nA Sense Pin Input Threshold VCL - 0.5 - V Input-Output Saturation Resistance (Note 2) RSAT - 170 350 V+IN = 9V, IOUT1 = 2mA - 50 100 V+IN = 15V, IOUT1 = 5mA - 35 70 VOUT 1mA < IOUT2 < 20mA - 1 3 IOUT 50A < IOUT1 < 5mA - 2 10 Load Regulation V+IN = 2V, IOUT1 = 1mA 7-139 Specifications ICL7663S Electrical Specifications Specifications Below Applicable to Both ICL7663S and ICL7663SA, Unless Otherwise Specified. V+IN = 9V, VOUT = 5V, TA = +25oC, Unless Otherwise Specified. Notes 4, 5. See Test Circuit, Figure 7 (Continued) PARAMETERS SYMBOL Available Output Current (VOUT2) IOUT2 Negative Tempco Output (Note 3) VTC Temperature Coefficient VTC Minimum Load Current IL(MIN) ITC TEST CONDITIONS MIN TYP MAX UNITS 40 - - mA Open Circuit Voltage - 0.9 - V Maximum Sink Current 0 8 2.0 mA Open Circuit - +2.5 - mV/oC - - 1.0 A - 0.2 5.0 A - 0.2 5.0 A 3V VIN 16V, VIN - VOUT2 = 1.5V T TA = +25oC Includes VSET Divider 0oC < TA < +70oC -25oC < TA < +85oC NOTES: 1. Connecting any terminal to voltages greater than (V+IN + 0.3V) or less than (GND - 0.3V) may cause destructive device latch-up. It is recommended that no inputs from sources operating on external power supplies be applied prior to ICL7663S power-up. 2. This parameter refers to the saturation resistance of the MOS pass transistor. The minimum input-output voltage differential at low current (under 5mA), can be determined by multiplying the load current (including set resistor current, but not quiescent current) by this resistance. 3. This output has a positive temperature coefficient. Using it in combination with the inverting input of the regulator at VSET, a negative coefficient results in the output voltage. See Figure 9 for details. Pin will not source current. 4. All pins are designed to withstand electrostatic discharge (ESD) levels in excess of 2000V. 5. All significant improvements over the industry standard ICL7663 are highlighted. Functional Diagram 3 8 V+IN VOUT1 2 VOUT2 1 C SENSE 6 VSET A 7 REF VTC B 5 SHUTDOWN 4 GND GND 7-140 ICL7663S Typical Performance Curves 5.000 2.0 4.995 o TA = +25 C 1.8 4.990 V+ = 9.0V 1.6 V+IN - VOUT1 (V) VOUT (V) 4.985 4.980 4.975 4.970 4.965 TA = +25oC V+IN = 2V 1.4 1.2 1.0 V+IN = 9V 0.8 0.6 4.960 0.4 4.955 0.2 V+IN = 15V 0 4.950 10-3 10-2 10-1 100 101 0 102 2 4 FIGURE 1. VOUT2 OUTPUT VOLTAGE AS A FUNCTION OF OUTPUT CURRENT 14 16 18 20 80 1.4 70 1.2 PSRR (dB) V+IN - VOUT1 (V) 12 90 TA = +25oC 1.6 V+IN = 2V 1.0 0.8 0.6 VIN = +9.0V 60 VIN = 2V 50 40 30 V+IN = 9V 0.4 20 V+IN = 15V 10 0.2 0 5 10 15 20 25 30 35 40 45 0 10-2 50 10-1 100 101 FREQUENCY (Hz) IOUT2 (mA) FIGURE 3. VOUT2 INPUT-OUTPUT DIFFERENTIAL vs OUTPUT CURRENT 102 1k FIGURE 4. INPUT POWER SUPPLY REJECTION RATIO 5.00 5.0 4.75 TA = -20oC 4.5 4.0 4.50 TA = -25oC 3.0 TA = -70oC 2.5 V+ = +15V 4.25 IO (A) 3.5 IO (A) 10 100 1.8 2.0 4.00 V+ = +9V 3.75 3.50 1.5 3.25 1.0 3.00 0.5 2.75 0 8 FIGURE 2. VOUT1 INPUT-OUTPUT DIFFERENTIAL vs OUTPUT CURRENT 2.0 0 6 IOUT1 (mA) IOUT (mA) V+ = +2V 2.50 0 2 4 6 8 10 12 14 16 -20 0 20 40 60 80 TEMPERATURE (oC) V+IN (V) FIGURE 5. QUIESCENT CURRENT AS A FUNCTION OF INPUT VOLTAGE 7-141 FIGURE 6. QUIESCENT CURRENT AS A FUNCTION OF TEMPERATURE ICL7663S Detailed Description The ICL7663S is a CMOS integrated circuit incorporating all the functions of a voltage regulator plus protection circuitry on a single monolithic chip. Referring to the Functional Diagram, the main blocks are a bandgap-type voltage reference, an error amplifier, and an output driver with both PMOS and NPN pass transistors. SENSE S2 + The amplifier, reference and comparator circuitry all operate at bias levels well below 1A to achieve extremely low quiescent current. This does limit the dynamic response of the circuits, however, and transients are best dealt with outside the regulator loop. Basic Operation The ICL7663S is designed to regulate battery voltages in the 5V to 15V region at maximum load currents of about 5mA to 30mA. Although intended as low power devices, power dissipation limits must be observed. For example, the power dissipation in the case of a 10V supply regulated down to 2V with a load current of 30mA clearly exceeds the power dissipation rating of the Mini-DIP: (10 - 2) (30) (10-3) = 240mW The circuit of Figure 8 illustrates proper use of the device. CMOS devices generally require two precautions: every input pin must go somewhere, and maximum values of applied voltages and current limits must be rigorously observed. Neglecting these precautions may lead to, at the least, incorrect or nonoperation, and at worst, destructive device failure. To avoid the problem of latchup, do not apply inputs to any pins before supply voltage is applied. Input Voltages - The ICL7663S accepts working inputs of 1.5V to 16V. When power is applied, the rate-of-rise of the input may be hundreds of volts per microsecond. This is potentially harmful to the regulators, where internal operating currents are in the nanoampere range. The 0.047F capacitor on the device side of the switch will limit inputs to a safe level around 2V/s. Use of this capacitor is suggested in all applications. In severe rate-of-rise cases, it may be advisable to use an RC network on the SHutDowN pin to delay output turn-on. Battery charging surges, transients, and assorted noise signals should be kept from the regulators by RC filtering, zener protection, or even fusing. - 0.047F VOUT S1 VOUT1 The bandgap output voltage, trimmed to 1.29V 15mV for the ICL7663SA, and the input voltage at the VSET terminal are compared in amplifier A. Error amplifier A drives a P-channel pass transistor which is sufficient for low (under about 5mA) currents. The high current output is passed by an NPN bipolar transistor connected as a follower. This configuration gives more gain and lower output impedance. Logic-controlled shutdown is implemented via a N-channel MOS transistor. Current-sensing is achieved with comparator C, which functions with the VOUT2 terminal. The ICL7663S has an output (VTC) from a buffer amplifier (B), which can be used in combination with amplifier A to generate programmable-temperature-coefficient output voltages. RCL VOUT2 R2 (7663 ONLY) VTC VSET GND SHDN + M IQ RL CL R1 1A MIN ON S3 OFF 1M 1.4V < VSHDN < V+IN NOTES: 1. S1 when closed disables output current limiting. 2. Close S2 for VOUT1, open S2 for VOUT2. 3. R2 + R1 VOUT = VSET. R1 4. IQ quiescent currents measured at GND pin by meter M. 5. S3 when ON, permits normal operation, when OFF, shuts down both VOUT1 and VOUT2. FIGURE 7. ICL7663S TEST CIRCUIT Output Voltages - The resistor divider R2/R1 is used to scale the reference voltage, VSET, to the desired output using the formula VOUT = (1 + R2/R1) VSET. Suitable arrangements of these resistors, using a potentiometer, enables exact values for VOUT to be obtained. In most applications the potentiometer may be eliminated by using the ICL7663SA. The ICL7663SA has VSET voltage guaranteed to be 1.29V 15mV and when used with 1% tolerance resistors for R1 and R2 the initial output voltage will be within 2.7% of ideal. The low leakage current of the VSET terminal allows R1 and R2 to be tens of megohms for minimum additional quiescent drain current. However, some load current is required for proper operation, so for extremely low-drain applications it is necessary to draw at least 1A. This can include the current for R2 and R1. Output voltages up to nearly the VIN supply may be obtained at low load currents, while the low limit is the reference voltage. The minimum input-output differential in each regulator is obtained using the VOUT1, terminal. The inputoutput differential increases to 1.5V when using VOUT2. Output Currents - Low output currents of less than 5mA are obtained with the least input-output differential from the VOUT1 terminal (connect VOUT2 to VOUT1). Where higher currents are needed, use VOUT2 (VOUT1, should be left open in this case). High output currents can be obtained only as far as package dissipation allows. It is strongly recommended that output current-limit sensing be used in such cases. Current-Limit Sensing - The on-chip comparator (C in the Functional Diagram) permits shutdown of the regulator 7-142 ICL7663S output in the event of excessive current drain. As Figure 8 shows, a current-limiting resistor, RCL, is placed in series with VOUT2 and the SENSE terminal is connected to the load side of RCL. When the current through RCL is high enough to produce a voltage drop equal to VCL (0.5V) the voltage feedback is by-passed and the regulator output will be limited to this current. Therefore, when the maximum load current (ILOAD) is determined, simply divide VCL by ILOAD to obtain the value for RCL. In addition, where such a capacitor is used, a current-limiting resistor is also suggested (see "Current-Limit Sensing"). Producing Output Voltages with Negative Temperature Coefficients - The ICL7663S has an additional output which is 0.9V relative to GND and has a tempco of +2.5mV/oC. By applying this voltage to the inverting input of amplifier A (i.e., the VSET pin), output voltages having negative TC may be produced. The TC of the output voltage is controlled by the R2/R3 ratio (see Figure 9 and its design equations). V+IN SENSE RCL 604k VIN VTC 0.047F R3 R2 VSET VOUT 10F V OUT CL VSET GND SHDN R2 + VOUT1 R1 20 - VOUT2 +5V 210k + V - TC R1 + V - REF R2 ( ) VOUT = ICL = R2 + R 1 R1 VCL RCL VSET = 5V EQ. 1:VOUT = VSET 1+ EQ. 2: - TC VOUT = R1 R2 R3 + R2 R3 (VSET - VTC) (TC VTC) in mV/oC Where: VSET = 1.3V VTC = 0.9V TCVTC = +2.5mV/oC = 25mA FIGURE 9. GENERATING NEGATIVE TEMPERATURE COEFFICIENTS FIGURE 8. POSITIVE REGULATOR WITH CURRENT LIMIT Logic-Controllable Shutdown - When equipment is not needed continuously (e.g., in remote data-acquisition systems), it is desirable to eliminate its drain on the system until it is required. This usually means switches, with their unreliable contacts. Instead, the ICL7663S can be shut down by a logic signal, leaving only IQ (under 4A) as a drain on the power source. Since this pin must not be left open, it should be tied to ground if not needed. A voltage of less than 0.3V for the ICL7663S will keep the regulator ON, and a voltage level of more than 1.4V but less than V+IN will turn the outputs OFF. If there is a possibility that the control signal could exceed the regulator input (V+IN) the current from this signal should be limited to 100A maximum by a high value (1M) series resistor. This situation may occur when the logic signal originates from a system powered separately from that of the regulator. Applications Boosting Output Current with External Transistor The maximum available output current from the ICL7663S is 40mA. To obtain output currents greater than 40mA, an external NPN transistor is used connected as shown in Figure 10. V+IN EXTERNAL PIN POWER TRANSISTOR VOUT1 VOUT2 100 0.47 VIN 10F SENSE 604k Additional Circuit Precautions - This regulator has poor rejection of voltage fluctuations from AC sources above 10Hz or so. To prevent the output from responding (where this might be a problem), a reservoir capacitor across the load is advised. The value of this capacitor is chosen so that the regulated output voltage reaches 90% of its final value in 20ms. From: V IOUT (20 x 10-3) I= C ,C = IOUT = 0.022 t VOUT 0.9VOUT VOUT VSET GND SHDN +5V 210k FIGURE 10. BOOSTING OUTPUT CURRENT WITH EXTERNAL TRANSISTOR 7-143 ICL7663S Generating a Temperature Compensated Display Drive Voltage Temperature has an important effect in the variation of threshold voltage in multiplexed LCD displays. As temperature rises, the threshold voltage goes down. For applications where the display temperature varies widely, a temperature compensated display voltage, VDISP, can be generated using the ICL7663S. This is shown in Figure 11 for the ICM7233 triplexed LCD display driver. +5V V+IN VOUT1 LOGIC SYSTEM, PROCESSOR, ETC. VOUT2 V+ 1.8M ICL7663S VSET 300K ICM7233 VTC 2.7M GND VDISP GND GND DATA BUS FIGURE 11. GENERATING A MULTIPLEXED LCD DISPLAY DRIVE VOLTAGE 7-144