CA1523 Voltage Regulator Control Circuit for Variable Switching Regulator April 1994 Features Description • Operates up to 200kHz The CA1523 monolithic silicon integrated circuit is a variable interval pulse regulator designed to provide the control circuitry for use in switching regulator circuits. It operates from 11V to 15V. • Pins ESD Protected • Remote ON/OFF • Slow Start with Reset • Overcurrent Sensing • Lower Peak Currents than PWM Regulator - Less Prone to Magnetic Saturation Ordering Information PART NUMBER CA1523E TEMPERATURE RANGE 0oC to +70oC PACKAGE 14 Lead Plastic DIP The regulator provides a single output drive capable of 300mA source/200mA sink. The maximum operating frequency is better than 200kHz. An attractive feature of the CA1523 is that the timing capacitor charge and discharge current is set up externally via a single resistor. The ratio of charge to discharge current is internally set at a maximum of 2 to 1 allowing simultaneous change in output pulse width with increased frequency at higher load. The pulse width variation at higher frequencies effectively compensates for the losses in magnetics and thereby increases the power supply efficiency at higher load end by as much as 20 percent. Pinout CA1523 (PDIP) TOP VIEW ERROR 1 14 TIMING CURRENT SENSE 2 13 ZENER GND 3 12 ON/OFF RISE TIME 4 11 OVER CURRENT OUTPUT GND 5 10 SLOW START OUTPUT 6 9 LOGIC OUTPUT VCC 7 8 NC CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 407-727-9207 | Copyright © Intersil Corporation 1999 7-11 File Number 1785.2 Specifications CA1523 Absolute Maximum Ratings Thermal Information DC Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15V Supply Current |6(MAX). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .±50mA |6(MAX), 1µs,1800pF Load . . . . . . . . . . . . . . . . . . . . +300, -200mA Device Dissipation Up to TA = 70oC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 530mW Above TA = 70oC. . . . . . . . . . . . . . . Derate Linearly at 6.7mW/oC Thermal Resistance θJA Plastic DIP Package . . . . . . . . . . . . . . . . . . . . . . . . 120oC/W Device Dissipation Up to TA = 70oC. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 665mW Ambient Temperature Range Operating. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0oC to +70oC Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -55oC to +150oC Lead Temperature (During Soldering) At distance 1/16 ± in. (1.59mm ±0.79mm) from case for 10s Max . . . . . . . . . . . . . . . . . . . . . . . . . . . . +265oC 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. Electrical Specifications PARAMETERS TA = +25oC, Refer to condition shown in test circuit; V7 = 13V, V1 = 5.9V Unless Otherwise Specified PIN TEST CONDITIONS MIN TYP MAX UNITS 9.5 13 - V 20 27 34 mA 7.8 8.4 8.9 V POWER SUPPLY, VCC (PIN 7) Supply Voltage 7 Supply Current 7 Zener Voltage 13 VCC = +13V OUTPUT PULSE (PIN 6) Maximum Pulse Width 6 Measured at 6V Threshold Level 5.5 6.5 7.5 µs Minimum Pulse Width 6 Measured at 6V Threshold Level 2 3 4 µs Output High Voltage 6 |6 = 0mA, V4 = 0V 11.1 12 12.6 V Output Low Voltage 6 |6 = 50mA, V12 = 0V 0.6 1 1.3 V Rise Time 6 Measured at 1.8V and 10V Threshold Levels 250 600 1250 ns Fall Time 6 Measured at 1.8V and 10V Threshold Levels 50 200 350 ns 1 Adjust RT; Observe Pin 6 Min/Max Frequency Range 5.9 6.8 7.5 V Charge Current 14 Adjust RT, V1 = 7.5V; Set V14 = 0V, Then V14 = 2.5V 190 220 250 µA Discharge Current 14 Adjust RT = 5.9V; Set V14 = 5.5V, Then 5V 95 110 125 µA Slow Start Discharge Current 14 Maintain V14 = 5V, V10 = 5.5V Set V10 = 5.5V, Measure I14 (Hi) Set V10 = 4V, Measure I14 (Lo) Limits = I14 (Hi) - I14 (Lo) 1.5 20 30 40 µA/V Discharge Voltage 10 Pin 12 = 1kΩ to GND 1.7 2.4 3.2 V Output Inhibit Voltage 7 Increase V7 Until V9 ≥ 2V 7.9 8.4 9.1 V Overcurrent Trip Voltage 11 V12 = 5V; V10 = 0V; Increase V11 Until V9 ≤ 0.5V 1.1 1.25 1.4 V ERROR VOLTAGE RANGE (PIN 1) Error Voltage Reference CHARGE CURRENT (PIN 14) LOGIC TESTS 7-12 CA1523 Other Desirable Features • Slow Start with Reset: Externally programmed against internal 3V reference. Reset is initiated upon Inhibit ensuring soft start at power up and restart. Other desirable features along with various circuit block function explanations are listed below. • The Oscillator is a sawtooth generator whose charge (rise) cycle determines the output pulse width and discharge which is continuously variable from very low to maximum of ICHARGE. • Over Current Sense: Internal stable thresholds of 1.2V. • Supply Voltage Monitors: Locks out the drive until VSUPPLY has reached 8V-9V. • Charge ICHARGE = IO -IDISCHARGE giving 2 to 1 pulse-width control • ON/OFF: Activates regulator independent of raw DC. • Discharge IDISCHARGE = approximately 0 to 1/2 IO to frequency control. • Error Amplifier: Compares output against a stable 6.8V internal reference and controls the discharge current sink on the timing capacitor. • Pulse Shaping: Applied to the oscillator output via RS Flip-Flop with parallel inhibit controlled by slow-start overcurrent sense, supply voltage monitor and ON/OFF functions. • Band-Gap: Reference voltage (internal) provides temperature compensated 1.2V and 6.8V references. • Separate GND: The power GND is separated from circuit ground for improved noise. • Pulse Rise Time: Modified to meet RFI requirements by external slow-down capacitor. • ESD Protection: Pins are protected against ESD. Block Diagram CURRENT SENSE VCC ZENER 2 7 13 CURRENT SETUP REF. VOLTAGE SOURCES IC IC/2 VCC 5V REF. S1 1 ERROR VOLTAGE VL 2.5V + S - 6.8V REF. ID 14 Q 4 RISE TIME F/F + ID ~ IC/2 FOR VI << 6.8V S2 OPEN WHEN VIO > 6.8V TIMING CAP Q HIGH CLOSES S1 +6.8V REF. VH 5V R 6 - PULSE OUTPUT - 3V REF. 5 S + Q OUTPUT GND F/F VCC > 8.4V 11 R 3 (CONTROL CIRCUIT GND) 1.2V REF. 3K GND OVER CURRENT + Q LOW S3 CLOSES S3 10 12 9 SLOW START ON/OFF LOGIC OUT 7-13 CA1523 VCC + 0.0033µF 56K 2 CHARGE CURRENT 13 ZENER 7 CURRENT SET UP REF. VOLT. SOURCES IC VCC IC/2 VCC S1 15K ERROR VOLTAGE +6.8V REF 1 RT 20K TRIM RES. 5V REF RISE/FALL VL 2.5V + S 4 Q 47pF F/F TIMING S2 ID IC/2 ˜ FOR VI <<6.8V S2 OPEN WHEN V10 > 6.8V 14 240pF Q HIGH CLOSES S1 - 6.8V REF 3V REF. NC 8 + - PULSE OUTPUT 6 R 5V VH 1800pF - 5 Q S + (CONTROL 3K CIRCUIT GND) 1.2V REF. OUTPUT GND F/F VCC >6.4V - R Q + 3 Q LOW S3 CLOSES S3 11 VCC 12K 12 ON/OFF ON SLOW 10 START 9 220 VCC 220 LOGIC OUT +5V OFF 30K 1K VIO FIGURE 1. TEST CIRCUIT FOR THE CA1523 7-14 OVER CURRENT V11 1K CA1523 TYP. INPUT 5.6k 10W NC NC NC 8 9 13 PRIMARY SENSE + 4.7µF 16k 68µF TYPICAL RECT. OUTPUT TRANSFORMER 0.85A 20k (TRIM RESISTOR) 13V 11V 11k + ------------ FEEDBACK 30k +150 SEC. “A” +150V RECTIFIED AC LINE INPUT V01 +130V V04 -24V SEC. “D” V02 +16V SEC. “C” SEC. “D” 10 220 ON/OFF BIAS VOLTAGE 1 7 V03 +24V 47Ω CA1523 1.5k 6 12 4 68 pF 14 3 2 11 5 RFP 7N40 10k 240 pF 68k 0.0033 µF 0.15 3W 22pF OPTO-COUPLER FIGURE 2. TYPICAL APPLICATION CIRCUIT FOR THE CA1523 VCC 7 +VCC 4K 15K 8K 8.3K +7.5V 10K + + 2K 10K 2 5.0V - 2K ERROR 1 +7.5V 6.8V BAND GAP REF VOLTAGE 1.21V 2.5V + 1.8K 2K 30K SLOW START 10 1.5K 14 1.5K +VCC 3K 12K 6K 9 LOGIC OUT FIGURE 3. TIMING CIRCUIT FOR THE CA1523 7-15 VH + R Q S Q VL CA1523 All Intersil semiconductor products are manufactured, assembled and tested under ISO9000 quality systems certification. Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design and/or specifications at any time without notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries. For information regarding Intersil Corporation and its products, see web site http://www.intersil.com Sales Office Headquarters NORTH AMERICA Intersil Corporation P. O. Box 883, Mail Stop 53-204 Melbourne, FL 32902 TEL: (407) 727-9207 FAX: (407) 724-7240 EUROPE Intersil SA Mercure Center 100, Rue de la Fusee 1130 Brussels, Belgium TEL: (32) 2.724.2111 FAX: (32) 2.724.22.05 7-16 ASIA Intersil (Taiwan) Ltd. Taiwan Limited 7F-6, No. 101 Fu Hsing North Road Taipei, Taiwan Republic of China TEL: (886) 2 2716 9310 FAX: (886) 2 2715 3029