isl8009a Intersil Corporation, isl8009a Datasheet
isl8009a
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isl8009a Summary of contents
Page 1
... ISL8009A discharges the output capacitor through a 100:resistor. Other features include internal digital soft-start, enable for power sequence, overcurrent protection, and thermal shutdown. The ISL8009A is offered in a 2mmx3mm 8 Ld DFN package with 1mm maximum height. The complete converter 2 occupies less than 1cm area ...
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... P-Channel MOSFET Peak Current Limit LX Maximum Duty Cycle PWM Switching Frequency LX Minimum On-Time Soft-Start-Up Time 2 ISL8009A Thermal Information Thermal Resistance (Typical, Notes 2x3 DFN Package . . . . . . . . . . Junction Temperature Range .-55°C to +12 5°C Storage Temperature Range . . . . . . . . . . . . . . . . . .-65°C to +15 0°C Pb-free reflow profile . . . . . . . . . . . . . . . . . . . . . . . . . .see link below http://www ...
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... Percentage of nominal regulation voltage Pulled up to 5.5V VFB Buck regulator output feedback. Connect to the output through a resistor divider for adjustable output voltage (ISL8009A-ADJ). For preset output voltage, connect this pin to the output. RSI This input resets the 2ms timer. When the output voltage is within the PGOOD window, an internal timer is started and generates a POR signal 2ms later when RSI is low ...
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... FIGURE 3. EFFICIENCY vs LOAD, V 1.24 1. 2.8V - PWM 5V - PWM IN IN 1.22 1.21 1.20 1.19 2.8V - PFM IN 3.3V - PWM IN 1.18 1.17 1.16 0.00 0.25 0.50 0.75 OUTPUT LOAD (A) FIGURE 5. V REGULATION vs LOAD, V OUT 4 ISL8009A (Unless otherwise noted, operating conditions are: T RSI = SKIP = 0V 2.2µ 20µ 100 90 2.5V - PWM OUT 1.00 1.25 1.50 0.05 = 3.3V PWM IN 100 90 - PWM OUT 80 3.3V - PWM OUT ...
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... FIGURE 9. V REGULATION VS LOAD, V OUT LOAD- PWM LOAD - PFM 2.75 3.25 3.75 4.25 V (V) IN FIGURE 11. POWER DISSIPATION 1.8V OUT 5 ISL8009A (Unless otherwise noted, operating conditions are: T RSI = SKIP = 0V 2.2µ 20µ 2.54 2.53 - PFM IN 2.52 2.51 2.50 4V -PFM IN 2.49 2.48 2.47 2.46 1.00 1.25 1.50 0.00 = 1.8V FIGURE 8. V OUT 0.7 ...
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... FIGURE 13. OUTPUT VOLTAGE REGULATION vs V MODE I 0.2A/DIV L FIGURE 15. STEADY STATE OPERATION AT NO LOAD (PFM), 1µs/DIV I 1A/DIV L FIGURE 17. LOAD TRANSIENT (PWM), 200µs/DIV 6 ISL8009A (Unless otherwise noted, operating conditions are: T RSI = SKIP = 0V 2.2µ 20µ 2V/DIV I 0.2A/DIV L 4.5 5.0 5.5 FIGURE 14. STEADY STATE OPERATION AT NO LOAD (PWM), ...
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... FIGURE 19. SOFT-START AT NO LOAD, 500µs/DIV EN 2V/DIV V OUT 0.5V/DIV FIGURE 21. SOFT-START AT FULL LOAD, 500µs/DIV FIGURE 23. OUTPUT SHORT CIRCUIT RECOVERY, 500µs/DIV 7 ISL8009A (Unless otherwise noted, operating conditions are: T RSI = SKIP = 0V 2.2µ 20µ OUT FIGURE 20. SOFT-START WITH PRE-BIASED 1V, 500µs/DIV I ...
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... R 1 100k Block Diagram SOFT- START SHUTDOWN EN 0.8V BANDGAP EAMP + VFB 0.864V + + 0.736V POR 2ms DELAY RSI 0.2V 8 ISL8009A VIN LX GND ISL8009A EN POR VFB SKIP RSI FIGURE 24. TYPICAL APPLICATION DIAGRAM 27pF 390k OSCILLATOR + COMP CONTROLLER PROTECTION + SLOP SLOPE E COMP COMP + OCP + SKIP SCP + FIGURE 25 ...
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... OUT SKIP Mode The ISL8009A enters a pulse-skipping mode at light load to minimize the switching loss by reducing the switching frequency. Figure 27 illustrates the skip-mode operation. A zero-cross sensing circuit shown in Figure 25 monitors the N-MOSFET current for zero crossing. When 8 consecutive cycles of the N-MOSFET crossing zero are detected, the regulator enters the skip mode ...
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... The regulator resumes normal PWM mode operation when the output voltage drops 1.5% below the nominal voltage. Mode Control The ISL8009A has a SKIP pin that controls the operation mode. When the SKIP pin is driven to low or shorted to ground, the regulator operates in a forced PWM mode. The forced PWM mode remains the fixed PWM frequency at light load instead of entering the skip mode ...
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... Layout Recommendation The layout is a very important converter design step to make sure the designed converter works well. For the ISL8009A buck converter, the power loop is composed of the output inductor L, the output capacitor C GND pin necessary to make the power loop as small as possible ...
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... 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 www.intersil.com 12 ISL8009A L8.2x3 8 LEAD DUAL FLAT NO-LEAD PLASTIC PACKAGE SYMBOL ...