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IMP38C4X Datasheet(PDF) 1 Page - IMP, Inc |
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IMP38C4X Datasheet(HTML) 1 Page - IMP, Inc |
1 / 10 page ![]() © 2000 IMP, Inc. 408-432-9100/www.impweb.com 1 IMP38C/HC/42/3/4/5 IMP38C/HC/42/3/4/5 POWER MANAGEMENT Key Features N 384x Series Pinout with BiCMOS Technology N Zero Cross-Conduction Current by Design N 1MHz Operation N 65ns Maximum Current-Sense Delay N 120µA Maximum Start-Up Current N 1.5mA Maximum Operating Current N High Output Current Drive – 1.0A, IMP38HC4x – 0.5A, IMP38C4x N 20V Maximum Supply Voltage N 2.5V, 1%, Trimmed Error Amplifier Reference N Trimmed Oscillator Discharge Current N Pin-for-Pin Enhanced Replacements for Micrel MIC38C/HC4x and GMT38C4x/HC4x Block Diagrams BiCMOS Cur BiCMOS Currrent-Mode ent-Mode PWM Contr PWM Controller ollerss – – 1MHz Oper 1MHz Operation ation – – N No Cr o Cros osss--Conduction Cur Conduction Currrent ent – – 50ns Cur 50ns Currrent-Sense Dela ent-Sense Delayy The IMP38C4x and IMP38HC4x are fixed frequency, high performance, current-mode PWM controllers that are pin compatible with bipolar 384x devices but feature improvements resulting from IMP’s BiCMOS processing and circuit design. Notable among the improvements are zero cross-conduction/shoot-through current, reduced start-up and operating current, lower current-sense delay, higher frequency operation, full supply voltage swing at the output and a 1% trimmed voltage reference. IMP38C4x and IMP38HC4x output driver stage has zero cross-conduction current. A proprietary output state-machine monitors each output MOSFET and guarantees by design zero cross-conduction current. This is an industry first for 384x PWM devices. Under-voltage lockout (UVL) performance has been improved. When the power supply voltage is below the startup voltage, internal circuitry puts the output into a low impedance state. The output will sink 20mA and remain below 1.3V, well below the turn-on threshold voltage of the external MOSFET. Even when VDD drops to zero volts, the out pin will not rise above approximately 1.3V because the output UVLO circuit is + – EA OUT 6 (10) RTCT 4 (7) COMP 1 (1) VDD VREF 5V Reference 7 (12) 8 (14) FB 2 (3) VD (11) – + + – UVLO + – COMP PGND (8) Oscillator TQ S Q R 1V R 2R 2.5V Ref ( ) Pins Are 14-Pin Devices Only 38C/HC_01.eps + – GND 5 AGND (9) 3 (5) ISNS Connection Notes IMP38C4X, IMP38HC4X (8-Pin Devices) 50% Maximum Duty Cycle: IMP38C44, IMP38HC44, IMP38C45, IMP38HC45 96% Maximum Duty Cycle: IMP38C42, IMP38HC42, IMP38C43, IMP38HC43 |