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L6911D

November 2001

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OPERATING SUPPLY IC VOLTAGE FROM 5V

TO 12V BUSES

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UP TO 1.3A GATE CURRENT CAPABILITY

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TTL-COMPATIBLE 5 BIT PROGRAMMABLE

OUTPUT COMPLIANT WITH VRM 9.0 :

1.100V TO 1.850V WITH 0.025V BINARY

STEPS

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VOLTAGE MODE PWM CONTROL

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EXCELLENT OUTPUT ACCURACY: ±1%

OVER LINE AND TEMPERATURE

VARIATIONS

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VERY FAST LOAD TRANSIENT RESPONSE:

FROM 0% TO 100% DUTY CYCLE

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POWER GOOD OUTPUT VOLTAGE

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OVERVOLTAGE PROTECTION AND

MONITOR

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OVERCURRENT PROTECTION REALIZED

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200KHz INTERNAL OSCILLATOR

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OSCILLATOR EXTERNALLY ADJUSTABLE

FROM 50KHz TO 1MHz

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SOFT START AND INHIBIT FUNCTIONS

APPLICATIONS

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POWER SUPPLY FOR ADVANCED

MICROPROCESSOR CORE

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DISTRIBUTED POWER SUPPLY

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HIGH POWER DC-DC REGULATORS

DESCRIPTION

The device is a power supply controller specifically de-

signed to provide a high performance DC/DC conver-

sion for high current microprocessors. A precise 5-bit

digital to analog converter (DAC) allows adjusting the

output voltage from 1.30V to 2.05V with 50mV binary

steps and from 2.10V to 3.50V with 100mV binary steps.

The high precision internal reference assures the se-

lected output voltage to be within ±1%. The high peak

current gate drive affords to have fast switching to the

external power mos providing low switching losses.

The device assures a fast protection against load

overcurrent and load overvoltage. An external SCR is

triggered to crowbar the input supply in case of hard

over-voltage. An internal crowbar is also provided

turning on the low side mosfet as long as the over-

voltage is detected. In case of over-current detection,

the soft start capacitor is discharged and the system

works in HICCUP mode.

SO-20

ORDERING NUMBERS: L6911D

L6911DTR (Tape and Reel)

5 BIT PROGRAMMABLE STEP DOWN CONTROLLER

WITH SYNCHRONOUS RECTIFICATION

BLOCK DIAGRAM

PGND

PHASE

GND

VFB

LGATE

BOOT

UGATE

VCC

OCSET

Vcc 5 to 12V

Vin 5V to12V

Vo

1.100V to 1.850V

PGOOD

COMP

VSEN

SS

OVP

RT

VD0

VD1

VD2

VD3

VD4

MONITOR and

PROTECTION

OSC

D/A

E/A

PWM

+

-

-

+

D98IN957_2