L6911E_07 Datasheet, PDF (1/34 Pages) STMicroelectronics – 5-Bit programmable step down controller with synchronous rectification

L6911E
5-Bit programmable step down controller
with synchronous rectification
Features
■ Operating supply IC voltage from 5V to 12V
buses
■ Up to 1.3A gate current capability
■ TTL-compatible 5 bit programmable output
compliant with VRM 8.5 :
1.050V to 1.825V with 0.025V binary steps
■ Voltage mode PWM control
■ Excellent output accuracy: ±1% over line and
temperature variations
■ Very fast load transient response: from 0% to
100% Duty Cycle
■ Power good output voltage
■ Overvoltage protection and monitor
■ Overcurrent protection realized using the upper
MOSFET's R_ds(ON)
■ 200kHz internal oscillator
■ Oscillator externally adjustable from 50kHz to
1MHz
■ Soft start and inhibit functions
Applications
■ Power supply for advanced
microprocessor core
■ Distributed power supply
SO-20
Description
The device is a power supply controller
specifically designed to provide a high
performance DC/DC conversion for high current
microprocessors. A precise 5 bit digital to analog
converter (DAC) allows to adjust the output
voltage from 1.050 to 1.825 with 25mV binary
steps.
The high precision internal reference assures the
selected 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 over-voltage. An external
SCR is triggered to crowbar the input supply in
case of hard overvoltage. 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 an the system works in HICCUP
mode.
Table 1. Device summary
Part Number
L6911E
L6911ETR
April 2007
Package
TSSOP8
TSSOP8
Rev 3
Packaging
Tube
Tape and reel
1/34
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