ST L6756 User Manual

for VR10, VR11.1 and AM2 processor applications

Features

■ LTB technology

response

■ 2 to 4 scalable phase operation

■ Dual-edge asynchronous architecture

■ PSI# input with programmable strategy

■ IMON output

■ Flexible driver support

■ 7/8 bit programmable output - VR10/11.x DAC

■ 6 bit programmable output - AMD AM2 DAC

■ 0.5 % output voltage accuracy

■ Full-differential current sense across DCR

■ Integrated remote sense buffer

■ Feedback disconnection protection

■ Adjustable oscillator from 100 kHz to 1 MHz

■ LSLess startup to manage pre-biased ouptut

■ Programmable Soft-start

■ Threshold sensitive enable Pin for VTT

Sensing

■ VFQFPN40 7x7 mm package

Applications

■ High-current VRM / VRD for desktop / server /

workstation CPUs

■ Graphic cards

■ Low-voltage, high-current power supplies

■ High-density DC / DC converters

®

enhances load transient

L6756

2/3/4 phase buck controller

Data Brief

VFQFPN40

Description

L6756 is a two-to-four phase controller designed
to power Intel’s most demanding Processors and,
most in general, low-voltage, high-current power
supplies. The device features LTB technology
provide the fastest response to load transients
thus minimizing the output filter composition.

L6756 embeds selectable DAC: Output Voltage is
programmable up to 1.6000 V (Intel VR10 and
VR11.x DACs) or up to 1.550 V (AMD 6bit DAC)
managing DVID transitions with ±0.5 % output
voltage accuracy over line, load and temperature
variations.

The device assures fast protection against load
over current and under / over voltage. Feedback
disconnection prevents from damaging the load in
case of misconnections in the system board.

Low-Side-Less start-up allows soft-start over pre­biased output avoiding dangerous current return
through the main inductors as well as negative
spike at the load side.

L6756 is available in VFQFPN40 7x7 mm
package.

®

to

Table 1. Device summary

Order code Package Packing

L6756

VFQFPN40 Tube

L6756TR VFQFPN40 Tape & Reel

February 2008 Rev 1 1/3

For further information contact your local STMicroelectronics sales office.

www.st.com

3

Revision history L6756

1 Revision history

Table 2. Document revision history

Date Revision Changes

15-Feb-2008 1 Initial release.

2/3