Data Brief
For further information contact your local STMicroelectronics sales office.
February 2008 Rev 1 1/3
3
L6756
2/3/4 phase buck controller
for VR10, VR11.1 and AM2 processor applications
Features
■ LTB technology
®
enhances load transient
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
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
®
to
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 pre-
biased 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.
VFQFPN40
Table 1. Device summary
Order code Package Packing
L6756
VFQFPN40 Tube
L6756TR VFQFPN40 Tape & Reel
www.st.com
