LX1676 Datasheet, PDF (1/16 Pages) Microsemi Corporation – Mobile AMD AthlonTM VRM Controller

INTEGRATED PRODUCTS
LX1676
Mobile AMD Athlon™ VRM Controller
PRELIMINARY DATA SHEET
DESCRIPTION
The LX1676 is a highly integrated maximizing regulator response.
VRM power supply controller IC A true differential input amplifier is
featuring two PWM switching used for remote voltage sensing at the
regulator stages.
processor core.
The two constant frequency A VID code generator provides an
voltage-mode PWM phases are internal reference that will set the
configured as a single biphase high output voltage. This VID code can be
current output core supply.
changed during operation and the
In biphase operation, the high reference will slew the output voltage to
current (>25A) output is generated by its new setting at a preset rate. During
a LoadSHARE^TM† technique that VID changes on the fly the Power Good
balances the currents in the two indication will stay valid.
phases. Power loss and noise, due to Current through the lower phase 1
the ESR of the input capacitors, are MOSFET will be sampled using its
minimized by operating the PWMs R_DS(ON) for current limit and shut
180° out of phase.
down.
A synchronized Transient For further protection, an over
Correction Loop† provides except- voltage circuit will trip at a specified
ional control of the output droop and setting and clamp the output by turning
overshoot during very high di/dt load off the upper MOSFETs and turning on
changes, the circuit can be configured the lower MOSFETs.
for droop only, overshoot only or The upper MOSFET drivers will use
both.
a bootstrap capacitor to provide the
This architecture also minimizes upper drive voltage over the input
capacitor requirements while voltage range of 6 to 24 volts.
IMPORTANT: For the most current data, consult MICROSEMI’s website: http://www.microsemi.com
† Patent numbers US6292378,US6285571,US6356063, US6605931
V in + 5 V
PRODUCT HIGHLIGHT
T ra n s ie n t C o rre c tio n L o o p
V in 6 to 2 4 V
70nH
5 B it V ID
LX1676
V in 6 to 2 4 V
KEY FEATURES
ƒ High Current Biphase
Operation
ƒ Outputs As Low As 0.925V
ƒ † Biphase LoadSHARE^TM
ƒ † Transient Correction Loop
Reduces Required
Capacitance
ƒ Differential Amplifier For
Remote Voltage Sensing
ƒ Integrated High Current
MOSFET Drivers
ƒ 200KHz to 1MHz Frequency
Operation
ƒ Programmable Slew Rate
Control For Start-Up Sequence
and VID change
ƒ VID Changes On The Fly
ƒ Power Good Indicator
ƒ Short Circuit Protection
ƒ Output Over Voltage and
Under Voltage Protection
ƒ No current-sense resistors
APPLICATIONS
ƒ AMD Mobile Athlon™ or
Duron™ Processor Core
Voltage Supply
ƒ Voltage Regulator Modules
Vout
T_J (°C)
0 to 70
PACKAGE ORDER INFO
Plastic TSSOP
Plastic MLPQ
PW _38-Pin
LQ _38-Pin
LX1676-CPW
LX1676-CLQ
Note: Available in Tape & Reel.
Append the letters “TR” to the part number.
(i.e. LX1676-CLQTR)
Copyright © 2000
Revision: 0.4b, 9/14/2004
Microsemi
Integrated Products Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: [phone]
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