LoadSHARE PWM. LX1672 Datasheet

LX1672 PWM. Datasheet pdf. Equivalent

Part LX1672
Description Multiple Output LoadSHARE PWM
Feature LX1672 TM ® Multiple Output LoadSHARE™ PWM P RELIMINARY D ATA S HEET DESCRIPTION KEY FEATURES WW.
Manufacture Microsemi Corporation
Datasheet
Download LX1672 Datasheet



LX1672
LX1672
TM ® Multiple Output LoadSHARE™ PWM
PRELIMINARY DATA SHEET
DESCRIPTION
The LX1672 is a highly integrated This patented approach also gives
power supply controller IC featuring system designers maximum flexibility with
www.tDwaotaShPeWet4MU.nestwitching regulator stages respect to MOSFET supply. Each phase
with an additional onboard linear can utilize different supply voltages, for
regulator driver.
efficient use of available supplies, while
The two constant frequency voltage- programming the ratio of current pulled
mode PWM phases can be easily from each using one of three methods (see
configured as a single Bi-Phase high application section).
current output, two independently The LX1672 incorporates fully
regulated outputs, or as a DDR memory programmable soft-start sequencing
I/O supply with a tracking DDR capabilities. Each output can be
termination voltage supply. Power loss configured to come up in any order
and noise, due to the ESR of the input necessary as required by the application.
capacitors, are minimized by operating The LX1672 features an additional
each PWM output 180° out of phase. Linear Regulator Driver output, which
This architecture also minimizes when coupled with an inexpensive
capacitor
requirements
while MOSFET is capable of supplying up to 5A
maximizing regulator response.
for I/O, memory, and other supplies
In bi-phase operation, the high surrounding today’s micro-processor
current output utilizes a patented current designs.
sharing architecture, called Forced Each regulator voltage output is
Current Sharing, to allow accurate programmed via a simple voltage-divider
current sharing without the use of network. The LX1672, utilizing MOSFET
expensive current sense resistors.
RDS(ON) impedance, monitors maximum
current limit conditions, in each PWM
phase without the use of expensive current
sense resistors.
IMPORTANT: For the most current data, consult MICROSEMI’s website: http://www.microsemi.com
LoadSHARE is a Trademark of Microsemi Corporation
PRODUCT HIGHLIGHT
KEY FEATURES
ƒ Up to Three Independently
Regulated Outputs
ƒ DDR Termination Compliant
ƒ Bi-phase Current Sharing
ƒ Outputs As Low As 0.8V
Generated From An Internal 1%
Reference
ƒ Multiphase High Current Output
Reduces Required Capacitance
ƒ Integrated High Current MOSFET
Drivers
ƒ 300KHz, 500KHz and 600KHz
High Frequency Operation
Minimizes External Component
Requirements
ƒ Independent Phase Programmable
Soft-Start and Power Sequencing
ƒ Adjustable Linear Regulator Driver
Output
ƒ No current-sense resistors
APPLICATIONS/BENEFITS
ƒ Multi-Output Power Supplies
ƒ Video Card Power Supplies
ƒ DDR, VDDQ and Termination
Supply
ƒ PC Peripherals
ƒ Portable PC Processor and I/O
Supply
Refer to Typical
Application for
com plete circuit.
DDR Term ination
....
Mem ory Core
12V
5V
3.3V
LX1672
Graphics
Controller
Memory Bus
I/O
DDR Mem ory
TA (°C)
0 to 70
0 to 70
0 to 70
Switching
Frequency (kHz)
300
500
600
PACKAGE ORDER INFO
Plastic TSSOP
PW 28-Pin
RoHS Compliant / Pb-free Transition DC: 0518
LX1672-03CPW
LX1672-05CPW
Plastic MLPQ
LQ 38-Pin
RoHS Compliant / Pb-free Transition DC: 0512
LX1672-03CLQ
LX1672-06CLQ
NOTE: Available in Tape & Reel. Append the letters “TR” to the part number (i.e. LX1672-06CLQ-TR)
Copyright © 2000
Rev. 0.3m, 2005-04-12
Microsemi
Linfinity Microelectronics Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 1



LX1672
LX1672
TM ® Multiple Output LoadSHARE™ PWM
PRELIMINARY DATA SHEET
ABSOLUTE MAXIMUM RATINGS
Supply Voltage (VCC) DC .................................................................-0.3V to 5.5V
Supply Voltage (VCC) Transient ......................................................-0.3V to 6.0V
Driver Supply Voltage (VCx, VCCL) DC ............................................-0.3V to 16V
Driver Supply Voltage (VCx, VCCL) Transient ..................................-0.3V to 18V
Current Sense Inputs (VSX, CSX) ....................................................... -0.3V to 12V
Error Amplifier Inputs (FBX, RF2)....................................................-0.3V to 5.5V
Input Voltage (SS/SHDN) ..................................................................-0.3V to5.5V
Output Drive Peak Current Source (HOx, LOx)....................................1A (500ns)
Output Drive Peak Current Sink (HOx, LOx) .......................................1A (500ns)
Operating Junction Temperature.................................................................. 150°C
Storage Temperature Range...........................................................-65°C to 150°C
RoHS Peak Package Solder Reflow Temperature
(40 second maximum exposure) ..................................................... 260°C (+0, -5)
Note: Exceeding these ratings could cause damage to the device. All voltages are with
respect to Ground. Currents are positive into, negative out of specified
terminal.
The limitation on transient time is thermal and is due to zener diodes on the
supply pins, brief application of maximum voltages will increase current into that
pin and increase package power dissipation..
x= Denote Phases 1 & 2
THERMAL DATA
PW Plastic TSSOP 28-Pin
THERMAL RESISTANCE-JUNCTION TO AMBIENT, θJA
85°C/W
LQ Plastic MLPQ 38-Pin
THERMAL RESISTANCE-JUNCTION TO AMBIENT, θJA
35°C/W
Junction Temperature Calculation: TJ = TA + (PD x θJC).
The θJA numbers are guidelines for the thermal performance of the device/pc-board system.
All of the above assume no ambient airflow.
PACKAGE PIN OUT
HO2
LO2
PG2
LDGD
LDFB
LDDIS
DGND
AGND
DIS2
SS2
RF2
FB2
EO2
CS2
1 28
2 27
3 26
4 25
5 24
6 23
7 22
8 21
9 20
10 19
11 18
12 17
13 16
14 15
PW PACKAGE
(Top View)
VC2
VC1
HO1
LO1
PG1
VCCL
VCC
VS1
CS1
EO1
FB1
SS1
DIS1
VS2
HO2
VC2
LDGD
LDFB
LDDIS
DGND
AGND
RSVD
SS2
RF2
FB2
EO2
1 38 37 36 35 34 33 32 31
2 30
3 29
4 28
5 27
6 Connect Bottom to 26
7
Power GND
25
8 24
9 23
10 22
11 21
12 13 14 15 16 17 18 19 20
N.C.
N.C.
VCCL
VCC
DIS2
DIS1
N.C.
N.C.
PWGD
N.C.
N.C.
N.C.
(N.C. – No Internal Connection
N/U – Not Used)
RoHS / Pb-free 100% Matte Tin Lead Finish
Copyright © 2000
Rev. 0.3m, 2005-04-12
Microsemi
Linfinity Microelectronics Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 2





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