LoadSHARE PWM. LX1671 Datasheet

LX1671 PWM. Datasheet pdf. Equivalent

Part LX1671
Description Multiple Output LoadSHARE PWM
Feature LX1671 I N T E G R A T E D P R O D U C T S Multiple Output LoadSHARE™ PWM P RODUCTION D ATA S HEET .
Manufacture Microsemi Corporation
Total Page 21 Pages
Datasheet
Download LX1671 Datasheet



LX1671
INTEGRATED PRODUCTS
LX1671
Multiple Output LoadSHARE™ PWM
PRODUCTION DATA SHEET
DESCRIPTION
The LX1671 is a highly integrated The additional outputs are capable of
power supply controller IC featuring supplying up to 5A (Linear Regulator
www.tDharteaeShPeeWt4UM.netswitching regulator stages Driver) and 15A (Switching Regulator)
with an additional onboard linear for I/O, memory, termination, and other
regulator driver.
supplies surrounding today’s micro-
Two of the constant frequency processor designs.
voltage-mode PWM phases can be Each PWM regulator output is
easily configured for a single Bi-Phase programmed via a simple voltage-divider
high current output or two in- network. The LX1671, utilizing
dependently regulated outputs. Each MOSFET RDS(ON) impedance, monitors
phase incorporates a fully pro- current limit conditions, in each PWM
grammable soft-start sequence. This phase, without the use of expensive
versatility yields either three or four current sense resistors.
independently regulated outputs with The LX1671 was designed to give
full power sequencing capability giving design engineers maximum flexibility
system designers the ultimate with respect to the MOSFET supply.
flexibility in power supply design.
Each phase can utilize different supply
In Bi-Phase operation, the high voltages for efficient use of available
current (>30A) output can utilize supply rails. Additionally, when two
different supply rails allowing Forced phases are configured in Bi-Phase output,
Current Sharingfrom different the LoadSHARETM topology can be
sources. Power loss and noise, due to programmed via inductor ESR selection.
the ESR of the input capacitors, are There are three other methods that can
minimized by operating each PWM also be used with LoadSHARETM. These
output 180° out of phase. This other methods are presented in the theory
architecture also minimizes capacitor of operation section of this data sheet.
requirements while maximizing re-
gulator response.
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 Four Independently
Regulated Outputs
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 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
ƒ DDR Termination Compliant
APPLICATIONS/BENEFITS
ƒ Multi-Output Power Supplies
ƒ Video Card Power Supplies
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
LX1671
Core
Graphics
Controller
Mem ory Bus
DDR Mem ory
3.3V
I/O
Copyright © 2000
Rev. 1.0a, 2004-06-14
TA (°C)
0 to 70
PACKAGE ORDER INFO
Plastic TSSOP
Plastic MLPQ
PW 38-Pin
LQ 38-Pin
LX1671-CPW
LX1671-CLQ
Note: Available in Tape & Reel. Append the letters “TR” to the part number (i.e. LX1671CPWTR)
Microsemi
Integrated Products, Power Management
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 1



LX1671
INTEGRATED PRODUCTS
LX1671
Multiple Output LoadSHARE™ PWM
PRODUCTION 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, LDFB)........................................-0.3V to 5.5V
Input Voltage (SS/ENABLE, LDDIS)..................................................-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
Lead Temperature (Soldering 180 seconds) ................................................ 235°C
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, application of maximum voltages will increase current into that
pin and increase package power dissipation..
x = Denotes Phase 1, 2, or 3
THERMAL DATA
PW Plastic TSSOP 38-Pin
THERMAL RESISTANCE-JUNCTION TO AMBIENT, θJA
85°C/W
LQ Plastic MLP 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
LO1
PG1
LO2
HO2
VC2
LDGD
LDFB
LDDIS
DGND
AGND
RSVD
SS2
RF2
FB2
EO2
CS2
VS2
SS1
FB1
1 38
19 20
PW PACKAGE
(Top View)
H01
VC1
VC3
HO3
LO3
PG3
VCCL
VCC
N/U
VS3
CS3
N.C.
N.C.
EO3
FB3
SS3
VS1
CS1
EO1
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
Connect
27
6
Bottom
26
7
to Power
25
GND
8 24
9 23
10 22
11 21
12 13 14 15 16 17 18 19 20
LO3
PG3
VCCL
VCC
N.C.
N.C.
VS3
CS3
N.C.
EO3
FB3
SS3
LQ PACKAGE
(Top View)
N.C. – No Internal Connection
N/U – Not Used
RSVD – Do Not Use
Copyright © 2000
Rev. 1.0a, 2004-06-14
Microsemi
Integrated Products, Power Management
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 2





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