IRU3146 Datasheet, PDF (1/30 Pages) International Rectifier – DUAL SYNCHRONOUS PWM CONTROLLER WITH CURRENT SHARING CIRCUITRY AND AUTO-RESTART

Data Sheet No.PD 94702
IRU3146
DUAL SYNCHRONOUS PWM CONTROLLER WITH
CURRENT SHARING CIRCUITRY AND AUTO-RESTART
FEATURES
Dual Synchronous Controller with 180 out-of-phase
Configurable to 2-Independent Outputs or 2-Phase
Single Output
Current Sharing Using Inductor's DCR
Current Limit using MOSFET's RDS(ON)
Hiccup/Latched Current Limit
Latched Over-Voltage Protection
Vcc from 4.5V to 16V Input
Programmable Switching Frequency up to 500KHz
Two Independent Soft-Starts/ Shutdowns
0.8V Precision Reference Voltage Available
Power Good Output
External Frequency Synchronization
APPLICATIONS
Embedded Computer Systems
Telecom Systems
Point of Load Power Architectures
DESCRIPTION
The IRU3146 IC combines a Dual synchronous Buck
controller, providing a cost-effective, high performance
and flexible solution. The IRU3146 can configured as 2-
independent or as 2-phase controller. The 2-phase con-
figuration is ideal for high current applications. The
IRU3146 features 180 out of phase operation which re-
duces the required input/output capacitance and results
to few number of capacitor quantity. Other key features
offered by this device include two independent program-
mable soft starts, programmable switching frequency up
to 500KHz per phase, under voltage lockout function.
The current limit is provided by sensing the lower
MOSFET's on-resistance for optimum cost and perfor-
mance.
2-Phase Power Supply
Graphic Card
DDR Memory Applications
C12
12V
D1
C11
PGood
C3 C4
C5
R2
C8 ^R3
C9 ^R4
C10
VCL VcH1 VOUT3 VcH2
Vcc
HDrv1
OCSet1
Hiccup
LDrv1
Sync
VREF
PGnd1
VP2
Rt
U1
IRU3146 ^VSEN1
Comp1
VSEN2
Fb1
Fb2
C13
R1
Comp2
PGood
SS1 / SD
SS2 / SD
HDrv2
R6
OCSet2
LDrv2
PGnd2
Gnd
C14
Q2
Q3
D2
BAT54A
L3
R5
C15
C17
Q4
Q5
R9
C18
L4
1.8V @ 30A
R10
C16
R11
R7
R8
Figure 1 - Typical application of IRU3146 in 2-phase configuration with inductor current sensing
PACKAGE ORDER INFORMATION
DEVICE
IRU3146CF
PACKAGE
28-Pin TSSOP (F)
Rev. 1.1
6/25/04
www.irf.com
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