IR3531A
4+1 Phase Dual Output Control IC
FEATURES DESCRIPTION
Integrated 6.8V/0.8A Buck Regulator provides
The IR3531A control IC provides all the necessary control,
bias to Control and Driver IC(s)
communication and protection to support compact dual
output power solutions up to 210W. The IR3531A can be
Adjustable switching frequency from 250 KHz up
combined with either discrete IR3535 driver ICs and Direct
to 1.5MHz per phase based on the synchronization
TM
Fets or our IR35XX family of footprint compatible and
SCLK input
TM
scalable PowIRstages which integrate the MOSFETs and
Sink and source tracking capability
driver into the same package.
Margining via SVID for both rails
The IR3531A provides overall system control and current
Pre-bias compatible
sharing while the Driver IC or power stages senses per-
Soft Stop capability
phase current locally and communicates it to the Control
IC. The IR3531A has tri-state PWM outputs to allow diode
0.5% overall system set point accuracy
emulation during light load events.
Voltage Mode Modulation for excellent transient
performance
The IR3531A provides a high performance transient
Single NTC thermistor for current reporting, OC
solution through classic voltage mode control and Body
TM TM
Threshold, and Load Line thermal compensation
Braking . Body Braking automatically turns off the low-
side MOSFET to help dissipate stored inductor energy at
Complete protection including over-current,
load turn-off.
over-voltage, over-temperature, open remote
sense and open control loop
Thermally enhanced 48L 7mm x 7mm MLPQ
package
RoHS compliant
PIN DIAGRAM
BASIC APPLICATION CIRCUIT
48 47 46 45 44 43 42 41 40 39 38 37
EN 1 36 BBR1#
VRHOT# 2 35 PWM4
VRRDY1 3 34 PWM3
VRRDY 4 33 TSENS
A
VCC 5 32 ROSC/OVP
IR3531A
SW 6 31 ADDR
V12V 7 30 ICCP
48 Pin 7 x 7 MLPQ
ALERT# 8 29 SCLK
Top View
VCLK 9 28 PWM2
VDIO 10 27 PWM1
PHSSHED 11 26 BBR#
49 GND
IMON_R1 12 25 TRACK
13 14 15 16 17 18 19 20 21 22 23 24
Figure 2: IR3531A Package Top View
Figure 1: IR3531A Basic Application Circuit,
showing a 4+1 Configuration
1 March 22, 2012 | FINAL | V1.11
IMON
PWM_R1
VDAC IIN_R1
VN VDAC1
VDRP
VDRP1
EA EA1
PSC FB1
FB VO1
VO VOSEN1+
VOSEN+ VOSEN1-
VOSEN- TRACK1
IIN1 IIN4
IIN2 IIN3IR3531A
4+1 Phase Dual Output Control IC
ORDERING INFORMATION
IR3531A M
Package Tape & Reel Qty Part Number
48 Lead MLPQ
100 IR3531A-MPBF
(7x7 mm body)
PBF Lead Free
48 Lead MLPQ
1
3000 IR3531A-MTRPBF
TR Tape and Reel
(7x7 mm body)
1
Note : Samples only.
48 47 46 45 44 43 42 41 40 39 38 37
EN 1 36 BBR1#
VRHOT# 2 35 PWM4
VRRDY1 3 34 PWM3
VRRDY 4 33 TSENS
VCC 5 32 ROSC/OVP
IR3531A
SW 6 31 ADDR
V12V 7 30 ICCP
48 Pin 7 x 7 MLPQ
ALERT# 8 29 SCLK
Top View
VCLK 9 28 PWM2
VDIO 10 27 PWM1
PHSSHED 11 26 BBR#
49 GND
IMON_R1 12 25 TRACK
13 14 15 16 17 18 19 20 21 22 23 24
Figure 3: Package Top View, Enlarged
2 March 22, 2012 | FINAL | V1.11
IMON PWM_R1
VDAC IIN_R1
VN VDAC1
VDRP VDRP1
EA EA1
PSC
FB1
FB VO1
VO VOSEN1+
VOSEN+ VOSEN1-
VOSEN- TRACK1
IIN1 IIN4
IIN2 IIN3