45A Integrated PowIRstage® IR3558
FEATURES
Peak efficiency up to 94.0% at 1.2V
Integrated driver, control MOSFET, synchronous
MOSFET and Schottky diode
Input voltage (VIN) operating range of 4.5V to 15V
Separate LVCC and HVCC from 4.5V to 13.2V to
optimize converter efficiency
Output current capability of 45A DC
Switching frequency up to 1.0MHz
Programmable thermal flag threshold from 70°C to
150°C
5V VCC with under voltage lockout
Low quiescent current
Enable control
Selectable regular 3.3V tri-state PWM logic or IR
Active Tri-Level (ATL) PWM logic
PCB footprint compatible with most IR3551 pins
Efficient dual sided cooling
Small 5mm x 6mm x 0.9mm PQFN package
Lead free RoHS compliant package
APPLICATIONS
Voltage Regulators for CPUs, GPUs, and DDR
memory arrays
High current, low profile DC-DC converters
DESCRIPTION
The IR3558 integrated PowIRstage® is a synchronous buck
gate driver co-packed with a control MOSFET and a
synchronous MOSFET with integrated Schottky diode. It is
optimized internally for PCB layout, heat transfer and
driver/MOSFET timing. Custom designed gate driver and
MOSFET combination enables higher efficiency at lower
output voltages required by cutting edge CPU, GPU and
DDR memory designs.
Up to 1.0MHz switching frequency enables fast transient
response, allowing miniaturization of output inductors as
well as input and output capacitors while maintaining high
efficiency. The IR3558’s superior efficiency enables
smallest size and lower solution cost. The IR3558 PCB
footprint is compatible with most pins of the IR3551 (50A).
The IR3558 provides two selectable PWM logic modes, the
3.3V tri-state PWM logic or International Rectifier’s Active
Tri-LevelTM (ATL) PWM logic. The ATL PWM logic eliminates
a dedicated Body-Braking® pin and improves the transient
response of the converter during load release.
The IR3558 provides a thermal flag output with
programmable threshold from 70°C to 150°C, which makes
it possible to adjust the thermal protection threshold
based on the PCB layout and thermal distribution.
The IR3558 is optimized specifically for CPU core power
delivery in server applications. The ability to meet the
stringent requirements of the server market also makes
the IR3558 ideally suited to powering GPU and DDR
memory designs and other high current applications.
BASIC APPLICATION
VCC
5V
OT#
PWM
ENABLE
PVCC
4.5V to 13.2V
VCC
IR3558 VIN
LGND
OT#
BOOST
OTSET
PWM
SW
EN
MODE
HVCC
LVCC
PGND
VIN
4.5V to 15V
VOUT
CS+ CS-
95 20
93 18
91 16
89 14
87 12
85 10
83 8
81 6
79 4
77 2
75 0
0 5 10 15 20 25 30 35 40 45
Output Current (A)
Figure 1: IR3558 Basic Application Circuit
Figure 2: Typical IR3558 Efficiency & Power Loss (See Note 2 on Page 7)
1 September 10, 2012 | FINAL DATASHEET
