IRDC3146EVAL Datasheet, PDF (1/15 Pages) International Rectifier – IRU3146 EVALUATION BOARD USER GUIDE

IRDC3146EVAL
IRU3146 EVALUATION BOARD USER GUIDE
INTRODUCTION
SPECIFICATION DATA
The IRU3146 IC is a Dual synchronous Buck controller,
providing a cost-effective, high performance and flexible
solution. The IRU3146 can be configured as a 2-inde-
pendent or as a 2-phase controller. The 2-phase configu-
ration is ideal for high current applications. The IRU3146
features 1808 out of phase operation which reduces the
required input/output capacitance and results in a fewer
number of capacitors needed. Other key features offered
by this device include two independent programmable
soft starts, programmable switching frequency up to
400KHz per phase, Hiccup current limit and an under
voltage lockout function. The current limit is provided by
sensing the lower MOSFET's on-resistance for optimum
cost and performance.
This reference board is designed to demonstrate all
the features of IRU3146 and can be configured to two
types of applications:
1) Dual outputs application (Independent Outputs)
2) 2-phase application (Single Output)
This user guide contains the schematic and bill of
materials for each of these applications, and the
design guidelines are described in data sheet.
The MOSFETs sockets on the evaluation board are
dual layout for SOIC-8 and Direct FET footprint.
INPUT/OUTPUT CONNECTIONS
The following is the input/output connections:
Inputs:
JP1: Vin and Gnd
JU4: VCC and Gnd
JU5: VCL/VCH1/VCH2
Outputs:
JP2: Vout1 for Dual output
JP5: Vout2 for Dual output
JP4: Vout for 2-phase application
Scope Probe connections:
J1 and J3: Inductor point for L2 and L3
J2 and J4: Outputs for Vout1 and Vout2
The connection points for dual output application are
shown in Figure 1. Connect the power supply cables
according to this figure, minimizing wire lengths to re-
duce losses in the wire. Test points J1, J2, J3 and J4
provide easy connection for oscilloscope voltage probe
to monitor the inductor points for each PWM section
and output voltages.
Dual Outputs
VIN = 12V
VOUT1 = 2.5V
IOUT1 = 10A
VOUT2 = 1.8V
IOUT1 = 10A
DVOUT = 50mV
FS = 300KHz
2-Phase
VIN = 12V
VOUT1 = 1.8V
IOUT1 = 35A
DVOUT = 50mV
FS = 300KHz
Rev.1.0
7/28/04
www.irf.com
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