IRDC38063-P1V2
3/21/2017
2
A well reg12V input supply should be connected to PVin+ and PVin-. A maximum of 25A load should
be connected to VOUT+ and VOUT-. The inputs and output connections of the board are listed in Table I.
IR38063 needs only one input supply and internal LDO generates Vcc from PVin. Another internal LDo
generates the 1.8V needed by the internal digital circuits. If operation with external Vcc is required, then R25
should be removed and external Vcc can be applied between Vcc+ and Vcc- pins. Vin pin and Vcc pins
should be shorted together for external Vcc operation by installing R24. For tracking operation R27 should
be populated with a 0 ohm resistor.
For normal, non-tracking operation, R27 should not be populated
and a 100 kOhm resistor should be connected from the Track_En pin to P1V8.
The board is configured for remote sensing. If local sense is desired, R8 should be uninstalled and R16
should be installed instead.
I2C/PMBus communication is established through the 4 pin header which allows connection to the
SCL/SDA/SALERT and GND lines from the host/dongle. For proper operation in digital communications
mode, R35 must always be populated.
External Enable signal can be applied to the board via exposed Enable pad and
R18 should be removed for
this purpose.
CONNECTIONS and OPERATING INSTRUCTIONS
LAYOUT
The PCB is a 6-layer board. All of layers are 2 Oz. copper. The IR38063 and most of the passive
components are
mounted on the top side of the board. Power supply decoupling capacitors and
feedback components are located close to IR38063. The feedback resistors are connected to the
output of the remote sense amplifier of the IR38063 and are located close to the IR38063. To improve
efficiency, the circuit board is designed to minimize the length of the on-board power ground current
path.
Separate power ground and analog ground are used and may be connected together using a 0
ohm resistor.
Table I. Connections
Connection
Signal Name
PVin+
PVin (+12V)
PVin-
Ground of PVin
Vout+
Vout(+1.2V)
Vout-
Ground for Vout
Vcc+
Vcc Pin
Vcc-
Ground for Vcc input
Enable
Enable
PGood
Power Good Signal