UG:307
vicorpower.com
Applications Engineering: 800 927.9474
Page 4
Board Operation Modes
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S101 provides control over enable.
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In the “OFF” position, the switch will connect SGND pin to the EN net, which disables the
regulator output.
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In the “ON” position, the EN net is allowed to float.
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The PI352x evaluation board supports the following operating modes:
Mode
S202
S201
S203
J201
(+VRS, -VRS)
Local loop, fixed
Nominal output
LS
FIXED
-
Place jumper (J201 pin 1-2) to
short R211 for accurate result
-
Local loop, with
Trim range (R206)
LS
ADJ
-
Turn (R206) clockwise to
increase the output voltage and
counterclockwise to decrease the
output voltage.
-
Remote loop,
fixed Nominal
output
-
FIXED
RS
Place jumper (J201 pin 1-2) to
short R211 for accurate result
Used to connect to point
of load. If not connected
(R223-R224 = 100
Ω
) will
be in the loop connecting
this node to local +VOUT
Remote loop, with
Trim range (R221)
-
ADJ
RS
Turn (R206) clockwise to
increase the output voltage and
counterclockwise to decrease the
output voltage.
Thermal Consideration
A fan blowing across the evaluation board is recommended for operation. The fan should be placed
about 4 inches away from the evaluation board edge. A typical bench top fan is recommended
providing about 1000LFM. Using the supplied rubber feet is also required in order to elevate the board
about 0.4 inches off a flat surface and enable air flow underneath the PCB.
Power Up Procedure
1.
Confirm bench equipment is powered off.
2.
Connect input DC power supply positive lead to +VIN input lug, then connect input power supply
negative lead to PGND input lug of the evaluation board.
3.
CVOUT lug to the electronic load positive input, connect the PGND output lug to the
electronic load negative input.
4.
Verify proper polarity of both input and output connections.
5.
Verify on-board mechanical switch (S101) desired actuator position. “ON” state allows power up
upon application of input voltage. S101 default actuator position is “ON” allowing the unit to
power up upon the application of an input voltage greater than V
UVLO_START
.
6.
Verify that three separate two position jumper socket are placed on header (J201) shorting the
following J201 pins 1 to 2, 3 to 4, 5 to 6.
7.
Verify desired feedback loop
operation:
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On-board mechanical switch (S202) default position is “LS” short for local sense loop
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On-board mechanical switch (S201) default position is “FIXED” implying the use of the populated
exact value resistors producing a regulated device specific nominal output voltage.
8.
Place measuring equipment such as DMM, scope probes as desired
