User`s guide

MCP1630 Dual Buck Demo Board User’s Guide
DS51531A-page 8 © 2005 Microchip Technology Inc.
2.3.1 Power Input and Output Connections
Powering the MCP1630 Dual Buck Demo Board.
1. Apply the input voltage to the connector (J3) provided. Connect the positive side
of the input source (+) to the test point (J3-1). Connect the negative (or return
side (-)) of the input source to the GND terminal (J3-2). J3 is the center two
position terminal block located on the left side of the board. A 14-gauge wire size
is recommended for evaluating the board at 20A per output. The power supply
input voltage must be in the specified operating range for the board to operate.
An undervoltage lockout circuit prevents the converter from running when the
input voltage is too low.
2. An on/off push-button switch (SW3) is used to turn the converter outputs on and
off. During normal power-up, the outputs are turned on by pressing SW3 once.
To turn the outputs off, press SW3 again.
3. In the event of a fault, (input voltage out-of-range, output voltage out-of-range or
power train overtemperature), both V
OUT1
and V
OUT2
will shut down, indicated
by the D1 power good LED flashing. To restart, the input voltage must be brought
to 0V and raised back to the specified input voltage range of the converter prior
to pressing the on/off button. A solid D1 power good LED indicates that the
regulator outputs are operating properly at their programmed values.
Applying the load to the MCP1630 Dual Buck Demo Board.
1. To apply a load to V
OUT1
of the MCP1630 Dual Buck Demo Board, the positive
side of the V
O1
load (+) should be connected to the terminal +V
O1
(J2-2). The
negative side of the V
O1
load should be connected to the terminal GND (J2-1).
2. To apply a load to V
OUT2
of the MCP1630 Dual Buck Demo Board, the positive
side of the V
O2
load (+) should be connected to the terminal +V
O2
(J4-2). The
negative side of the V
O2
load should be connected to the terminal GND (J4-1).
3. Outputs V
O1
and V
O2
are independent of each other and are loaded separately.
Both outputs have independent over current protection, overtemperature and
short-circuit protection.
2.3.2 Power Present and Power Good Indication
1. The MCP1630 Dual Buck Demo Board has two status LED’s. One LED (D3) is
used to determine if input voltage is present.
2. The second LED (D1) is used for fault and power good indication. During normal
operation, if both regulator outputs are within regulation, D1 is illuminated to
provide indication that power is good. If either output is out of regulation, D1 will
blink, providing indication that one or both of the outputs are not in regulation.
Note: The maximum rated load is 20A per output. When loading the board over
10A, airflow is necessary to prevent the overtemperature protection
circuitry from automatically turing off the power train that has the
overtemperature condition.