Evaluation Board User Guide
UG-456
Rev. 0 | Page 3 of 12
USING THE EVALUATION BOARD
POWERING UP THE EVALUATION BOARD
The
ADP2442-EVALZ
evaluation board is provided fully
assembled and tested. Before applying power to the evaluation
board, follow the procedures in the following sections.
Input Power Source
The power source voltage must not exceed 36 V, the maximum
operation input voltage of the
ADP2442
.
Ensure that the power source is switched off before connecting
it to the
ADP2442-EVALZ
evaluation board. Connect the positive
terminal of the power source to the evaluation board V
IN
terminal
(T1), and the negative terminal of the power source to the
evaluation board GND terminal (T2). If the power source includes
an ammeter, connect the ammeter in series with the input source
voltage. Connect the positive lead (+) of the power source to the
ammeter positive (+) connection, the negative lead (−) of the
ammeter to the evaluation board V
IN
terminal (T1), and the
negative lead (−) of the power source to the evaluation board
GND terminal (T2).
Output Load
Ensure that the evaluation board is switched off before connecting
the load. Connect the load directly to the evaluation board, with
the positive (+) load connection to the VOUT terminal (T3) and
the negative (−) load connection to the PGND terminal (T4). If
an ammeter is used, connect it in series with the load: connect
the positive (+) ammeter terminal to the evaluation board VOUT
terminal (T3), the negative (−) ammeter terminal to the positive
(+) load terminal, and the negative (−) load terminal to the
evaluation board PGND terminal (T4).
When the load is connected, ensure that it is set to the proper
current before powering the
ADP2442-EVALZ
evaluation board.
Before connecting a load to the output of the evaluation board,
ensure that the output voltage does not exceed the maximum
operating voltage range of the load.
Enabling and Disabling the DC-to-DC Switching
Regulator
In the evaluation board, a voltage divider is used to generate an
enable signal for the IC. As soon as voltage is applied to VIN
(24 V), IC is enabled.
Alternatively, the TP1 (EN) header is available to enable and
disable the evaluation board. To enable the output, connect the
TP1 header to the VIN supply or to an external voltage source. To
disable the output, connect the TP1 header to the GND.
PGOOD Signals
When the output is enabled and the output voltage, V
OUT
, is in
regulation, the logic signal at the PGOOD test point is high. In
a typical application, a pull-up resistor from the PGOOD pin to
the external supply is used to generate this logic signal.
On the evaluation board, the pull-up resistor (R7) is available to
connect to the external supply through the jumper (JP1). The TP2
test point is available to connect the external supply of 5 V.
Figure 2. PGOOD Signal
SYNC/MODE Pin
The SYNC/MODE pin is a multifunctional pin. When the
SYNC/MODE pin is connected to VCC or a high logic, the
PWM mode is enabled. When the SYNC pin is connected to
AGND, the pulse skip mode is enabled. The external clock can
be applied for the synchronization.
On the evaluation board, the SYNC/MODE pin can be connected
to VCC or AGND through JP2 (as shown in Figure 3). Users can
apply a clock input to the SMB connector, which is connected to
the SYNC pin.
Table 1. Mode Selection
SYNC Pin
Mode of Operation
Low
Pulse skip mode
High
Forced PWM mode
Clock signal
Forced PWM mode
Figure 3. SYNC/MODE Signal
PGOOD
TP2: EXTERNAL
SUPPLY: 5V
JP1
R7
50k
Ω
10949-
002
VCC
JP2
SYNC/MODE
CLOCK
J1
10949-
003
