Evaluation Board User Guide UG-279
Rev. 0 | Page 3 of 12
USING THE EVALUATION BOARD
POWERING UP THE EVALUATION BOARD
The ADP5033 evaluation board is supplied fully assembled and
tested. Before applying power to the evaluation board, follow
the procedures in this section.
Enable JP4 (EnA) and JP5 (EnB)
When the ADP5033 has an input voltage above the minimum
UVLO setting, the ADP5033 BUCK2 and LDO1 are enabled by
connecting JP4 (EnA) from Pin 1 to Pin 2. BUCK1 and LDO2
are enabled by connecting JP5 (EnB) from Pin 1 to Pin 2.
Jumper JP3 (Mode)
Jumper JP3 (Mode) pulled high to J1 (VIN_1) forces BUCK1
and BUCK2 into forced PWM operation. JP3 (Mode) pulled
low to J11 (GND1) allows BUCK1 and BUCK2 to operate in
automatic PWM/PSM operation.
Input Power Source
If the input power source includes a current meter, use that meter
to monitor the input current. Connect the positive terminal of the
power source to J1 (VIN_1) on the evaluation board, and the nega-
tive terminal of the power source to J11 (GND1).
If the power source does not include a current meter, connect a
current meter 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 power source to J11
(GND1) on the evaluation board, and the negative lead (−) of
the ammeter to J1 (VIN_1) on the board. Be aware that the current
meters add resistance to the input source and this voltage reduces
with high output currents.
Output Load
Connect an electronic load or resistor to set the load current. If
the load includes an ammeter, or if the current is not measured,
connect the load directly to the evaluation board, with the positive
(+) load connected to one of the channels. For example, connect
BUCK1, J5 (VOUT1) and the negative (−) load connection to J8
(PGND).
If an ammeter is used, connect it in series with the load. Connect
the positive (+) ammeter terminal to the evaluation board for
BUCK1, J5 (VOUT1), the negative (−) ammeter terminal to the
positive (+) load terminal, and the negative (−) load terminal to the
evaluation board J8 (PGND).
Input and Output Voltmeters
Measure the input and output voltages with voltmeters. Make
sure that the voltmeters are connected to the appropriate
evaluation board terminals and not to the load or power source
themselves.
If the voltmeters are not connected directly to the evaluation
board, the measured voltages will be incorrect due to the
voltage drop across the leads and/or connections between the
evaluation board, the power source, and/or the load.
Connect the input voltage measuring voltmeter positive termi-
nal (+) to the evaluation board via J1 (VIN_1), and the negative
(−) terminal to the evaluation board via J11 (GND1) .
Connect the output voltage measuring voltmeter positive (+)
terminal to the evaluation board via J5 (VOUT1) for measuring
the output voltage of BUCK1 and the negative (−) terminal to the
evaluation board via J8 (PGND).
Turning On the Evaluation Board
When the power source and load are connected to the ADP5033
evaluation board, the board can be powered for operation.
Perform the following steps:
1. Ensure that the power source voltage is greater than 4.2 V
but less than 5.5 V.
2. Ensure that the desired channel is enabled, and monitor
the output voltage.
If the load is not already enabled, enable the load; check that it
is drawing the proper current, and that the output voltage
maintains voltage regulation.
MEASURING EVALUATION BOARD PERFORMANCE
Measuring Output Voltage Ripple on the Buck Regulator
To observe the output voltage ripple of BUCK1, place an oscillo-
scope probe across the output capacitor (COUT_1) with the
probe ground lead at the negative (−) capacitor terminal and
the probe tip at the positive (+) capacitor terminal. Set the
oscilloscope to ac, 20 mV/division, and 2 μs/division time base.
Measuring the Switching Waveform
To observe the switching waveform with an oscilloscope, place
the oscilloscope probe tip at the end of the inductor with the
probe ground at GND. Set the oscilloscope to dc, 2 V/division,
and 2 μs/division time base.
