Analog Devices ADP2302 Evaluation Board ADP2302-EVALZ ADP2302-EVALZ Datenbogen

Evaluation Board User Guide 

UG-189

 

Rev. 0 | Page 3 of 12 

USING THE EVALUATION BOARD 

evaluation boards are fully assembled 

and tested. Before applying power to the evaluation board, follow 
the procedures in this section. 

Jumper J5 enables/disables the ADP2302/ADP2303. Set J5 to 
EN HIGH to enable the device, and set J5 to EN LOW to 
disable the device. 

Jumper J8 connects/disconnects the power-good signal to VIN. 
To pull the power good (PGOOD) pin up, connect J8 to the 
input voltage through a 100 kΩ resistor. Disconnect J8 to leave 
PGOOD open. 

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 J2 (VIN) on the evaluation 
board and the negative terminal of the power source to J4 
(GND) of the evaluation board.  

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 positive (+) 
ammeter terminal, the negative lead (−) of the power source to 
J4 (GND), and the negative lead (−) of the ammeter to J2 (VIN). 

Make sure that the board is turned off before connecting the 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 connection to J1 (VOUT) and the negative (−) load 
connection to J3 (GND). 

If an ammeter is used, connect it in series with the load. 
Connect the positive (+) ammeter terminal to J1 (VOUT), the 
negative (−) ammeter terminal to the positive (+) load terminal, 
and the negative (−) load terminal to J3 (GND). 

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. If the 
voltmeters are not connected directly to the evaluation board, 
the measured voltages are incorrect due to the voltage drop 
across the leads and/or connections between the evaluation 
board, the power source, and/or the load. 

To measure the input voltage, connect the positive terminal of 
the voltmeter to J2 (VIN) and the negative terminal to J4 (GND). 
Likewise, to measure the output voltage, connect the positive 
terminal of the voltmeter to J1 (VOUT) and the negative 
terminal to J3 (GND).  

Once the power source and load are connected to the evaluation 
board, it can be powered for operation. 

Perform the following steps: 

1.  Ensure that the power source voltage is >V

OUT

 + 2.1 V  

and <20 V. 

2.  Ensure that J5 (EN) is high and monitor the output voltage. 

If the load is not already enabled, enable the load, check that the 
load is drawing the proper current, and verify that the output 
voltage maintains voltage regulation. 

To observe the switching waveform with an oscilloscope,  
place the oscilloscope probe tip at Test Point J7 (SW) with the  
probe ground at GND. Set the scope to dc with the appropriate 
voltage and time divisions. The switching waveform should 
alternate between 0 V and approximate the input voltage. 

Load regulation should be tested by increasing the load at the 
output and by observing the change in output voltage. To 
minimize voltage drop, it is recommended to use short low 
resistance wires. 

Vary the input voltage and examine the change in the output 
voltage at a fixed output current. 

The efficiency, η, is measured by comparing the input power 
with the output power. 

×

×

=

 

Measure the input and output voltages as close as possible to the 
input and output capacitors to reduce the effect of voltage drop. 

The inductor current can be measured by removing one end of 
the inductor from its pad and connecting a current loop in 
series. A current probe can be connected to this wire.