Evaluation Board User Guide
UG-439
Rev. A | Page 3 of 13
USING THE EVALUATION BOARD
POWERING UP THE EVALUATION BOARD
The
ADP5034
TSSOP evaluation board,
ADP5034RE-EVALZ
,
is supplied fully assembled and tested. Before applying power to
the evaluation board, follow the procedures in this section.
Enable
Each channel has its own enable pin (EN1, EN2, EN3, and
EN4), which must be pulled high via the corresponding
jumpers to enable that channel (see Table 1).
Table 1. Channels of the Enable Jumper
Channel
Enable Jumper
1
JEN1
2
JEN2
3
JEN3
4
JEN4
Jumper JMODE (MODE)
Jumper JMODE, as shown in Figure 1, connects the MODE pin
of the device to either ground or VIN1. To force Buck 1 and
Buck 2 into forced PWM operation, shunt the center contact of
Jumper JMODE to the top pin header to pull the MODE pin high
to VIN1. To allow Buck 1 and Buck 2 to operate in automatic
PWM/PSM operation, shunt the center contact of JMODE to
the bottom pin header to pull the MODE pin low to PGND on
the
ADP5034RE-EVALZ
.
Input Power Source
If the input power source includes a current meter, use that meter
to monitor the input current. VIN1 directly connects to AVIN
and VIN2. Attach a header on JVIN3 to connect the supply of
LDO1 to VIN1, and attach a header on JVIN4 to connect the
supply of LDO2 to VIN1. Connect the positive terminal of the
power source to VIN1 on the evaluation board and the negative
terminal of the power source to PGND.
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 PGND
on the evaluation board, and the negative lead (−) of the ammeter
to VIN1 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
the Buck 1 output, VOUT1, and the negative (−) load connection
to PGND.
If an ammeter is used, connect it in series with the load. Connect
the positive (+) ammeter terminal to the evaluation board for
Buck 1, VOUT1, the negative (−) ammeter terminal to the positive
(+) load terminal, and the negative (−) load terminal to the
evaluation board at PGND.
Input and Output Voltmeters
Measure the input and output voltages with voltmeters. Make
sure to connect the voltmeters to the appropriate evaluation
board terminals and not to the load or power sources themselves.
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.
Connect the input voltage measuring voltmeter positive terminal
(+) to the evaluation board at VIN1, and input voltage measuring
voltmeter negative (−) terminal to the evaluation board at PGND.
Connect the output voltage measuring voltmeter positive (+)
terminal to the evaluation board at VOUT1 to measure the
output voltage of Buck 1, and connect the output voltage
measuring voltmeter negative (−) terminal to the evaluation
board at GND.
Turning On the Evaluation Board
When the power source and load are connected to the evaluation
board, the board can be powered for operation. Ensure the
following:
•
The power source voltage for the buck regulators (VIN1,
VIN2) is from 2.3 V to 5.5 V.
•
The power source voltage for the LDO regulators (VIN3,
VIN4) is from the LDO output v 0.5 V (or 1.7 V,
whichever is greater) to 5.5 V.
•
The voltage supplied on VIN3 and VIN4 must be equal to
or less than the voltage supplied on VIN1 and VIN2.
•
The desired channel is enabled and monitors the output
voltage.
If the load is not enabled, enable the load; check that it is drawing
the proper current and that the output voltage maintains voltage
regulation.
Setting the Output Voltage of the Buck Regulators
The buck output voltage is set through external resistor dividers,
shown in Figure 2 for Buck 1. The output voltage can optionally
be factory programmed to default values as indicated in the
data sheet. In this event, R1 and R2 are not needed, and FB1 can
be left unconnected. In all cases, VOUT1 must be connected to
the output capacitor. FB1 is 0.5 V.
