Renesas ISL9122AIIN-EVZ, Manual

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R12UZ0080EU0102 Rev.1.02 Page 4
Apr 1, 2022
ISL9122AIIN-EVZ, ISL9122AIRN-EVZ Evaluation Board Manual
1.2 Setup and Configuration
For both evaluation boards, the default output voltage is set at 3.3V. Use the following procedures to configure
and power-up the board for proper operation. During the power-on process, the expected waveforms are shown in
Figure 3 .
1. Connect the power supply to J1, with voltage setting between 1.8V and 5.5V.
2. Connect the electronic load to J2.
3. Place the scope probes on VOUT test point and other test points of interest.
4. Ensure that the EN pin jumper (J4) is pulled up to V
IN
.
5. Turn on the power supply. At the end of the soft start sequence, the ISL9122A is operating in Regulation mode
by default with V
OUT
= 3.3V. Note : A minimum effective output capacitance of 6µF is required. Therefore,
depending on the performance specifications of the capacitor, an additional output capacitor might be required
for higher output voltage settings.
6. Monitor the output voltage start-up sequence on the scope. The waveforms should look similar to those shown
in Figure 3 .
7. Turn on the electronic load.
8. Measure the output voltage with the voltmeter. The voltage should regulate within the datasheet specification
limits.
9. To determine efficiency, measure input and output voltages at the Kelvin sense test points (S+ and S-), which
are part of J1 and J2 headers. The bench power supply can be connected to the VIN and GND headers on J1.
The electronic load can be connected to the VOUT and GND headers on J2. Measure the input and output
currents. Calculate the efficiency based on these measurements.
1.3 Evaluation Software Installation and Use
The ISL9122 evaluation software and evaluation software guide are available for download from the Renesas
website .
10. Save the evaluation software executable file and install the evaluation software (refer to the evaluation software
manual). When the evaluation software launches, (refer to the Setup and Configuration and) connect the power
supply, DC load, and other test equipment to the evaluation board; next, apply power.
11. The ISL9122A has five control registers. See the ISL9122 datasheet for detailed register descriptions.
12. Register RO_REG1 (Address: 0x02) provides chip identification information. The Get IC INFO_RO_REG1
button reads from this read-only register.
13. To change the output voltage, you can use the VSET Control slider in the VSET register (Address: 0x11) panel
and perform a Write REG operation. The output voltage ramps up at the slew rate specified in the DVSRATE
Figure 3. ISL9122A Start-Up with V
IN
= 3.6V and V
OUT
= 3.3V
200
μ s
/Div