Test Procedure for the NIS5102QP1 and NIS5102QP2 Evaluation Boards
07/01/2005
The NIS5102 demo-board has several test points that are used to measure different device functions. The test procedure for each of the tests to be performed will be referenced to the test points highlighted in the below Figure 1 and labeled in the schematic of Figure 2.
Note that the pin labeled ‘TPE’ is being used for the enable function, not the pin labeled ‘Enable.’
Figure 1: NIS5102 Evaluation Board
Output Enabl
PwrG Input
Groun Switc
Figure 2: NIS5102 Evaluation Board Schematic
Equipment
Variable power supply (It is recommended that a power supply with at least 10 A of output current capability be used.) Power supply
2 Voltmeters
Digital oscilloscope (current and voltage probes) Electrolytic capacitor of 1,000 uF (50 V)
1. Functionality test
The purpose of this test is to determine if the board is operable.
a. Apply 12 V at the input pins
b. Connect a voltmeter at the output pins
c. Turn-on the switch and measure the voltage at the output. The output voltage should be similar to the input voltage (± 3%
variation). If this is not the case the board should be considered non-operable.
2. Enable function test
The purpose of this test is to check the enable function. This test should be applied only after the board has passed the functionality test.
a. Apply 12 V at the input pins
b. Connect a voltmeter at the output pins and turn-on the switch. The voltmeter should show the output voltage reading similar to the input voltage.
c. Connect a second power supply with common ground to the 12 V supply and set to 5 V.
d. Apply the 5 V signal to the enable pin (labeled ‘TPE’ on the board). At this point the output voltage should be close to 0 V.
Remove the 5 V signal from the enable pin and check that the output voltage is back to its original value.
3. UVLO test
The purpose of this test is to check the under-voltage function of the device.
a. Connect a variable power supply to the input pins and set the initial voltage value to 0 V.
b. Connect a voltmeter at the input pins and other one at the output pins.
c. Turn-on the switch and increase the supply voltage slowly until finding the point where the device turns-on (device should turn-on between 9.35 V and 12.65 V). At this point the output voltage should be similar to the input voltage.
d. Reduce the supply voltage slowly until finding the point where the device turns back off (device should turn-off between 8.85 V and 12.15 V). At this point the output voltage should be close to 0 V.
4. OVLO test
The purpose of this test is to check the over-voltage function of the device.
a. Connect a variable power supply to the input pins and set the initial voltage value to 12 V.
b. Connect a voltmeter at the input pins and other one at the output pins.
c. Turn-on the switch and check that the device is on (output voltage should be similar to the input voltage).
d. Increase the supply voltage slowly until finding the point where the device turns-off (device should turn-off between 12.5 V and 14 V). At this point the output voltage should be close to 0 V.
e. Reduce the supply voltage slowly until finding the point where the device turns back on (device should turn-on between 12 V and 13.5 V). At this point the output voltage should be similar to the input voltage.
5. Short circuit test
a) Attach the oscilloscopes current probe to the input + wire (1A/div, Ch3), and set the input voltage to 12 V.
b) Connect a voltage probe at the input pins (Ch1), and a second one at the output pins (Ch2). Important: use the input - as the common pin (ground) for the voltage probes to avoid grounding problems.
c) Turn-on the switch and make sure the device has turned-on (output voltage should be similar to the input voltage).
d) Set the oscilloscope for a single acquisition function, and apply a short circuit in the output pins by using two small wires.
e) Measure the resulting peak current which should be between 3.5 A and 5.5 A. If the device is the auto-retry version (NIS5102QP2), the waveform should look like Figure 3 (device keeps auto-retrying). If the device is the latch-off version (NIS5102QP1) then the waveform should look like Figure 4 (device turns-off after it reaches thermal limit).
6. Turn-on Delay time and power good delay
a. Attach the oscilloscopes current probe to the input + wire (1A/div, Ch3), and set the input voltage to 12 V.
b. Connect a voltage probe between pin 1 of the device and ground (Ch1), and a second one at the output pins (Ch2) and connect a third one between the PwrGd pin and ground (ch4). Important: use the input - as the common pin (ground) for the voltage probes to avoid grounding problems.
c. Connect an electrolytic capacitor of 1,000 uF (50 V) at the output pins. Set the oscilloscope for a single acquisition function.
d. Turn-on the switch and measure the turn-on delay time by using the oscilloscopes vertical cursors (Ch3). The turn-on delay time is measured from the point where the input voltage is applied to the point where the device starts conducting current (see Figure 5 for better reference). The delay time should be between 2.0 ms and 6.0 ms.
Input Voltage
Output Current
Output Voltage
Device Reaching Thermal Limit
Power Good Input Voltage
Output Current
Output Voltage
Device Reaching Thermal Limit
Power Good Input Voltage
Output Current
Output Voltage
Device Reaching Thermal Limit Input Voltage
Output Current
Output Voltage
Device Reaching Thermal Limit
Figure 3 – Auto-retry version Figure 4 – Latch-off version
e. Make sure that the power signal is being triggered (ch4) and measure the power good delay time. The power good delay time is measured from the point where the output voltage reaches the same level as the input voltage to the point where the power good goes high (Figure 5). The power good delay time should be between 10 ms and 20 ms.
Figure 5 – Turn-on Delay time and power good measurement
Output
Voltage Power Good Input Voltage
Power Good Delay time
Output Current Turn on
Delay time
