Vicor PI5101-EVAL1 3.3V/60A High Side Active ORing Evaluation Board - Manual (Page 7)

Picor Corporation • picorpower.com PI5101-EVAL1 User Guide Rev 1.0 Page 7 of 12
5. Initial Functional Test
5.1. Enable (turn ON) PS1 power supply output.
5.2. Turn on the electronic load.
5.3. Verify that the electronic load input voltage
reading is one diode voltage drop below 3.3 V.
5.4. Enable (turn ON) PS3 power supply output.
5.5. Verify that the electronic load voltage reading
increases to a few millivolts below 3.3 V. This
verifies that the MOSFET is in conduction mode.
5.6. LED D1 should be off. This verifies that there is
no fault condition.
5.7. Reduce PS1 output voltage to 2 V,
5.8. LED D1 should turn on, this verifies that the
circuit is in an under-voltage fault condition.
5.9. Increase PS1 output to 3.3 V, LED D1 should
turn off, then increase PS1 output to 4 V, LED
D1 should turn on indicating an over-voltage
fault condition
5.10. Verify that Vin2 is at 0V. This verifies that the
PI2001 (U2) MOSFET (M2) is off.
5.11. Enable (turn ON) PS2 output.
5.12. Verify that both PS1 and PS2 are sharing load
current evenly by looking at the supply current.
Power supplies output may need adjustment to
set current sharing between the supplies.
5.13. Disable (turn OFF) PS1, PS2 and PS3 outputs.
5.14. Enable (turn ON) PS2 output then Enable PS3
output.
5.15. Verify that the electronic load voltage reading is
few millivolts below 3.3 V. This verifies that the
PI2001 (U2) MOSFET (M2) is in conduction
mode.
5.16. LED D2 should be off. This verifies that there is
no fault condition.
5.17. Reduce PS2 output voltage to 2 V,
5.18. LED D2 should turn on, this verifies that the
circuit is in an under-voltage fault condition.
5.19. Increase PS2 output to 3.3 V, LED D2 should
turn off, then increase PS2 output to 4 V, LED
D2 should turn on indicating an over voltage
fault condition.
5.20. Verify that Vin1 is at 0V. This verifies that the
PI2001 (U1) FET (Q1) is off.
6. PI5101 R
DS(on)
Measurement:
6.1. The PI5101 R
DS(on)
can be measured with a
voltmeter between the test point S1 and test
point D1 Kelvin connection for M1 and between
the test point S2 and test point D2 Kelvin
connection for M2. The potential between test
point S1 and test point D1 is Drain-to-Source
voltage difference of M1 and the R
DS(on)
is:
Where:
: Drain-to-Source voltage difference
: Input current.
Note: The R
DS(on)
value is temperature dependent and the
junction temperature increases directly
proportional to power dissipation.
7. Input short circuit test:
PI2001 has a very fast response (160ns) to a reverse
current (Input short) fault condition. Measuring such
short period of event is critical and before the set-up is
completed, consider the following:
7.1. To emulate a real application, the BUS supplies
for this test should have a solid output source
such as a DC-DC converter that supplies high
current and can be connected very close to the
evaluation board to reduce stray parasitic
inductance. Or use the prospective supply
sources of the end application where the PI5101
and/or PI2001 will be used. Typical bench power
supplies have slow response to output load
change. In this test when the power supply
output is shorted and then released, the bench
power supply may produce high output voltage
with high current capability that may damage the
device under test.
7.2. Do not install Input capacitors (C4 and/or C5) in
this test.
7.3. Output capacitor (C3) should be installed.
7.4. Place the scope probes very close to the MOSFET
drain and source to measure Vout and Vin, and
make sure that the scope ground leads are very
short. You may use a close by ground pad for the
scope probe return, such as C4, C5, C6 and C7
Gnd pads.
7.5. Apply a short at one of the inputs (Vin1 or Vin2)
when both controllers (U1 and U2) are on, PS1,
PS2 and PS3 are enabled. The short can be
applied electronically using a MOSFET connected
between Vin and Gnd or simply by connecting
Vin to Gnd. Then measure the response time
between when the short is applied and the
MOSFET is disconnected (or turned off). An
example for PI2001 response time to an input
short circuit is shown in Figure 5.