PI2007-EVAL2 datasheet(6/9 Pages) VICOR

6 / 9 page

Picor Corporation • picorpower.com

PI2007-EVAL2 User Guide Rev. 1.1 Page 6 of 9

Before initial power-up follow these steps to configure

the evaluation board for specific end application

requirement:

Note that PI2007 will not turn off the MOSFET unless it

senses current in the reverse direction through the

MOSFET. This means that if both input power source

are turned on and both MOSFET are in on condition,

then one off the power source is turned off, the

associated PI2007 will not turn off the MOSFET unless

the power source sinks current from the output when it

turns off and cause a reverse current in the MOSFET that

generates negative voltage equal or greater than 6mV.

Control Circuitry Bias:

PI2007 control circuitry and the gate driver for the

MOSFET are biased through the VC pin. An internal

regulator clamps VC pin voltage with respect to PG

pin (VVC-PG) to 11.7V typically. In a 12V application

the input voltage can vary between 10V and 14V

which is higher than the VC clamp voltage. A bias

resistor between VC pin and input voltage is required

to accommodate VC clamp.

PI2007-EVAL2 has two options for the bias resistor. A

420Ω internal resistor connected between VC pin

and VR pin, or 430Ω 1% external resistor (R3 and R4).

R3 and R4 installed in PI2007-EVAL2. If the internal

resistor is desired for the test, remove R3 and R4,

and install 0Ω resistor (jumper) for R7 and R8 to

connect PI2007 VR pin to its input.

Hook Up of the Evaluation Board

3.1. Connect the positive terminal of PS1 power

supply to Vin1. Connect the ground terminal of

PS1 to its local Rtn. Set the power supply to

12V. Keep PS1 output disabled, off.

3.2. Connect the positive terminal of PS2 power

supply to Vin2. Connect the ground terminal of

PS2 to its local Rtn. Set the power supply to

12V. Keep PS2 output disabled, off.

3.3. Connect the logic power supply PS3 positive

terminal to VL1 and VL2. Connect the ground

terminal of this power supply to a Rtn terminal.

Set the power supply to the desired logic

voltage level, 3.3V or 5V. Keep PS3 output

disabled, off.

3.4. Connect the electronic load to the output

between Vout and its local Rtn. Set the load

current to 5A.

3.5. Enable (turn on) PS1 power supply output.

3.6. Enable (turn on) PS3 power supply output.

3.7. Turn on the electronic load.

3.8. Verify that the load voltage (Vout) is few

millivolts below 12V. This verifies that the Q1

MOSFET is in conduction mode.

3.9. Verify that Vin2 is low. This verifies that Q2

MOSFET is off.

3.10. Enable (turn on) PS2 output.

3.11. 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.

3.12. Disable (turn off) PS1, PS2, and PS3 outputs.

3.13. Enable (turn on) PS2 output then Enable and PS3

outputs.

3.14. Verify that Vout is few millivolts below 12V. This

verifies that the MOSFET Q2 is in conduction

mode.

3.15. D2 should be off. This verifies that there is no

fault condition.

3.16. Verify that Vin1 is low. This verifies that the

MOSFET (Q1) is off.

Input short circuit test:

PI2007 has a very fast response (80ns) to a reverse current

(Input short) fault condition. Measuring a short period

event requires attention to the test set-up. Before

proceeding, consider the following:

4.1. 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 PI2007

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.

4.2. Do not install Input capacitors (C1 and/or C2) in

this test.

4.3. Output capacitor (C7) should be installed.

4.4. Place the scope probes very close to the MOSFET

drain and source to measure Vout and Vin, and

PI2007-EVAL2 bảng dữ liệu(PDF) 6 Page - Vicor Corporation

PI2007-EVAL2 bảng dữ liệu(HTML) 6 Page - Vicor Corporation

Html Pages

1 2 3 4 5 6 7 8 9

bảng dữ liệu tải về

Link URL