Datasheet

Test Procedure

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6 Test Procedure

6.1 Load Regulation Measurement Procedure

1. Ensure the LOAD is set to constant-current mode and to set to sink 0 A.

2. Increase V

SOURCE

from 0 V to 4.5 V

. VOUT should be in regulation once V1 shows VIN is 4.5 V or

greater.

3. Vary LOAD from 0 A to 30 A. VOUT should remain within regulation per Table 1.

6.2 Line Regulation Measurement Procedure

1. Set LOAD to constant-current mode and to set to sink 30 A.

2. Vary V

SOURCE

so that V1 measures 4.5 V

to 15.0 V

. VOUT should remain within regulation per

Table 1.

6.3 Control Loop Gain and Phase Measurement Procedure

1. Connect a 1-kHz to 1-MHz isolation transformer to CHA and CHB, referenced to TP15.

2. Connect the input signal amplitude measurement probe (Channel A) to CHA with the ground lead

connected to TP15.

3. Connect the output signal amplitude measurement probe (Channel B) to CHB with the ground lead

connected to TP15.

4. Inject a 25-mV, or less, signal across CHA and CHB through the isolation transformer.

5. Sweep the frequency from 100 Hz to 1 MHz with 1-Hz or lower post filter.

6. Control loop gain can be measured by 20 x LOG(ChB/ChA)

7. Control loop phase is measured by the phase difference between ChA and ChB.

8. Disconnect the isolation transformer from the EVM before making other measurements. The signal

injection into the feedback may interfere with the accuracy of other measurements.

6.4 Enabling/Disabling the Outputs

1. The User may disable the output by shorting TP13 (EN/SS) to ground.

2. Enable the output by removing the short from TP13 (EN/S) and leaving TP13 open.

6.5 Equipment Shutdown

1. Shut down LOAD.

2. Shut down V

SOURCE

3. Shut off fan.

Dual-Phase, Single-Output, Synchronous Buck Converter SLUU926–May 2012

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