Agilent Technologies N3280A manual Transient Response Tests, Current Priority Ripple and Noise

Performance and Calibration Procedures

Current Priority Ripple and Noise

Periodic and random deviations (PARD) in the output combine to produce a residual ac current, as well as an ac voltage superimposed on the dc output. PARD is specified as the rms output current in a frequency range specified in Appendix A.

NOTE: The voltage limits in Current Priority Mode are not programmable.

Action Program Commands

1.Turn off the dc source and connect the output as shown in Figure B-1d to an ac rms voltmeter. Remember to include a 50 ohm series resistor at the dc source end of the cable. Also connect a 16k ohm load resistor across the HI and LO terminals.

2.Turn on the dc source and program the Current Priority mode. Program the current to the maximum value (0.5mA).

3.Read back the N3280A status to be sure that it’s in the CC mode. This query should return a Bit value of “8” for CC mode.

4.Divide the voltage reading ac rms voltmeter by 16k (the value of the load resistor). The result should be within the limit in the performance test record card under Current Priority PARD Current.

“OUTP ON,(@1)” “SOUR:FUNC:MODE CURR,(@1)” “CURR 0.0005,(@1)”

“STAT:OPER:COND? (@1)”

Transient Response Tests

Voltage Priority, Transient Recovery Time

This test measures the time for the output voltage to recover to within the specified value following a 50% change in the load current using an RC network of a 10∝F capacitor and 0.2 ohm resistor across the output. The test must be performed in all three bandwidths: 10kHz, 20kHz, and 30kHz.

Action

1.Turn off the dc source and connect the output as in Figure B-1e with the oscilloscope across the HI and LO sense terminals. Remember to connect the RC network (10∝F & 0.2 ohm).

2.Turn on the dc source and program the Voltage Priority mode (this is the default mode). Program the output voltage to the full-scale value (10.0V), the current to the maximum value (0.5A), and the bandwidth to 10kHz.

3.Program the Electronic Load as follows:

Input current = 0.25A	Transient current level = 0.5A
Transient frequency = 2kHz	Current slew rate = 0.167A/∝s
Transient duty cycle = 50%	Turn the transient generator on.

4.Adjust the oscilloscope for a waveform similar to that in Figure B-2. The output voltage should return to within ±40mV in less than 60∝s, 45∝s, or 35∝s following a 0.25A to 0.5A load change. Check both loading and unloading transients by triggering on the positive and negative slope. Record the voltage at time “t” in the performance test record card under Voltage Priority Transient Response Voltage.

5.Repeat steps 2 through 4 for the 20kHz and the 30kHz bandwidths.

Program Commands

“OUTP OFF,(@1)”

“OUTP ON,(@1)” “SOUR:FUNC:MODE VOLT,(@1)” “VOLT 10,(@1)” “CURR:LIM 0.5,(@1)” “VOLT:ALC:BWID 10000,(@1)”

Loading

ttttTransient

v		t
	t	v

Unloading

Transient

“VOLT:ALC:BWID 20000,(@1)” “VOLT:ALC:BWID 30000,(@1)”

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