Constant Current (Cc) Tests; Test Setup; Test Procedures - Agilent Technologies 668xA Service Manual

Constant Current (CC) Tests

Test Setup

Connect the appropriate current monitoring resistor (see Table 2-l) as shown in Fig. 2-3. The accuracy of the resistor must
be as specified in the table.

Test Procedures

The test procedures are given in Table 2-5. The tests are independent and may be performed in any order. The CC tests are:
•
Current Programming and Readback Accuracy.
•
CC Load Effect.
•
CC Source Effect.
•
CC Noise (PARD).
This test verifies that the current programming and readback are within specification.
1 Turn off the power supply and connect the current monitoring resistor as
shown in Fig. 2-3. Connect a DVM across the resistor .
2 Turn on the power supply and program the output for 5 volts and 0
amperes.
3 Short the load.
4 Observe the DVM voltage reading. Divide this by the resistance of the
current monitor resistor. Record the result as the Low Current value.
5 Record the front panel display readback.
6 Program output current to full scale (see Table 2-2).
7 Repeat Steps 4 and 5.
Table 2-5. Constant Current (CC) Tests
Action
Current Programming and Readback Accuracy
Normal Result
Value within specified Low Current
limits.
Value within specified readback limits.
Both current readings within specified
High Current and readback limits.
Verification 19