CS51411EVB_TEST_PROCEDURE - 189.0 KB

Test Procedure for the CS51411
02/7/2005
Figure 1: Test Setup
DC Power Supply
100 mA load (33 Ω resistor or
electronic load)
Table 1: Required Equipment
Two Multimeters
1 A load (3.3 Ω resistor or electronic
load)
Oscilloscope
CS51411 demo board
*Note: Resistor loads heat up quickly at higher input voltages.
Test Procedure:
Equipment set up (see Figure 1):
1. Connect DC power supply to positive Vin (J2) and GND (J1).
2. Connect multimeter to measure Iin.
3. Connect another multimeter across J4 (+) and GND (J5) to measure Vout.
Test procedure:
4. Set current limit low on power supply and slowly increase Vin to 6 V.
5. At this point the board should be switching. Check the switch node (J3) with the Oscilloscope.
6. Check 0 mA < IIN < 50 mA.
7. Increase Vin = 12 V. Vout should be around 3.8 V.
8. Connect a 100 mA load (33 Ω resistor) across J4 and J5.
9. Check Vout = 3.3 V. Check switch node (Figure 2). Frequency should be around 260 kHz.
10. Connect a 1 A load (3.3 Ω resistor) across J4 and J5.
11. Check Vout = 3.3 V. Check switch node (Figure 3). Frequency should be around 260 kHz.
12. Note Iin.
13. Short the output. Iin should be between 0 and Iin with 1 A load.
14. Increase Vin= 16 V.
15. Vout = 3.3 V. Note improved switch node duty cycle (Figure 4). Frequency should remain around 260
kHz.
16. Short the shut down pin, SHDNB (J7). Verify the board turns off (J3).
Figure 2: Switch node, Vin = 12 V, 100 mA load
Figure 3: Switch node, Vin = 12 V, 1 A load
Figure 4: Switch node, Vin = 16 V, 1 A load
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