Texas Instruments UCC2977EVM - Manual (Page 22)

Test Setup
3-4
3.1.3 Burst Dimming Test
Connect pin 2 to pin 3 of JP1 to disable the open-lamp detection circuit during
burst dimming. A low frequency ( >100 Hz) 0~4 V square wave applied to BD
modulates the lamp current.
Figure 3–3. Test Setup for Burst Dimming
Power Supply
Function
Generator
+ –
CCFL
Lamp