This application note contains the benefit
of using UCC25640X at LED lighting PSU. The key benefit used previously is repeated
here.
- UCC25640X HS pin has wide dv/dt sensing range and is very helpful for LED lighting
PSU to optimize the resonant tank design and also adding the CDS for EMI
performance.
- The cost is the top priority for
customer, so UCC256402/4 also supports the HV startup to charge the Vcc capacitor by
itself, then the customer can save the cost of Auxpower.
- LED lighting PSU also needs to support wide ambient temperature, and causes the Vcc
equivalent capacitance drifted so higher Vcc startup voltage helps to avoid Vcc
dropped to UVLO during startup.
- LED lighting PSU needs to avoid the burst mode to cause the LED flicking, but still
needs to minimize the no load power consumption, so programmable burst mode
threshold is helpful to balance the trade-off.
- UCC25640x also has diversity version to fulfill different requirement.