By Texas Instruments 39
Texas Instruments' TPS92001 family of general LED lighting PWM controllers contains control and drive circuitry required for off-line isolated or non-isolated LED lighting applications.
The controllers can support Phase Cut TRIAC dimming with minimal external components. The controllers can also be implemented for stage conversion where the power factor (PF) exceeds regulatory requirements for lighting. These controllers also have an accessible 5 V reference that could be used to power a microcontroller or other low power peripheral components. The controllers operate in fixed frequency current mode switching with minimal external parts count. Internally implemented circuits include undervoltage lockout featuring startup current less than 100 µA, logic to ensure latched operation, a PWM comparator, and a totem pole output stage to sink or source peak current.