peculiarity
Critical conduction mode PFC
Overvoltage protection
Feedback short-circuit protection
70:1 PWM phase dimmer decoding
Analog dimming
Programmable dimming range
Detection of digital angles and dimmers
Holds current dynamically
Smooth dimming transitions
Low-power operation
Biases that start the preregulator
Precision voltage reference
illustrate
The LM3450/50A is a stand-alone phase dimming decoder for a power factor controller (PFC). PFC regulates the output voltage while maintaining a good power factor. The phase angle interpreted by the phase dimming decoder and remapped to the 500Hz PWM output. This device is ideal for implementing dimmable offline LED drivers for 10 - 100W loads.
Phase dimming decoders have some unique features. I/O mapping provides flexibility in programmable design, while a dynamic filter and variable sample rate provide smooth and uniform brightness. A dynamic hold circuit ensures that the angle of the phase dimmer is correctly decoded while minimizing additional power loss.
The LM3450A is a circuit operating anomaly identical to the LM3450. The LM3450 dynamically holds current for sampling while it is constantly on the LM3450A. The difference between these two devices is defined for each suitable application. The following are general guidelines for choosing the right device:
Any 120V design with P OUT> 15W - LM3450A
Anything with P> 25W 230V designed - LM3450A
Level 2 120V design with P OUT 230V 2, Stage Design with P OUT
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Dimming spotlights, troffers, lowbays
Large size bulbs
SSL for indoor and outdoor areas
Power supply PFC