ON Semiconductor has introduced two new LED drivers - the NCL30051 stage, power factor correction (PFC) and resonant half bridge driver and the NCL30160 dimmable constant current step-down (buck) LED driver.

The NCL30051 is a step-down DC-DC converter/LED driver that combines a critical conduction mode (CrM), PFC controller and a half-bridge resonant controller with a built-in 600 volt (V) driver, is optimised for off-line power supply applications.

The chip’s half-bridge stage operates at a fixed frequency. Regulation is achieved by adjusting the PFC stage output voltage. The device integrates open feedback loop protection, plus PFC overvoltage and undervoltage detection mechanisms, as well as an adjustable frequency oscillator which can be set at up to 75kHz.
 
The NCL30160, a switching regulator for high power LEDs, takes the constant voltage delivered by the NCL30051-enabled power supply and steps down the voltage to provide a constant current across the LED string. 

An 98% efficiency is achieved by using the low 55mΩ internal mosfet and the ability to operate at 100% duty cycle. This constant current device operates with an input voltage range from 6.3 V to 40 V, which makes it suitable for industrial and automotive applications. 

Switching frequencies is up to 1.4MHz.

Both the NCL30051 and the NCL30160 have operating junction temperature ranges of -40 to +125 deg C.
 
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