3-TERMINAL 1.5A POSITIVE VOLTAGE REGULATOR

DESCRIPTION

The UTC UL537 is multichannel channel high power factor high

voltage linear constant current LED driver chip.UL537 use linear

constant current technology to set LED light string drive current with

the external resistor. LED twinkle light adopts four period of

structure.The solution can adapt to the application requirement of 3

~ 15 watts of the LED lamps and lanterns with high power factor and

low harmonic distortion.

UL537 have over temperature protection function.When the

system temperature is too high,it reduce the output current to

achieve the effect of lowering the temperature. Over temperature

protection point can be set through the external resistors.

UL537 has the function of the line voltage compensation.When

the input voltage is too high,it reduce the output current to ensure

that the input power does not change with the input voltage. The

amplitude of electric current reducing can be set through the external

resistors.

UL537 has dimmer function, can be set power through external

resistance or external PWM signal and realize various dimming

applications from 1% ~ 100%.

UL537 has a low harmonic distortion mode and can achieve low

harmonic distortion by external resistance divide VAC to connect the

PWM.

FEATURES

* Output constant current :5~100mA

* High precision constant current<±5%

* High PF and low harmonic distortion

* Overheating protection function

* Line voltage compensation function can be set

* Realize stepless dimmer with PWM interface

* Application solutions without EMI problems

* The simple line and low cost power supply