Features
 Constant Output Current:
o V9921 – 20mA
o V9922 – 50mA
o V9923 – 30mA
Universal 85-264VAC Operation
Fixed OFF-Time Buck Converter
Internal 500V Power MOSFET

Applications
Decorative Lighting
Low Power Lighting Fixtures

General Description
The V9921/22/23 are pulse width modulated (PWM)
high-effi ciency LED driver control ICs. They allow effi cient
operation of LED strings from voltage sources ranging up
to 400VDC. The V9921/22/23 include an internal high
voltage switching MOSFET controlled with fi xed off-time TOFF
of approximately 10μs. The LED string is driven at constant
current, thus providing constant light output and enhanced
reliability. The output current is internally fixed at 20mA for
V9921, 50mA for V9922, and 30mA for the V9923. The
peak current control scheme provides good regulation of the
output current throughout the universal AC line voltage range
of 85 to 264VAC or DC input voltage of 20 to 400V