HV9921 Datasheet, PDF (1/10 Pages) Supertex, Inc – 3-Pin Switch-Mode LED Lamp Driver IC

HV9921/22
Initial Release
3-Pin Switch-Mode LED Lamp Driver IC
Features
Constant Output Current:
o HV9921 – 20mA
o HV9922 – 50mA
Universal 85-264VAC Operation
Fixed OFF-Time Buck Converter
Internal 500V Power MOSFET
Applications
Decorative Lighting
Low Power Lighting Fixtures
General Description
The HV9921/22 are pulse width modulated (PWM)
high-efficiency LED driver control ICs. They allow
efficient operation of LED strings from voltage
sources ranging up to 400VDC. The HV9921/22
include an internal high-voltage switching MOSFET
controlled with fixed off-time T_OFF 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 HV9921 and 50mA for HV9922. 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.
Typical Application Circuit
~
AC
~
BR1
C_IN
C₀
LED₁
-
LED_N
D1
L1
3 V_DD
U1
DRAIN 1
HV9921/22
C_DD
GND
2
NR042205
NR030805