HV9925 Datasheet, PDF (1/10 Pages) Supertex, Inc – Programmable-Current LED Lamp Driver IC with PWM Dimming

HV9925
Initial Release
Programmable-Current LED Lamp Driver IC
with PWM Dimming
Features
 Programmable Output Current to 50mA
 PWM Dimming / Enable
 Universal 85-264VAC Operation
 Fixed OFF-Time Buck Converter
 Internal 500V Power MOSFET
 Over Temperature Protection with Hysteresis
Applications
 Decorative Lighting
 Low Power Lighting Fixtures
Typical Application Circuit
General Description
The HV9925 is a pulse width modulated (PWM) high-efficiency
LED driver control IC with PWM dimming capabilities. It
allows efficient operation of high brightness LED strings from
voltage sources ranging up to 400VDC. The HV9925 includes
an internal high-voltage switching MOSFET controlled with a
fixed off-time T_OFF of approximately 10µs. The LED string is
driven at constant current, thus providing constant light output
and enhanced reliability. Selecting a value of a current sense
resistor can externally program the output LED current of the
HV9925. 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. The HV9925 is designed with a built in thermal
shutdown to prevent excessive power dissipation in the IC.
~
AC
~
BR1
C_IN
C_O
LED₁
LED_N
D1
L1
Enable
C_DD
6
3
Drain
PWMD
7
Drain
8
Drain
HV9925
4 VDD
U1
RSENSE
1
GND
2
R_SENSE
NR021506
1