HV9931 Datasheet, PDF (1/7 Pages) Supertex, Inc – UNITY POWER FACTOR LED LAMP DRIVER

HV9931
Initial Release
HV9931 Unity Power Factor LED Lamp Driver
Features
Constant Output Current
Large Step-Down Ratio
Unity Power Factor
Low Input Current Harmonic Distortion
Fixed Frequency or Fixed Off-Time Operation
Internal 450V Linear Regulator
Input and output current sensing
Input Current limit
Enable, PWM and Phase Dimming
Applications
Offline LED Lamps and Fixtures
Street lamps
Traffic Signals
Decorative Lighting
Typical Application Circuit
D1
General Description
The HV9931 is a fixed frequency PWM controller IC designed
to control an LED lamp driver using a single-stage PFC
buckboost-buck topology. It can achieve a unity power factor
and a very high step-down ratio that enables driving a single
high-brightness LED from the 85-264VAC input without a
need for a power transformer. This topology allows reducing
the filter capacitors and using non-electrolytic capacitors to
improve reliability. The HV9931 uses open-loop peak current
control to regulate both the input and the output current. This
control technique eliminates a need for loop compensation,
limits the input inrush current, and is inherently protected
from input under-voltage condition. Capacitive isolation
protects the LED Lamp from failure of the switching MOSFET.
HV9931 provides a low-frequency PWM dimming input that
can accept an external control signal with a duty ratio of 0-
100% and a frequency of up to a few kilohertz. The PWM
dimming capability enables HV9931 phase control solutions
that can work with standard wall dimmers.
L1
D4
C1
D2
L2
VIN
-
C_IN
Q1
D3
VO
~AC ~AC
R_S1
R_S2
+
R_ref1
R_CS1
HV9931
V_IN
GATE
RT
PWMD
CS1
CS2
GND
V_DD
R_CS2
RT
R_ref2
C2
NR081505
1