Doc.# DSDB-HV9910BDB3
A032813
HV9910BDB3
General Description
The HV9910BDB3 demoboard is a high current LED driver 
designed to drive one LED or two LEDs in series at currents 
up to 1.0A from a 10 – 30VDC input. The demoboard uses 
Supertex’s  HV9910B  Universal  LED  driver  IC  to  drive  a 
buck converter.
The HV9910BDB3 can be congured to operate in either a 
constant frequency mode (for driving a single LED) or in a 
constant o-time mode (for driving two LEDs).
The output current can be adjusted in two ways – either 
with  linear  dimming  using  the  onboard  potentiometer  or 
with PWM dimming by applying a TTL – compatible square 
wave signal at the PWMD terminal. Using linear dimming, 
the output current of the HV9910DB1 can be lowered to 
about  0.01A  (note:  zero  output  current  can  be  obtained 
only by PWM dimming).
Connection Diagram
Low Voltage, High Current, 
LED Driver Demoboard
Specications
Parameter Value
Input voltage 10 - 30VDC
Output voltage - 
constant frequency mode 2.0 -  4.5V 
Output voltage -
constant o-time mode 4.0 -  8.0V
Maximum output current 1.0A ± 10%
Output current ripple (typ) 20% (peak-peak)
Efciency (@ 12V input) 86% (for one LED)
93% (for two LEDs)
Open LED protection yes
Output short circuit protection no
Dimensions 48.2mm X 29.0mm
Connections
1.    Input  Connection  -  Connect  the  input  DC  voltage 
between VIN and GND terminals of connector J1 as shown 
in the connection diagram.
2.    Output  Connection  -  Connect  the  LEDs  between 
LED+  (anode  of  LED  string)  and LED-  (cathode  of  LED 
string) of connector J2.
  a.  If the load is one LED, short the RT and FREQ 
terminals of connector J4 using a jumper.
  b.  If the load is two LEDs, short the RT and OFFT 
terminals of connector J4 using a jumper.
3.  PWM Dimming Connection
  a.  If no PWM dimming is required, short PWMD and 
VDD terminals of connector J3.
  b.   If  PWM  dimming is  required,  connect  the TTL-
compatible  PWM  sourc  between  PWMD  and  GND 
terminals  of  connector  J3.  The  recommended  PWM 
dimming frequency is ≤ 1.0kHz.
+
Short for constant
frequency mode
+
-
Short for 
constant o-time mode