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1235 Bordeaux Drive, Sunnyvale, CA 94089
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Tel: 408-222-8888
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www.supertex.com
1
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 – 30V DC input. The demoboard uses
Supertex’s HV9910B Universal LED driver IC to drive a
buck converter.
The HV9910BDB3 can be configured to operate in either a
constant frequency mode (for driving a single LED) or in a
constant off-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
HV9910BDB3
Low Voltage, High Current, LED Driver Demoboard
Specifications
Parameter
Value
Input voltage
10 - 30VDC
Output voltage -
constant frequency mode
2.0 - 4.5V
Output voltage -
constant off-time mode
4.0 - 8.0V
Maximum output current
1.0A ± 10%
Output current ripple (typ)
20% (peak-peak)
Efficiency (@ 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 source between
PWMD
and
GND
terminals
of
connector J3. The recommended PWM dimming frequency is ≤ 1.0kHz.
+
Short for
constant frequency mode
+
-
Short for
constant off-time mode