Supertex inc.
Supertex inc. ● 1235 Bordeaux Drive, Sunnyvale, CA 94089 ● Tel: 408-222-8888 ● www.supertex.com
HV9967DB1
General Description
The HV9967DB1 demoboard is a high-brightness LED
driver designed to drive 4 LEDs in series at currents up to
350mA from a 20 - 60V DC input. The demoboard uses the
Supertex’s HV9967 in a buck configuration in a constant off-
time mode.
The HV9967DB1 LED driver features tight regulation of the
LED current within a few milliamps over the entire range of
the input voltage (i.e. 20 - 60VDC). The LED current accuracy
is almost insensitive to the passive component tolerances,
such as the output filter inductance or the timing resistor.
PWM dimming can be achieved by applying a pulse-width-
modulated square wave signal between the PWMD and
GND pins.
4W LED Driver Demoboard
with Accurate Average-Mode Constant Current Control
Connection Diagram
Connect the LED string between LED+ (Anode of
LED string) and LED- (Cathode of LED string).
Connect the PWMD terminal to the VDD terminal
to enable the LED driver if PWM dimming is not re-
quired.
1.
2.
Connect the input DC voltage between the VIN+
and VIN- terminals.
3.
Connections
Parameter Specification
Input voltage 20 - 60 VDC
Output voltage 10 -15VDC (4 x LEDs)
Output current 350mA ± 5%
Output current ripple
20% pk-pk
(Typical, depending on
the type of LED)
Switching frequency Variable with constant
TOFF = 5µs ± 20%
Full load efficiency Typical 80% minimum
Output short circuit protection Included, hiccup mode
Specifications
VLED (+)
VLED (-)
VIN (+) VIN (-) VDD PWMD GND
2
HV9967DB1
Supertex inc. ● 1235 Bordeaux Drive, Sunnyvale, CA 94089 ● Tel: 408-222-8888 ● www.supertex.com
Circuit Schematic
Typical Characteristics
VDD
PGND
PWMD
RSENSE
81
3
6
4
2
RT
AGND
7
SW
U1
HV9967
C4
47µF
100V
C3
1.0µF
100V
C1
1.0µF
16V
R2 1k0
R4 52k3 1%
R1
0R68
1/4W
TP1
TP2
J3
3
2
1
1
2
2
1
C2
4.7µF
25V
D1
B1100
+
L1
330µH
J1
J2
Output Current vs. Input Voltage (@ VO = 12V)
0.300
0.320
0.340
0.360
0.380
Efficiency vs. Input Voltage (@VO = 12V)
80%
82%
84%
86%
88%
90%
Input Voltage (V)
Switching Frequency vs. Input Voltage (@VO =12V)
20
60
100
140
180
10 20 30 40 50 60 70
OFF-Time vs. Input Voltage (@ VO = 12V)
3.0
4.0
5.0
6.0
10 20 30 40 50 60 70
10 20 30 40 50 60 70
10 20 30 40 50 60 70
Input Voltage (V)
Input Voltage (V)
Input Voltage (V)
Output Current (A)
Switching Frequency (kHz)
Off Time (µs) Efficiency (A)
3
HV9967DB1
Supertex inc. ● 1235 Bordeaux Drive, Sunnyvale, CA 94089 ● Tel: 408-222-8888 ● www.supertex.com
Normal Operation:
Fig.1-4 shows the waveforms during normal operation at loading of 4 x LED in series at different input.
Fig.1: 20V Input Fig.2: 30V Input
Fig.3: 40V Input Fig.4: 60V Input
Ch1 (Blue) : Drain-Source Voltage (10V/div)
Ch4 (Green) : Output LED Current (50mA/div)
Time Scale : 4µs/div
4
HV9967DB1
Supertex inc. ● 1235 Bordeaux Drive, Sunnyvale, CA 94089 ● Tel: 408-222-8888 ● www.supertex.com
PWM Dimming Operation:
PWM dimming operation at 4xLED in series with an external TTL square wave signal is shown in Figs.5 - 7. Fig.5
shows the overall operation of the circuit with PWM dimming input and Fig.6 and 7 show the rise and fall times of
the LED current during PWM dimming.
Fig.5: PWM Dimming at 24V
Fig.6: PWM Dimming at 24V – Rise Time Fig.7: PWM Dimming at 24V – Fall Time
Ch1 (Blue) : Drain-Source Voltage (2V/div)
Ch4 (Green) : Output LED Current (50mA/div)
Time Scale : 2ms/div
Ch1 (Blue) : Drain-Source Voltage (2V/div)
Ch4 (Green) : Output LED Current (50mA/div)
Time Scale : 2µs/div
Supertex inc. does not recommend the use of its products in life support applications, and will not knowingly sell them for use in such applications unless it receives
an adequate “product liability indemnification insurance agreement.” Supertex inc. does not assume responsibility for use of devices described, and limits its liability
to the replacement of the devices determined defective due to workmanship. No responsibility is assumed for possible omissions and inaccuracies. Circuitry and
specifications are subject to change without notice. For the latest product specifications refer to the Supertex inc. (website: http//www.supertex.com)
©2010 Supertex inc. All rights reserved. Unauthorized use or reproduction is prohibited. Supertex inc.
1235 Bordeaux Drive, Sunnyvale, CA 94089
Tel: 408-222-8888
www.supertex.com
5
HV9967DB1
Bill of Materials
010311
Item# Qty Ref
Des Description Package Manufacturer Manufacturer’s
Part Number
1 1 C1 1µF 16V X7R
ceramic chip capacitor SMD 0805 Murata GRM21BR71C105KA88L
2 1 C2 4.7µF 25V X7R
ceramic chip capacitor SMD 1206 Murata GRM31CR71E475KA88L
3 1 C3 1µF 100V X7R
ceramic chip capacitor SMD 1210 Murata GRM32CR72A105KA88L
4 1 C4 47µF 100V 105deg.C
electrolytic capacitor SMT Panasonic EEVFK2A470Q
5 1 D1 100V 1A schottky rectifier SMA Diodes Inc B1100-13-F
6 2 J1, J2 2 position 5.08mm pitch
vertical header Thru-hole Molex 10-08-5021
7 1 J3 3 position 2.54mm pitch
vertical header Thru-hole Molex 22-03-2031
8 1 L1 330µH 0.39A 0.45A sat inductor SMT Wurth
Elektronik 744 777 233
9 1 R1 0R68 1/4W 1% chip resistor SMD 1206 - -
10 1 R2 1K0 1/8W 1% chip resistor SMD 0805 - -
11 1 R4 52K3 1/8W 1% chip resistor SMD 0805 - -
12 1 U1 Universal LED Driver MSOP-8 Supertex HV9967MG-G
