HV9910DB1
Off-Line High Brightness LED Driver Demo Board
Introduction
The Supertex HV9910DB1 demo board is a
complete high current, high brightness (HB) LED
power driver to supply a string of LEDs using the
HV9910 IC. The demo board can be used to test the
performance of the HV9910 as a constant current
driver to power a string or multiple strings of LEDs.
HV9910DB1 can supply a maximum output current
of 1.5A to drive LED strings that are 40V or less from
a 120V, 60Hz input. It has an efficiency of about
90% at full load and operates typically at 85% input
power factor.
The power conversion stage of HV9910DB1
consists of a passive power factor corrector circuit
followed by a current-controlled buck converter
operating at a switching frequency of 80kHz. The
nominal output current of the demo board can be
adjusted to any value between 350mA and 1.5A
using the on-board trimming potentiometer. PWM
dimming can be achieved by applying a pulse-width-
modulated square wave signal between the PWMD
and GND pins.
Actual Size: 100.5mm x 57.5mm
Specifications
Input
Load Current
90VAC – 135VAC
1500mA maximum
(adjustable down to 350mA)
40V maximum
50kHz
90% (typ.)
LED String Voltage
Switching Frequency
Efficiency
Board Layout and Connections
90-135Vac
60Hz
Enable
Connection
PWM Dimming
(optional)
A082804
HV9910B1
Instructions
AC Input:
Connect these pins to a standard 120V
line voltage outlet (or a DC voltage between 100V –
200V). Use a two-wire cable without ground
connection.
Note:
Apply AC line voltage as a last step to power
up LED string, after you connect LED to demo
board! Disconnected LED string would not damage
the board, however it is not advisable.
ATTENTION: The LED demo board and
connected LEDs are not isolated from line
voltage. None of the demo board terminals are
galvanic isolated from the AC line voltage. All
measuring instruments, as scopes and meters
must be isolated from ground (floating) using
isolating transformers.
OUTPUT:
These two terminals are the output
terminals of the converter and must be connected to
the LED string. Positive-Marked end is to be
connected to positive (anode) terminal of LED string,
Negative-Marked to be connected to the negative
(cathode) terminal.
Note:
Both terminals will have active live voltage
when input AC line is applied!
VDD:
This pin is connected to the VDD pin of the
HV9910. The typical voltage on the pin is 7.6V.
This voltage can be used to drive any additional
circuitry required.
Please see the datasheet
regarding the output current capability at the VDD
pin.
GND:
This pin is connected to the Ground
connection of the buck converter.
PWMD:
This terminal can be used to either
enable/disable the converter or to apply a PWM
dimming signal.
To just enable the converter, connect the PWMD pin
to the VDD pin. Disconnecting the PWMD pin will
cause the circuit to stop.
PWM dimming of the LED light can be achieved by
turning on and off the converter with low frequency
50Hz to 1000Hz TTL logic level signal. Changing the
Duty Ratio of the signal changes the effective
average current via the LEDs, changing the light
emission.
Note: In the case of PWM dimming, the PWMD
pin should not be connected to the VDD pin.
Also, the signal generator or the device applying
the signal to PWMD pin must be isolated from
the input mains.
Testing HV9910DB1
Connect the LED string to the output terminals.
Check the polarity of the LED connection, anode
end of the string should be connected to the positive
output, cathode should be connected to the negative
output. Connect the AC input to the input terminals
(there is no polarity to be considered). Short the
PWMD pin to VDD. Apply a 120VAC at input
terminals and the LED string should start to glow.
An ammeter can be connected in series with the
LEDs to measure the output current. The current
level can then be changed by adjusting the trimming
potentiometer.
Note: Make sure the LED string is fully functional.
One way is to use a DC current limited source to test
the string. A 40V/300mA power supply should be a
good solution.
Open LED Test:
After the initial test of functionality, the demo board
can be tested at open LED string. The test is non-
destructive and not time restricted. Disconnect one
end of the LEDs and power up the demo. There will
be no light emission and the AC current withdrawn
from the line will be very low. There is no switching
at the switching node.
Linear Dimming Test:
Gradual change of current via LEDs is possible by
using the trimming potentiometer R5 placed on the
demo board. The HV9910 has a preset voltage
reference level of 250mV when the voltage at the LD
oin of the IC is above 250mV. The external resistor
divider consisting of R2, R3 and potentiometer R5
can change that level by pulling down the pin LD
below 250mV, reducing the LED string current in
linear fashion.
The maximum output current of the HV9910DB1 is
1.5A. It can be reduced using R5 or can be changed
to ½ of it by removing one of the two current sense
resistors R4 and R6.
PWM Dimming Test:
During normal demo board operation, by applying a
PWM TTL level signal to pin PWMD, the output
current through the LEDs can be changed in PWM
fashion in a 0 to 100% range. In this dimming mode,
the output current has normally two levels – zero
and nominal current, except at very low duty ratios
where inductor current cannot ramp up to the
nominal value within the short time.
A082804
2
HV9910B1
Schematic Diagram
V+
V+
C11
C1
100uF, 160V
D21
FR1G-13
F1
3
4
AC INPUT
1
2
2A, 125V
U2
1uF, 250V
VDD
U3
1
D18
BYV26B
R1
464K
Q5
Vds 1
J11
1
2
Conn_2pin
L2
C12
NTC1
R
C13
0.1uF, 250V
AC1
AC2
POS
NEG
D20
FR1G-13
R2
178K
R5
5K
C8
12
13
9
C7
0.1uf, 25V
Vin
Vdd
HD
Gnd
EN
Rosc
Gate
CS
14
8
4
2
HV9910
1000uH, 2A
IRF840 (D2PAK)
2
1
0.1uF, 250V
L1
C4
2.2uF, 16V
J16
J17
J18
J19
D19
FR1G-13
100uF, 160V
GND
PWMD
R3
1K
R4
0.27
R6
0.27
HV9910DB1 – Bill of Materials
Quantity RefDes
2
2
1
1
1
2
1
3
1
1
1
1
1
1
1
1
2
1
1
1
1
1
J11,AC INPUT
C1,C8
C4
C7
C11
C12,C13
D18
D19,D20,D21
F1
L1
L2
NTC1
Q5
R1
R2
R3
R4,R6
R5
U1
U2
Description
Manufacturer
Onshore Tech.
Panasonic
Panasonic
Panasonic
Panasonic
Panasonic
Philips
Diodes, Inc.
Littelfuse Inc
Coilcraft
Coilcraft
Thermometrics
International Rectifier
Panasonic
Panasonic
Panasonic
Panasonic
BC components
Supertex
Diodes, Inc.
Aavid Thermalloy
Molex/ Waldom
Manufacturer's Part Number
ED555/2DS
EEU-EB2C101
ECJ-2FB1C225K
ECJ-2VF1E104Z
ECW-F2105JB
ECQ-U2A104MV
BYV26B
FR1G-13
0460002.UR
BU9-2820R5B
PCV-2-105-02
CL-130
IRF840AS
ERJ-6ENF4643V
ERJ-6ENF1783V
ERJ-6ENF1001V
ERJ-14RQJR27U
CT-94W-502
HV9910NG
DF04S
573100d00000
22-28-4030
Terminal Block
100uF, 160V Electrolytic Capacitor
2.2uF, 16V SMD 0805 ceramic capacitor
0.1uf, 25V SMD 0805 ceramic capacitor
1uF, 250V Metallized Polypropylene capacitor
0.1uF, 250V Metallized Polyester capacitors
400V, 1.5A Fast - Soft recovery diode
400V, 1A SMB Fast Recovery Diode
Slow Blo SMD 125V, 2A fuse
Low profile common mode choke
1000uH, 2A inductor
NTC inrush current limiter
500V, 8A D2PAK Mosfet
464K, 1/8W 0805 SMD resistor
178K, 1/8W 0805 SMD resistor
1K, 1/10W 0805 SMD resistor
0.27 ohm, 1/4W 1210 resistor
Top adjust 5K trim pot
Universal LED driver
400V, 1A, DF-S, Single Phase diode bridge
D2PAK Heat Sink
VDD,PWMD, GND 3 Position Breakaway Header
5
A082804
3
RF/Wirelessly
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