HV9910DB2v2
General Description
The Supertex HV9910DB2v2 demo board is a complete high
current, high brightness (HB) LED power driver to supply
a string of LEDs using the HV9910B IC from a universal
AC input voltage. The demo board can be used to test the
performance of HV9910B as a constant current driver to
power a string or multiple strings of LEDs.
HV9910DB2v2 can supply a maximum output current of
350mA to drive LED strings from a wide input voltage – 90 to
265VAC, 50/60Hz. This wide input voltage range makes this
demo board usable all over the world.
Obsolete
Refer to
HV9910BDB2
Off-Line, High Brightness,
LED Driver Demo Board
Specifications
Input voltage:
Load current:
Output voltage:
Input voltage
110VAC
Actual Dimensions: 74.5mm x 42.5mm
220VAC
LED string voltage
Min (V)
10
20
Max (V)
40
50
90VAC – 265VAC
350mA maximum
(adjustable down to 50mA)
For driving LED strings whose voltage is greater than one-
half of the input voltage, see the HV9910DB3v3 datasheet.
The power conversion stage of HV9910DB2v2 consists of a
diode bridge rectifier followed by a current-controlled buck
converter operating at a switching frequency of 50kHz. The
nominal output current of the demo board can be adjusted
to any value between 35mA and 350mA 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.
Board Layout and Connections
90-265Vac
50/60Hz
Enable
Connection
PWM Dimming
(optional)
1
HV9910DB2v2
Instructions
AC Input:
Connect these pins to a standard line voltage
outlet (or a DC voltage between 100 – 375V). Use a two-
wire cable without ground connection.
Note:
Apply AC line voltage as a last step to power up the
LED string, after you connect the LED to the demo board!
Disconnecting the LED string will 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.
The Positive-Marked end is to be connected to the positive
(anode) terminal of LED string, the Negative-Marked end is
to be connected to the negative (cathode) terminal.
Obsolete
Refer to
HV9910BDB2
Testing the HV9910DB2v2
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 an AC voltage at the
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.
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 HV9910B.
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
the converter on and off with a 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.
Linear Dimming Test
Gradual change of current via LEDs is possible by using
the trimming potentiometer R5 placed on the demo board.
The HV9910B has a preset voltage reference level of
250mV when the voltage at the LD pin 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 HV9910DB2v2 is 350mA.
It can be reduced to 50mA using R5.
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.
2
HV9910DB2v2
Schematic Diagram
AC Input
Bill of Materials
Qty
2
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Ref
OUTPUT,
AC INPUT
C1
C2
C3
C4
D1
F1
L1
NTC1
Q1
R1
R2
R3
R4
POT1
U2
U3
-
Obsolete
Refer to
HV9910BDB2
VIN
VDD
LD
RT
GATE
CS
EN
GND
HV9910B
PWMD
GND
Description
Manufacturer
Manufacturer’s Part
Number
ED350/2
Terminal block
Onshore Tech.
Panasonic
Panasonic
Panasonic
Panasonic
Philips
22µF, 400V electrolytic capacitor
0.1µF, 400V Metallized polypropylene
capacitor
2.2µF, 16V SMD 0805 ceramic capacitor
0.1µF, 25V SMD 0805 ceramic capacitor
400V, 1.5A Fast - soft recovery diode
2A, 250VAC Sub miniature fuse
4.7mH, 0.4A Inductor
NTC inrush current limiter
500V, 8A D2PAK MOSFET
464KΩ, 1/8W 0805 SMD resistor
178KΩ, 1/8W 0805 SMD resistor
1KΩ, 1/10W 0805 SMD resistor
0.56Ω, 1%, 1/4W SMD 1206 resistor
Top adjust 5KΩ trim pot
400V, 1A, DF-S, Single phase diode bridge
Universal LED driver
D2PAK heat sink
EEU-EB2G220S
ECW-F4104JB
ECJ-2FB1C225K
ECJ-2VF1E104Z
BYV26B
BK/PCC-2
PCH-45-475
CL-130
IRF840AS
ERJ-6ENF4643V
ERJ-6ENF1783V
ERJ-6ENF1001V
ERJ-8RQFR56V
PVG3A502A01R00
DF04S
HV9910BNG-G
573100d00000
22-28-4030
Cooper Bussman
Coilcraft
Thermometrics
International Rectifier
Panasonic
Panasonic
Panasonic
Panasonic
Murata
Diodes, Inc.
Supertex
Aavid Thermalloy
Molex/Waldom
VDD, PWMD,
3-Position breakaway header
GND
3
嵌入式系统
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