HV9930DB2 User Guide

Supertex inc.
HV9930DB2
Boost-Buck High Brightness
LED Driver Demoboard
General Description
The HV9930DB2 is a LED driver demoboard capable
of driving 4 3-watt LEDs in series from an input of 9
- 25V DC. The demoboard uses Supertex’s HV9930
in a boost-buck topology. The converter has excellent
line and load regulation over the entire input and
output voltage range. The full load efficiency of the
converter is typically greater than 80%. The converter
is also protected against open LED and output short
circuit conditions.
Specifications
Parameter
Value
Input voltage (steady state):
Output LED string voltage:
Output current:
9V – 25V DC
16V max
750mA +/-5%
Output current ripple:
20% typical
Switching frequency:
variable 135kHz
(typical at 13V input)
Efficiency:
Open LED protection:
Included; clamps at 20V
Output short circuit protection: Included; limits current at 750mA
Input current limit:
PWM dimming frequency:
Dimensions:
2.25A
Up to 1.0kHz
58mm X 35mm
Board Layout and Connection Diagram
_
VIN
PWM
Dimming
+
-
+
3
2
+
1
Enable
Actual Size:58mm X 35mm
Connections:
Input - The input is connected between the terminals of
connector J1 as shown in the Connection Diagram.
between terminals 1 and 3 of connector J3 as shown by the
dotted lines.
Output - The output is connected between the terminals of
connector J2 as shown.
Note:
During PWM dimming, pin 2 of connector J3 should be left
open. Also, the PWM signal must have the proper polarity
with the positive connected to pin 1 of J3. Note that pin 3
of J3 is internally connected to the return path of the input
voltage.
Enable/PWM Dimming - To just enable the board, short
pins 1 and 2 of connector J3 as shown. To PWM dim the
board, connect the external push-pull square wave source
Doc.# DSDB-HV9930DB2
A032913
Supertex inc.
www.supertex.com
HV9930DB2
Testing the Demoboard
Fig.2 shows the output current variation over the input
voltage range at full load. The LED current has a variation of
about 5.0mA over the entire voltage range.
Normal Operation: Connect the input source and the output
LEDs as shown in the Connection Diagram and enable the
board. The LEDs will glow with a steady intensity. Connecting
an ammeter in series with the LEDs will allow measurement
of the LED current. The current will be 750mA +/- 5%.
Output Current (A)
0.747
Open LED test: Connect a voltmeter across the output
terminals of the HV9930DB2. Start the demoboard normally
and once the LED current reaches steady state, unplug
one end of the LED string from the demoboard. The output
voltage will rise to about 20V and stabilize.
16
20
24
Output Current (A)
0.748
0.746
0.744
2
6
10
14
18
Output Voltage (V)
Fig. 3. Load Regulation of the Output Current
Switching Frequency (kHz)
Fig. 4 shows the variation of the switching frequency over
the input voltage range at full load. The frequency varies
from 90kHz to 180kHz over the entire input voltage range.
90
Efficiency (%)
12
Fig.3 shows the variation of the output current with varying
output voltage (different number or LEDs) at 13V input.
Fig.1 shows the efficiency plot for the HV9930DB2 over the
input voltage range. The converter has efficiencies greater
than 80% over 13V input.
85
80
75
16
20
24
Input Voltage (V)
200
160
120
80
8
12
16
20
24
Input Voltage (V)
Fig. 4. Switching Frequency Regulation
Fig. 1. Efficiency vs Input Voltage
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Fig. 2. Line Regulation of the Output Current
Typical Results
12
0.741
Input Voltage (V)
PWM Dimming: With the input voltage to the board
disconnected, apply a TTL compatible, push-pull square wave
signal between PWMD and GND terminals of connector J3
as shown in the Connection Diagram. Turn the input voltage
back on and adjust the duty cycle and / or frequency of the
PWM dimming signal. The output current will track the PWM
dimming signal. Note that although the converter operates
perfectly well at 1.0kHz PWM dimming frequency, the best
PWM dimming ratio can be obtained at lower frequencies
like 100 or 200Hz.
8
0.743
0.739
Short Circuit Test: When the HV9930DB2 is operating
in steady state, connect a jumper across the terminals of
the LED string. Notice that the output current will remain
steady.
70
0.745
2
Supertex inc.
www.supertex.com
HV9930DB2
The waveforms in Fig. 5 show the drain voltage of the FET
(channel 2 (pink); 20V/div) and the LED current (channel
4 (green); 500mA/div) at two different operating conditions
– 12V input and 24V input.
Fig. 7 shows the PWM dimming performance of the
HV9930DB1 with a 250Hz, 5.0V square wave signal. The
converter can easily operate at PWM dimming duty cycles
from 1% - 99%.
Fig. 5 Drain Voltage and LED Current Waveforms
in Steady State
Fig. 7 PWM Dimming Performance
(a) - 1%
(a)
(b) - 50%
(b)
Fig. 6a shows the drain (channel 2 (pink); 20V/div) and input
current (channel 4 (green); 500mA/div) waveforms during
startup and Fig. 6b shows the drain waveform (channel 2
(pink); 20V/div) and the output current (channel 4 (green);
500mA/div) during startup.
Fig. 6 Startup Waveforms
(c) - 99%
(a)
(b)
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Supertex inc.
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HV9930DB2
Fig. 8 shows the rise and fall times of the output current
during PWM dimming. The converter has nearly symmetric
rise and fall times of about 8.0µs. These rise and fall times can
be reduced (if desired) by reducing the output capacitance
C6. However, this will lead to increased ripple in the output
current.
Fig. 8 Dynamic Performance during PWM Dimming
(a) - Rise Time
(b) - Fall Time
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Supertex inc.
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Doc.# DSDB-HV9930DB2
A032913
5
J3A
1
2
J3B
3
J3C
2
J1B
1
REF
C2
4.7µF
25V
C8
2.2µF
16V
R6
10kΩ
VIN–
C2
4.7µF
25V
5
2
6
VIN
REF
PWMD
CS1
GND
CS2
GATE
HV9930
VDD
U1
D4
1N4148
R4
4.42kΩ
C2
4.7µF
25V
B220-13
D1
1
3
J1A
7
4
8
1
R5
10Ω
2
C7
0.1µF
16V
Q2
FMMT2907A
R3
0.39Ω
1/2W
R1
0.47Ω
1/2W
UP4B-151
L1
REF
1
Q1
IRF7452
R2
8.2Ω
1/2W
C5
15µF
50V
D3
B2100-13
C1
2.2µF
50V
1
R9
100Ω
R8
1.28Ω
1/4W
R7
1.28Ω
1/4W
D2
20V
500mW
DR125-221
L2
R11
10kΩ
R10
4.32kΩ
2
REF
2
J2B
C6
0.1µF
25V
1
J2A
HV9930DB2
Board Layout and Connections
Supertex inc.
www.supertex.com
HV9930DB2
Top Layer
Bottom Layer
Silk Screen
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Supertex inc.
www.supertex.com
HV9930DB2
Bill of Materials
#
Quan Ref Des
C1
Description
Package
Manufacturer
Manufacturer’s Part
Number
2.2µF, 50V, X7R ceramic chip capacitor
SMD1210
TDK Corp.
C3225X7R1H225K
SMD1210
Panasonic
ECJ-4YB1E475K
SMT
Nichion
UUD1H150MCL1GS
1
1
2
3
3
1
C5
15µF, 50V electrolytic capacitor
4
1
C6
0.1µF, 25V, X7R ceramic chip capacitor
SMD1206
Panasonic
ECJ-3VB1E104K
5
1
C7
0.1µF, 16V, X7R ceramic chip capacitor
SMD0805
Panasonic
ECJ-2VB1C104K
6
1
C8
2.2µF, 16V X7R ceramic capacitor
SMD0805
TDK Corp.
C2012X7R1C225K
7
1
D1
20V, 2.0A schottky diode
SMB
Diodes Inc.
B220-13
8
1
D2
20V, 500mW zener diode
SOD123
ON Semi
MMSZ5250BT1
9
1
D3
100V, 2.0A schottky diode
SMB
Diodes Inc.
B2100-13
10
1
D4
75V, 400mW switching diode
SOD123
Diodes Inc.
1N4148W-7
11
2
J1,J2
2 pin, 2.5mm pitch right angle connector
Thru-Hole
JST Sales
S2B-EH
12
1
J3
3 pin, 2.5mm pitch right angle connector
Thru-Hole
JST Sales
S3B-EH
13
1
L1
150µH, 1.7A rms, 3.0A sat inductor
SMT
Coiltronics
UP4B-151
14
1
L2
220µH, 1.19A rms, 1.51A sat inductor
SMT
Coiltronics
DR125-221
15
1
Q1
100V, 4.5A N channel MOSFET
SO-8
IR
IRF7452
16
1
Q2
-60V, 600mA PNP transistor
SOT-23
Zetex Inc.
FMMT2907ATA
17
1
R1
0.47Ω, 1/2W, 5% chip resistor
SMD2010
Panasonic
ERJ-12ZQJR47U
18
1
R2
8.2Ω, 1/2W, 5% chip resistor
SMD2010
Panasonic
ERJ-12ZYJ8R2U
19
1
R3
0.39Ω, 1/2W, 5% chip resistor
SMD2010
Panasonic
ERJ-12ZQJR39U
20
1
R4
4.42kΩ, 1/8W, 1% chip resistor
SMD0805
Yageo
9C08052A4421FKHFT
21
1
R5
10Ω, 1/8W, 1% chip resistor
SMD0805
Yageo
9C08052A10R0FKHFT
22
2
R6,R11
10kΩ, 1/8W, 1% chip resistor
SMD0805
Yageo
9C08052A1002FKHFT
23
2
R7,R8
1.28Ω, 1/4W, 1% chip resistor
SMD1206
Yageo
9C12063A1R28FGHFT
24
1
R9
100Ω, 1/8W, 1% chip resistor
SMD0805
Yageo
9C08052A1000FKHFT
25
1
R10
4.32kΩ, 1/8W, 1% chip resistor
SMD0805
Yageo
9C08052A4321FKHFT
26
1
U1
Boost-Buck LED Driver
8-Lead SOIC
Supertex
HV9930LG-G
C2,C3,C4 4.7µF, 25V X5R ceramic capacitor
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)
Supertex inc.
©2013 Supertex inc. All rights reserved. Unauthorized use or reproduction is prohibited.
Doc.# DSDB-HV9930DB2
A032913
7
1235 Bordeaux Drive, Sunnyvale, CA 94089
Tel: 408-222-8888
www.supertex.com