HV9911DB2 User Guide

Supertex inc.
HV9911DB2
Boost LED Driver Demoboard
with 1:3000 Dimming Ratio and Excellent Current Regulation
General Description
Specifications
The HV9911DB2 is an LED driver capable of driving up to
twenty 100mA LEDs in series from an input of 9 - 16V DC. The
demoboard uses Supertex’s HV9911 IC in a boost topology.
The converter has a very good initial regulation, (+/-5%), and
excellent line and load regulation over the entire input and output
voltage range (<+/- 1%). The full load efficiency of the converter
is typically greater than 85%.
Parameter
Input voltage (steady state):
Output LED string voltage:
Output current:
The HV9911DB2 is also protected against open LED and
output short circuit conditions. It has an excellent PWM dimming
response, with typical rise and fall times less than 2.0μs, which
will allow high PWM dimming ratios. The HV9911DB2 also
features an ENABLE input which can be used to shut down the
IC and allow a very small power draw from the input.
Value
9 - 16V DC
35V min - 80V max
100mA +/-5%
Output current ripple:
10% typical
Switching frequency:
200kHz
Full load efficiency:
87% (at 12V input)
Shut down current:
100μA (typ)
Open LED protection:
Output short circuit protection:
PWM dimming frequency:
Shuts down at 92V
Included
1:3000 dimming ratio
at 200Hz
The switching frequency of the HV9911DB2 can be synchronized
to other HV9911 boards or to an external 200kHz clock by
connecting the clock to the SYNC pin of the HV9911DB2.
Board Layout and Connection Diagram
VIN
Actual Size: 64mm X 31mm
Connections:
Input - The input is connected between the terminals of
connector J1 as shown in the Connection Diagram.
GND of connector J3 as shown by the solid lines. Note that
EN should be connected to the input voltage.
Output - The output is connected between the terminals of
connector J2 as shown.
SYNC - To synchronize two or more boards, connect the
SYNC pins of all the boards together. To synchronize the
HV9911DB1 to an external 200kHz clock, connect the clock
between the SYNC terminal and GND pin of terminal J3.
Enable - To Enable to board, connect the EN pin of the
connector J3 to the input voltage as shown in the Connection
Diagram. This will enable the IC and a small current will
be drawn from the input. However, this will not start the
converter. To start the converter, connect the PWMD pin to
the VDD pin of the connector J3.
PWM Dimming - To PWM dim the board, connect the external
push-pull waveform source between terminals PWMD and
Doc.# DSDB-HV9911DB2
A032713
Note:
During PWM dimming, pin VDD of connector J3 should
be left open. Also, the PWM signal must have the proper
polarity with the positive connected to pin PWMD of J3.
Note that pin GND of J3 is internally connected to the
return path of the input voltage.
Supertex inc.
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HV9911DB2
Testing The Demoboard:
Fig. 1. Efficiency vs Output Voltage
Open LED test: Connect a voltmeter across the output
terminals of the HV9911DB2. 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 92V and then the HV9911DB2 will shut down.
To restart the converter, disconnect and reconnect the input
voltage (recycle the power to the board).
Short Circuit Test: When the HV9911DB2 is operating in
steady state, connect a jumper across the terminals of the
LED string. Notice that the output current will immediately
go to zero and the converter will shut down. To restart the
HV9911DB2, recycle the input power to the demoboard.
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 widest
PWM dimming ratio can be obtained at lower frequencies like
100 or 200Hz.
Efficiency (%)
88
87
86
35
45
55
65
75
Output Voltage (V)
Fig. 2. Efficiency vs Input Voltage
90
89
88
87
86
85
9
11
13
15
Input Voltage (V)
Fig. 3. Output Current vs Input Voltage
101
100.5
100
99.5
99
9
11
13
15
Input Voltage (V)
1. Efficiency: The efficiency of the converter at various LED
string voltages are shown in Fig.1 (measured at the nominal
input voltage of 24V). Fig.2 shows the full load efficiency of the
converter at varying input voltages. The minimum efficiency of
86% for the converter occurs at 9V input and full load output.
2. Current Regulation: Figs. 3 and 4 show the output current
regulation vs. input voltage and load voltage respectively. The
total current regulation (line and load combined) is found to
be less than 1%.
Output Current (mA)
Fig. 4. Output Current vs Load Voltage
Typical Results
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89
85
Efficiency (%)
Current Regulation: With the input power to the converter
disconnected, change the LED string voltage within the
specifications mentioned. The current output of the HV9911DB2
will remain very steady over the entire load range. Vary the
input voltage while the circuit is operational. The current will
be regulated over the entire line range.
90
Output Current (mA)
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 100mA +/- 5%.
101
100.5
100
99.5
99
35
45
55
65
75
Output Voltage (V)
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HV9911DB2
3. Open LED Protection: Open LED protection for the circuit is set at 92V. The waveforms in Fig. 5 shows the output voltage, drain voltage and output current during an open
LED condition. The time taken for the over voltage protection
to shut the IC down will depend on the size of the output
capacitor.
Fig. 7a: Rise time of LED Current at 80V output (5μs/div)
PWM dimming input
Fig. 5: Open LED Protection (20μ/div)
LED Current
Output Voltage
Fig. 7b: Fall time of LED Current at 80V output (5μs/div)
Output Current
Drain Voltage (Q1)
PWM dimming input
4. Output Short Circuit Protection: Fig. 6 shows the waveforms for output short circuit condition. The disconnected
FET is turned off in less than 300ns. The rise in the output
current will depend on the input voltage and the value of
inductor L1. The same protection will also help in protecting
the LEDs in case the output voltage increases beyond the
LED string voltage.
LED Current
Fig. 8a: Rise time of LED Current at 40V output (5μs/div)
Fig. 6: Open Short Circuit Protection (500ns/div)
PWM dimming input
LED Current
Output Voltage
Output Current
Fig. 8b: Fall time of LED Current at 40V output (5μs/div)
5. PWM Dimming: The rise and fall transitions of the LED
current during PWM dimming are shown in Figs. 7 and 8, at
output voltages of 80 and 40V respectively. The timescale
for all waveforms is set at 5.0μs/div. The rise and fall times
are less than 1.0μs in each case. Thus, a PWM dimming
ratio of 1:3000 is achievable at a PWM dimming frequency
of 200Hz.
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PWM dimming input
LED Current
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J1A
1
REF
REF
C2
2.2µF
16V
C1
2.2µF
16V
R18
R9
6.04kΩ
open
C7
2.2nF
18.2kΩ
C8
6.65kΩ
R12
R11
0.1µF 16V
C6
REF
R4
19.1kΩ
R8
open
R7
Io_SNS
open
J3C
OVP
FAULT
CS
GATE
RT
Q3
TP0610T
JX;;33
J3A
CLIM
COMP
FDBK
IREF
REF
SYNC
U1
1.0µF 16V
J10
low standby current
J3B
C5
R17
100kΩ
Q4
10kΩ
R16
Used to acheive
10kΩ
C10
1.0nF
J3D
R15
10kΩ
VIN
2
VDD
PWM
4
SC
Doc.# DSDB-HV9911DB2
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GND
J1B
1
453kΩ
R2
10uH
L1
J5
2
J6
J7
R6
0.08Ω
1/4W
Q1
FDS3692
(B32529)
C4
0.33µF
100V
B1100-13
D1
J8
Io_SNS
C9
0.33µF
100V
J2A
J2B
R10
3.3Ω
1/8W
Q2
VN2110
2
R3
1.13kΩ
R1
82.5kΩ
1
HV9911DB2
Circuit Schematic:
Supertex inc.
www.supertex.com
HV9911DB2
Top Layer:
Bottom Layer:
Silk Screen:
Doc.# DSDB-HV9911DB2
A032713
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HV9911DB2
Bill of Materials
Item
Quan
#
RefDes
Description
Package
Manufacturer
Manufacturer’s Part
Number
1
2
C1,C2
2.2μF, 16V X7R ceramic chip capacitor
SMD1206
Murata
GRM31MR71C225MA35L
2
2
C4,C9
0.33μF, 100V metal Film capacitors
Thru-Hole
EPCOS Inc
B32529C1334J
3
1
C5
1μF, 16V X7R ceramic chip capacitor
SMD0805
TDK Corp
4
1
C6
0.1μF, 16V X7R ceramic chip capacitor
SMD0805
Murata
5
1
C7
2.2nF, 5%, 50V C0G ceramic chip
capacitor
SMD0805
TDK Corp
6
3
-
-
7
1
C10
1nF, 50V, X7R ceramic chip capacitor
SMD0805
TDK Corp
C2012X7R1H102K
8
1
D1
100V, 1A schottky diode
SMA
Diodes Inc.
B1100-13
9
2
J1,J2
Side Entry 2-pin male header
Thru-Hole
JST Sales Amer. S2B-EH
10
1
J3
Side Entry 4-pin male header
Thru-Hole
JST Sales Amer. S4B-EH
11
1
L1
10μH, 5.5A sat, 4.3A rms inductor
SMT
Sumida
CDR10D48MN-100
12
1
Q1
100V, 4.55A N-Channel MOSFET
SO-8
Fairchild
FDS3692
13
1
Q2
100V, 4.0Ω N-Channel MOSFET
SOT-89
Supertex
VN2110K1
14
1
Q3
-60V, 10Ω P-Channel MOSFET
SOT-23
Supertex
TP0610T
15
1
Q4
40V, 600mA NPN Transistor
SOT-23
ST Micro
MMBT2222A
16
1
R1
82.5k, 1%, 1/8W chip resistor
SMD0805
Yageo
RC0805FR-0782K5L
17
1
R2
453k, 1%, 1/8W chip resistor
SMD0805
Yageo
RC0805FR-07453KL
18
1
R3
1.13k, 1%, 1/8W chip resistor
SMD0805
Yageo
RC0805FR-071K13L
19
1
R6
0.08, 1%, 1/4W chip resistor
SMD1206
Vishay/ Dale
WSL1206R0800FEA
20
1
R8
19.1k, 1%, 1/8W chip resistor
SMD0805
Yageo
RC0805FR-0719K1L
21
1
R9
6.04k, 1%, 1/8W chip resistor
SMD0805
Yageo
RC0805FR-076K04L
22
1
R10
3.3, 1%, 1/8W chip resistor
SMD0805
Panasonic
23
1
R11
18.2k, 1%, 1/8W chip resistor
SMD0805
Yageo
RC0805FR-0718K2L
24
1
R12
6.65k, 1%, 1/8W chip resistor
SMD0805
Yageo
RC0805FR-076K65L
25
1
R15, R16,
10.0k, 1%, 1/8W chip resistor
R18
SMD0805
Yageo
RC0805JR-0710KL
26
1
R17
100k, 1%, 1/8W chip resistor
SMD0805
Yageo
RC0805JR-07100KL
27
1
U1
Switchmode LED Driver
with High Current Accuracy
SO-16
Supertex
R4, R7, C8 open
C2012X7R1C105K
GRM219R71C104KA01D
C2012C0G1H222J
-
ERJ-6RQF3R3V
HV9911NG-G
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-HV9911DB2
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6
1235 Bordeaux Drive, Sunnyvale, CA 94089
Tel: 408-222-8888
www.supertex.com