HV9980DB1 User Guide

Supertex inc.
HV9980DB1
3-Channel LED Array Driver IC
General Description
The HV9980B1 demoboard is an RGB or multi-channel
white LED backlight driver designed to drive LEDs for
a large-screen TV. The HV9980DB1 can drive three
common-anode LED strings from a 100 - 140V input at
currents up to 70mA in steady state. It can also drive the
LEDs at currents as large as 160mA for short durations to
facilitate backlight scanning mode.
Each of the three channels can be individually controlled
by PWM dimming. The demoboard is also protected from
short circuit conditions across any string and recovers
automatically once the condition disappears.
Specifications
Parameter
Input voltage (VIN)
IC supply voltage (VDD)
Output voltage
Output current (steady state)
Value
100 - 140V
6.0 - 10V
20V (min)
< ½ of input voltage (max)
70mA (max)
Output current (short durations)
160mA (max)
Switching frequency (requires an
external 1.8MHz clock signal)
300kHz
REF input
0 - 1.0V
Output current ripple (typ)
Efficiency (@ 120V input and
40V, 50mA output)
<5% peak - peak
~90%
Open LED protection
YES
Output short circuit protection
YES
Connection Diagram
120V
0 - 0.9V
+
-
+
+
-
8.0V
Actual Board Size: 68.8mm x 36.1mm
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HV9980DB1
Connections
Pin
Connection
VIN
Powers the three LED strings, providing the LED string voltage is less than ½ of the input voltage. Connect a
high voltage 100 - 140V source at this terminal.
VDD
Powers the HV9980 control circuit. Connect a 6.0 - 10V source at this terminal.
REF
Voltage at the REF terminal controls the output current level. The peak inductor current is approximately 1/5th
of the REF voltage.
CLK
Provides a clock input to the HV9980. The switching frequency is 1/6th of the CLK frequency. Connect a
1.8MHz TTL compatible signal at this terminal.
These inputs can be used to PWM dim the three channels. Connect these pins to VDD to enable all three
PWMD1-3 channels permanently. A TTL compatible, low frequency (<1kHz) square wave can be used to PWM dim each
channel individually.
GND(s)
The two GND terminals are wired together on the board. They form the return path for all the input signals.
COM
This is the common anode connection for all three LED strings.
Ch1-3
These terminals are the cathode connections for the three LED strings.
Typical Results
Efficiency vs. Input Voltage
(@VO = 40V; IO = 50mA)
92
95
Efficiency (%)
Efficiency (%)
91
90
89
Efficiency vs. Load Voltage
(@VIN = 120V; IO = 50mA)
90
85
80
88
87
90
110
130
75
15
150
Line Regulation of Output Current
Output Current (mA)
Output Current (mA)
55
53
51
49
130
150
15
25
35
45
Load Voltage (V)
Input Voltage (V)
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(@VIN = 120V)
57
110
45
Load Regulation of Output Current
(@VO = 40V)
49.5
49
90
35
Load Voltage (V)
Input Voltage (V)
50
25
2
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HV9980DB1
Fig.1 shows the drain voltage and LED current waveforms during normal operation. The three channels are phase shifted
by 120° with respect to each other. The switching frequency for each channel is 300kHz (1/6th of the CLK frequency).
Drain of channel 1
Drain of channel 2
Drain of channel 3
LED current in Channel 1
Fig. 1: Steady State Operation
(Time scale: 1.0µs/div)
Fig. 2 shows the hiccup mode short circuit protection of the HV9980. The output of channel is shorted by connecting COM to
CH1. Channel 1 tries to restart every 200μs. The other two channels work normally and are not affected by the short circuit
on one channel. The short circuit timing is started when the voltage at RS reaches 1.15V (about 230mA).
Drain of channel 1
Drain of channel 2
LED current in Channel 1
Drain of channel 3
Fig. 2: Operation during Output Short Circuit
(Time scale: 50µs/div)
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HV9980DB1
Fig. 3 shows the recovery of Channel 1 from short circuit condition to normal operation. The circuit transitions from a fault
condition to normal operation does not cause any overshoots in the LED current.
Drain Voltage of Channel 1
LED Current for Channel 1
Fig. 3: Recovery from a short circuit condition
(Time scale: 50µs/div)
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HV9980DB1
Fig. 4 shows the PWM dimming performance of the HV9980DB1 for one of the channels. The driver has a 25μs rise time
and 50μs fall time.
PWM Dimming signal
LED Current
(a): PWM Dimming Operation
(Time scale: 500µs/div)
PWM Dimming signal
PWM Dimming signal
LED Current
LED Current
(b): PWM Dimming Rise
(c): PWM Dimming Fall
(Time scale: 50µs/div)
(Time scale: 50µs/div)
Fig. 4: PWM Dimming performance
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HV9980DB1
Fig. 5 shows the response of the HV9980DB1 to a quickly varying reference voltage, similar to variation found in the backlight-scanning mode. The reference voltage is varied from 250mV to 500mV using a square wave signal (corresponding to
an LED current variation from 50mA to 100mA). The LED current transitions quickly between the two levels within 10μs.
REF signal
LED Current
(a): Operation with a REF change
(Time scale: 500µs/div)
REF signal
REF signal
LED Current
LED Current
(b) : Rise Time of LED Current
(c) : Fall Time of LED Current
(Time scale: 10µs/div)
(Time scale: 10µs/div)
Fig. 5: REF change response
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REF
VDD
GND1
GND
VIN
7
0
C4
1.0nF
1k
R4
C1
1.0µF
0
C5
1.0nF
1k
R5
C2
1.0µF
C9
0.22µF
250V
C6
1.0nF
1k
R6
C3
1.0µF
PWMD3
PWMD2
PWMD1
REF3
REF2
REF1
VDD3
VDD2
D1
GND3
CS3
RS3
D3
GND2
CS2
RS2
D2
GND1
CS1
RS1
HV9980
VDD1
CLK
POL
GND
U1
PWMD3
12
9
4
10
7
1
11
8
2
3
6
5
PWMD2
0
PWMD1
CLK
13
14
15
16
20
19
18
17
24
23
22
21
4.99
R3
4.99
R2
4.99
R1
1
1
1
2
3.3mHz
L3
3.3mHz
L2
3.3mHz
L1
2
2
C12
0.1µF
250V
C11
0.1µF
250V
C10
0.1µF
250V
CH3
CH2
CH1
COM
HV9980DB1
Circuit Schematic
Supertex inc.
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D3
BAV20W
D2
BAV20W
D1
BAV20W
HV9980DB1
Bill of Materials
Item
#
Qty
RefDes
Description
Package
Mfg
Mfg Part Number
SMT
Keystone
Electronics
5016
1
13
PWMD1-3,
Ch1-3, REF,
VDD, VIN, Compact surface mount test points
COM, GND,
GND1, CLK
2
3
C1, C2, C3
1.0uF, 16V X7R ceramic chip capacitor
SMD0805
TDK Corp
C2012X7R1C105K
3
3
C4, C5, C6
1.0nF, 50V X7R ceramic chip capacitor
SMD0805
Kemet
C0805C102K5RACTU
4
1
C9
Radial
Epcos Inc.
B32521C3224J
5
3
C10, C11,
C12
0.1µF, 200V, X7R ceramic chip capacitor SMD1210
AVX Corp
12102C104KAT2A
6
3
D1, D2, D3
200V, 200mA switching diode
SOD-123
Diodes Inc
BAV20W
7
3
L1, L2, L3
3.3mH, 225mA sat, 150mA rms inductor
Radial
Coilcraft
RFB0810-332
-
-
---
Cross Reference (for L1, L2, and L3)
Radial
Renco USA
RL-5480-3-3300
8
3
R1, R2, R3
4.99Ω, 1/8W, 1% chip resistor
SMD0805
---
---
9
3
R4, R5, R6
1.0kΩ, 1/8W, 5% chip resistor
SMD0805
---
---
10
1
U1
Three Channel LED Driver
SOIC-24
Supertex
HV9980WG-G
0.22µF, 250V metal film 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-HV9980DB1
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1235 Bordeaux Drive, Sunnyvale, CA 94089
Tel: 408-222-8888
www.supertex.com