Eval Board

IS32BL3552 BOOST TYPE LED DRIVER
WITH 2-CHANNEL CURRENT SOURCE
QUICK START
DESCRIPTION
The IS32BL3552 is a white LED driver for backlight
applications based on a highly efficient boost controller
operating over a wide input voltage range of 4.5V to
33V.
The IS32BL3552 contains two regulated current
sources with 1.5% (Typ.) current matching between
strings for a uniform LED brightness. Each current
source can be programmed via an external resistor to
drive from 40mA to 360mA. A fast slew rate current
source allows high frequency and narrow pulse width
dimming signals to achieve a very high contrast ratio.
The device operating frequency can be adjusted from
0.1MHz to 1MHz.
The IS32BL3552 has safety protection features to
prevent damage during fault conditions. Protection
features include an internal soft-start circuit to prevent
a high inrush current during start up, open/short LED
protection to automatically disable a faulty current
source,
over
temperature
protection
(OTP),
cycle-by-cycle current limit, under voltage lockout
(UVLO), programmable OVP, VOUT short / Schottky
diode open protection and Schottky Diode short-circuit
protection.
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RECOMMENDED EQUIPMENT
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Input voltage range: 4.5V to 33V
2-Channel LED current sinks, 360mA per string
LED current adjustable from 40mA to 360mA
String-to-string current matching accuracy: 1.5%
Adjustable operating frequency: 100kHz to 1MHz
External PWM dimming
High contrast ratio
Less than 3µA shutdown current
Programmable soft-start
Built-in protection features
- OCP, OTP, UVLO
- Open/short LED protection
- Programmable OVP
- Schottky Diode/inductor short-circuit protection
Automotive AEC-Q100 qualified
12V, 3A power supply
LED load board
Excel Calculator download from the ISSI website
www.issi.com/US/product-analog-backlight-driver.shtml
ABSOLUTE MAXIMUM RATINGS
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FEATURES
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Figure 1: Photo of IS32BL3552 Evaluation Board
≤ 33V power supply
All LED channels must be connected to an LED
load.
Caution: Do not exceed the conditions listed above, otherwise
the board will be damaged.
PROCEDURE
The IS32BL3552 evaluation board is fully assembled
and tested. Follow the steps listed below to verify
board operation.
Caution: Do not turn on the power supply until all connections
are completed.
1)
2)
Connect the ground terminal of the power supply
to the GND and the positive terminal to the VCC.
Or connect the DC power to the connector (DC
IN).
Turn on the power supply and pay attention to the
supply current. If the current exceeds 2A, please
check for circuit fault.
ORDERING INFORMATION
Part No.
Temperature Range
Package
IS32BL3552-ZLA3-EB
-40°C ~ +125°C (Automotive)
eTSSOP-16, Lead-free
Table 1: Ordering Information
For pricing, delivery, and ordering information, please contacts ISSI’s analog marketing team at
[email protected] or (408) 969-6600.
Integrated Silicon Solution, Inc. – www.issi.com
Rev. C, 07/24/2015
1
IS32BL3552 BOOST TYPE LED DRIVER
WITH 2-CHANNEL CURRENT SOURCE
2. W2 Overvoltage Protection – VOVP can be adjusted
from 10.6V to 50V by W2. VOVP should be set to 1.2
times VOUT to ensure OVP function. The IS32BL3552
operation is unstable if VOVP is set to less than VOUT.
EVALUATION BOARD OPERATION
IS32BL3552 evaluation board drives two strings of
WLEDs. There are three variable resistors used for
adjusting the operating frequency (W1), OVP voltage
(W2) and LED current (W3). A clockwise rotation will
increase the resistance resulting in a lower operating
frequency, lower OVP and lower LED current. Use an
ohmmeter to measure the adjusted resistance value.
3. W3 LED Current – The LED channel current (ICH)
can be adjusted from 90mA to 360mA by W3. RCS =
0.135Ω is calculated by setting VIN = 12V, VOUT = 32V,
ICH = 360mA, L1/L2 = 10µH, fOSC = 1MHz. RCS should be
reduced when ICH = 360mA and fOSC is less than 1MHz
or the IC will enter into the power limit mode.
The default parameters of the evaluation board are: VIN
= 12V, VOUT = 32V, fOSC = 1MHz (W1= 9kΩ), VOVP = 39V
(W2 = 13kΩ), ICH = 120mA (W3 =13.2kΩ), RCS = 0.135Ω,
L1/L2 =10µH. Note that W1, W2 and W3 are set at the
factory. The operating temperature is from -40°C to
+125°C.
4. Excel Calculator – W1, W2 and W3 cannot be
randomly changed. Please use the IS32BL3552 Excel
Calculator to define the system parameters.
It is recommended to maintain the switching duty cycle
less than 70% when ICH > 300mA and fOSC > 0.8MHz.
Otherwise the switching MOSFET and Diode will have
large power losses, will heat up resulting in reduced
power conversion efficiency.
Note: Please follow the suggested procedures below when
modifying the DEMO board parameters.
1. W1 Set Switch Frequency – Clockwise rotation of
W1 will adjust the switching frequency (fOSC) from
1MHz to 100kHz and the inductor L1/L2 peak current
(IPEAK) will increase from 1.8 A to 5.17A.
For operation with TA > 85°C, the MOSFET should be
thermally protected with the addition of a heat sink.
Also the temperature stability of magnetic saturation
current for inductor and the temperature stability of
compensation capacitor for COMP should be selected
for elevated temperature operation.
Caution: An IPEAK of 5.17A is too high for the installed 10µH
inductor L1/L2. A higher IPEAK current will affect other
component selections such as inductor L1/L2 and current sense
resistor RCS (R1||R2). We recommend a lower fOSC by using a
47µH inductor instead of 10µH to keep IPEAK below 2.22A.
Note: A higher inductor value will reduce the PWM dimming
contrast. For the default L1/L2 value, the contrast is 1000:1.
Choosing a smaller inductor like 4.7µH will increase the
contrast to 2000:1(Max.). Notice that the inductor should be
higher than LCCM(Min.).
VIN
L1/L2
2
1
VIN
GND
2
1
6
22uF/50V
Vo
GND
VCC
STATUS
VCC
OUT
DIM
EN
7
R6
10k
DIM R7
10k
EN
5
4
R13
2R
3
2
9
R5
R8
C11
300k
300k
NC
R3
0--500K
43k
C7
R15
220nF
R1
0.27R
C2
NC
R2
0.27R
1
R10
1M
C4
22uF/100V 22uF/100V
R11
43K
2X10
820pF
0--200K
W2
EN
OVP
DIM
CH1
16
10
13
CH1
CH2
RT
Iset
NC
15 R9
6.8k
W3
8
C3
C8
STATUS
R9'
R12
C10
220nF
0R
VCC
CH2
W1
C9
220nF
Q1
13N06
IS32BL3552
STATUS
2
1
VIN
R14
100k
Vo
SS310
CS
C6
D1
0R
C5
NC
2.2uF
2
1
10uH
U1
R4
0R
C1
FB
COM
GND
12
0--20K
V0
CH1
CH2
1
2
3
1k
IS32BL3552
Figure 2: IS32BL3552 Application Schematic
Integrated Silicon Solution, Inc. – www.issi.com
Rev. C, 07/24/2015
2
IS32BL3552 BOOST TYPE LED DRIVER
WITH 2-CHANNEL CURRENT SOURCE
BILL OF MATERIALS
Name
Symbol
LED Driver
U1
Inductor
L1/L2
Diode
D1
Ferrite Bead
Description
Qty
Supplier
Part No.
Boost backlight LED driver
1
ISSI
IS32BL3552
IND,10µH±20%,SMD
1
Würth
Elektronik
7447709100
Schottky Diode, SS310 SMD
1
FB
600R@100M SMD
1
NMOS
Q1
100V N-Channel MOSFET
SMD
1
Fairchild
FQD19N10L
Resistor
R1,R2
RES,0.27Ω,1/10W,±1%,SMD
2
Yageo
RL0805FR-070R27L
Resistor
R3,R4
RES,0Ω,1/10W,±1%,SMD
2
Yageo
RL0805FR-0700RL
Resistor
R5,R8
RES,300k,1/10W,±5%,SMD
2
Yageo
RC0805JR-07300KL
Resistor
R6,R7
RES,10k,1/10W,±5%,SMD
2
Yageo
RC0805JR-0710KL
Resistor
R9
RES,6.8k,1/10W,±1%,SMD
1
Yageo
RC0805FR-076K8L
Resistor
R10
RES,1M,1/10W,±1%,SMD
1
Yageo
RC0805FR-071ML
Resistor
R11
RES,43k,1/10W,±1%,SMD
1
Yageo
RC0805FR-0743KL
Resistor
R12
RES,43k,1/10W,±1%,SMD
1
Yageo
RC0805FR-0743KL
Resistor
R13
RES,2Ω,1/10W,±5%,SMD
1
Yageo
RC0805JR-072RL
Resistor
R14
RES,100k,1/10W,±5%,SMD
1
Yageo
RC0805JR-07100KL
Resistor
R15
RES,1k,1/10W,±5%,SMD
1
Yageo
RC0805JR-071KL
Capacitor
C1
CAP,22µF,50V,±20%,SMD
1
Capacitor
C3,C4
CAP,22µF,100V,±20%,SMD
2
Capacitor
C6
CAP, 2.2µF,16V,±10%,SMD
1
Yageo
CC0805JKX7R7BB225
Capacitor
C7,C9,C10
CAP,0.22µF,16V,±10%,SMD
3
Yageo
CC0805JKX7R7BB224
Capacitor
C8
CAP,820pF,16V,±10%,SMD
1
Yageo
CC0805JKX7R7BB821
Variable
Resistor
W1
RES,0~500k
1
Variable
Resistor
W2
RES,0~200k
1
Variable
Resistor
W3
RES,0~20k
1
R9’,C2,C5,C11
Not Connect
4
SS310
Bill of materials, refer to Figure 2 above.
Integrated Silicon Solution, Inc. – www.issi.com
Rev. C, 07/24/2015
3
IS32BL3552 BOOST TYPE LED DRIVER
WITH 2-CHANNEL CURRENT SOURCE
10
10
4
2
1
2
1
4
5
8
8
4
4
5
8
2
1
3
4
2
3
2
4
1
1
8
3
2
1
3
2
1
10
10
Figure 3: Board Component Placement Guide - Top Layer
Figure 4: Board PCB Layout - Top Layer
Integrated Silicon Solution, Inc. – www.issi.com
Rev. C, 07/24/2015
4
IS32BL3552 BOOST TYPE LED DRIVER
WITH 2-CHANNEL CURRENT SOURCE
10
10
4
2
1
2
1
4
5
8
8
4
4
5
8
2
1
3
4
2
3
2
4
1
1
8
3
2
1
3
2
1
10
10
Figure 5: Board Component Placement Guide - Bottom Layer
Figure 6: Board PCB Layout - Bottom Layer
Copyright © 2015 Integrated Silicon Solution, Inc. All rights reserved. ISSI reserves the right to make changes to this specification and its
products at any time without notice. ISSI assumes no liability arising out of the application or use of any information, products or services
described herein. Customers are advised to obtain the latest version of this device specification before relying on any published information
and before placing orders for products.
Integrated Silicon Solution, Inc. does not recommend the use of any of its products in life support applications where the failure or malfunction
of the product can reasonably be expected to cause failure of the life support system or to significantly affect its safety or effectiveness.
Products are not authorized for use in such applications unless Integrated Silicon Solution, Inc. receives written assurance to its satisfaction,
that:
a.) the risk of injury or damage has been minimized;
b.) the user assume all such risks; and
c.) potential liability of Integrated Silicon Solution, Inc is adequately protected under the circumstances
Integrated Silicon Solution, Inc. – www.issi.com
Rev. C, 07/24/2015
5