LED Drivers for LCD Backlights
Backlight LED Driver
for Small LCD Panels (Charge Pump Type)
BD1204GWL
No.10040EAT07
●Description
BD1204GWL is 3ch or 4ch parallel LED driver for the portable instruments.
This IC is equipped with an automatic transition charge pump and 16-step LED drivers. Hence this IC realizes high efficiency
and high accuracy drive of LEDs. Additionally, this IC can synchronize LED drive with external PWM signal. This IC is best
suited to turn on white LEDs that require high-accuracy LED brightness control.
●Features
1) 3ch or 4ch parallel LED driver is mounted
2) 16-step LED current adjust function
3) LED current matching is 5: 5% or less
4) Driving control via a single-line digital control interface
5) Automatic transition charge pump type DC/DC converter (×1, ×1.5, ×2)
6) High efficiency achieved (Maximum over 93%)
7) It transits for the most suitable power operating by the LED terminal processof the 4th light when 3 light driving
8) Various protection functions such as output voltage protection and thermal shutdown circuit are mounted.
9) The input external PWM is possible and the back light control interlocked with the motion picture is possible.
10) Package: UCSP50L1 (Thick 0.55mm MAX, Pin pitch 0.4mm) CSP14pin package
●Absolute
maximum ratings (Ta=25℃)
Parameter
Power supply voltage
Input voltage ( EN , PWMIN )
Power dissipation
Operating temperature range
Storage temperature range
Symbol
VMAX
Vdin
Pd
Topr
Tstg
Ratings
7
GND-0.3 ~ VBAT+0.3
840
-30 ~ +85
-55 ~ +150
Unit
V
V
mW
℃
℃
Note 1) The measurement value which was mounted on the PCB by ROHM.
When a glass epoxy substrate (70mm × 70mm × 1.6mm) has been mounted, this loss will decrease 6.72mW/℃
if Ta is higher than or equal to 25℃.
●Operating
Conditions (Ta = -30 ~ 85
℃)
Parameter
Operating power supply voltage
Symbol
VBAT
Limits
2.7 ~ 5.5
Unit
V
*This chip is not designed to protect itself against radioactive rays.
*This material may be changed on its way to designing.
*This material is not the official specification.
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© 2010 ROHM Co., Ltd. All rights reserved.
1/12
2010.02 - Rev.A
BD1204GWL
●Electrical
Characteristics (Unless otherwise noted, Ta = +25
o
C, VBAT=3.6V)
Parameter
Current Consumption
Quiescent Current
Current Consumption1
Current Consumption2
Charge Pump
Oscillator frequency
Current Source
LED maximum current
LED current accuracy
LED current matching
LED control voltage
Logic control terminal
Low threshold voltage
High threshold voltage
High level Input current
Low level Input current
Minimum EN High time
Minimum EN Low time
EN Off Timeout
Latch time
Access available time
V
IL
V
IH
I
IH
I
IL
T
HI
T
LO
T
OFF
T
LAT
Tacc
-
1.4
-
-1
0.05
0.3
1
1
1
-
-
0
0
-
-
-
-
-
0.4
-
1
-
100
100
-
-
5
V
V
μA
μA
μs
μs
ms
ms
ms
EN , PWMIN
EN , PWMIN
I
LED-max
I
LED-diff
I
LED-match
V
LED
18
-
-
-
20
-
0.5
0.15
22
10.0
5.0
0.25
mA
%
%
V
VBAT≥3.0V
f
OSC
0.56
0.85
1.14
MHz
I
q
I
dd1
I
dd2
-
-
-
0.1
41.3
82.6
1
42.5
83.9
μA
mA
mA
EN=0V
Symbol
Limits
Min.
Typ.
Max.
Units
Technical Note
Conditions
x 1.0 Mode
Include LED current (40mA)
x 2.0 Mode
Include LED current (40mA)
LED current setting is 10.0mA,
LED terminal voltage is 1.0V
LED current setting is 10.0mA,
LED terminal voltage is 1.0V
Minimum voltage from LED1 to LED4 pins
EN = VBAT, PWMIN = VBAT
EN = 0V, PWMIN = 0V
Described in Fig.5
Described in Fig.5
Described in Fig.5
Described in Fig.5
Described in Fig.5
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© 2010 ROHM Co., Ltd. All rights reserved.
2/12
2010.02 - Rev.A
BD1204GWL
●Pin
Descriptions
Terminal
Pin No.
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
●Pin
ESD Type
D3
C4
D4
B4
A4
A3
C2
D2
D1
C1
B1
B3
A1
A2
Technical Note
Pin Name
VBAT
C1P
C1N
C2P
C2N
VOUT
EN
LED1
LED2
LED3
LED4
PWMIN
GND
ISET
In/Out
-
In/Out
In/Out
In/Out
In/Out
Out
In
Out
Out
Out
Out
In
-
Out
Type
A
A
B
A
B
A
C
A
A
A
A
C
D
B
Power supply
Function
Flying capacitor pin positive (+) side
Flying capacitor pin negative (-) side
Flying capacitor pin positive (+) side
Flying capacitor pin negative (-) side
Charge pump output
ON/OFF and dimming control
LED current driver output 1
LED current driver output 2
LED current driver output 3
LED current driver output 4
PWM Control
GND
LED standard current
Type A
Type B
VBAT
Type C
VBAT
PAD
PAD
GND
GND
GND
PAD
Type D
VBAT
PAD
Fig. 4 Pin ESD Type
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© 2010 ROHM Co., Ltd. All rights reserved.
5/12
2010.02 - Rev.A
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