LED Drivers for LED Backlights
Backlight LED Driver
for Small LCD Panels (Charge Pump Type)
BD1606MVV
No.11040EAT24
●Description
The multi-level brightness control white LED driver not only ensures efficient boost by automatically changing the boost rate
but also works as a constant current driver in 64 steps, so that the driving current can be adjusted finely. This IC is best
suited to turn on white LEDs that require high-accuracy LED brightness control.
●Features
1) A 6 parallel LED driver is mounted
2) 64-step LED current adjust function
3) Inter-LED relative current accuracy: 3% or less
2
4) LED individual lighting/dimming control via a I C BUS interface
5) Automatic transition charge pump type DC/DC converter (×1,×1.5 and ×2)
6) High efficiency achieved (90% or more at maximum)
7) Various protection functions such as output voltage protection, overcurrent limiter and thermal shutdown circuit are mounted.
8) Small QFN package
●Applications
This driver is applicable for various fields such as mobile phones, portable game machines and white goods.
●Absolute
Maximum Rating (Ta=25℃)
Parameter
Power supply voltage
Operating temperature range
Storage temperature range
Power dissipation
Symbol
VMAX
Topr
Tstg
Pd
Limits
7
-30 ~ +85
-55 ~ +150
780 (*1)
Unit
V
℃
℃
mW
(*1) When a glass epoxy substrate (70mm × 70mm × 1.6mm) has been mounted,
this loss will decrease 6.2mW/℃ if Ta is higher than or equal to 25℃.
●Recommended
Operation Range (Ta=-30℃ to +85℃)
Parameter
Operating power supply voltage
Symbol
VCC
Limits
2.7~5.5
Unit
V
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© 2011 ROHM Co., Ltd. All rights reserved.
1/11
2011.04 - Rev.A
BD1606MVV
●Electrical
Characteristics (Unless otherwise stated, Ta is 25℃ and Vin is 3.6V)
Limits
Parameter
Symbol
Min.
Typ.
Max.
Input voltage range
Quiescent current
Circuit current 1
[Charge pump]
Output current
Oscillation frequency
[LED driver]
LED current absolute precision
LED current relative precision
LED control voltage
[Logic interface]
Input ‘L’ voltage
Input ‘H’ voltage
Input ‘H’ current
Input ‘L’ current
‘L’ level SDA output
[I C BUS interface (standard mode)]
SCL clock frequency
SCL Low duration
SCL High duration
Data hold time
Data setup time
Setup time – restart condition
Hold time – restart condition
Setup time – stop condition
Bus free tine between start and stop
[I C BUS interface (fast mode)]
SCL clock frequency
SCL Low duration
SCL High duration
Data hold time
Data setup time
Setup time – restart condition
Hold time – restart condition
Setup time – stop condition
Bus free time between start and stop
Interface startup time
*1)
2
2
Technical Note
Unit
V
μA
mA
mA
MHz
V
in
pin
Condition
V
in
I
q
I
DD1
I
OUT
f
OSC
2.7
-
-
-
0.8
3.6
0
1.0
-
1.0
5.5
7
2.6
120
1.2
EN=0V, V
in
=3.6V
×1 mode, I
out
=0mA, V
in
=3,6V
V
OUT
=4.0V, V
in
=3.6V
Add=0x03, D6=’0’
I
LED
=16.5mA(LEDxCNT=0x20),
LED pin voltage 1.0 V
I
LED
=16.5mA(LEDxCNT=0x20) ,
LED pin voltage 1.0V
ILEDA*/B*/C*
EN, SCL, SDA
EN, SCL, SDA
EN, SCL, SDA=V
in
EN, SCL, SDA=GND
SDA, 3mA source
SDA, 6mA source
I
LED-ERR
I
LED-to-LED
V
LED
V
IL
V
IH
I
IH
I
IL
V
OL
-
-
-
-
1.6
-
-10
-
-
0
4.7
4.0
0
250
4.7
4.0
4.0
4.7
0
1.3
0.6
0
100
0.6
0.6
0.6
1.3
-
-
0.5
0.2
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
±6.5
±3.75*
1)
0.25
0.4
-
10
-
0.4
0.6
100
-
-
3.45
-
-
-
-
-
400
-
-
0.9
-
-
-
-
-
350
%
%
V
V
V
μA
μA
V
V
kHz
μs
μs
μs
ns
μs
μs
μs
μs
kHz
μs
μs
μs
ns
μs
μs
μs
μs
μs
f
SCLC
t
LOW
t
HIGH
tHD;DAT
tSU;DAT
tSU;STA
tHD;STA
tSU;STO
tBUF
f
SCL
t
LOW
t
HIGH
tHD;DAT
tSU;DAT
tSU;STA
tHD;STA
tSU;STO
tBUF
TEN
Bus startup time (after En=‘H’)
The following expression is used for calculation:
I
LED-match
={(Imax-Imin)/(Imax+Imin)} × 100
Imax= Current value in a channel with the maximum current value among all channels
Imin=Current value in a channel with the minimum current value among all channels
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© 2011 ROHM Co., Ltd. All rights reserved.
2/11
2011.04 - Rev.A
BD1606MVV
●Reference
Data
2.0
1.6
3.0
2.5
2.0
IDD1[mA]
1.5
1.0
0.5
0.0
2
3
4
Vin[V]
5
6
7
2
3
4
Vin[V]
5
6
7
EFFICIENCY [%]
100
90
Technical Note
DOWN
80
70
60
50
40
2
3
4
5
Vin[V] (Ta=25oC)
6
7
1.2
Iq [μA]
0.8
Ta=25℃
Ta=85℃
Ta=-30℃
Ta=25
℃
Ta=-30℃
Ta=85
℃
0.4
0.0
UP
Fig.1 Circuit Current (Standby)
100
90
80
EFFICIENCY [%]
70
60
50
40
30
20
10
0
2.5
3
3.5
4
4.5 5 5.5
Vin[V]
6
6.5
7
100
90
80
EFFICIENCY [%]
60
50
40
30
20
10
0
2.5
Fig.2 Circuit Current
(Operation in ×1.0 Mode)
100
90
80
EFFICIENCY [%]
Fig.3 Efficiency Hysteresis
(13mA × 6 Lights)
Ta=-30
℃
Ta=-30
℃
70
Ta=-30
℃
70
60
50
40
30
20
10
0
2.5
Ta=25
℃
Ta=85
℃
Ta=25
℃
Ta=85
℃
Ta=25
℃
Ta=85
℃
3
3.5
4
4.5 5 5.5
Vin[V]
6
6.5
7
3
3.5
4
4.5 5 5.5
Vin[V]
6
6.5
7
Fig.4 Efficiency (3.5mA x 6 Lights)
20.0
17.5
LED current [mA]
15.0
Fig.5 Efficiency (10mA x 6 Lights)
2.0
1.5
1.0
Fig.6 Efficiency (20mA x 6 Lights)
2.0
Ta=25
℃
Ta=-30
℃
Ta=85
℃
INL [LSB]
1.5
1.0
0.5
0.0
Ta=25
℃
Ta=-30
℃
Ta=85
℃
Ta=25
℃
Ta=85
℃
Ta=-30
℃
10.0
7.5
5.0
2.5
0.0
0.0
0.4
0.8
DNL [LSB]
12.5
0.5
0.0
-0.5
-1.0
-1.5
-2.0
-0.5
-1.0
-1.5
-2.0
1.2
V
LED
[V]
1.6
2.0
0
10
20
30
40
50
STATE[DEC]
60
0
10
20
30
40
50
STATE[DEC]
60
Fig.7 LED Current Characteristics
(LED current 16.5mA)
Fig.8 LED Current Characteristics
(Differential Linearity Error)
Fig.9 LED Current Characteristics
(Integral Linearity Error)
5.0
4.5
4.0
3.5
3.0
[%]
2.5
2.0
1.5
1.0
0.5
0.0
0
10
20
30
40
50
STATE[DEC]
60
20.0
17.5
LED current [mA]
15.0
12.5
Ta=-30
℃
Ta=85
℃
Ta=25
℃
Ta=-30
℃
7.5
5.0
2.5
0.0
0
1
2
3
4
Vin[V]
5
6
7
10.0
Ta=25
℃
Ta=85
℃
Fig.10 LED Current matching
Fig.11 LED Current vs. V
IN
(LED current 16.5mA)
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© 2011 ROHM Co., Ltd. All rights reserved.
3/11
2011.04 - Rev.A
BD1606MVV
●Block
Diagram and Recommended Circuit Example
C1 = 1μF
C1N
C2 = 1μF
C2P
Technical Note
Battery
Cin
= 1μF
VIN
×1, ×1.5, ×2
Charge Pump
Over Voltage
Protect
Charge Pump
Mode Control
C1P
C2N
VOUT
C
OUT
= 1μF
OSC
EN
TSD
SCL
I C I/F
&
Control
Logic
2
VOUT Control
ILEDA1
LEDA1
ILEDA2
LEDA1
ILEDB1
LEDB1
LEDB2
LEDC1
LEDC2
LEDACNT
Current
SDA
6
DAC
LEDBCNT
Current
6
DAC
ILEDB2
ILEDC2
LEDCCNT
Current
6
DAC
ILEDC2
GND
Fig.12 Block Diagram and Recommended Circuit Example
●Pin
Table
Pin
Pin name
number
1
2
3
4
5
6
7
8
LEDA1
SDA
SCL
EN
VOUT
VIN
C1N
C1P
In/Out
Out
In
In
In
Out
-
In/Out
Function
LED current driver output
I
2
C BUS control pin
I
2
C BUS control pin
ON/OFF control
Charge pump output
Power supply
Pin
Pin name
number
9
10
11
12
13
14
15
16
C2N
C2P
GND
LEDC2
LEDC1
LEDB2
LEDB1
LEDA2
In/Out
In/Out
Function
Flying capacitor pin negative
(-) side
Flying capacitor pin positive
In/Out
(+) side
-
Out
Out
Out
Out
Out
GND
LED current driver output
LED current driver output
LED current driver output
LED current driver output
LED current driver output
Flying capacitor pin negative
(-) side
Flying capacitor pin positive
In/Out
(+) side
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© 2011 ROHM Co., Ltd. All rights reserved.
4/11
2011.04 - Rev.A
BD1606MVV
Technical Note
●Description
of Operations
(1) LED driver
2
・I
C BUS interface
BD1606MVV can control the LED ON/OFF, brightness and charge pump switching frequency change by writing to the
2
2
register via the I C BUS interface. Control by the I C BUS interface is effective when EN is at ‘H’ kevel. When EN is at ‘L’
level, this LSI is completely shut down and control and associated functions via the I
2
C BUS interface are all stopped.
2
As shown in Fig.13 below, the I C BUS interface of BD1606MVV operates using the Ven voltage (buffering the EN pin
2
voltage) as supply voltage. For this reason, it is desirable that the ‘H’ voltage in the I C BUS interface is equal to the EN
pin voltage.
Ven
EN
Ven
I
2
C interface buffer
SDA
SCL
Fig.13 I
2
C BUS Interface Buffer
SDA
t
BUF
t
f
t
LOW
t
SU;DAT
t
HD;STA
t
r
SCL
t
HD;STA
S
t
SU;STA
t
HIGH
Sr
t
SU;STO
t
HD
;
DAT
P
S
Fig.14 I
2
C BUS Interface Timing
BD1606MVV operates as a slave device for the I
2
C BUS interface.
a) Slave address
A7
A6
1
1
A5
0
A4
0
A3
1
A2
1
A1
0
R/W
1/0
b) Data format
The data format is shown below.
Write format:
S
Slave address
7 bit
W
As
One-byte register
address
8 bit
One-byte register
address
8 bit
One-byte register
address
8 bit
As Sr
Slave address
7 bit
R
As
One-byte register data
As
P
8 bit
Or
S
Slave address
7 bit
W
As
As
One-byte register data
As
P
8 bit
Read format:
S
Slave address
7 bit
W
As
As
Sr
Slave address
7 bit
R
As
One-byte register data
Am
P
8 bit
Note)
S: Start condition
W: ‘0=Write
R: ‘1=Read
As: Acknowledge (slave -> master)
Am: No acknowledge
Sr: Repeated start condition
P: Stop condition
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5/11
2011.04 - Rev.A
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