Six-Channel White LED Backlight
Charge Pump with Flash
Typical Characteristics–White LED Backlight Driver Section
Unless otherwise noted, V
IN
= 3.6V, C
IN
= C
OUT
= C
1
= C
2
= C
3
= 1.0μF; T
A
= 25°C.
AAT2803
Efficiency vs. Supply Voltage
100
90
4.1mA
V
F
= 2.9V
10.2mA
V
F
= 3.1V
20mA
V
F
= 3.4V
Turn-On to 1X Mode
(V
IN
= 4.2V; 20mA Load)
Efficiency (%)
EN
(2V/div)
CP
(2V/div)
V
SINK
(500mV/div)
I
IN
(200mA/div)
80
70
60
50
2.8
3.0
3.2
3.4
3.6
3.8
4.0
4.2
Supply Voltage (V)
μ
100μs/div
Turn-On to 1.5X Mode
(V
IN
= 3.8V; 20mA Load)
Turn-On to 2X Mode
(V
IN
= 2.8V; 20mA Load)
EN
(2V/div)
CP
(2V/div)
V
SINK
(500mV/div)
I
IN
(200mA/div)
μ
100μs/div
EN
(2V/div)
CP
(2V/div)
V
SINK
(500mV/div)
I
IN
(200mA/div)
μ
100μs/div
Turn-Off from 1.5X Mode
(V
IN
= 3.5V; 20mA Load)
20.2
Current Matching vs. Temperature
Channel 2
20.0
Channel 1
EN
(2V/div)
Current (mA)
V
F
(1V/div)
I
IN
(100mA/div)
19.8
19.6
Channel 3
19.4
19.2
-40
-20
0
20
40
60
Channel 5
Channel 4
Channel 6
80
μ
100μs/div
Temperature (°C)
°
8
2803.2006.12.1.6
AAT [ ADVANCED ANALOG TECHNOLOGY, INC. ]
