High-Current Charge Pump with S
2
Cwire™
Control and Dual LDO for Backlight and Flash
Typical Characteristics
V
IN
= 3.6V; C
IN
= 4.7µF; C
OUT
= 2.2µF; C
1
= C
2
= 1.0µF; T
A
= -40°C to +85°C, unless otherwise noted. Typical
values are at T
A
= 25°C.
AAT2842
Backlight Efficiency vs. Supply Voltage
100
90
100
Flash Efficiency vs. Supply Voltage
Efficiency (%)
80
70
60
50
40
30
Efficiency (%)
30mA/ch
V
F
= 3.7V
90
80
70
60
50
40
30
150mA total
V
F
= 2.9V
7.5mA/ch
V
F
= 3.1V
2.1mA/ch
V
F
= 2.9V
300mA total
V
F
= 3.0V
200mA total
V
F
= 2.9V
2.7 2.8 2.9 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 4.0 4.1 4.2
2.7 2.9 3.1 3.3 3.5 3.7 3.9 4.1 4.3 4.5 4.7 4.9 5.1 5.3 5.5
Supply Voltage (V)
Supply Voltage (V)
Turn On to 1X Mode Backlight
(30mA/ch; Data 1; V
IN
= 4.2V)
Turn On to 1.5X Mode Backlight
(30mA/ch; Data 1; V
IN
= 3.5V)
EN
(2V/div)
OUT
(2V/div)
V
SINK
(500mV/div)
I
IN
(100mA/div)
Time (200µs/div)
EN
(2V/div)
OUT
(2V/div)
V
SINK
(500mV/div)
I
IN
(200mA/div)
Time (200µs/div)
Turn On to 2X Mode Backlight
(30mA/ch; Data 1; V
IN
= 3.2V)
Turn Off from 1.5X Mode Backlight
(30mA/ch; Data 1)
EN
(2V/div)
OUT
(2V/div)
V
SINK
(500mV/div)
I
IN
(200mA/div)
Time (200µs/div)
EN
(2V/div)
OUT
(2V/div)
I
IN
(200mA/div)
Time (100µs/div)
2842.2006.10.1.0
7
ANALOGICTECH [ ADVANCED ANALOGIC TECHNOLOGIES ]
