AAT3131
High Efficiency 1X/1.5X Fractional
Charge Pump for White LED Applications
Typical Characteristics
Unless otherwise noted, V
IN
= 3.5V, C
IN
= C
OUT
= C
1
= C
2
= 1µF, T
A
= 25°C.
Efficiency vs. Input Voltage
(4x20mA)
100
95
90
85
80
75
70
65
60
55
50
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
V
DIODE
= 3.5V
V
DIODE
= 3.6V
V
DIODE
= 3.3V
V
DIODE
= 3.4V
90
85
80
75
V
DIODE
= 3.3V
I
DIODE
vs. Input Voltage
(4x20mA)
V
DIODE
= 3.4V
V
DIODE
= 3.5V
V
DIODE
= 3.6V
Efficiency (%)
I
DIODE
(mA)
70
65
60
55
50
45
40
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
Input Voltage (V)
Input Voltage (V)
Quiescent Current vs. Input Voltage
2.4
2.2
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
2.50
0.850
0.825
0.800
0.775
0.750
V
DIODE
= 3.3V
V
DIODE
= 3.4V
V
DIODE
= 3.5V
V
DIODE
= 3.6V
0.725
0.700
0.675
0.650
0.625
0.600
3.00
3.50
4.00
4.50
5.00
5.50
2.5
3.0
V
IH
and V
IL
vs. V
IN
Quiescent Current (mA)
V
IH
V
IL
3.5
4.0
4.5
5.0
5.5
Input Voltage (V)
V
IN
(V)
3131.2005.12.1.2
5
AAT [ ADVANCED ANALOG TECHNOLOGY, INC. ]
