AAT3113, AAT3114/14A
High Efficiency 1.5X Fractional Charge
Pumps For White LED Applications
Test Current/Channel Disable
Thermal Protection
Each channel of the output is equipped with a test
current function. The AAT3113 and AAT3114 use a
small (~2µA) current source injected into each out-
put pin to detect the presence of an LED. Unused
channels that are tied to ground or LED load fail
short will be automatically diasbled instead of wast-
ing the programmed output current. The test current
in the AAT3114A is higher (~150µA) to accommo-
date LEDs with lower impedance in failure mode.
The AAT3113 and AAT3114/14A have a thermal
protection circuit that will shut down the charge
pump and current outputs if the die temperature
rises above the thermal limit. However, thermal
resistance of the QFN package is so low that if, in
the case of the AAT3114/14A, all six outputs are
shorted to ground at maximum 20mA output level,
the die temperature will not rise sufficiently to trip
the thermal protection. The thermal protection will
only trip if COUT is shorted to ground and the ambi-
ent temperature is high.
Application Circuits
Typical AAT3113 Application Circuit:
VIN
C1+
C1
1μF
C1-
C2+
OUT
CIN
COUT
C2
1μF
VBATTERY
AAT3113
1μF
1μF
C2-
D1
D2
D3
D4
EN/SET
EN/SET
GND
D4
D3
D2
D1
T
HI > 50ns
300ns < TLO < 75μs
50ns minimum to enable
OFF
n
ON/1
2
3
4
5
6
(n < =32)
Enable / Disable / LED Brightness Level Set Data Input
12
3113.2006.07.1.9
AAT [ ADVANCED ANALOG TECHNOLOGY, INC. ]
