AAT3113/4
High Efficiency 1.5X Fractional Charge
Pumps For White LED Applications
Driving White LED display module back lights
and individual white LED's connected in parallel:
parallel connected. This feature is particularly use-
ful to power pre-manufactured display modules
which are pre-wired with white LED backlights con-
nected in a parallel circuit configuration. All output
may be connected in parallel to drive groups of
LED's as well. The internal current source refer-
ence circuit bases feedback from current sensed on
the D1 output. For best operation, the only require-
ment for this application is the output D1 should
always be connected to the load circuit.
The AAT3113/14 D1 to D6 outputs are true constant
current sources capable of driving up to 20mA each
over the operation input voltage range. Since these
outputs are true constant current sources, they may
be connected in parallel to drive a single power out-
put. Any combination of outputs (D1 to D6) may be
connected in parallel. The maximum total output
current is a sum of how many current sources are
AAT3114 application driving a display module with six parallel connected white LEDs:
V
C1+
IN
C1
1µF
C1-
V
OUT
C2+
C
1µF
C
OUT
1µF
IN
C2
V
BATTERY
AAT3114
1µF
C2-
D1
D2
D3
D4
D5
D6
Display Module
D5 D6
EN/SET
EN/SET
GND
D1
D2
D3
D4
R
R
R
R
R
R
Resistor R is optional
AAT3114 Dual Backlight Control Circuit:
V
IN
C1+
C1
1µF
C1-
V
OUT
C2+
C
1µF
C
OUT
1µF
IN
C2
V
AAT3114
BATTERY
1µF
C2-
Keyboard Backlight
D1
D2
D3
D4
Display Backlight
D4
D5
D6
EN/SET
EN/SET
D5
D6
GND
D1
D2
D3
Enable Keyboard Backlight
Enable Display Backlight
12
3113.2004.07.1.4
ANALOGICTECH [ ADVANCED ANALOGIC TECHNOLOGIES ]
