AAT3170 Datasheet, PDF (12/15 Pages) Advanced Analogic Technologies – High Current LED Flash Driver Charge Pump IC

AAT3170
High Current LED Flash Driver Charge Pump IC
2.7V to 5.5V
EN/SET
C1
C2
1µF
1µF
C1+
VIN
C1- C2+ C2-
VOUT
CIN
4.7µF
AAT 3170
EN/SET
F1
CT
F2
GND
COUT
2.2µF
Flash
LED
AUX_EN
2.7V to 5.5V
EN/SET
Figure 1: Flash Plus Auxiliary Lighting.
C1
C2
1µF
1µF
C1+
VIN
C1- C2+ C2+
VOUT
CIN
4.7µF
AAT 3170
EN/SET
F1
CT
F2
GND
COUT
2.2µF
Flash
LED
STAT1
STAT2
Figure 2: Flash Plus Status Lighting.
LED Selection
The AAT3170 is designed to drive high-intensity
white LEDs. It is particularly suitable for LEDs with
an operating forward-voltage in the range of 4.2V
to 1.5V.
The charge pump device can also drive other loads
that have similar characteristics to white LEDs. For
various load types, the AAT3170 provides a high-cur-
rent, programmable ideal constant current source.
12
Device Power Efficiency
The AAT3170 power conversion efficiency
depends on the charge pump mode. By definition,
device efficiency is expressed as the output power
delivered to the LED divided by the total input
power consumed.
η
=
P_OUT
P_IN
3170.2006.10.1.0