IA2505 Four Channel LED
Current Source for Flash
and Backlighting IA2505
3x3 DFN PIN ASSIGNMENT DESCRIPTION
The IA2505 is a high-efficiency, low-cost, high-current, parallel LED driver
current source specifically designed for running flash and backlighting LEDs.
The LED current can be set from 5mA to 80mA on each channel, and the
individual LED currents are matched to within +/-10%. LED pulse current can
be as high as 200mA for duration of 20msec or less.
LED brightness can be varied up to the programmed LED current by applying
a Pulse Width Modulated (PWM) signal to the EN pin of the device. The LED
output current of the IA2505 is tightly controlled over temperature and
voltage.
The input supply range is from 2.7V to 5.5V which is ideally suited for singlecell Li-Ion battery supplies. Dropout voltage is only 30mV at 20mA, permitting
direct operation from a Li-Ion battery. The IA2505 can also be operated from
two or three Alkaline batteries. The only external component required is a
resistor that sets the current on each of the four channels.
The IA2505 typically draws only 40ВµA when operating in the no-load condition
and draws less than 0.01ВµA when the device is shutdown.
The IA2505 is available in a space-saving 3mm x 3mm DFN package. TYPICAL APPLICATION See back page for ordering information. FEATURES High efficiency of 83% at VCC = 3.6V for VF
= 3V 30mV dropout at 20mA allows operation at
low Vin No internal switching signals – Eliminates
EMI LED current settable from 5mA to 80mA …