ACE703 Datasheet, PDF (1/16 Pages) ACE Technology Co., LTD. – White LED PFM Step-Up DC-DC Converter

Technology
ACE703
White LED PFM Step-Up DC-DC Converter
Description
The ACE703 is a PFM step-up DC-DC converter specifically designed to drive white LEDs with a
constant current. It can deliver stable constant output current from 0mA to 500mA by adjusting the
external resistor.
The ACE703 can drive one or more LEDs in parallel connection, also it can drive two in series, several
in parallel connection from one or two battery cells. With overvoltage limit protection circuit interiorly, the
chip and the external circuits will be safe even if the load is not connected. The device also can deliver
steady constant output voltage from 2.5V to 6.0V by adjusting the external resistor.
The ACE703 integrates stable reference circuits and it uses trimming technology in the process, so it can
afford high precision and low temperature-drift coefficient output current or output voltage.
The ACE703 devices are available in SOT-89-5 package.
Features
• Low start-up voltage (when the output current is 1mA)--------------------------0.8V
• The converter can output constant voltage from 2.5V to 6.0V or it can output constant current from
0 to 500mA by adjusting the external resistor.
• Output current accuracy -----------±10％
• Low temperature-drift coefficient of the output current------------------±100ppm/℃
• Only four external components are necessary: an inductor, a Schottky diode, an output filter capacitor
and a resistor.
• High conversion efficiency (When Vin=2.5V, for 1W LED)----------80％
Application
• Power source for white LED
• Supply constant current
• Power source for a single or dual-cell battery-powered equipments
Absolute Maximum Ratings
Parameter
Symbol
Max
Unit
Input supply voltage
-0.3~10
V
LX pin voltage
-0.3 ~ Vout+0.3 V
CE pin voltage
-0.3 ~ Vout+0.3 V
IFB pin voltage
-0.3 ~ Vout+0.3 V
Lx pin output current
1.5
A
Power Dissipation PD@T=25 ^OC
SOT-89-5
0.5
W
Junction temperature
Storage temperature
Operating free-air temperature
150
O_C
- 40 to 125 ^OC
-20 ~ 85 ^OC
VER 1.2 1