DESCRIPTION

A7531 series are CMOS-based PFM step-up DC-DC Controller with low supply current and high output voltage accuracy. Quiescent current drawn from power source is as low as 6uA. It is capable of delivering 500mA output current at 4.0V output with 2V input voltage. Only four external components are necessary: An inductor, a schottky diode, an output filter capacitor and a NMOSFET or a NPN transistor. All of these features make A7531 series be suitable for the portable devices, which are supplied by a single battery to four-cell batteries.

A7531 has a drive pin (EXT) for external transistor. So it is possible to load a large output current with a power transistor which has a low voltage dropout.

A7531 integrates stable reference circuits and trimming technology, so it can afford high precision and low temperature-drift coefficient of the output voltage.

A7531 can be switch on or off easily by EN pin, to minimize the standby supply current.

The A7531 is available in SOT-25 package.

FEATURES

? Deliver 500mA at 4 .0V o utput voltage with 2V

input Voltage

? The controller output voltage can be adjusted

from 2.5V 6.0V(In 0.1V step)

? Output voltage accuracy ±2

? Low temperature drift coefficient of the output

voltage ± 100ppm/°C

? Only four external components are necessary:

An inductor, a s chottky diode, an output filter

capacitor and a NMOSFET or a NPN transistor

? High power conversion efficiency 90

? Low quiescent current drawn from power source

6uA

? Available in SOT-25 p ackage

APPLICATION

? Power source for PDA, DSC, MP3 Player,

electronic toy and wireless mouse

? Power source for a single or dual cell

battery po wered equipments

? Power source for LED