Active-semi IC ACT355

FEATURES
Multiple Patent-Pending Primary Side
Regulation Technology
No Opto-coupler
Best Constant Voltage, Constant Current
Over All Accuracy
Minimum External Components
Integrated Line and Primary Inductance
Compensation
Integrated Output Cord Resistance Compensation
Line Under-Voltage Protection
Short Circuit Protection
Over Temperature Protection
Flyback Topology in DCM Operation
Complies with all Global Energy Efficient
Regulations: 0.3W Standby Power and CEC
Average Efficiency
SOT23-5 Package
APPLICATIONS
Chargers for Cell Phones, PDAs, MP3,
Portable Media Players, DSCs, and Other
Portable Devices and Appliances
RCC Adapter Replacements
Linear Adapter Replacements
Standby and Auxiliary Supplies
GENERAL DESCRIPTION
The ACT355A belongs to the high performance, multiple
patent-pending ActivePSRTM Family of universal-
input AC/DC off-line controllers for battery
charger and adapter applications. It is designed for
the flyback topology working in a discontinuous conduction
mode (DCM). In addition to being the industrys
most accurate primary side regulator, the
ACT355A meets all of the global energy efficiency
regulations (CEC, European Blue Angel, and US
Energy Star standards) while using very few external
components.
The ACT355A ensures safe operation with complete
protection against all fault conditions. Built-in
protection circuitry is provided for output shortcircuit,
line under-voltage, and over-temperature
conditions.
The ACT355A ActivePSR is optimized for costsensitive
applications, and utilizes Active-semis
proprietary primary-side feedback architecture to
provide accurate constant voltage, constant current
(CV/CC) regulation without the need of an optocoupler
or reference device. Integrated line and
primary inductance compensation circuitry provides
accurate constant current operation despite wide
variations in line voltage and primary inductance.
Integrated output cord resistance compensation
further enhances output accuracy. These products
achieve excellent regulation and transient response,
yet requires less than 300mW of standby
power.
The ACT355A is optimized for 2.5W to 3.5W applications
(such as 5V/500mA to 5V/700mA CV/CC
chargers). It is available in a tiny SOT23-5 package.

Active-semi IC ACT355