PRIMARY SIDE REGULATED SWITCHING MODE POWER SUPPLY CONTROLLER

DESCRIPTION

The UTC UPSR105 is a high performance AC/DC power supply

controller for battery charger and adapter applications. It can meet

less than 10mW standby power for “Super Star” charger criteria.

The device uses Pulse Frequency Modulation (PFM) method to

build discontinuous conduction mode (DCM) flyback power

supplies.

The UTC UPSR105 provides accurate constant voltage (CV),

constant current (CC) and outstanding dynamic performance

without requiring an opto-coupler. It also eliminates the need of

loop compensation circuitry while maintaining stability.

The UTC UPSR105 is equipped with both cable drop compensation function to meet various cables with

different lengths and gauges and adjustable line voltage compensation function.

When UTC UPSR105 is used with 2nd-side synchronous rectification, better under-shoot performance and

higher conversion efficiency can be achieved.

The UTC UPSR105 has internal over temperature protection for itself, and also provides dedicated pin for ex

ternal over temperature protection.

FEATURES

* Primary Side Control for Eliminating Opto-coupler

* 10mW No-load Input Power

* Flyback Topology in DCM Operation

* External Adjustable Line Compensation for CC

* External Adjustable Cable Compensation for CV

* Multiple PWM/PFM Control Mode to Improve Audio Noise Efficiency

* VCS Jitter to Reduce System EMI

* Valley-on for the Higher Efficiency and Better EMI

* Multiple Protections:

-Over Voltage Protection (OVP)

-Output Short Circuit Protection (SCP)

-Transformer Saturation Protection (TSP) via Primary Peak

-Current Limitation

-OTP and External Over Temperature Protection (OTP)

* Matching 2nd-side synchronous rectification with Schottky Synchronous Rectifier Solution