DESCRIPTION

The UTC UPSRB03 is a primary control unit for switch mode

charger and adapter applications. The controlled variable is

transferred by an auxiliary winding from the secondary to the

primary side. The device uses multi-mode operations to achieve

high performance and high efficiency. Device operations in PFM

in CC mode at large load condition and it operates in PWM with

frequency reduction at light/medium load which can cancel audio

noise.

The UTC  UPSRB03 operates in primary-side sensing and

regulation. Opto-coupler and TL431 could be eliminated. It also

eliminates the need of loop compensation circuitry while

maintaining stability.  

The UTC UPSRB03 achieves high precision CV/CC regulation

and high power efficiency. It offers comprehensive protection

coverage with auto-recovery features including Cycle-by-cycle

current limiting, output over voltage protection, VDD over voltage

protection, feedback loop open protection, short circuit protection,

leading edge blanking, VDD under voltage lockout, etc. 

FEATURES

* Multi-Mode control for cancel audio noise  

* ±5% constant voltage regulation at universal AC input

* Primary side control without TL431 and opto-coupler

* High precision constant current regulation at universal AC input

* Programmable CV and CC regulation

* Eliminates control loop compensation circuitry

* Flyback topology in DCM operation

* Driver BJT switch

* Built-in Line CC compensation

* Built-in leading edge blanking

* Driver soft start

* Built-in primary winding inductance compensation

* Open circuit protection

* Output over voltage protection

* VDD over voltage protection

* Short circuit protection