UPSRB02G-AG6-R datasheet(6/7 Pages) UTC

6 / 7 page

UPSRB02

Preliminary

LINEAR INTEGRATED CIRCUIT

UNISONICTECHNOLOGIESCO.,LTD

6 of 7

www.unisonic.com.tw

QW-R103-079.a



OPERATION DESCRIPTION (Cont.)

At no load, the actual CS threshold is:

VCS_no_Load=0.5-(ICS_MAX)×Rd

(V)

Current Sensing and Leading Edge Blanking

Cycle-by-cycle current limiting is offered in UTC UPSRB02. The switch current is detected by a sense resistor into

the CS pin. When the power switch is turned on, a turn-on spike will occur on this resistor. A 500ns leading-edge

blanking is built in to avoid false-termination of the switching pulse so that the external RC filtering is no longer

needed.

Drive BJT

The driver is a push pull stage with the supply voltage VDD. It provides the driving current for the external power

bipolar transistor. The output signal is current-limited to IOUT(SOURCE).

Protection Control

Good power supply system reliability is achieved with its comprehensive protection features including output

over-voltage protection, VDD over voltage protection, OTP, feedback loop open protection, Cycle-by-cycle current

limiting, short circuit protection, leading edge blanking and UVLO, etc.

VDD is supplied by transformer auxiliary winding output. The output of UTC UPSRB02 is shutdown when VDD drops

below VTH(OFF) and the power converter enters power on start-up sequence thereafter.

UPSRB02G-AG6-R データシート(PDF) 6 Page - Unisonic Technologies