UC3875LG-S08-R datasheet(8/11 Pages) UTC

8 / 11 page

UC3875L

CMOS IC

UNISONICTECHNOLOGIESCO.,LTD

8 of 11

www.unisonic.com.tw

QW-R103-125 .A



OPERATION DESCRIPTION (Cont.)

Protection Controls

The IC takes on more protection functions such as OVP, OLP and OTP etc. In case of those failure modes for

continual blanking time, the driver is shut down. Driver is reset after failure is eliminated.

OVP

The OVP will shut down the switching of the power MOSFET whenever VDD>VOVP. The OVP event as followed

Fig.3.

Fig.3 OVP case

Fig.4 OLP case

OLP

OLP will shut down driver when VFB>VOLP for continual a blanking time. The OLP event as followed Fig.4.

OTP

OTP will shut down driver when junction temperature TJ>T (THR).

PCB Layout Note

Noise from the current sense or the control signal can cause significant pulse width jitter in continuous-conduction

mode, and slope compensation helps alleviate these problems. Good placement and layout practices should be

followed. Avoiding long PCB traces and component leads, locating compensation and filter components near the

UTC UC3875L, and increasing the power MOS gate resistance is advised.

UC3875LG-S08-R Arkusz danych(PDF) 8 Page - Unisonic Technologies