UC3800G-S08-R datasheet(8/10 Pages) UTC

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UC3800

Preliminary

LINEAR INTEGRATED CIRCUIT

UNISONICTECHNOLOGIESCO.,LTD

8 of 10

www.unisonic.com.tw

QW-R103-083.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 time. The OLP event as followed Fig.4.

LNO-OVP and BNO

LNO will shut down driver when LNO> VTH_LNO or LNO<VTH_BNO for continual time.

OTP

The internal OTP circuit is implemented to detect the Temperature. As soon as the Temperature is higher than the

145

C, the driver will shut down.

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 UC3800, and increasing the power MOS gate resistance is advised.

UC3800G-S08-R 数据表(PDF) 8 Page - Unisonic Technologies