Weltrend

Products

WT7181R

【 General Description 】

The WT7181R is a high performance multi-mode (CCM/Valley Switching) Flyback PWM controller. It is specifically designed to work with USB PD controller to provide a total solution for quick cell phone charger or USB PD. It minimizes the components counts and is available in a tiny SOT-26 package. The controller operates in Continuous Current Mode (CCM) during heavy load and operates in discontinuous conduction mode with valley switching during light load. The WT7181R helps to improve the overall efficiency and optimize the product performance. The controller provides with important protection features, such as DC Brown In/Out, Vo UVP, VDD OVP, OLP, OCP and Output Short Circuit Protection.

【 Features 】
●	Ultra-low Start-up current (1.5μA Typ.)
●	Optimized for Wide Output Voltage Operation
	- Wide VDD Range: 7.5V to 68V (Typ.)
	- Adjustable OCP Line Compensation
	- Adaptive Green Mode Control
	- No External VDD Linear Regulator Circuit
	- Only One VDD Auxiliary Winding
●	CCM/DCM/Valley-Switching Multi-Mode Operation
●	DRV pin with Soft Driver to Reduce EMI Noise
●	Internal Soft-Start Function
●	Protection:
	- DC Brown In/Out Protection on VS Pin
	- Output Under Voltage Protection (VS_UVP)
	- Output Over Voltage Protection (VS_OVP)
	- VDD Over Voltage Protection (VDD_OVP)
	- Open Loop Protection (OLP) when Feedback Loop Open
	- Over Current Protection (OCP)
	- Internal Over Temperature Protection
	- CS Pin Open/Short Protection
	- Output Rectifier Short Protection
●	Package: SOT-26

【 Application Circuit 】

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