HV Buck Power Switch

FEATURES

◆   Built-in 800V Power BJT and start resistance

◆   Direct Drive of Low Cost BJT

◆   CV Mode Control

◆   Work at BCM

◆   Cycle-by-Cycle Current Limiting

◆   Leading Edge Blanking (LEB)

◆   Pin Floating Protection

◆   VDD UVLO,  Clamp

APPLICATIONS

◆   Emergency lamp

◆   Home appliance

GENERAL DESCRIPTION

SF4711 is a high precision, highly integrated BCM HV buck power switch for offline small power converter applications. It has built-in power BJT, which can further lower system cost. 

SF4711 has built-in proprietary NC-Cap/HV buck-I^TM control for CV control, which eliminates external compensation or filtering capacitor. It has built-in cable drop compensation function, which can provide excellent CV performance. The IC uses Multi Mode Control to improve efficiency and reliability and to decrease audio noise energy @ light loadings.

SF4711 integrates proprietary “Audio Noise Cancellation” control for audio noise free operation. The IC has built-in “Fast Dynamic Response” control to meet USB Charge requirements. SF4711 also integrates proprietary “Zero-Output Startup” control to achieve startup when output is near zero voltage. The IC has proprietary “Smart Output Short Protection”, which can protect the system with large leakage inductance when output is short circuit.

SF4711 integrates functions and protections of FB Short Protection, Under Voltage Lockout (UVLO), VDD Over Voltage Protection (VDD OVP), Soft Start, Cycle-by-cycle Current Limiting (OCP), Pin Floating Protection, VDD Clamping.

SF4711 is available SOT23-6 packages.