The HF1070 is a highly integrated continuous conduction mode (CCM)/quasi-resonant (QR) flyback regulator with an integrated 1700V SiC. The QR control method is suitable for high-performance and high-efficiency design. Unlike a conventional QR flyback controller, the frequency foldback in the HF1070 can ensure high efficiency across the entire load range. 

The HF1070 is a secondary-side regulation (SSR)-based primary controller that requires secondary-side feedback circuitry. The HF1070 integrates a 1200V, high-voltage (HV) start-up circuit. 

The HF1070 adopts the patented valley-lock technique to restrain valley jumping from one to another during operation, which avoids audible noise completely. When the HV pin's voltage (V_HV) is below the high-line voltage threshold (V_VH__HL), the HF1070 operates in LL mode, which supports CCM/QR control. After the HF1070 enters HL mode, it disables CCM control to prevent stress problems caused by current accumulation. 

The HF1070 has a maximum frequency limit to prevent excessive switching loss. The device can be enabled/disabled via an external signal on the ADJ pin. In addition, it features advanced protections, including primary-sense output over-voltage protection (ZCD OVP), primary-sense output under-voltage protection (ZCD UVP), VCC voltage over voltage protection (V_CC OVP), output overload protection (OLP), configurable input brown-in/brownout (B/I and B/O), configurable input OVP, short-circuit protection (SCP), current-sensing short protection (SSP), current-sensing open protection, internal thermal shutdown (OTP), and V_CC under-voltage lockout (UVLO).  

The HF1070 is available in an SOIC14-9L package.