VIPERGAN50 Datasheet Advanced quasi-resonant offline high voltage converter with E-mode GaN HEMT Features Quasi-resonant (QR) flyback controller 650 V E-mode power GaN transistor Embedded sense FET Dynamic blanking time and adjustable valley synchronization delay functions, to maximize efficiency at any input line and load condition Valley-lock to ensure constant valley skipping Advanced power management for less than 30 mW standby power consumption with adaptive burst-mode Output OVP protection Input voltage feed-forward compensation for mains independent OPP variation Brown-in and brown-out protection Input OVP protection Embedded thermal shutdown Frequency jitter for EMI suppression Application High efficiency power adapters Fast battery chargers Auxiliary power supply for appliances, industrial, consumers, lighting Product status link Description VIPERGAN50 The VIPERGAN50 is a high voltage converter, designed for medium power quasi- resonant ZVS (Zero Voltage Switching at switch turn-on) flyback converters, capable Product label to provide an output power up to 50 W in wide range. It integrates a complete set of features that provide an extremely flexible and easy to use chip and helps to design a highly efficient offline power supply. The ZVS quasi-resonant operation with the dynamic blanking time feature and the valley synchronization function, that turns on the power switch always at the valley of the drain resonance, reduces the switching losses and maximizes the overall efficiency at any input line and load condition. The advanced power management with the low quiescent helps to achieve low stand-by consumptions. The feed-forward Figure 1. TYPICAL APPLICATION compensation minimizes the maximum output peak power variation over the entire input voltage range. In addition to the above functions, the device offers protection features that considerably increase end-products safety and reliability: the output overvoltage protection, the overtemperature protection (OTP), the overload protection (OLP), the brown-in/out protection, that set the input voltage level to power on and power off the converter and the input overvoltage protection (iOVP), that protects the system in case of an abnormal increase of the input line. All the protections are auto-restart mode. DS13888 - Rev 1 - January 2022 www.st.com For further information contact your local STMicroelectronics sales office.VIPERGAN50 Pin connections and function 1 Pin connections and function Figure 2. Connection diagram (top view) Table 1. Pin function Pin N. Name Function 1,2,3,4, GND Device ground for current return. Input brown-in and brown-out protection. A 10 nF capacitor between this pin and GND is required. If 5 BR the feature is not used, the pin must be connected to GND. 6 iOVP Input OVP protection. If the feature is not required, the pin must be connected to GND. Not available for user. This pin is mechanically connected to the controller die pad of the frame. In order 7 N.A. to improve noise immunity it must be connected to GND. Start-up pin. Connect to the main through a resistor to provide the bias to the HV start-up generator. It is also used as upper resistor to set the BR and iOVP functions. Select a value in the range 10-30 M to minimize the residual consumptions. 8 HV A 220 pF ceramic capacitor must be connected between this pin and GND for proper functionality of high voltage start-up control logic. Blanking time adjustment and valley synchronization. During on-time, a resistor connected between TB and the auxiliary winding increases the blanking time proportionally to the input voltage, to reduce the switching losses at high line. 9 TB During off-time, a voltage divider connected among auxiliary winding, TB and GND allows adjusting the turn-on delay time after demagnetization, to precisely synchronize the GaN turn-on with the valley of the resonance. Connect the pin to GND if both functions are not used. Feedback. This pin is used to set the peak current value required by the control loop for a given output load. 10 FB The pin is the input for the optocoupler. A level 100 mV below the threshold V activates the burst- FBB mode operation. A level close to the threshold V approaches the cycle-by-cycle overcurrent set point. FBH 11 ZCD ZCD. Transformer s demagnetization sensing for quasi-resonant operation. DS13888 - Rev 1 page 2/37