VIPER26 Datasheet Fixed frequency VIPer plus family Features 800 V avalanche rugged power MOSFET allowing wide range V input range AC to be covered Embedded HV startup and sense-FET DIP-7 Current mode PWM controller Minimized system input power consumption: SO16 narrow Less than 30 mW 230 V in no-load condition AC DC Input Voltage DC Output Voltage Less than 400 mW 230 V with 250 mW load AC Limiting current with adjustable set point - Jittered switching frequency to reduce the EMI filter cost: 60 kHz 4 kHz (L type) DRAINDRAIN COMPCOMP 115 kHz 8 kHz (H type) VIPER26VIPER26 Embedded error amplifier GNDGND VDDVDD LIMLIM FBFB Hysteretic thermal shutdown Built-in soft-start for improved system reliability Protections with automatic restart: overload/short-circuit (OLP), feedback loop disconnection Application Auxiliary power supply for appliances Power metering Product status link LED drivers VIPER26 SMPS for set-top boxes, DVD players and recorders Product label Description The VIPER26 device is a smart high voltage converter that integrates an 800 V avalanche-rugged power MOSFET with PWM current mode control. The power MOSFET with 800 V breakdown voltage allows an extended input voltage range to be applied, as well as the size of the DRAIN snubber circuit to be reduced. This IC meets the most stringent energy-saving standards with very low consumption and burst mode operation under light load. The design of flyback, buck and buck boost converters is supported. The integrated HV startup, sense-FET, error amplifier and oscillator with jitter allow complete application designs with a minimum number of components. DS6901 - Rev 3 - October 2020 www.st.com For further information contact your local STMicroelectronics sales office.8 1 16 1 VIPER26 Pin settings 1 Pin settings Figure 1. Connection diagram (top view) SO16N DIP7 GND DRAIN GND DRAIN GND DRAIN N.C. DRAIN DRAIN VDD N.A. DRAIN VDD N.C. LIM N.C. LIMLIM FB N.C. FB COMP N.C. COMP Note: The copper area for heat dissipation has to be designed under the DRAIN pins. Table 1. Pin descriptions Pin number Name Function DIP7 SO16N Ground and MOSFET source. Connection of the source of the internal MOSFET and controller GND 1 1-2 ground reference. - 3 N.C. Not connected. This pin can be soldered to GND. Not available for user. This pin is mechanically connected to the controller die pad of the frame. In - 4 N. A. order to improve noise immunity, it is highly recommended to connect it to GND (pin 1,2). Controller Supply. An external storage capacitor has to be connected across this pin and GND. The pin, internally connected to the high voltage current source, provides the VDD capacitor charging 2 5 VDD current at startup and during fault conditions. A small bypass capacitor (0.1 F typ.) in parallel, placed as close as possible to the IC, is also recommended for noise filtering purposes. Drain current limitation. This pin allows setting the drain current limitation to a lower value than the default I value. The limit can be reduced by connecting an external resistor between this pin and Dlim 3 6 LIM GND. In case of high electrical noise, a capacitor may be connected between this pin and GND the capacitor value must be lower than 470 nF in order to not impact the functionality of the pin. The pin can be left open if the default drain current limitation, I , is used. Dlim Direct feedback. It is the inverting input of the internal transconductance E/A, which is internally referenced to 3.3 V with respect to GND. In a non-isolated converter, the output voltage information is 4 7 FB directly fed into the pin through a voltage divider. In primary regulation, the FB voltage divider is connected to the VCC. The E/A is disabled by soldering FB to GND. Compensation. It is the output of the internal E/A. A compensation network is placed between this pin and GND to achieve stability and good dynamic performance of the control loop. In case of 5 8 COMP isolated secondary side regulation, the internal E/A must be disabled and the COMP directly driven by the optocoupler to control the DRAIN peak current setpoint. Not internally connected. These pins must be left floating in order to ensure a safe clearance - 9-12 N.C. distance. MOSFET drain. The internal high voltage current source sinks current from this pin to charge the VCC capacitor at startup. These pins are mechanically connected to the internal metal PAD of the 7,8 13-16 DRAIN MOSFET in order to facilitate heat dissipation. On the PCB, the copper area must be placed under these pins in order to decrease the total junction-to-ambient thermal resistance, thus facilitating the power dissipation. DS6901 - Rev 3 page 2/34