VIPER25LN

VIPER25 Datasheet Off-line high voltage converters Features • • • • • • • • 800 V avalanche rugged power section Quasi-resonant (QR) control for valley switching operation Standby power < 50 mW at 265 Vac Limiting current with adjustable set point Adjustable and accurate overvoltage protection On-board soft-start Safe auto-restart after a fault condition Hysteretic thermal shutdown Application • • Product status link VIPER25 • Adapters for PDA, camcorders, shavers, cellular phones, cordless phones, videogames Auxiliary power supply for LCD/PDP TV, monitors, audio systems, computer, industrial systems, LED driver, No el-cap LED driver, utility power meter SMPS for set-top boxes, DVD players andrecorders, white goods Description Product label VIPER25 is an off-line converter with an 800 V rugged power section, a PWM control, double levels of overcurrent protection, overvoltage and overload protections, hysteretic thermal protection, soft-start and safe auto-restart after any fault condition removal. Burst mode operation and device very low consumption helps to meet the standby energy saving regulations. The quasiresonant feature reduces EMI filter cost. Brownout and brown-in function protects the switch mode power supply when the rectified input voltage level is below the normal minimum level specified for the system. The high voltage start-up circuit is embedded in the device. Figure 1. Typical topology DS6205 - Rev 5 - February 2022 For further information contact your local STMicroelectronics sales office. www.st.com VIPER25 Block diagram 1 Block diagram Figure 2. Block diagram DS6205 - Rev 5 page 2/37 VIPER25 Typical power 2 Typical power Table 1. Typical power Part number VIPER25 230 VAC 85-265 VAC Adapter(1) Open frame(2) Adapter (1) Open frame(2) 18W 20 W 10 W 12 W 1. Typical continuous power in non ventilated enclosed adapter measured at 50 °C ambient. 2. Maximum practical continuous power in an open frame design at 50 °C ambient, with adequate heat sinking. DS6205 - Rev 5 page 3/37 VIPER25 Pin settings 3 Pin settings Figure 3. Connection diagram (top view) Note: The copper area for heat dissipation has to be designed under the DRAIN pins. Table 2. Pin description Pin n. SO16 Name Function 1...2 GND This pin represents the device ground and the source of the power section. 3 N.C. Not available for user. It can be connected to GND (pins 1-2) or left not connected. 4 N.A. Not available for user. It can be connected to GND (pins 1-2) or left not connected. 5 VDD Supply voltage of the control section. This pin also provides the charging current of the external capacitor during power-up. This is a multifunction pin. 6 DS6205 - Rev 5 1. Input for the zero current detection circuit for transformer demagnetization sensing.(i.e. RLIM, RFF, ROVP and DOVP, Figure 34) 2. User defined drain current limit set-point and voltage feed forward. The resistor, RLIM, connected between ZCD pin and GND causes the current IZCD and then it limits the static maximum drain current. 3. The resistor RFF, between ZCD pin and the auxiliary winding, performs the feed-forward operation and then the drain current limitation changes according to the converter input voltage. 4. Output overvoltage protection. Avoltage exceeding VOVP threshold, (see Table 7. Controller section), shuts the IC down reducing the device consumption. This function is strobed and digitally filtered for high noise immunity. ZCD 7 FB Control input for duty cycle control. Internal current generator provides bias current for loop regulation. A voltage below the threshold VFBbm activates the burst-mode operation. A level close to the threshold VFBlin means that we are approaching the cycle-by-cycle over-current set point. 8 BR Brownout protection input with hysteresis. A voltage below the threshold VBRth shuts down (not latch) the device and lowers the power consumption. Device operation restarts as the voltage exceeds the threshold VBRth + VBRhyst. It can be connected to ground when not used. 13...16 DRAIN High voltage drain pin. The built-in high voltage switched start-up bias current is drawn from this pin too. Pins connected to the metal frame to facilitate heat dissipation. page 4/37 VIPER25 Electrical data 4 Electrical data 4.1 Maximum ratings Table 3. Absolute maximum ratings Symbol VDRAIN Value Min. Max. Drain-to-source (ground) voltage Unit 800 V EAV Repetitive avalanche energy (limited by TJ = 150 °C) 5 mJ IAR Repetitive avalanche current (limited by TJ=150 °C) 1.5 A 3 A IDRAIN Pulse drain current (limited by TJ = 150 °C) VZCD Control input pin voltage (with IZCD = 1 mA) -0.3 Self limited V VFB Feedback voltage -0.3 5.5 V VBR Brown-out input pin voltage (with IBR = 0.5 mA) -0.3 Self limited V VDD Supply voltage (IDD = 25 mA) -0.3 Self limited V IDD Input current 25 mA Power dissipation at TA