VIPER22A SMPS Controller IC: Circuit, Equivalent and Datasheet

VIPER22A is a switched-mode power supply controller IC introduced by STMicroelectronics that has been extensively used in AC to DC Converters in offline power circuit designs. This controller IC consists of an in-built PWM controller with a power MOSFET.  The MOSFET is connected to the primary side of a power transformer which when switched will produce the required output voltage based on transformer design.

VIPER22A Pinout

VIPER22A Pin Description

Footprint

●Operating Voltage: 9 Volts – 38 Volts

●Internal Oscillator Frequency: 60 kHz

●Drain to Source Voltage: 730 Volts

●Feedback Current: 3 mA

●Typical Peak Current Limit: 0.7 A

●Off-state Drain Current: 0.1 mA

●Fall Time: 100ns

●Rise Time: 50ns

●Input Feedback Impedance: 1.2 Kohms

●SMPS Switching Controller IC

●AC to DC converter

●Available in PDIP and SO 8-pin Package

Example Circuit

As you can see in the example circuit above, the transformer plays an important role in the overall design. It has three coils, namely primary, secondary and auxiliary (the second coil on the primary side). The primary side of the transformer is connected to the rectified power supply voltage through the MOSFET in the Viper controller IC, and the power supply DC will be switched according to the feedback to the IC. The auxiliary coil of the transformer is used to power the Viper IC, and the secondary side of the transformer provides the required output voltage.

VIPER12A, AP8012

– Large input voltage range on the VDD pin accommodates changes in auxiliary supply voltage. This feature is well adapted to battery charger adapter configurations.

– Automatic burst mode in low load condition.

– Overvoltage protection in hiccup mode.

■Used in Low Power Supply Systems

■Used in LED Drivers

■Used in Remote Microcontroller Designs

■Used in SMPS Circuits

■Used in Auxiliary Power Supply

■Used in Industrial Applications

■Used in Battery Chargers

■Used in Automobiles

VIPER22A Mechanical Data

STMicroelectronics is a French-Italian multinational electronics and semiconductor manufacturer, headquartered in Plan-les-Oates near Geneva, Switzerland. 

The company originated from the merger of two state-owned semiconductor companies in 1987: "Thomson Semiconductors" in France and "SGS Microelettronica" in Italy. 

It is often referred to as "ST" and is the largest semiconductor chip manufacturer in Europe by revenue. STMicroelectronics corporate headquarters and EMEA regional headquarters are located in Geneva, while the holding company STMicroelectronics N.V. is incorporated in the Netherlands. 

The company's US headquarters are located in Koper, Texas. The Asia-Pacific region is headquartered in Singapore, while the Japan and South Korea operations are headquartered in Tokyo. The headquarter of the company in China is in Shanghai.