Key facts
- Brand
- STMicroelectronics
- Model
- VIPER20
- Industry
- Industrial
- Documents
- 4
- Languages
- EN
- Last added
- 2012-08-06
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STMicroelectronics AN1317 VIPer20 Non Isolated Power Supplies Application Note
This application note explains how to design non-isolated power supplies (1W to 5W) using the VIPer20 integrated switching device. It covers two main topologies: Buck and Inverter (Buck-Boost), detailing their schematics, operation principles, and differences. The document highlights that the VIPer20 replaces conventional PWM driver circuits and high-voltage MOSFETs, offering a compact and cost-effective solution for applications like home appliances and industrial motor control where galvanic isolation is not required.
The note provides design methodologies for selecting switching frequency, duty cycle, and inductor values. It discusses the startup sequence, output voltage regulation via the internal error amplifier, and specific considerations for low input voltage conditions, such as the need for zener diodes in Buck topology to prevent overvoltage. Detailed schematics and formulas for calculating component values are included for both topologies.
STMicroelectronics VIPER20 specifications
| Output Power Range | 1W to 5W |
|---|---|
| Minimum Turn On Time | 500 ns typ. |
| Recommended Switching Frequency Range | 20 kHz to 30 kHz |
Source: STMicroelectronics AN1317 VIPer20 Non Isolated Power Supplies Application Note
All STMicroelectronics VIPER20 documents by type
How to use the product for one specific task, with worked examples.
Ratings, dimensions and ordering codes, for selection and design work.
Questions answered in these manuals
What is the main advantage of using VIPer20 for non-isolated power supplies?
It replaces the conventional PWM driver circuit, associated high voltage Power MOSFET switch, and a full set of other passive components, allowing for simple, robust, and compact designs.
From: STMicroelectronics AN1317 VIPer20 Non Isolated Power Supplies Application Note
What is the typical switching frequency range recommended for these topologies?
The switching frequency is chosen just above audible values, in the 20 kHz to 30 kHz range.
From: STMicroelectronics AN1317 VIPer20 Non Isolated Power Supplies Application Note
What is the typical operating supply current at 12 V and 100 kHz?
At 12 V and 100 kHz the operating supply current is about 13 mA.
From: STMicroelectronics VIPer20/SP/DIP VIPer20A/ASP/ADIP Manual
What temperature triggers thermal shutdown?
Thermal shutdown occurs between 140 °C and 190 °C depending on the device.
From: STMicroelectronics VIPer20/SP/DIP VIPer20A/ASP/ADIP Manual
What is the typical oscillator frequency range?
The oscillator frequency is typically set between 90 kHz and 110 kHz.
From: STMicroelectronics VIPer20/SP/DIP and VIPer20A/ASP/ADIP Datasheet
Does the device include an undervoltage lock‑out?
Yes, it features an undervoltage lock‑out with hysteresis.
From: STMicroelectronics ViPer20/SP/DIP & VIPer20A/ASP/ADIP Datasheet