Reference design demonstrates digital power advantages

Chandler, AZ[NASDAQ: MCHP] — Microchip Technology announces its Pure Sine Wave Uninterruptible Power Supply (UPS) Reference Design, which is based on the dsPIC33F “GS” series of digital-power Digital Signal Controllers (DSCs).

This reference design demonstrates how digital-power techniques—when applied to UPS applications—enable easy modifications through software, the use of smaller magnetics, intelligent battery charging, higher efficiency, compact designs, lower audible and electrical noise via a purer sine-wave output, USB communication and a lower overall bill-of-materials cost.

Though not available for purchase, all of the documentation, software and Gerber files needed to build this reference design can be obtained for free from Microchip’s Web site. Additionally, demonstration units are available from the Company’s field sales force.

Video available through YouTube: http://www.youtube.com/watch?v=Chc2VD4fV10

Microchip’s UPS Reference Design utilizes high-frequency switching techniques to implement three optimized digital power-conversion stages. The Push-Pull DC/DC Converter stage boosts the battery voltage to drive the inverter stage.

The Full-Bridge Inverter stage creates Pure Sine Wave AC power to the load. Finally, the Flyback Switch-Mode Charger charges the battery from the AC line power.

The dsPIC33F “GS” series of digital-power DSCs from Microchip is the heart of this Offline UPS reference design. The dsPIC33F controls all critical operations of the system, as well as the housekeeping operations.

Fast and reliable switchover from mains to inverter, and vice-versa, is done intelligently to ensure that power to the load is transferred without surges and sags. The reference design also features USB connectivity and an LCD panel, for communication with the external world.

“This reference design jumpstarts our customers’ advanced UPS designs and brings the benefits of digital power to their products quickly,” says Sumit Mitra, vice president of Microchip’s High Performance Microcontroller Division. “It uses the flexible dsPIC33F

“GS” series of DSCs, which enables easy customization and configuration through simple modifications to the control software.”

Digital Power brings many benefits, such as enabling greener power via smarter and more efficient systems. It can lower the carbon footprints of many UPS designs, and help ease the burden on the world’s strained power grids. Additional key design specifications include: 

• Input range AC.
  • 85 to 135 V, 60 HZ +/-3.
  • 145 to 280 V, 50 HZ +/-3.
• Output voltage AC.
  • 110V @ 60 Hz +/-3.
  • 220V @ 50 Hz +/-3.
• DC input.
  • 36V (12 VDC x3).
  • Lead acid battery.
• Adjustable charging current.
• Efficiency >85 percent.
• Pure sine wave output with THD <5 percent.
• Rating
  • 1000 VA steady-state output power.
  • 1350 VA peak power (Surge).
• Mains to battery transfer time <10 ms.
• Supports crest factor of 3:1.
• Fault indications.

For more information visit www.microchip.com