Summit Microelectronics - Applications Note 35

This application note was jointly authored by Volterra Semiconductor and Summit Microelectronics.

Tech Support: Applications Note 35
Lossless Tracking Procedure and Results Summary
Reference Design: Volterra VT223 Regulator and SMT4214 TRAKKER™

The layout of the HTML version of the application note follows the page breaks in the PDF version. To navigate, you may click on a page number (below) to jump to another other page. You may also download/view the entire application note in PDF format [PDF format].

00 1 2 3 4 5 6 7 8 9 Next -->

Lossless Tracking Procedure and Results Summary
Reference Design: Volterra VT223 Regulator and SMT4214 TRAKKER™

PAGE 1

Download this entire Applications Note in PDF format.

BACKGROUND

As discussed in AN-26, Summit Microelectronic's SMT4004 also performs low level, loss-less supply voltage tracking of a discrete PWM controller often used to generate system level power. This Application Note describes another example of low-level tracking using Summit's SMT4214 Quad Tracking Manager and Volterra's VT223C-ADJ Step-Down Switching Regulator. A complete solution is provided presented using the low-level tracking technique to properly power-on a Xilinx FPGA.

Typical Supply Voltage Tracking

As depicted in Figure 1 through Figure 3, the SMT4214 typically tracks power supply voltages using series power MOSFETs. An on-board charge pump (VGG_CAP) drives the MOSFET gate terminals well into enhancement upon command from the PWR_ON# pin or via the I²C interface. The SMT4214 also tracks down the supplies by de-asserting the PWR_ON# pin or by using the I²C software interface command. In addition to providing voltage tracking, the use of the series MOSFETs provides a means of quickly disconnecting the power supplies from the load using the voltage/current fault monitoring features of the SMT4214.

Figure 1: SMT4214 Tracking 4 Power Supplies Using Series Power MOSFETs

00 1 2 3 4 5 6 7 8 9 Next -->

SUMMIT Microelectronics, Inc. reserves the right to make changes to the products contained in this publication in order to improve design, performance or reliability. SUMMIT Microelectronics, Inc. assumes no responsibility for the use of any circuits described herein, conveys no license under any patent or other right, and makes no representation that the circuits are free of patent infringement. Charts and schedules contained herein reflect representative operating parameters, and may vary depending upon a user's specific application. While the information in this publication has been carefully checked, SUMMIT Microelectronics, Inc. shall not be liable for any damages arising as a result of any error or omission.

SUMMIT Microelectronics, Inc. does not recommend the use of any of its products in life support or aviation applications where the failure or malfunction of the product can reasonably be expected to cause any failure of either system or to significantly affect their safety or effectiveness. Products are not authorized for use in such applications unless SUMMIT Microelectronics, Inc. receives written assurances, to its satisfaction, that: (a) the risk of injury or damage has been minimized; (b) the user assumes all such risks; and (c) potential liability of SUMMIT Microelectronics, Inc. is adequately protected under the circumstances.

Revision 1.0 - This document supersedes all previous versions. Please check the Summit Microelectronics Inc. web site at www.summitmicro.com for updates.
"Xilinx" and the Xilinx logo are registered trademarks of Xilinx, Inc.
Silicon Power Solutions™ and Volterra are registered trademarks of Volterra Semiconductor Corporation.
I²C is a trademark of Philips Corporation.

Copyright © 2003 SUMMIT MICROELECTRONICS, Inc.
Power Management for Communications™

The Adobe PDF logo and Adobe Acrobat logo are either registered trademarks or trademarks of Adobe Systems Incorporated in the United States and/or other countries.