Browse Prior Art Database

Low voltage radio battery with integrated DC/DC converter

IP.com Disclosure Number: IPCOM000019174D
Original Publication Date: 2003-Sep-03
Included in the Prior Art Database: 2003-Sep-03
Document File: 1 page(s) / 21K

Publishing Venue

Motorola

Related People

Christoph Gebauer: AUTHOR

Abstract

An integrated DC/DC converter provides an additional higher supply voltage inside a low voltage radio battery case

This text was extracted from a Microsoft Word document.
This is the abbreviated version, containing approximately 92% of the total text.

Low voltage radio battery with integrated DC/DC converter

by Christoph Gebauer

Abstract

An integrated DC/DC converter provides an additional higher supply voltage inside a low voltage radio battery case

Introduction

This paper describes improvements in the field of power supply methods used for portable radios.

Problem(s) To Be Solved

Modern portable radios use low voltage batteries e.g. 3.6V lithium cells for power supply. But mostly at least one higher supply voltage is needed for tuning or control purposes e.g. charge pump circuitry in a PLL or as DAC reference voltage. That means that the low voltage battery has to be converted to an additional higher supply voltage by a switched regulator (DC/DC-converter) on the radio PCB. Because of the voltage converting method which causes a large frequency spectrum the placement as well as the shielding and grounding are realize difficulty. Furthermore the switching regulator occupies valuable PCB space.

Proposed Solution to the Problem(s)

The idea to resolve the problem is to locate the switching regulator circuitry inside the battery case taking advantage of the battery low impedance as charging capacitance. The switched regulator output voltage is available at an additional battery output pin. An optional shielding of the switching regulator can avoid radiated emission that impacts the radio performance (self quieting, transmitting spurs). The switched regulator could be switched on/off e.g. by a control line. Generally the adva...