Dismiss
InnovationQ will be updated on Sunday, Oct. 22, from 10am ET - noon. You may experience brief service interruptions during that time.
Browse Prior Art Database

Precision Voltage Source With High Speed Polarity Control

IP.com Disclosure Number: IPCOM000077956D
Original Publication Date: 1972-Oct-01
Included in the Prior Art Database: 2005-Feb-25
Document File: 2 page(s) / 38K

Publishing Venue

IBM

Related People

Hellwarth, GA: AUTHOR [+2]

Abstract

Precisely controlled voltages of either polarity with equal or controllably proportional magnitudes, are produced by a switching arrangement associated with a common avalanche or zener diode type element.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 75% of the total text.

Page 1 of 2

Precision Voltage Source With High Speed Polarity Control

Precisely controlled voltages of either polarity with equal or controllably proportional magnitudes, are produced by a switching arrangement associated with a common avalanche or zener diode type element.

Floating reference voltage Vz is developed by driving zener diode 10 with a floating current source or with two current sources 11 and 12, as shown in Fig. 1. Current source 11 supplies a bias current 1 to diode 10 and source 12 provides a sink for this current.

The potential difference between points A and B is then set by the diode zener-voltage Vz and floats on any potential applied to point A or B. Two switches 15 and 16 selectively apply either a potential V1 to point B or V2 to Point A.

The output voltages are then V1 + Vz at point A or V2 - Vz at point B, respectively. For V1 and V2 zero, the output potentials at A and B become, respectively, +Vz or -Vz providing selectable reference voltages of equal magnitude and opposite polarities. A single reference voltage with high-speed polarity control can be obtained by placing a voltage divider between the terminals A and B. With equal resistors 17 and 18, the reference +1/2 Vz is available at C.

Fig. 2 shows an implementation of the two current source technique. Devices 21 and 22 are two current sources biased by like devices 24 and 23 and resistors 25 - 29. The two current sources drive diode 20. Inverted bipolar transistors 30 and 31 are used for swit...