Browse Prior Art Database

Dual Source Series Regulator

IP.com Disclosure Number: IPCOM000088802D
Original Publication Date: 1977-Aug-01
Included in the Prior Art Database: 2005-Mar-04
Document File: 2 page(s) / 29K

Publishing Venue

IBM

Related People

Norton, DE: AUTHOR

Abstract

The device depicted in the figure assures that the output voltage of a regulator remains in tolerance at cold temperature and low value of bulk supply. In addition, it assures that at higher chip temperatures the current is supplied by the lower bulk supply.

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 81% of the total text.

Page 1 of 2

Dual Source Series Regulator

The device depicted in the figure assures that the output voltage of a regulator remains in tolerance at cold temperature and low value of bulk supply. In addition, it assures that at higher chip temperatures the current is supplied by the lower bulk supply.

This device automatically steers the current for a series regulator from two bulk supplies VL and VH depending on whether the lower of the two supplies can deliver the current and still retain the output voltage tolerance. Generally, on monolithic chips it is often desired to supply current from the lower value supply consistent with the circuit requirements. This allows chip power to be kept at as low a level as possible. However, this places a significant burden on the power distribution of the low voltage supply at high current. Furthermore, the feature of low power is most important at the higher chip temperatures and is of very little concern when the chip is cold. The regulator circuit assures that, when hot, the regulator's output current is delivered from the VL (2.75 + or - 4%) voltage supply, When the chip is cold and VL is at its low value (2.75 - 4%-distribution drop), then the current is supplied from VH (+5 volts). In essence, the 2.75-volt supply may range from +2.75 -4% to +5 +10% while still retaining the output tolerance of the regulator.

With VL high enough to supply the output reguirements, transistor T1 is on, VBT1 = 4 VBE, VCO1T2 = 4 VBE-VSH, VBT2-VOUT = 3 VB...