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Integrated Separately Switchable Current Sources

IP.com Disclosure Number: IPCOM000075546D
Original Publication Date: 1971-Oct-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 50K

Publishing Venue

IBM

Related People

Berger, HH: AUTHOR

Abstract

The integrated circuit device is shown in cross section in Fig. 1 and in plan view in Fig. 2. It provides three current sources, each separately switchable. Structurally, each current source essentially consists of a lateral transistor structure.

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Integrated Separately Switchable Current Sources

The integrated circuit device is shown in cross section in Fig. 1 and in plan view in Fig. 2. It provides three current sources, each separately switchable. Structurally, each current source essentially consists of a lateral transistor structure.

An N-type conductive semiconductor substrate 1 contains three P-type conductive diffused emitter zones E1, E2, and E3. Each of these emitter zones is surrounded by a frame-like diffused P-type conductive collector, zone C1, C2, or C3, respectively. The base zone is common to all three transistor structures and is the N-type semiconductor substrate. The contact for the base zone is via a diffused N+ conductive zone B.

An additional frame-like zone C1', C2', or C3', respectively, of the same conductivity type as the collector or emitter zone, is diffused into the base zone between the frame-like collector zone and the emitter zone. The emitter zones E1, E2, and E3 are connected to a common line 2 for supplying an emitter current Ie. The collectors C1, C2, and C3 are connected via lines 3, 4, and 5 and to associated loads, not shown, and to which are applied their associated collector currents Ic1, Ic2, and Ic3.

The additional zones C1', C2', and C3' are connected, via lines 7, 8, and 9 to associated switches S1, S2, S3, respectively, and to a suitable potential (ground). The common base region contact B is connected to suitable potential (ground) by way of line 6.

The potent...