Device for regulating the threshold voltages of I.G.F.E.T. transistors circuitry

US4311923A · kind A · utility

Assignee

• Ebauches, S.A. · CH

Inventors

• Jakob Luscher · Carouge, CH
• Andreas Rusznyak · Chêne-Bougeries, CH

Key dates

• Filing date: Jun 21, 1979
• Grant date: Jan 19, 1982
• Expiry date: Jun 21, 1999

Classification

• Technology area (CPC H): Electricity
• CPC primary: H03K17/145
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

To regulate the threshold voltage of insulated-gate field-effect transistors (IGFETs) in an integrated circuit, such as that of an electronic wristwatch, capacitors and other IGFETs of the same conductivity type as those of the controlled circuit are incorporated in the substrate thereof to form a regulating transistor, a constant-current generator and one or more voltage multipliers. The current generator and the main electrodes (source and drain) of the regulating transistor, whose gate is tied to its source, are connected in series across a generator of reference voltage constituted by one or more such multipliers. One of the main electrodes of the regulating transistor is connected, directly or through a further voltage multiplier, to the reference terminal (O) of the controlled circuit while still another such multiplier may be inserted between the ouptut of the constant-current generator and the interconnected source and gate electrodes of the regulating transistor. The current generator may comprise a storage capacitor periodically charged through a first IGFET (T.sub.1) in the presence of the leading edge of an applied pulse, such as a half-cycle of a square wave, and disch…