Intelligent bias voltage generating circuit

• US 5,892,394 A
• Filed: 09/20/1996
• Issued: 04/06/1999
• Est. Priority Date: 07/19/1996
• Status: Expired due to Fees

• Current Assignee: Holtek Semiconductor Incorporated
• Original Assignee: Holtek Microelectronics, Inc. (United Microelectronics Corporation)
• Inventors: Wu, Rong-Tyan
• Primary Examiner(s): Cunningham, Terry D.
• Application Number:
  US08/717,069
• Time in Patent Office: 928 Days
• Field of Search: 327/143, 327/312, 327/313, 327/314, 327/320, 327/321, 327/323, 327/325, 327/328, 327/333, 327/530, 327/541, 327/543, 327/545, 327/546
• US Class Current: 327/546
• CPC Class Codes: G05F 3/247 producing a voltage or current as a predetermined function of the supply voltage

Abstract

An intelligent bias voltage generating circuit capable of providing an electronic device with a reliable bias signal includes a power input terminal which is electrically connected to a power generating device for providing a power input, and a bias voltage generating circuit which is electrically connected to the power input terminal for responding to power fluctuations and generating a bias voltage signal output by a multi-section linear variation method.

Claims

1. A circuit for generating a bias voltage for an electronic device, said bias voltage generating circuit comprising:

a detecting circuit;

a control circuit; and

a multi-section bias voltage generating circuit comprising a plurality of bias voltage generating sections;

said detecting circuit being fed by a power source signal and producing output signals in response to power fluctuations;

said control circuit generating control signals in response to said output signals, said control signals being applied to said multi-section bias voltage generating circuit alternately, such that only one of said sections is active at a given time;

said multi-section bias voltage generating circuit producing said bias voltage, an amplitude of said bias voltage depending on which section of said multi-section bias voltage generating circuit is active.

2. A circuit according to claim 1, wherein said detection circuit further comprises a plurality of diode circuits.

3. A circuit according to claim 2, wherein each diode circuit is of said plurality of diode circuits an equivalent circuit of diodes formed by MOS transistors that are connected by diode connection.

4. A circuit according to claim 1, wherein said control circuit further comprises a plurality of logic gates for producing a plurality of sets of control signals capable of responding to the potential of said power source status detection signal and enabling one of said compound number of sets of logic gates to produce and output a corresponding control signal.

5. A circuit according to claim 1, wherein each section of said multi-section bias voltage generating section circuit comprises a plurality of bias voltage generating circuits capable of responding to said plurality of control signals and enabling one of said plurality of bias voltage generating circuits to produce and output a corresponding bias voltage signal.

6. A circuit according to claim 5, wherein each bias voltage generating circuit of said plurality of bias voltage generating circuits comprises an on/off control device.

7. A circuit according to claim 6, wherein said on/off control device comprises a PMOS or a NMOS transistor.