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US5686848A Expired / Lapsed US ⏱️ 0.0 years remaining

Power-up/power-down reset circuit for low voltage interval

Assignee: Mosaid Technologies Inc
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Filing: 1996-04-29
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Granted: 1997-11-11
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Expires: 2016-04-29
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Abstract

Abstract A power up, power down reset circuit formed of charge storage apparatus for receiving and storing charge from one pole of a voltage supply, a pair of complementary field effect transistors having source-drain circuits connected in series aiding direction between the charge storage apparatus and another pole of the voltage supply, apparatus for connecting the one pole of the voltage supply to a gate of one transistor of the pair of transistors, apparatus for applying a voltage derived from the one pole of the voltage supply but having a value reduced from voltage of the voltage supply, to a gate of another transistor of the pair of transistors, and apparatus for providing a reset pulse from a junction between the source-drain circuits of the pair of transistors.

Inventors

  • 👤 Ian Mes
  • 👤 Graham Allan

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-04 17:09
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/22; H03K17/223

Claims Analysis

Total Claims: 10
Claim 1
Independent Claim 134 words
A power up, power down reset circuit comprising: (a) charge storage means for receiving and storing charge from one pole of a voltage supply, (b) a pair of complementary field effect transistors having source-drain circuits connected in series aiding direction between the charge storage means and another pole of the voltage supply, (c) means for connecting said one pole of the voltage supply directly to a gate of one transistor of said pair of transistors, (d) means for applying a voltage derived from said one pole of the voltage supply but having a value reduced from the voltage of the voltage supply, to a gate of the other transistor of said pair of transistors, and (e) means for providing a reset pulse from a junction between the source-drain circuits of said pair of transistors.
Claim 2
Dependent Claim 134 words
A power up, power down reset circuit comprising: (a) charge storage means for receiving and storing charge from one pole of a voltage supply, (b) a pair of complementary field effect transistors having source-drain circuits connected in series aiding direction between the charge storage means and another pole of the voltage supply, (c) means for connecting said one pole of the voltage supply directly to a gate of one transistor of said pair of transistors, (d) means for applying a voltage derived from said one pole of the voltage supply but having a value reduced from the voltage of the voltage supply, to a gate of the other transistor of said pair of transistors, and (e) means for providing a reset pulse from a junction between the source-drain circuits of said pair of transistors.
Claim 3
Dependent Claim 17 words
A reset circuit as defined in claim 1 in which said pair of transistors form an inverter.
Claim 4
Dependent Claim 49 words
A reset circuit as defined in claim 2 in which said applying means comprising a resistor voltage divider connected between said one pole of the voltage supply and ground, a tap of the voltage divider being connected to the gate of said another transistor of said pair of transistors.
Claim 5
Dependent Claim 69 words
A reset circuit as defined in claim 2 in which said applying means comprising diode means connected between said one pole of the voltage supply and the gate of said another of said transistors and a capacitor means having capacitance larger than a gate capacitance of said another of said transistors connected between said one pole of the voltage supply and the gate of said another of the transistor.
Claim 6
Dependent Claim 53 words
A reset circuit as defined in claim 4 in which said one pole of the voltage supply is positive (VCC), the pair of field effect transistors comprising a PMOS field effect transistor having its source connected to the charge storage means and an NMOS field effect transistor having its source connected to ground.
Claim 7
Dependent Claim 48 words
A reset circuit as defined in claim 5 in which the charge storage means comprises a storage capacitor, the capacitor being connected through a further diode to VCC, and to ground, the diode being connected in a polarity direction such as to block discharge of the storage capacitor.
Claim 8
Dependent Claim 50 words
A reset circuit as defined in claim 6 further including a second NMOS field effect transistor having its drain connected to the junction of the storage capacitor and the further diode, its emitter to ground, and its gate to the junction between the source-drain circuits of said pair of transistors.
Claim 9
Dependent Claim 47 words
A reset circuit as defined in claim 4 further including an output transistor having its source-drain circuit connected between a discharge node and one of the poles of the voltage supply, and its gate connected to the junction between the source-drain circuits of said pair of transistors.
Claim 10
Dependent Claim 43 words
A reset circuit as defined in claim 6 further including an output NMOS transistor having its source connected to ground, its drain connected to a discharge node, and its gate to the junction between the source drain circuits of said pair of transistors.

References Cited (Backward Citations)

US4746822A Cited
US4983857A Cited
US5203867A Cited
JPH03206709A Cited
JPH05235727A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2000-11-10 2001-05-12 2001-11-11 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2004-11-10 2005-05-12 2005-11-11 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2008-11-10 2009-05-12 2009-11-11 $7700.00 Window Closed / Lapsed

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