Power-up detector circuit

Details Power-up detector circuit Power-up detector circuit

1996-07-02

1998-10-27

Callahan, Timothy P.

Miscellaneous active electrical nonlinear devices, circuits, and

Signal converting, shaping, or generating

Synchronizing

327 80, 327198, H03L 700

Patent

active

058282513

ABSTRACT:
An integrated circuit includes a power-up detector circuit that includes a node that is held at a charged state by a capacitor during normal operation. The voltage on the node is sensed by a sensing circuit, typically an inverter that produces a power-up reset pulse when power is initially applied. However, the voltage on the node may not properly discharge in all cases during brief power interruptions. Therefore, to increase the reliability of the power-up detector, a discharge circuit is included to help ensure that the voltage sensed by the power supply voltage-sensing circuit is at the proper level when the power supply voltage drops below a given level. The discharge circuit comprises a first capacitor that turns on a node discharge transistor when the power supply voltage drops below the given level. To provide protection against false discharge, a second capacitor is optionally provided that prevents the discharge transistor from conducting during very brief power supply voltage interruptions. In a preferred embodiment, the second capacitor is effectively disabled at low power supply voltages. This facilitates conduction of the discharge transistor for power supply voltage interruptions resulting from slow changes (low slew rate) in the power supply voltage.

REFERENCES:
patent: 4366560 (1982-12-01), McDermott et al.
patent: 4797584 (1989-01-01), Aguti et al.
patent: 5027320 (1991-06-01), Pathak et al.
patent: 5109163 (1992-04-01), Benhamida
patent: 5396115 (1995-03-01), Coffman et al.
patent: 5528184 (1996-06-01), Gola et al.

Affiliated with

Also associated with

Rating

Power-up detector circuit does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Power-up detector circuit, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Power-up detector circuit will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1616359