Drive circuit with over-voltage protection for use with pixel cells and other circuits
AssigneeAgilent Technologies, Inc.
InventorMatthew M. Borg
Life of this patent
Estimating the term…
Abstract
A drive circuit that produces an over-voltage signal and protects circuit components from the over-voltage signal (i.e., such that circuit components operate within process specification limits). A photosensitive pixel cell can be driven by the drive circuit. Use of the drive circuit increases dynamic range of the pixel cell and reduces "ghost images." Control logic selectively passes an over-voltage signal to individual rows of a 2-D pixel array.
Claims21
An integrated circuit apparatus, comprising:
- an over-voltage circuit, that is capable of operating at a given power supply voltage level, and that produces an over-voltage signal that is greater in magnitude than said power supply voltage level;
- a gate circuit that controllably passes said over-voltage signal, wherein a bias voltage of said gate circuit floats relative to said over-voltage signal so as to provide over-voltage protection at said gate circuit;
- wherein said gate circuit includes a transistor that is configured to controllably pass said over-voltage signal, said transistor effectively having an input and an output and a control electrode, and wherein said floating relative bias voltage is delivered to said control electrode;
- wherein said output is coupled to a node in a path through which a capacitive voltage from a device coupled at said output can be drained;
- and
- wherein a buffer transistor device is coupled between said output and said node to protect components in said voltage drain path from said over-voltage signal at said output.
An over-voltage creating and passing apparatus, comprising:
- a semiconductor substrate having a functional electronic circuit formed therein;
- an over-voltage creating circuit formed in said same semiconductor substrate and having power supply rails of ground and a supply voltage, said over-voltage creating circuit creating an over-voltage signal that is greater in magnitude than the difference between said rails;
- and
- an over-voltage passing circuit provided in said same semiconductor substrate and coupled to said over-voltage circuit that selectively passes said over-voltage signal from said over-voltage circuit to said functional circuit.
An integrated circuit apparatus, comprising:
- a ground and a V.sub.DD conductor;
- a capacitor for storing a supplemental voltage;
- a circuit that adds said supplemental voltage and an input signal of V.sub.DD or less to produce an over-voltage signal greater than V.sub.DD ;
- and
- an over-voltage passing circuit including a gating device for selectively passing said over-voltage signal.
An over-voltage producing integrated circuit apparatus, comprising:
- an over-voltage circuit that is capable of operating at a given power supply voltage level and creates an over-voltage signal that is greater in magnitude than said power supply voltage level;
- and
- a gate circuit that controllably passes said over-voltage signal, wherein a bias voltage of said gate circuit floats relative to said over-voltage signal so as to provide over-voltage protection at said gate circuit.
Dependencies are inferred from the claim text.