Back to results
US 10,484,676 B2Granted
Circuit and method for on-chip testing of a pixel array
AssigneeSTMicroelectronics (Grenoble 2) SAS
InventorsRichun Fei, Salvador Mir, Jocelyn Moreau
Life of this patent
Estimating the term…
Abstract
Testing of control wires of a pixel array of an image sensor is performed by applying a signal transition to a control wire and detecting, based on a voltage signal detected on the control wire, the duration of at least part of the signal transition on the control wire. An electrical fault in the control wire is indicated based on a comparison of the detected duration to a threshold.
Claims22
A method, comprising:
- applying a signal to a control wire connected to control inputs of a plurality of pixels in a row of a pixel array of an image sensor;
- detecting, based on a change of a voltage of the applied signal on the control wire, a transition period of time over which the voltage of said applied signal on the control wire changes from a first threshold voltage to a second threshold voltage;
- and
- detecting an electrical fault in the control wire if the detected transition period of time exceeds a reference period of time.
1 more element
A circuit, comprising:
- a control circuit configured to apply a signal to a control wire connected to control inputs of a plurality of pixels in a row of a pixel array of an image sensor;
- and
- a fault detection circuit coupled to the control wire and configured to:
- determine based on a change in voltage of the applied signal on the control wire a transition period of time over which the voltage of said applied signal on the control wire changes from a first threshold voltage to a second threshold voltage;
- and
- detect an electrical fault in the control wire if the determined transition period of time exceeds a reference period of time.
3 more elements
A system, comprising:
- a plurality of testing circuits, each testing circuit coupled to a corresponding one of a plurality of control wires, wherein each testing circuit comprises:
- a control circuit configured to apply a signal to a control wire connected to control inputs of a plurality of pixels in a row of a pixel array of an image sensor;
- and
- a fault detection circuit coupled to the control wire and configured to:
- determine based on a change in voltage of the applied signal on the control wire a time duration over which the voltage of said applied signal on the control wire changes from a first threshold voltage to a second threshold voltage;
- and
- detect an electrical fault in the control wire if the determined time duration exceeds a reference time duration;
- and
- a plurality of synchronous devices configured to store information indicating the detected electrical fault, wherein the synchronous devices are daisy-chained together for serial output of the stored information for each of the plurality of control wires.
6 more elements
Dependencies are inferred from the claim text.