Voltage domain global shutter readout circuit timing

    公开(公告)号:US11750950B1

    公开(公告)日:2023-09-05

    申请号:US17804238

    申请日:2022-05-26

    CPC classification number: H04N25/75 H01L27/14612 H04N25/531 H04N25/77

    Abstract: A global shutter readout circuit includes a pixel enable signal and a first sample and hold (SH) signal that are configured to turn ON a pixel enable transistor and a first storage transistor at a first time during a global transfer period. The pixel enable signal is configured to begin a transition to an OFF level at a second time and complete the transition to the OFF level at a third time to turn OFF the pixel enable transistor. The first SH signal is configured to begin a transition to the OFF level at a fourth time, which occurs after the second and third times, and complete the transition to the OFF level at a fifth time to turn OFF the first storage transistor. An OFF transition duration between the fourth and fifth times is greater than an ON transition duration of the first SH signal at the first time.

    Real GS and OFG timing design for 1-by-2 shared HDR VDGS

    公开(公告)号:US12200388B2

    公开(公告)日:2025-01-14

    申请号:US18313957

    申请日:2023-05-08

    Abstract: An imaging system includes a pixel array with odd and even pixel cells. Each of the odd and even pixel cells includes a photodiode, a floating diffusion, a transfer transistor, a reset transistor, a lateral overflow integration capacitor (LOFIC), and an overflow gate (OFG) transistor. The imaging system further includes a readout circuit with a sample and hold (SH) circuit and an analog to digital converter. The OFG transistor of each of the odd and even pixel cells is configured to direct the image charge photogenerated by the respective photodiode away from the respective transfer transistor and reduce photodiode exposure shift during LOFIC readouts during a global transfer period.

    REAL GS AND OFG TIMING DESIGN FOR 1-BY-2 SHARED HDR VDGS

    公开(公告)号:US20240381002A1

    公开(公告)日:2024-11-14

    申请号:US18313957

    申请日:2023-05-08

    Abstract: An imaging system includes a pixel array with odd and even pixel cells. Each of the odd and even pixel cells includes a photodiode, a floating diffusion, a transfer transistor, a reset transistor, a lateral overflow integration capacitor (LOFIC), and an overflow gate (OFG) transistor. The imaging system further includes a readout circuit with a sample and hold (SH) circuit and an analog to digital converter. The OFG transistor of each of the odd and even pixel cells is configured to direct the image charge photogenerated by the respective photodiode away from the respective transfer transistor and reduce photodiode exposure shift during LOFIC readouts during a global transfer period.

    Resettle timing for low power pixel readout

    公开(公告)号:US11683611B1

    公开(公告)日:2023-06-20

    申请号:US17714738

    申请日:2022-04-06

    Inventor: Zheng Yang Ling Fu

    CPC classification number: H04N25/75 H04N25/709 H04N25/772

    Abstract: A pixel readout circuit includes an analog to digital converter coupled to the bitline output of the pixel circuit. A switch is coupled between the bitline output of the pixel circuit and a reference voltage. The switch is pulsed on and off a first time to settle the bitline to the reference voltage prior to an autozero operation of the analog to digital converter. The switch is pulsed on and off a second time to settle the bitline to the reference voltage after the autozero operation and prior to a first analog to digital conversion. The switch is configured to be pulsed on and off a third time to settle the bitline to the reference voltage after the first analog to digital conversion operation and prior to a second analog to digital conversion operation.

    Voltage domain global shutter readout circuit

    公开(公告)号:US11729529B1

    公开(公告)日:2023-08-15

    申请号:US17825797

    申请日:2022-05-26

    CPC classification number: H04N25/75 H04N25/53 H04N25/62 H04N25/65 H04N25/771

    Abstract: A global shutter readout circuit includes a reset transistor coupled between a reset voltage and a bitline. A pixel enable transistor is coupled between the reset transistor and a source follower transistor. First and second terminals of the pixel enable transistor are coupled together in response to a pixel enable signal coupled to a third terminal of the pixel enable transistor. A first storage transistor coupled to the second terminal of the pixel enable transistor and the gate of the source follower transistor. A first storage capacitor is coupled to the first storage transistor. A second storage transistor coupled to the second terminal of the pixel enable transistor and the gate of the source follower transistor. A second storage capacitor is coupled to the second storage transistor. A row select transistor is coupled to the source follower transistor to generate an output signal from the global shutter readout circuit.

    EVENT DRIVEN PIXEL FOR SPATIAL INFORMATION EXTRACTION

    公开(公告)号:US20220199671A1

    公开(公告)日:2022-06-23

    申请号:US17125619

    申请日:2020-12-17

    Abstract: An event driven sensor includes an arrangement of photodiodes including an inner portion laterally surrounded by an outer portion. An outer pixel cell circuit is coupled to generate an outer pixel value in response to photocurrent generated by the outer portion. The outer pixel value is a binned signal representative of an average value of brightness of incident light on the arrangement of photodiodes. An inner pixel cell circuit is coupled to the inner portion to generate an inner pixel value in response to photocurrent generated by from the inner portion. An event driven circuit is coupled to the outer pixel cell circuit and the inner pixel cell circuit. The event driven circuit is coupled to generate an output signal responsive to an inner brightness indicated by the inner pixel value relative to an outer brightness indicated by the outer pixel value.

    SAMPLE AND HOLD SWITCH DRIVER CIRCUITRY WITH SLOPE CONTROL

    公开(公告)号:US20210021769A1

    公开(公告)日:2021-01-21

    申请号:US16516067

    申请日:2019-07-18

    Abstract: A switch driver circuit includes a first transistor coupled between a voltage supply and a first output node. A second transistor is coupled between the first output node and a first discharge node. A first slope control circuit is coupled to the first discharge node to discharge the first discharge node at a first slope. A third transistor is coupled between the voltage supply and a second output node. A fourth transistor is coupled between the second output node and a second discharge node. A second slope control circuit coupled to the second discharge node to discharge the second discharge node at a second slope. The first and second slopes are mismatched.

    SAMPLE AND HOLD SWITCH DRIVER CIRCUITRY WITH SLOPE CONTROL

    公开(公告)号:US20220078360A1

    公开(公告)日:2022-03-10

    申请号:US17530316

    申请日:2021-11-18

    Abstract: A switch driver circuit includes a plurality of pullup transistors. The plurality of pullup transistors includes a first pullup transistor coupled between a voltage supply and a first output node. A plurality of pulldown transistors includes a first pulldown transistor coupled between the first output node and a ground node. A slope control circuit is coupled to the ground node. A plurality of global connection switches includes a first global connection switch coupled between the first output node and the slope control circuit.

    Sample and hold switch driver circuitry with slope control

    公开(公告)号:US11212467B2

    公开(公告)日:2021-12-28

    申请号:US16516067

    申请日:2019-07-18

    Abstract: A switch driver circuit includes a first transistor coupled between a voltage supply and a first output node. A second transistor is coupled between the first output node and a first discharge node. A first slope control circuit is coupled to the first discharge node to discharge the first discharge node at a first slope. A third transistor is coupled between the voltage supply and a second output node. A fourth transistor is coupled between the second output node and a second discharge node. A second slope control circuit coupled to the second discharge node to discharge the second discharge node at a second slope. The first and second slopes are mismatched.

    High dynamic range high speed CMOS image sensor design

    公开(公告)号:US11140352B1

    公开(公告)日:2021-10-05

    申请号:US17121423

    申请日:2020-12-14

    Abstract: A readout circuit for use in an image sensor includes a first sample and hold (SH) circuit coupled to a bitline that is coupled to a pixel array. A second SH circuit is coupled to the bitline. A bypass switch is coupled to the bitline, the first SH circuit, and the second SH circuit. An analog to digital converter (ADC) is coupled to the bypass switch. The bypass switch is configured to provide an image charge value from the pixel array to the ADC through the bitline, or through one of the first SH circuit or the second SH circuit in response to a switch select signal.

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