| 发明名称 |
PROGRAMMABLE CURRENT SOURCE FOR A TIME OF FLIGHT 3D IMAGE SENSOR |
| 摘要 |
A programmable current source for use with a time of flight pixel cell includes a first transistor. A current through the first transistor is responsive to a gate-source voltage of the first transistor. A current control circuit is coupled to the first transistor and coupled to a reference current source to selectively couple a reference current of the reference current source through the first transistor during a sample operation. A sample and hold circuit is coupled to the first transistor to sample a gate-source voltage of the first transistor during the sample operation. The sample and hold circuit is coupled to hold the gate-source voltage during a hold operation after the sample operation substantially equal to the gate-source voltage during the sample operation. A hold current through the first transistor during the hold operation is substantially equal to the reference current. |
| 申请公布号 |
US2016054447(A1) |
申请公布日期 |
2016.02.25 |
| 申请号 |
US201414464453 |
申请日期 |
2014.08.20 |
| 申请人 |
OMNIVISION TECHNOLOGIES, INC. |
发明人 |
Sun Tianjia;Wang Rui;Dai Tiejun |
| 分类号 |
G01S17/89;G01S7/484;G01S17/42 |
主分类号 |
G01S17/89 |
| 代理机构 |
|
代理人 |
|
| 主权项 |
1. A programmable current source for use with a time of flight pixel cell, comprising:
a first transistor having a gate terminal, a source terminal, and a drain terminal, wherein a current through the first transistor is responsive to a gate-source voltage of the first transistor; a current control circuit coupled to the first transistor and coupled to a reference current source, wherein the current control circuit is coupled to selectively couple a reference current of the reference current source through the first transistor during a sample operation; and a sample and hold circuit coupled to the first transistor, wherein the sample and hold circuit is coupled to sample a gate-source voltage of the first transistor during the sample operation, wherein the sample and hold circuit is coupled to hold the gate-source voltage during a hold operation after the sample operation substantially equal to the gate-source voltage during the sample operation, wherein a hold current through the first transistor during the hold operation is substantially equal to the reference current. |
| 地址 |
Santa Clara CA US |
