发明名称 |
Light receiving circuit having an automatic threshold control circuit for forming and allowing electric current flowing between a second potential line and first and second connection points |
摘要 |
A light receiving circuit includes a photodiode, a transimpedance amp having a feedback resistor, an electric current comparator and an automatic threshold control circuit that includes a current mirror circuit for forming a current according to the mirror effect. With this light receiving circuit, regardless of how powerful the input light signal is, low pulse width distortion characteristics can be achieved. |
申请公布号 |
US8847140(B2) |
申请公布日期 |
2014.09.30 |
申请号 |
US201213605800 |
申请日期 |
2012.09.06 |
申请人 |
Kabushiki Kaisha Toshiba |
发明人 |
Sugizaki Masayuki;Sakura Shigeyuki |
分类号 |
H01J40/14 |
主分类号 |
H01J40/14 |
代理机构 |
Patterson & Sheridan, LLP |
代理人 |
Patterson & Sheridan, LLP |
主权项 |
1. A light receiving circuit comprising:
a photodiode for converting a light signal into an electric signal, having one end connected to a first potential line and the other end connected to a first internal terminal; a transimpedance amp having a feedback resistor with one end connected to the first internal terminal, a first MOS transistor of a first electric conduction type with a gate connected to the first internal terminal and a drain connected to a second internal terminal, and a first constant electric current source connected between the second internal terminal and a second potential line; an electric current comparator having a second MOS transistor of the first electric conduction type with a drain connected to an output terminal, a source connected to the first potential line, and a gate connected to the second internal terminal, and a second constant electric current source connected between the output terminal and the second potential line; and an automatic threshold control circuit having a current mirror circuit for forming an electric current flowing between the second potential line and a first connection point, and allowing an electric current to flow between the second potential line and a second connection point connected to the output terminal, a third constant electric current source with one end connected to the second potential line and the other end connected to the first connection point, and a third MOS transistor of the first electric conduction type with a drain connected to the first connection point, a source connected to the first potential line, and a gate connected to the second internal terminal. |
地址 |
Tokyo JP |