发明名称 |
Integrated circuit with precision current source |
摘要 |
An integrated circuit with precision current source includes a first MOSFET, a second MOSFET, an op-amp and a resistor formed on a common semiconductor substrate. The first MOSFET is characterized by a first multiplier (xM1) and the second MOSFET is characterized by a second multiplier (xM2) where a ratio of xM2 to xM1 is greater than one. An inverting input of the op-amp is coupled to a drain of the first MOSFET and an output of the op-amp is coupled to a gate of the first MOSFET. A negative feedback circuit limits a rise in output current under low output voltage conditions. |
申请公布号 |
US9148140(B1) |
申请公布日期 |
2015.09.29 |
申请号 |
US201414170557 |
申请日期 |
2014.01.31 |
申请人 |
Maxim Integrated Systems, Inc. |
发明人 |
Tanase Gabriel E. |
分类号 |
H03K17/56;H03K17/687;H05B33/08 |
主分类号 |
H03K17/56 |
代理机构 |
TIPS Group |
代理人 |
TIPS Group |
主权项 |
1. A method for providing high current with low dropout and current limiting comprising:
splitting an output current at a current output node into a first current which flows through a series connection of a first MOSFET and a sensing resistor to ground and a second current which flows through a second MOSFET to ground, where the second current is greater than the first current; maintaining a first gate-to-source voltage at the first MOSFET which is substantially equal to a second gate-to-source voltage at the second MOSFET, wherein an output of an operational amplifier (op-amp) is directly connected to a gate of the first MOSFET, a current source is directly connected between a gate of the second MOSFET and ground, and a resistor is directly connected between the output of the op-amp and the second MOSFET; and using negative feedback to limit a current flowing through the second MOSFET. |
地址 |
San Jose CA US |