公开(公告)号：US06680642B2

公开(公告)日：2004-01-20

申请号：US10154045

申请日：2002-05-23

Applicant: David J. Edell ,  Sean V. Sexton ,  Ying-Ping Liu

Inventor： David J. Edell ,  Sean V. Sexton ,  Ying-Ping Liu

IPC: G05F110

CPC classification number: G05F1/10

Abstract: A precision current source is disclosed that includes a voltage setting circuit that precisely sets the voltage across a range setting resistor to set the current flowing in a load resistance connected in series with the range setting resistor. The voltage setting circuit precisely sets the voltage across the range setting resistor as a function of an input reference voltage. The voltage setting circuit includes an instrumentation amplifier that determines the voltage across the range setting resistor and the difference between this voltage and the reference voltage is used drive a drive voltage amplifier. The drive voltage amplifier output adjusts to minimize the difference between the reference voltage and the voltage across the range setting resistor. Other embodiments include the use of a DC blocking capacitor to allow only AC coupling and various nulling. circuits to remove any charge buildup on a DC blocking capacitor.

Abstract translation: 公开了一种精密电流源，其包括电压设定电路，其精确地设定跨越范围设定电阻器的电压，以设定与与量程设定电阻器串联连接的负载电阻中流动的电流。 电压设置电路根据输入参考电压精确地设置范围设置电阻两端的电压。 电压设定电路包括一个仪表放大器，用于确定范围设定电阻器两端的电压，并且该电压与参考电压之差用于驱动驱动电压放大器。 驱动电压放大器输出调整为最小化参考电压和范围设置电阻两端的电压之间的差异。 其他实施例包括使用隔直流电容器仅允许AC耦合和各种零位。 电路去除直流阻塞电容器上的任何电荷积累。