| 摘要 |
An input amplifier 62 for a DMM is coupled to test probes 66, 88 and comprises a buffer 64 and an integrator 74,80,84. The integrator acts to bring the potential of the test probe 66 to that of the DMM earth, whereby the potential of the output node 94 with respect to the DMM earth becomes equal and opposite to the potential between test nodes 66 and 88. The circuit provides a high signal-to-noise ratio, a stable input impedance, and a good frequency response. |
