I. Nakamura and M. Takemura, “Fast Respoinse of a Very Low-Level dc Current Amplifier Using Improve ment of Feedback Resistor Shielding Structure,” IEICE Transactions on Electronics, Vol. J72-C-II, No. 10, 1989, pp. 885-892.

has been cited by the following article:

• TITLE: Design of a Switched Capacitor Negative Feedback Circuit for a Very Low Level DC Current Amplifier

  AUTHORS: Hiroki Higa, Naoki Nakamura

  KEYWORDS: DC Amplifier; Small Current Measurement; Switched Capacitor

  JOURNAL NAME: Circuits and Systems, Vol.4 No.4, August 12, 2013

  ABSTRACT: To miniaturize a very low level dc current amplifier and to improve its output response speed, the switched capacitor negative feedback circuit (SCNF), instead of the conventionally used high-ohmage resistor, is presented in this paper. In our system, a switched capacitor filter (SCF) and an offset controller are also used to decrease vibrations and offset voltage at the output of the amplifier using SCNF. The theoretical output voltage of the very low level dc current amplifier using SCNF is obtained. The experimental results show that the unnecessary components of the amplifier’s output are much decreased, and that the response speed of the amplifier with both the SCNF and SCF is faster than that using high-ohmage resistor.