A 40-dB dynamic range, dc–4-GHz parallel-summation logarithmic amplifier is presented in this paper. The amplifier realizes a piecewise approximation to an exact logarithmic response. A design procedure that yields breakpoints on the exact response is described, along with delay-matching networks for parallel-summation logarithmic amplifiers. The amplifier was constructed in a 35-GHz silicon bi...

State-of-the-art logarithmic amplifiers use a transimpedance technique based on the exponential dependence between input current and output voltage as exhibited by p-n junction diodes, bipolar transistors and MOS transistors in the subthreshold region. Presented is a CMOS current-input current-output logarithmic amplifier based on a translinear Ohm’s law principle which involves a floating volt...

A new OTA-based logarithmic-control variable gain current amplifier (LCCA) is presented. It consists of two Operational Transconductance Amplifier (OTA) and two PMOS transistors biased in weak inversion region. The circuit operates from 0.6V DC power supply and consumes 0.6 μW. The linear-dB controllable output range is 43 dB with maximum error less than 0.5dB. The functionality of the proposed...

In this work, parallel feedback amplifiers (PFAs) are presented as a means of generating ultra broadband logarithmic amplifiers. The low frequency gain equations and an AC model of PFAs are given. A circuit is presented for automatic, on-chip DC offset error reduction. In addition, circuits for achieving temperature and process stable, high power, low noise logarithmic amplifiers are described....

Abstrac t-A logarithmic current-to-voltage converter for measuring DC currents in a wide dynamic range (from 1 pA to 1 mA) is described here. The converter is based on an operational amplifier circuit with a standard commercially-available LED diode used as a nonlinear feedback. A temperature compensation method requiring only one reference amplifier was used. This significantly reduces the com...