A new current-mode Tow-Thomas biquad filter based on employing current differencing transconductance amplifiers (CDTAs) is introduced. The filter circuit uses two grounded capacitors and realizes a lowpass (LP) and a bandpass (BP) responses, simultaneously. The proposed circuit is electronically tunable by adjusting the biasing current of the CDTAs. The circuit requires no component matching co...

The Libbrecht-Hall circuit is a well-known, low-noise current driver for narrow-linewidth diode lasers. An important feature of the circuit is a current limit to protect the laser diode. As the current approaches the maximum limit, however, the noise in the laser current increases dramatically. This paper documents this behavior and explores simple circuit modifications to alleviate this issue.

This paper proposes a low voltage CMOS nano-ampere current reference circuit and presents its performance with circuit simulations in 180-nm technology. The proposed circuit consists of biasvoltage, current-source and offset-voltage sub-circuits with most of MOSFETs operating in subthreshold region. Simulation results show that the circuit generates a stable reference current of 110-nA in suppl...