Home // International Journal On Advances in Systems and Measurements, volume 12, numbers 1 and 2, 2019 // View article
Authors:
Hiroo Wakaumi
Keywords: CMOS; operational amplifier; dynamic switching; switched capacitor circuit; filter
Abstract:
Wideband filters employing Operational Amplifiers (OP Amps) are required in sensing devices such as video cameras for environment sensing. A high-speed low-voltage Folded-Cascode (FC) OP Amp with a Dynamic Switching Bias (DSB) circuit capable of processing video signals, which enables low power consumption, high gain with wide bandwidths, and a wide dynamic range, was proposed. Through simulations, it was shown that the OP Amp with the reduced 3-V power supply is able to operate at a 14.3 MHz dynamic switching rate, allowing processing video signals, and a dissipated power of 57 % compared to that in the conventional 5-V power DSBFC OP Amp while keeping a 0.6 V wide output dynamic range. The 2nd-order switched capacitor Low-Pass Filter (LPF) and the 4th-order switched capacitor LPF were tested as its applications. The response of the former was near the theoretical frequency response within frequencies below 5 MHz. The sample-hold circuit in the latter was optimized considering the feed-through phenomenon. The latter showed practical level gains in frequencies over 5 MHz within a stop-band while showing a sharp roll-off near the theoretical frequency response within frequencies below 4 MHz. The power dissipation of either of these switched capacitor LPFs was also reduced to nearly 57 % of that in each switched capacitor LPF with the conventional 5-V power DSBFC OP Amp.
Pages: 32 to 40
Copyright: Copyright (c) to authors, 2019. Used with permission.
Publication date: June 30, 2019
Published in: journal
ISSN: 1942-261x