An input-free V/sub T/ extractor circuit using a two-transistor differential amplifier

An RF Energy Harvester With 44.1% PCE at Input Available Power of -12 dBm

“…In this design, is generated from a bandgap circuit and is made adjustable through an external resistor to account for process and temperature variations. A threshold-voltage-tracking circuit as that in [27] can be used to generate for better robustness. The switching occurs more frequently when the power level increases, and the However, the change of changes as indicated in Fig.…”

Sub-1 V Supply Nano-Watt MOSFET-Only Threshold Voltage Extractor Circuit

“…For example, [7] uses a continu ous transistor model [8] and proposes a circuit based on the channel conductance-to-current ratio ( gch / id) methodology, requiring a good estimation of the specific current of the fabrication process to correctly bias the transistor. Still it is hard to make any fair comparison, since circuits from [2][3][4][5][6] are based on different definitions for VTO• We do not state that these solutions are not good but our topology is the only one that works in the n W range, being more interesting for low power applications.…”

“…A threshold voltage extractor is a circuit that ideally de livers the estimated VTO value as a voltage directly from its operational conditions, without parametric setups, curve fitting and/or any subsequent calculations. Through the years, many circuits have been proposed for this purpose [2], [3], [4], [5] and [6], but all of them are based on the strong inversion quadratic model for the drain current. In a few topologies another inversion regime is used for the MOSFET VTO extraction.…”

Low-Power Analog Circuits for Sub-Band Speech Processing

“…The circuit used here was first reported by R. Fried and C. Enz in Electronics Letters, 1997[4]. An alternative approach is presented in[14]. In this alternate method, there are limitations on the input voltage levels to prevent the transistors in the circuit from getting cut off or getting saturated.…”

“…In this alternate method, there are limitations on the input voltage levels to prevent the transistors in the circuit from getting cut off or getting saturated. But the main limiting factor is that, the ciruit presented in[14] operates in strong-inversion, making it unsuitable for low-power applications. Only a single MOSFET is used to convert the voltage to current for each input and even the output current is transformed to voltage using only a single such MOSFET.…”