Constant trans-conductance bias circuit for C-type inverter

Abstract

The invention discloses a constant trans-conductance bias circuit for a C-type inverter. The constant trans-conductance bias circuit comprises an inverter-based switched capacitor integrator and a constant trans-conductance bias circuit body, wherein an OTA in the inverter-based switched capacitor integrator is communicated with the constant trans-conductance bias circuit body through a modulating signal Vdda; the inverter-based switched capacitor integrator comprises an inverter composed of a first NMOS transistor and a first PMOS transistor; the constant trans-conductance bias circuit body comprises a mirror working point sensing device, a complementary type constant trans-conductance bias current source, an operational amplifier and an output load transistor; through the complementary constant trans-conductance bias current source, the total trans-conductance of a bias inverter can be constant, and prevented from changing along with the process bias and the temperature of the NMOS transistor and the PMOS transistor. Therefore, the unity-gain bandwidth and built-up time of the inverter can also keep constant when the process bias and the temperature change, and the stability of a circuit can be improved.

Description

technical field [0001] The invention relates to the technical field of integrated circuits, in particular to a constant transconductance bias circuit of a class-C inverter. Background technique [0002] With the development of integrated circuits, the feature size of transistors is getting smaller and smaller, the power supply voltage is reduced, the chip integration level is increased and the operating frequency is increased, and the power consumption per unit chip area is getting higher and higher. With the growth of the mobile and portable device market, the The requirement for low power consumption of integrated circuits is increasing, which puts forward requirements for low-voltage and low-power consumption design. However, as the power supply voltage decreases, the transistor threshold voltage does not decrease proportionally, and the input signal swing decreases, especially for the design of operational transconductance amplifiers (Operational Transconductance Amplifi...

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Problems solved by technology

[0004] However, a simple inverter can only provide a very low power supply rejection ratio (PSRR). Due to temperature-induced threshold voltage variation, the unity-gain bandwidth of the inverter will be strongly dependent on temperature. Since it operates in the subthreshold region, when the transistor At the slow process corner, the transconductance and current of the transistor will decrease, and the bandwidth and slew rate of the inverter will be severely reduced, causing performance loss

The quiescent current and bandwidth of the inverter are heavily dependent on the process, power supply voltage, temperature, and the circuit stability decreases

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