Realization of Current-Mode Inverting and Non-inverting Schmitt Trigger Circuit using Current Follower Transconductance Amplifier (CFTA)

Abstract

This article proposes a current mode inverting and non-inverting Schmitt trigger circuit, which utilizes a Current Follower Transconductance Amplifier (CFTA) and its application in square and triangular wave generators. The hysteresis of a Schmitt trigger is directly influenced by the process variations and transistor mismatches. This issue is more challenging in applications where the level of noise and disturbances is not predictable. To overcome this deficiency, Schmitt triggers with tunable hysteresis can be used as a practical solution. The suggested circuit consists of a single CFTA analog building block laterally with one grounded resistor. The grounded resistor makes the realization of the above-mentioned circuit possible. The proposed circuit has low input impedance and high output impedance, which is preferred in current mode (CM) circuits. It is characterized by adjustable thresholds and low power consumption. It provides both inverting and non-inverting responses without extra floating elements. Additionally, it has electronically adjustable threshold levels and a wide bandwidth. All these specifications have been validated through PSPICE simulations. The design focuses on reducing power consumption by incorporating active elements and grounded resistors. It's Optimizing for low voltage operation, while effectively managing current to ensure high performance without excessive energy use. It is an efficient and low-power method for generating square and triangular waves. The PSPICE simulation results are illustrated, and the given results coincide well with the theoretical expectation. The total power consumption is 1.26mW at ±1.5V supply voltage.

Keywords

• Schmitt trigger
• CFTA
• Current mode