Transconductance (g) cell based analog and/or digital circuitry

Abstract

Transconductance (g)-cell based circuitry is well suited for low power, low voltage complementary metal oxide silicon (CMOS) design in deep sub micro technology. This circuitry includes a gcell as the basic building block. As such, it is desirable to have the transconductance of the gcell to be constant against temperature and process corners. The present disclosure describes various g-cell based circuitry having a controllable transconductance. Preferably, the controllable transconductance can be selectively controlled to be equal to the inverse of the value of an on-chip resistor. For example, the g-cell based circuitry can sense the transconductance of an internal replica unit and can use negative feedback circuitry to cause this transconductance to be approximately equal a value of an on-chip resistor. However, in some situations, a value of this on-chip resistor is not accurately controlled. Therefore, the present disclosure also discloses a manner of calibrating the g-cell based circuitry against an external resistor with a known accurate value.