Switched-capacitor finite impulse response interpolators without the input sample-and-hold filtering effect

This paper presents new Switched-Capacitor (SC) Finite Impulse Response (FIR) interpolators whose frequency responses are no longer affected by the input sample-and-hold filtering effect that occurred in previous circuits. Two different types of polyphase architectures are discussed, one based on the Direct-Form (DF) and another employing Active-Delayed Blocks (ADB). The DF polyphase structure is analysed either with input sampled-and-held signals or with arbitrary input signal formats, while the ADB structure is presented only with arbitrary input signal formats. Examples are given to illustrate both types of SC FIR interpolator circuits.