New impulse sampled IIR switched-capacitor interpolators

This paper presents new Switched-Capacitor (SC) Infinite Impulse Response (IIR) Interpolators employing an efficient combination of Active-Delayed Blocks (ADB) polyphase structures and recursive direct-form II structures with frequency responses no longer affected by the input sample-and-hold filtering effect. Two different architectures are analysed: the first requires slower Operational Amplifiers (OAs) while the second allows the reduction of the number of clock phases and ADBs (1 OA per ADB). Examples are given to illustrate the behaviour of both types of SC interpolators with arbitrary input signal formats.