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Field programmable analog array (FPAA) based on switched capacitor circuits operating with operational amplifiers and numerous switches incorporate many classes (subsystems) of interconnections. Important components of the array are programmable capacitor banks, where interconnections and switches are used to make proper parallel connections of unit capacitors to obtain an application determined capacitance value. FPAA can implement various analog functions using set of configurable analog block (CAB) and programmable interconnect network. Each CAB can implement a number of analog signal processing functions such as amplification, integration, differentiation, addition, subtraction, multiplication, comparison, log, and exponential. The interconnection network routes signals from one CAB to another, and to and from the I/O blocks. A configuration bit string stores the information used to configure the FPAA.

FPAAs are designed in both the continuous-time and discrete-time domains. A discrete-time FPAA, designed with switched-capacitor or switched-current technology has advantages in terms of programmability and insensitivity to resistance in programming switches, but is limited to signal frequencies significantly lower than the clock frequency. A continuous-time FPAA, usually designed using transconductors, has advantages in terms of bandwidth, but has a narrower programming range for its parameters, and its performance is prone to degradation from circuit parasitic.

Application:
• Complex analog filter circuits,
• Closed loop control systems,
• Sensor signaling conditioning,
• Adaptive DSP front end,
• Custom analog signal processing.