FPAA for Analog Circuit Design
Field Programmable Analog Arrays (FPAA) have ability to:
ÃƒËœ Translate complex analog circuits to a simple set of low-level functions giving the analog equivalent of a Field Programmable Gate Arrays (FPGA), providing a basis for the development of dynamically reconfigurable analog/digital hardware.
ÃƒËœ Place analog functions under real-time software control within the system.
ÃƒËœ By providing the analog equivalent of logic gates, FPAAs give designers the ability to describe analog functions such as gain stages and filters without reference to op amps, capacitors, resistors.
ÃƒËœ A (FPAA), built in CMOS technology, contains:
Ã‚Â§ operational amplifiers
Ã‚Â§ banks of programmable switched capacitors
Ã‚Â§ filters for analog signals
ÃƒËœ The chip is divided into 20 identical, configurable analog blocks (CABs), each composed of an operational amplifier, five capacitor banks, and switches that can be used to interconnect the cell components and determine their operation.
ÃƒËœ FPAA technology has four main elements:
1. FPAA Software
2. Configurable Analog Modules (CAM)
3. FPAA silicon
4. Configurable Analog Blocks (CAB)
ÃƒËœ Trends from the digital to analog design:
ÃƒËœ EDA tools and design modules for complete analog design automation â€œ remove the complexity
ÃƒËœ Pre-built and pre-tested FPAAs â€œ reduce analog implementation from months to minutes
ÃƒËœ Reconfigurability and real-time updating of the FPAA during operation â€œ allows one piece of silicon to continually adapt to maintain precision and/or perform new functions
It develops a FPAA synthesis tool, synthesizes behavioral level analog descriptions into its implementations. This synthesis flow, consists of four major phases:
Placement and Routing
l. Function decomposition
The high level description of analog functions can be cataloged into two groups as:
ll. Macro-cell synthesis
The sub-routine of macro-block generation maps the decomposed transfer functions into SC ckts, fit in the structure of (CAB) in the targeted FPAA chip making design space large .
lll. Placement and Routing
Maps the synthesized analog circuit into the FPAA chip
reducing the performance degradation caused by the
parasitic effects in the interconnection networks using
parameters like cost function © & signal sensitivity (S).
2.Configurable Analog Modules (CAM):
CAMs move the design process from the component level to the functional level. All of these functions are available:
ÃƒËœ Filter stages
ÃƒËœ Gain stages
ÃƒËœ Summing /difference stage
ÃƒËœ Voltage multiplication
all having user-programmable attributes.
Applications of FPAA:
ÃƒÂ¼ Integrating analog functionality and saving up to 90% development time.
ÃƒÂ¼ Calibrating or repurposing the FPAA during operation.
ÃƒÂ¼ Integrating the analog I/O around processor- and/or DSP-based systems.
ÃƒÂ¼ The ability of the FPAA to be changed dynamically.
FPAA Product Overview (AN10E40 ):
ÃƒËœ Drag and drop circuit design
ÃƒËœ User parameterizable CAMs/IP Modules pre-package common analog functions.
ÃƒËœ Single-ended switched capacitor as FPAA base.
ÃƒËœ Architecture with analog switch fabric
ÃƒËœ Input/output structure with Single-ended 13 analog I/O cells
ÃƒËœ Performs Bandwidth DC to 250 kHz & Broadband SNR up to 65 dB
ÃƒËœ Silicon platform
ÃƒËœ Static FPAA reconfigurability
ÃƒËœ Use of EDA tools
The FPAA technology offers a device with very attractive and universal features, which can be used and exploited in various applications. The FPAA can be very easily and inexpensively utilized in studentâ„¢s laboratories such as:
ÃƒËœ The IDT interface provides virtual wiring (drag and drop) and removes the requirement for linking of hardware components,
ÃƒËœ Students can quickly build complex analog hardware,
ÃƒËœ Students can see the relationship between analog and digital signal processing, can experience design work, and hardware testing, etc.,
ÃƒËœ Students are stimulated to perform additional experiments and develop new features of FPAA for practical use.
FPAA will find more applications because of its flexibility, low cost and ease of programming.