In-system reprogrammable 5th-order lowpass filter

A Lattice Semiconductor UK product story

Edited by the Electronicstalk editorial team Dec 18, 2001

Lattice Semiconductor has added to its ispPAC programmable analogue device family with the ispPAC81 in-system programmable continuous time filter.

Lattice Semiconductor has added to its ispPAC programmable analogue device family with the ispPAC81 in-system programmable continuous time filter.

The ispPAC81 implements tens of thousands of 5th order lowpass filters with corner frequencies ranging from 10 to 75kHz.

The ispPAC81device is an in-system programmable, precision, all-in-one, continuous-time 5th-order lowpass filter.

This device can implement filters in Butterworth, Chebychev, elliptical and other topologies.

It is a sequel to Lattice Semiconductor's award-winning ispPAC80 device.

The ispPAC80 addresses 50 to 750kHz needs, while the new ispPAC81 device extends that range downwards to 10kHz.

"The task of implementing higher-order filters gets more complicated as the frequency of operation is reduced", said Andy Robin, VP of New Venture Business for Lattice.

"Engineers need to handle larger capacitors and resistors with lower tolerance ratings.

The ispPAC81 device offers the user unprecedented accuracy of filter implementation, in a remarkably small PCB area coupled with reduced design time and increased manufacturability".

In DSP systems, an ispPAC81 device is ideal for implementing anti-alias and reconstruction filters.

Systems using this device will be able to operate at a reduced sampling rate and also will be more manufacturable, thus reducing the overall system cost.

The ispPAC81 device's lower frequency range makes it very attractive for use in vibration analysis systems reducing noise and improving dynamic range.

The frequency range of the ispPAC81 device is also suited for applications like ultrasonic systems, GPS, radar, systems that use velocity and acceleration transducers and many others.

The ispPAC81 device is supported by Lattice's popular PAC-Designer version 1.3 software.

PAC-Designer software is an intuitive schematic design entry and simulation tool.

A new capability introduced in this latest version is manufacturing support library functions.

These functions can be used by developers of automated test systems to calibrate the analogue parameters of their circuit on the manufacturing line to compensate for other components' tolerances, resulting in higher performance, higher yield and reduced time and cost.

The PACsystem80/81 is a low cost development tool designed to enable designers to build quick prototypes of their circuit implementation and to measure its performance.

The design implemented using the PAC-Designer software is downloaded into the device through the ispDownload cable that connects to the PC's parallel port.

The PACsystem80/81 is comprised of an evaluation board for both the ispPAC80 and the ispPAC81, an ispDownload cable, ispPAC handbook, PAC-Designer v1.3 software, and samples of the ispPAC80 and ispPAC81 devices.

The ispPAC81 device in industrial temperature grade (-40 to +85C) is priced under $7 per device in thousands.

The ispPAC81 device is available in both 16-pin SOIC and 16-pin DIL packages.

The ordering part numbers of the devices in these two packages are ispPAC81-01SI and ispPAC81-01PI, respectively.

PACsystem80/81 development kits are available through authorised Lattice distributors or on the Lattice website at a suggested retail price of $149.

(This was Electronicstalk's Top Story on 17 December 2001).