Filter modules - Our range of filters at a glance

 

 

Programmable Switched Capacitor Filter (SCF) Module:

-10th order Low Pass, Root raised Cosine

This module provides the user with an off-the-shelf Programmable Filter, capable of a wide range of filtering applications, where the desired cut-off frequency is either unknown by the user or the user requires a filter that can be reconfigured and re-used in a wide number of applications. By adjusting a single 11-turn variable resistor and setting 3 jumpers, the user of this module can select a cut-off frequency between 2kHz and 350kHz. The module can operate from double or single sided supplies and accepts differential or single-ended inputs. The filter can be configured to work from an external clock.

 

 

Low Pass, Continuous Time Filter Module with Programmable Cut-off Frequency and Gain:

- 8th Order Elliptic Type

This module can act as either an antialiasing or reconstruction filter for our SCF module and as a general purpose continuous time antialiasing or low pass filter. By rotating a 16-position switch, the user can select a cut-off frequency between 10kHz to 150kHz, in 10kHz steps. A second 16-position switch allows the user to adjust the gain of the the filter between 1 and 16, in 1v/v steps.

No other components are required to implement a programmable filter with one of these modules

 

 

Fixed Frequency High/low Pass Filter Module:

- 2nd/3rd Order Butterworth, Chebychev or Bessel Responses

This module is a Sallen and Key circuit configuration filter with unity gain in the pass-band. It can be used to realise 3rd order low or high pass filters up to 100kHz and 2nd order low-pass filters up to 1MHz with appropriate choice of op-amp. When used as a 2nd order low-pass filter, the 1st R-C stage can be used as a 1st order “roofing” filter to prevent high frequency components getting into the op-amp which are beyond its capability to suppress.

 

The module can be purchased ready built to the customers own specification. Contact us by phone or e-mail to discuss your filtering requirements. We will help you with the selection of the right filter for your application and if we think we can make the filter you need we will provide an estimated cost and delivery time. Alternatively, fill in and submit the following form and we'll contact you back.

 

 

 

Fixed Frequency High/Low/Band Pass Filter Module:

- 4th to 8th Order Butterworth, Chebyshev or Bessel Responses

This module includes 4 single amplifier blocks which could be configured to provide up to 4 bi-quadratic, low-pass or high-pass, filter stages. Each stage is realised in Sallen and Key circuit configuration. The 1st block is preceeded by a passive R-C stage which can be used as a 1st order “roofing” filter to prevent high frequency components from entering the op-amp. Additionally, the passive RC stage could be used to make the overall filter an odd order. Stages not being used for filtering can be used as buffers/gain stages.

This module can be purchased ready built to the customers own specification. Contact us by phone or e-mail to discuss your filtering requirements. We will help you with the selection of the right filter for your application and if we think we can make the filter you need we will provide an estimated cost and delivery time. Alternatively, fill in and submit the following form and we'll contact you back.

 

 



Table of current range of filter modules
Name Type Order Response
Programmable Switched Capacitor Filter (SCF) Low-pass 10th Root raised cosine
Programmable Continuous Time Filter (CTF) Low-pass 8th Elliptic
Fixed Frequency Continous Time Filter Low/high-pass 2nd or 3rd Butterworth, Chebychev, Bessel
Fixed Frequency Continous Time Filter Low/high/band-pass 4th-8th Butterworth, Chebychev, Bessel