LP4FP & LP8FP Flat/Pulse Low-Pass Filter Technology

You Want Your Analog Data to Come Clean Before Digital Conversion

The 28000 Signal Conditioning System has a variety of high performance filter characteristics available for HP, LP or BP Precision filtering.

28000 System Filter Characteristics

Flat/Pulse Low-Pass Filters

Our new choice of LP4FP 4-pole or LP8FP 8-pole flat/pulse low-pass filters provide the user with the versatility to address applications in either the time or frequency domain and are available on many 28000 card models. Frequencies can range as high as 204.6 kHz with fixed frequency choices for economy.

LP4F and LP4P Amplitude Response
LP8F and LP8P Amplitude Response

Flat Mode Low-Pass Filters

Precision LP4F and LP8F “flat” mode characteristics are specified to have outstanding passband flatness equivalent to the Butterworth yet deliver roll-off characteristics that are superior to the Butterworth response.

The LP4F and LP8F are excellent choices for anti-aliasing filtering and for applications such as spectral analysis. The LP8F has zero passband ripple and over 100 dB/octave attenuation slope.

LP4F and LP8F Versus Butterworth Amplitude Response
LP4F and LP8F Butterworth Passband Response

Pulse Mode Low-Pass Filters

For the time domain, there are the LP4P and LP8P “pulse” mode low-pass filters. These filters have excellent transient response and phase linearity making them ideal filters for time domain applications including transient (shock) measurements and time-domain waveform analysis … all with roll-off characteristics superior to their Bessel filter counterparts.

LP8P Versus 8-Pole Bessel Amplitude Response
LP8P and LP4P  Passband Response
LP8P and LP4P Step Response

High-Pass and Band-Pass Filters

For high-pass filtering, we offer the HP4F 4-pole and HP8F 8-pole characteristics. For band-pass filtering, choose the HP4F/LP4FP band-pass characteristic to provide programmable bandwidth and center frequency filters. For more selective band-pass filtering, cascade an HP8F with an LP8F.

Band-Pass Amplitude Response HP4F and LP4F Cascaded
Band-Pass Amplitude Response HP8F and LP8F Cascaded

Traditional Filters

Of course, we also offer the traditional filter types such as Butterworth and Bessel characteristics … just ask!

Regardless of which filter you chose, you can be assured that a “Precision Filter” will have very tightly controlled response with better than 0.1dB adherence to the theoretical amplitude characteristic and better than 1 degree channel-to-channel phase match.