npi DPA 2FX/FS

The DPA 2FX differential amplifier / filter is designed to amplify and filter small bio-electrical signals. The input voltage range is ±12 V, the inputs are protected up to ±15 V. Two overload-LEDs indicate if the linear region of the amplifier is exceeded. All inputs and the output are BNC-connectors.

The INPUT impedance is 10 MΩ. Thus, the module can be used for direct recording of bioelectric signals, e.g. from peripheral nerves. Using the differential INPUT configuration common mode signals and noise are removed allowing processing of signals with small amplitudes. The INPUT stage is followed by the offset compensation operated with two controls (10-turn potentiometer and ±0.1 V, ±1 V, ±10 V toggle switch).

The GAIN range is x1 to x10000 and can be set with two switches (1-2-5-10-20-50-100 rotary switch and 1-10-100 toggle switch). The output signal is passed through the high- and lowpass filter.

The DPA filter module is also available as DPA 2FS with different filter specifications.

Specifications

INPUT RANGE:
±12 V; protected up to ±15 V

INPUT IMPEDANCE:
10 MΩ related to ground

INPUT CAPACITANCE:
30 pF

AC COUPLING AT INPUT:
corner frequency of 0.1 Hz (if AC/0/DC-switch at BNC connector is switched to AC)

OFFSET COMPENSATION:
±0.1 V, ±1 V or ±10 V, set by toggle switch and ten-turn potentiometer

HIGHPASS FILTER: DPA 2FX
single pole, attenuation: -6 dB/octave, corner frequencies (Hz): 3, 30, 100, 300, 400, 500, 600, 800, 1k, 3k, 10k

LOWPASS FILTER: DPA 2FX
single pole, attenuation: -6 dB/octave, corner frequencies (Hz): 30, 100, 300, 500, 700, 900, 1.3k, 1.5k, 1.7k, 3k, 10k, 20k

HIGHPASS FILTER: DPA 2FS
single pole, attenuation: -6 dB/octave, corner frequencies (Hz): OFF, 0.3, 5, 100, 300, 400, 500, 600, 800, 1k, 3k, 10k

LOWPASS FILTER: DPA 2FS
single pole, attenuation: -6 dB/octave, corner frequencies (Hz): 30, 100, 300, 500, 700, 1k, 1.3k, 1.5k, 3k, 5k, 10k, 20k

GAIN:
rotary-switch: 1-2-5-10-20-50-100

GAIN RANGE:
selectable with toggle switch x1, x10, x100

GAIN and GAIN RANGE are multiplied giving a maximum amplification of 10000

OVERLOAD LEDS:
starting to light up at ±10 V

OUTPUT:
impedance 50 Ω, max ±12 V, short circuit protected

DIMENSIONS:
front panel 12 HP (60.6 mm) x 3U (128,5 mm), 7" (175 mm) deep.

Options

DPA 2FX Low and high pass one-pole Bessel filter module with gain

DPA 2FS Low and high pass one-pole Bessel filter module with gain

Customized configurations are possible.