npi BF-48DGX

Low pass Bessel Filter Module with gain
Description

BF-48DGX 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 ±40 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 1 MΩ (other impedances are available on request). 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.

The one-pole Bessel HIGHPASS FILTER (option) has 11 corner frequencies (0.3 Hz - 10 kHz) and can be bypassed. The eight-pole Bessel LOWPASS FILTER has 12 corner frequencies (30 Hz - 20 kHz). The filter can also be bypassed. Optionally, a NOTCH filter can be used to eliminate 50 / 60 Hz noise. The NOTCH filter can be bypassed with a toggle switch. Filters and gain are monitored at BNC connectors (1V / step).

 

Specifications

INPUT RANGE:
±12 V; protected up to ±40 V

INPUT IMPEDANCE:
1 MΩ related to ground (other values possible), 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 by toggle switch and ten-turn potentiometer

LOWPASS FILTER:
8-pole Bessel, attenuation: -48 dB/octave, corner frequencies (Hz): 30, 100, 300, 500, 700, 900, 1.3k, 1.5k, 1.7k, 3k, 10k, 20k

HIGHPASS FILTER (option):
single pole, attenuation: -6 dB/octave, corner frequencies (Hz): 0.3, 3, 10, 30, 100, 300, 500, 800, 1k, 3k, 10k

GAIN:
rotary switch: 1-2-5-10-20-50-100-200-500-1000

OVERLOAD LEDS:
starting to light up at ±10 V

FULL POWER BANDWIDTH:
20 kHz

OUTPUT IMPEDANCE:
250 Ω

OUTPUT VOLTAGE:
max. ±12 V, short-circuit protected

LOAD CAPACITANCE:
max. 10 nF

GAIN / FREQUENCY MONITOR:
1V / step

DIMENSIONS:
24 HP (121.5 mm) x 3U (128.5 mm), 7" (175 mm) deep

 

Options

BF-48DGX-4L Low pass Bessel filter module with gain
   4-pole Bessel filter with 12  corner frequencies

BF-48DGX-4HL Low and high pass Bessel filter module with gain
   4-pole low pass Bessel filter with 12  corner frequencies; 
   1-pole high pass Bessel filter with 11 corner frequencies

BF-48DGX-8L   Low pass Bessel filter module with gain
   8-pole Bessel filter with 12  corner frequencies

BF-48DGX-8HL   Low and high pass Bessel filter module with gain
   8-pole low pass Bessel filter with 12  corner frequencies; 
   1-pole high pass Bessel filter with 11  corner frequencies