Home  >  Products  >  Filter Listings  >  Model Modules

Keyword Search

DESCRIPTION
The NEW  3A, 3B, 3C and 3D Series of continuous-time fixed-frequency precision active filter modules from Krohn-Hite provide filtering in a 1 to 8-poles and 16-pole compact package, with the choice of cutoff frequencies selectable within the frequency range from 1Hz to 2MHz low-pass and 1Hz to 600kHz high-pass.

Choose between Butterworth or Bessel responses, user-defined input and output gain from 1 to 100 in 1% increments (0dB to 40dB). Functions of low-pass, high-pass and band-pass. Each one factory tuned to a user-specified cutoff frequency, number of poles, response, function, single-ended or differential input gains and output gains.

APPLICATIONS
Applications include: anti-alias filtering, data acquisition systems, aerospace (sonar and navigation), sound and vibration testing, medical electronics, communication systems, real and compressed time data analysis, noise elimination and signal reconstruction.

AVAILABLE FILTER MODULES

FMB300 and FMB302 MINI FILTER BOX (optional)
The Mini Filter Boxes FMB300 (single channel) and FMB302 (two channel) provide housing for any Krohn-Hite filter modules. Each is provided with input BNC connectors for differential or single-ended input signals, a BNC connector for the output and a barrier strip (optional AC wallmount adapter) for applying ±5Vdc to ±15Vdc power to the unit. Internal sockets are provide for easy installation and removal of the modules.

SPECIFICATIONS

USER-DEFINED CHARACTERISTICS
Number of poles, function, response type, cutoff frequency, cutoff frequency accuracy, differential or single-ended input gain, output gain,

FILTER CHARACTERISTICS (single-ended)
Functions: High-Pass, Low-Pass or Band-Pass (total of 2 to 8-poles for band-pass modules).
Number of Poles: 1 to 8 and 16.
Response Types: Butterworth or Bessel.
Cutoff Frequency: Any fixed value in the range from 1Hz to 1MHz, High-Pass; 0.1Hz to 2MHz, Low-Pass.
Relative Gain at fc: –3.01dB for both Butterworth and Bessel.
Cutoff Frequency Accuracy: 2%.
Temperature Coefficient: 0.05%/°C.
Passband Response Deviation from Theoretical (non-inverting):
   Low-Pass: 1Hz to 50kHz, ±0.1dB; to 200kHz, ±0.2dB.
   High-Pass (small signal, 0.4Vp-p): Cutoffs below 100Hz and input frequencies to 200kHz, ±0.1dB, -3dB
   point approximately 2.5MHz; cutoffs above 100Hz, ±0.1dB for input frequencies to 2MHz, ±0.2dB for input
   frequencies to 5MHz, +2dB to -3dB for input frequencies to 25MHz.
Stopband Attenuation (Signal Rejection):
   Low-Pass: >100dB to 100kHz, >80dB to 1MHz, >60dB to 5MHz, >50dB to 10MHz.
   High-Pass: >100dB.
   Signal rejection is printed circuit layout dependent. Use good grounding and shielding practices.

INPUT CHARACTERISTICS (with no input gain)
Impedance: 10k ohm or greater. Impedance will vary depending upon cutoff frequency selected.
Voltage Range: ±10V peak (typically ±12V peak for ±15V supplies). Reduced in proportion to supply voltages.
Maximum Safe Voltage: Equal to supply voltages.

INPUT GAIN CHARACTERISTICS
Gain: 1 to 100, ±1%.
Input Impedance: 1M ohm or greater.
Maximum Voltage Without Damage: Equal to supply voltages.
Input Type: Bipolar (FET input available).
Bias Current: Single-ended input, typically 200nA, 600nA max.; differential input, typically 4µA, 12µA max., (1µA max. offset current).
Single-Ended Gain:
   3B Package: 1 to 4-poles.
   3C Package: 5 to 8-poles.
   3D Package: 16-poles.
Gain Bandwidth (GB) Factor for Determining Useful High-Pass Bandwidth: 3B Package, for high-pass cutoffs <100Hz, 2MHz GB; all other packages: 20MHz GB.
Differential Gain: Available in the 3C and 3D modules.
Common Mode Maximum Signal Amplitude (For linear operation with ±15V supplies):
(differential signal) X (input gain) + (common mode signal) must be <±10V peak reduced in proportion to power supply voltages.
CMMR: >80dB to 1kHz.
Maximum Common Mode or Differential Mode Without Damage: Equal to supply voltages.
Gain Bandwidth: Typically 5MHz with unity input gain; 700kHz, X100 input gain; full power bandwidth, typically 240kHz.

OUTPUT CHARACTERISTICS
Impedance:  <0.1 ohm to 200kHz.
Linear Operating Range: ±10V peak for ±15V supplies, (typically ±12V peak). Reduced in proportion to supply voltages.
Low-Pass Maximum Voltage: 20Vp-p (24p-p typical), 1Hz to 200kHz.

The above specifications are without input and output gain performance limits and apply to modules
with ±15V supplies. Reduce output performance in proportion to the reduced supply voltage, and
input and output gain bandwidth limits.

Maximum Current (2k load): ±5mA peak with 10V output.
Offset Voltage: <10mV settable to zero with offset control.
Offset Temperature Coefficient: <0.2mV/°C.
Noise (with input shorted to ground and detector bandwidth of 5Hz to 300kHz): typically
25µV, 50µVrms max. referred to input.
Noise Spectral Density: <100nV/ÖHz, 100Hz to 300kHz, typically 40nV/ÖHz. For 8-pole
Butterworth modules specification may be 3 times higher near the cutoff region.
Signal-to-Noise Ratio (at 7Vrms): >100dB.

OUTPUT GAIN CHARACTERISTICS
Output gain is available in 1 to 4-pole modules in the 3B package, 4 to 8 poles modules in the
3C package and 9 to 16 poles in the 3D package.
Gain: 1 to 100, ±1%.
Gain Bandwidth: 100MHz for output gains of 5 or greater. For gains less than 5, max. useful
bandwidth is a fixed 20MHz.

POWER SUPPLY (±Vs)
Specifications Apply at ±5Vdc to ±15Vdc or single supply from 10Vdc to 30Vdc.
Operating Range: ±5Vdc to ±18Vdc.
Maximum Safe Voltage: ±18Vdc.
Current:
   3A and 3B Package, <15mA
   3C Package with gain, <30mA.
   3D Package with gain, <35mA.
   Consult factory for ultra-low power version.

GENERAL
Output Short Circuit Protection: Limited to short duration.
Operating Temperature Range: 0ºC to +70ºC.
Storage Temperature Range: -25ºC to +85ºC.

OPTIONS
FMB300: Single Channel Filter Module Box for use with any Krohn-Hite Filter Modules.
Connectors: BNC, input and output
Barrier Strip: Connections for +, - and ground dc power connections
Option 001: AC Wallmount Power Adapter for 115V operation replaces Barrier Strip

FMB302: 2 Channel Filter Module Box for use with any Krohn-Hite Filter Modules.
Connectors: BNC, input and output
Barrier Strip: Connections for +, - and ground dc power connections
Option 001: AC Wallmount Power Adapter for 115V operation replaces Barrier Strip

Click for larger view

  
                      Top View                                              Side View

FMB302B: Battery Operated 2 Channel Filter Module Box for use with any Krohn-Hite Filter Modules.
Connectors: BNC, input and output
Barrier Strip: Connections for +, - and ground dc power connections
Option 001: AC Wallmount Power Adapter for 115V operation replaces Barrier Strip

Click for larger view

    
                  Top View                                                      Side View
 

Specifications apply at 25ºC ±5ºC.

If the filter you need is not listed on this data sheet, consult factory for other variations and options
that may fill your requirement.

Specifications subject to change without notice.

-------------------------------------------------------- How To Order --------------------------------------------------------------

The following is a description on how to construct the Filter Module part number.

Example:
For a 25kHz Low-Pass Butterworth with a Differential Input and Input Gain of 5 Output Gain of 10.

Part Number: 3CD8TL-25kg-N5U10