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> Filter low-pass programmable fc=200-51.2KHZ, 8 pole
Filter low-pass programmable fc=200-51.2KHZ, 8 pole
Digitally programmable low-pass active filter with corner frequency tunable in 256 steps. Convenient, low profile, easy to use, fully finished, requires no external components or adjustments. It features low harmonic distortion, and near theoretical phase and amplitude characteristics.
* Manufacturer: Frequency Devices Inc., USA
* Model: 828L8D80-5 (low pass, 8 pole, constant delay)
* Cut off frequency: range = 200 Hz - 51.2 KHz; step = 200 Hz
* Stopband Attenuation: 80 dB
* Control: 8 bit input (15V CMOS level! - use MC14504 for TTL to CMOS level shifting)
* Condition: used, but OK (removed from a working board)
The filter passes signals from 0 Hz (DC) up to fc. fc depends on the byte applied to the D7-D0 inputs and it's given by the formula:
fc(N) = (N+1)x200 Hz, where N = input byte (0-255)
Every increment/decrement shifts the fc 200 Hz higher/lower.
fc(0010'0111) = (39+1)x200 = 8 KHz
fc(1111'1111) = (255+1)x200 = 51.2 KHz
Important note from the manufacturer
Power-Up and Power-Down Sequence: Do not plug-in or un-plug module while power is applied. It is imperative that power is supplied to the + 15 V pin on the filter module before or at the same instance that any digital pin is pulled High (> 0.0 V). Failure to do this will result in excessive current flowing through the digital input pin and through a protection diode internal to the 4000 logic, which will result in damage to the module.
