Description The D828 Series are digitally programmable lowpass and high-pass active filters with differential input that are tunable over a 256:1 frequency range. D828 filters are available with any one of five standard factory-set tuning ranges or 8-bit custom ranges from to 102.4 kHz. These units contain 8 CMOS logic inputs. All D828 Series models are convenient, low profile, easy to use fully finished filters which require no external components or adjustments. They feature low harmonic distortion, and near theoretical phase and amplitude characteristics. D828 filters operate from non-critical � 18 Vdc power supplies, have 10 k (min.) input and a 10 (max.) output impedance. Features/Benefits: Compact x 2" design minimizes board space requirements. Low harmonic distortion and wide signal-to-noise ratio to 16 bit resolution. Digitally programmable corner frequency allows selecting cut-off frequencies specific to each application. Plug-in ready-to-use, reducing engineering design and manufacturing cycle time. Factory-set tuning range, no external clocks or adjustments needed Broad range of transfer characteristics and corner frequencies to meet a wide range of applications. Applications Anti-alias filtering Data acquisition systems Communication systems and electronics Medical electronics equipment and research Aerospace, navigation and sonar applications Sound and vibration testing Real and compressed time data analysis Noise elimination Signal reconstruction
Programmable Specifications:. Page Digital Tuning & Control. 2 Available Low-Pass Models:. D828L8B 8-pole Butterworth. 8-pole, 6 zero elliptic, 8-pole, 6 zero elliptic, 8-pole, 6 zero elliptic, D828L8L 8-pole Bessel. D828L8D60 8-pole constant delay D828L8D80 8-pole constant delay D828L8D10 8-pole constant delay (-100dB). 4 Available High-Pass Models:. D828H8B 8-pole Butterworth. 8-pole, 6 zero elliptic, 8-pole, 6 zero elliptic, 8-pole, 6 zero elliptic, (-100dB). 5 General Specifications: Ordering information. 6 Pin-out/package data. 6
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The digital tuning interface circuits are a parallel set of eight (8) 4053 CMOS switches which accept CMOS compatible inputs for the eight tuning bits - D7). Filter tuning follows the tuning equation given below: 2 ] where or "1", and fmax = Maximum tuning frequency; fc = corner frequency; Minimum tunable frequency fmax/256 (D0 thru = 0); Minimum frequency step (Resolution) = fmax/256
IN OUT GND +Vs -Vs Os Analog Input Signal Analog Output Signal Power and Signal Return Supply Voltage, Positive Supply Voltage, Negative Offset Adjustment D7 Tuning D6 Tuning D5 Tuning D4 Tuning D3 Tuning D2 Tuning D1 Tuning D0 Tuning Bit 7 (MSB) (LSB)Input Data Levels (CMOS Logic) 4 Vdc max. 15 Vdc max. -1 �A max.. +1 �A max. 7.5 pF max.
Input Voltage (Vs = 15 Vdc) Low Level In 0 Vdc min. High Level In 11 Vdc min. Input Current High Level In Low Level In Input Capacitance Input Data Format Positive Logic Bit Weighting D0 D7 Frequency Range 10 �A typ. +10 �A typ. 5 pF typ
Frequency Select Bits Logic "1" = +Vs Logic "0" = Gnd (Binary-Coded) LSB (least significant bit) MSB (most significant bit) : 1, Binary Weighted
Model Product Specifications Transfer Function Size Range fc, fr Theoretical Transfer Characteristics Passband RippleStopband Attenuation Rate Cutoff Frequency Stability Amplitude Phase Filter Attenuation
Total Harmonic Distortion @ 1 kHz Wide Band Noise
1.Unit to unit match for the same transfer function, set to the same frequency and operating configuration, and from the same manufacturing lot.