Description The 424 Series are 4-pole digitally programmable low-pass and high-pass active filters. These new filters take advantage of the company's proprietary designs using surface-mount technology to provide a low profile, compact package in minimal board space. 424 filters are factory tuned to one of ten preset 4-bit binary ranges from to 102.4 kHz. Contact the factory for custom discrete tuning ranges, maximum span 1000:1. All 424 Series models are easy to use fully finished filters which require no external components or adjustment. They feature low harmonic distortion, near theoretical phase and amplitude characteristics and operate over a dynamic input voltage range from non-critical to ±18V power supplies. Features/Benefits:· Low harmonic distortion and wide signal-to-noise ratio to 16-bit resolution.· Compact x 0.3"H min. (32-pin DIP footprint) minimizes board space requirements.· 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 tuned, 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· Acoustic and vibration analysis and control· Real and compressed time data analysis· Noise elimination· Signal reconstruction
Programmable Specifications. Page Digital Tuning & Control. 2 Available Low-Pass Models:. 424L4B 4-pole Butterworth. 424L4L 4-pole Bessel. 424L4Y2 4-pole Cheby (0.2 dB Ripple). 424L4Y5 4-pole Cheby (0.5 dB Ripple). 3 Available High-Pass Models:. 424H4B 4-pole Butterworth. 424H4Y2 4-pole Cheby (0.2 dB Ripple). 424H4Y5 4-pole Cheby (0.5 dB Ripple). 4 General Specifications: Ordering information. 5 Pin-out/package data. 5
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The digital tuning interface circuits are a parallel set of CMOS switches which accept CMOS compatible inputs for the four tuning bits D 3).
Pin-Out Key IN Analog Input Signal D2 D0 Tuning Bit 3 (MSB) Tuning Bit 2 Tuning Bit 1 Tuning Bit 0 (LSB) OUT Analog Output Signal +Vs -Vs Os Supply Voltage, Positive Offset Adjustment
Binary T uning Equation: = (f max [1+ 0] where or "1", and fmax = Maximum tuning frequency fc = Corner frequency; Minimum tunable frequency = f max (D 0 thru = 0); Minimum frequency step (Resolution) = f max /16
Data Input Specifications Input Data Levels Input Voltage (Vs=15 Vdc) Low Level In High Level In Input Current High Level In Low Level In Input Capacitance Input Data Format Positive Logic Bit Weight D3 (+5Vdc CMOS Logic) 0 Vdc min. 3.5 Vdc min. 20 pF typ. 0.5 Vdc max. 5.0 Vdc max. 30 pF max.
Discrete Tuning Equation: f2, f3 are the incremental frequency shifts for the data bits D1, D2 and D3. They are selected to realize the five customer specified programming frequencies FB F4. Other programming codes produce valid fc's between FB and F4.
Frequency Select Bits Logic = (+5Vdc) Logic "0" = Gnd (Binary-Coded) LSB (least significant bit) MSB (most significant bit)
Model Product Specifications Transfer Function Size Range fc Theoretical Transfer Characteristics Passband Ripple
Stopband Attenuation Rate Cutoff Frequency Stability Amplitude Phase Filter Attenuation
0.2 dB max. 0.1 dB typ. 0.3 dB max. 0.15 dB typ. 100 dB typ. 200 mVrms typ. 50 mVrms typ.
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.