Description
The 828 Series are digitally programmable low-pass and high-pass active filters that are tunable over a 256:1 frequency range. 828 filters are available with any one of five standard factory-set tuning ranges or 8-bit custom ranges from 1.0 Hz to 102.4 kHz. These units contain 8 CMOS logic inputs.
All 828 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. 828 filters operate from non-critical ± 12 to ± 18 Vdc power supplies, have a 10 kΩ (min.) input and a 10 Ω (max.) output impedance.
Features/Benefits:
- Compact 2" 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.
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- Programmable Tuning and Control
Digital Tuning & Control
Available Low-Pass Models:
(Click model number to view datasheet)
- 828L8B
- 8-pole Butterworth
- 828L8E
- 8-pole, 6 zero elliptic, 1.77 (-80dB)
- 828L8EX
- 8-pole, 6 zero elliptic, 1.56 (-80dB)
- 828L8EY
- 8-pole, 6 zero elliptic, 2.00 (-100dB)
- 828L8L
- 8-pole Bessel
- 828L8D60
- 8-pole constant delay (-60 dB)
- 828L8D80
- 8-pole constant delay (-80 dB)
- 828L8D10
- 8-pole constant delay (-100 dB)
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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
Available High-Pass Models:
(Click model number to view datasheet)
- 828H8B
- 8-pole Butterworth
- 828H8E
- 8-pole, 6 zero elliptic, 1.77 (-80dB)
- 828H8EX
- 8-pole, 6 zero elliptic, 1.56 (-80dB)
- 828H8EY
- 8-pole, 6 zero elliptic, 2.00 (-100dB)
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8-Bit Programmable Filters
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828 Series
Digital Tuning &
Control Characteristics
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| Digital Tuning Characteristics
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 (D0 - D7 ).
Filter tuning follows the tuning equation given below:
fc = ( fmax/256 ) [ 1 + D7 x 27 + D6 x 26 + D5 x 25 + D4 x 24 +
D3 x 23 + D2 x 22 + D1 x 21 + D0 x 20]
where D1 - D7 = "0" or "1", and
fmax = Maximum tuning frequency;
fc = corner frequency;
Minimum tunable frequency = fmax/256 (D0 thru D7 = 0);
Minimum frequency step (Resolution) = fmax/256
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MSB
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LSB
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Bit
Weight
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27
D7
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26
D6
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25
D5
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24
D4
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23
D3
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22
D2
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21
D1
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20
D0
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fc
Corner
Frequency
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0
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0
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0
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0
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0
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0
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0
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0
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fmax/256
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0
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0
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0
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0
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0
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0
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0
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1
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fmax/128
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0
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0
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0
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0
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0
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0
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1
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1
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fmax/64
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0
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0
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0
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0
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0
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1
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1
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1
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fmax/32
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0
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0
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0
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0
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1
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1
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1
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1
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fmax/16
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0
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0
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0
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1
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1
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1
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1
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1
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fmax/8
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0
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0
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1
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1
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1
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1
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1
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1
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fmax/4
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0
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1
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1
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1
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1
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1
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1
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1
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fmax/2
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1
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1
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1
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1
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1
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1
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1
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1
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fmax
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Pin-Out Key
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IN
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Analog Input Signal
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D7
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Tuning Bit 7 (MSB)
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OUT
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Analog Output Signal
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D6
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Tuning Bit 6
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GND
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Power and Signal Return
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D5
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Tuning Bit 5
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+Vs
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Supply Voltage, Positive
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D4
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Tuning Bit 4
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-Vs
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Supply Voltage, Negative
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D3
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Tuning Bit 3
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Os
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Offset Adjustment
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D2 |
Tuning Bit 2
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D1 |
Tuning Bit 1
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D0 |
Tuning Bit 0 (LSB)
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Data Input Specifications
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Input Data Levels
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(CMOS Logic)
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| Input Voltage (Vs=15 Vdc ) |
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| Low Level In |
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0 Vdc min. |
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4 Vdc max. |
| High Level In |
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11 Vdc min. |
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15 Vdc max. |
| Input Current |
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| High Level In |
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-10-5 µA typ. |
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-1 µA max. |
| Low Level In |
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+10-5 µA typ. |
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+1 µA max. |
| Input Capacitance |
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5 pF typ |
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7.5 pF max. |
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Input Data Format
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Frequency Select Bits
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| Positive Logic |
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Logic "1" = +Vs |
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Logic "0" = Gnd |
| Bit Weight |
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(Binary-Coded) |
| D0 |
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LSB (least significant bit) |
| D7 |
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MSB (most significant bit) |
Frequency Range 256 : 1, Binary Weighted
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8-Bit Programmable 8-Pole Low-Pass Filters
| Model |
828L8B |
828L8E |
828L8EX |
828L8EY |
| Product Specifications |
Transfer Function
Size
Range fc, fr |
8-Pole Butterworth
2.0” x 2.0” x 0.5”
1.0 Hz to 102.4 kHz |
8-Pole, 6 zero
Elliptic
2.0” x 2.0” x 0.5”
1.0 Hz to 102.4 kHz |
8-Pole, 6 zero
Elliptic
2.0” x 2.0” x 0.5”
1.0 Hz to 102.4 kHz |
8-Pole, 6 zero
Elliptic
2.0” x 2.0” x 0.5”
1.0 Hz to 102.4 kHz |
Theoretical Transfer
Characteristics |
Click to view
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Click to view
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Click to view
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Click to view
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Passband Ripple
(theoretical) |
0.0 dB |
± 0.035 dB |
-0.05 dB |
-0.05 dB |
DC Voltage Gain
(non-inverting) |
0 ± 0.1 dB max.
0 ± 0.05 dB typ. |
0 ± 0.1 dB max.
0 ± 0.05 dB typ. |
0 ± 0.1 dB max.
0 ± 0.05 dB typ. |
0 ± 0.1 dB max.
0 ± 0.05 dB typ. |
Stopband
Attenuation Rate |
48 dB/octave |
80 dB min. |
80 dB min. |
100 dB min. |
Cutoff Frequency
Stability
Amplitude
Phase |
fc ± 2% max.
± 0.01% /°c
-3 dB
-360° |
fr ± 2% max.
± 0.01% /°c
-0.035 dB
-323.5° |
fr ± 2% max.
± 0.01% /°c
-0.05 dB
-414° |
fr ± 2% max.
± 0.01% /°c
-0.05 dB
-419° |
Filter Attenuation
(theoretical) |
0.12 dB 0.80 fc
3.01 dB 1.00 fc
60.0 dB 2.37 fc
80.0 dB 3.16 fc |
0.035 dB 1.00 fr
3.01 dB 1.13 fr
60.0 dB 1.67 fr
80.0 dB 1.77 fr |
0.05 dB 1.00 fr
3.01 dB 1.05 fr
60.0 dB 1.45 fr
80.0 dB 1.56 fr |
0.05 dB 1.00 fr
3.01 dB 1.06 fr
80.0 dB 1.83 fr
100.0 dB 2.00 fr |
| Phase Match1 |
- 0 - 0.8 fc
- ± 2° max.
± 1° typ.
- 0.8 fc - 1.0 fc
- ± 3° max.
± 1.5° typ.
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- 0 - 0.8 fr
- ± 2° max.
± 1° typ.
- 0.8 fr - 1.0 fr
- ± 4° max.
± 2° typ.
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- 0 - 0.8 fr
- ± 3° max.
± 1.5° typ.
- 0.8 fr - 1.0 fr
- ± 4° max.
± 2° typ.
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- 0 - 0.8 fr
- ± 3° max.
± 1.5° typ.
- 0.8 fr - 1.0 fr
- ± 4° max.
± 2° typ.
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Amplitude Accuracy
(theoretical) |
- 0 - 0.8 fc
- ± 0.2 dB max.
± 0.1 dB typ.
- 0.8 fc - 1.0 fc
- ± 0.3 dB max.
± 0.15 dB typ.
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- 0 - 0.8 fr
- ± .2 dB max.
± .1 dB typ.
- 0.8 fr - 1.0 fr
- ± .3 dB max.
± .15 dB typ.
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- 0 - 0.8 fr
- ± 0.2 dB max.
± 0.1 dB typ.
- 0.8 fr - 1.0 fr
- ± 0.5 dB max.
± 0.25 dB typ.
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- 0 - 0.8 fr
- ± 0.2 dB max.
± 0.1 dB typ.
- 0.8 fr - 1.0 fr
- ± 0.5 dB max.
± 0.25 dB typ.
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Total Harmonic
Distortion @ 1 kHz |
< - 100 dB typ. |
< - 88 dB typ. |
< - 88 dB typ. |
< - 88 dB typ. |
Wide Band Noise
(5 Hz - 2 MHz) |
200 µVrms typ. |
200 µVrms typ. |
250 µVrms typ. |
250 µVrms typ. |
Narrow Band Noise
(5 Hz - 100 kHz) |
50 µVrms typ. |
50 µVrms typ. |
75 µVrms typ. |
75 µVrms typ. |
Filter Mounting
Assembly |
FMA-02A |
FMA-02A |
FMA-02A |
FMA-02A |
1. Unit to unit match for the same transfer function, set to the same frequency and operating configuration, and from the same manufacturing lot. |
8-Bit Programmable 8-Pole Low-Pass Filters
| Model |
828L8L |
828L8D60 |
828L8D80 |
828L8D10 |
| Product Specifications |
Transfer Function
Size
Range fc |
8-Pole
Bessel
2.0” x 2.0” x 0.5”
1.0 Hz to 102.4 kHz |
8-Pole, 6 zero
Constant Delay
2.0” x 2.0” x 0.5”
1.0 Hz to 102.4 kHz |
8-Pole, 6 zero
Constant Delay
2.0” x 2.0” x 0.5”
1.0 Hz to 102.4 kHz |
8-Pole, 6 zero
Constant Delay
2.0” x 2.0” x 0.5”
1.0 Hz to 102.4 kHz |
Theoretical Transfer
Characteristics |
Click to view
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Click to view
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Click to view
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Click to view
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Passband Ripple
(theoretical) |
0.0 dB |
0.15 dB |
0.15 dB |
0.15 dB |
DC Voltage Gain
(non-inverting) |
0 ± 0.1 dB max.
0 ± 0.05 dB typ. |
0 ± 0.1 dB max.
0 ± 0.05 dB typ. |
0 ± 0.1 dB max.
0 ± 0.05 dB typ. |
0 ± 0.1 dB max.
0 ± 0.05 dB typ. |
Stopband
Attenuation Rate |
48 dB/octave |
60 dB min. |
80 dB min. |
100 dB min. |
Cutoff Frequency
Stability
Amplitude
Phase |
fc ± 2% max.
± 0.01% /°c
-3 dB
-182° |
fc ± 2% max.
± 0.01% /°c
-3 dB
-306° |
fc ± 2% max.
± 0.01% /°c
-3 dB
-306° |
fc ± 2% max.
± 0.01% /°c
-3 dB
-311° |
Filter Attenuation
(theoretical) |
1.91 dB 0.80 fc
3.01 dB 1.00 fc
60.0 dB 4.52 fc
80.0 dB 6.07 fc |
3.01 dB 1.00 fc
40.0 dB 2.28 fc
60.0 dB 2.64 fc |
3.01 dB 1.00 fc
60.0 dB 3.08 fc
80.0 dB 3.57 fc |
3.01 dB 1.00 fc
80.0 dB 4.45 fc
100.0 dB 5.20 fc |
| Phase Match1 |
- 0 - fc ± 2° max.
- ± 1° typ.
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- 0 - fc ± 2° max.
- ± 1° typ.
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- 0 - fc ± 2° max.
- ± 1° typ.
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- 0 - fc ± 2° max.
- ± 1° typ.
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Amplitude Accuracy
(theoretical) |
- 0 - fc
- ± 0.2 dB max.
± 0.1 dB typ.
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- 0 - 0.8 fc
- ± 0.2 dB max.
± 0.1 dB typ.
- 0.8 fc - 1.0 fc
- ± 0.3 dB max.
± 0.15 dB typ.
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- 0 - 0.8 fc
- ± 0.2 dB max.
± 0.1 dB typ.
- 0.8 fc - 1.0 fc
- ± 0.3 dB max.
± 0.15 dB typ.
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- 0 - 0.8 fc
- ± 0.2 dB max.
± 0.1 dB typ.
- 0.8 fc - 1.0 fc
- ± 0.3 dB max.
± 0.15 dB typ.
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Total Harmonic
Distortion @ 1 kHz |
< - 100 dB typ. |
< - 100 dB typ. |
< - 100 dB typ. |
< - 100 dB typ. |
Wide Band Noise
(5 Hz - 2 MHz) |
200 µVrms typ. |
200 µVrms typ. |
200 µVrms typ. |
200 µVrms typ. |
Narrow Band Noise
(5 Hz - 100 kHz) |
50 µVrms typ. |
50 µVrms typ. |
50 µVrms typ. |
50 µVrms typ. |
Filter Mounting
Assembly |
FMA-02A |
FMA-02A |
FMA-02A |
FMA-02A |
1. Unit to unit match for the same transfer function, set to the same frequency and operating configuration, and from the same manufacturing lot. |
8-Bit Programmable 8-Pole High-Pass Filters
| Model |
828H8B |
828H8E |
828H8EX |
828H8EY |
| Product Specifications |
Transfer Function
Size
Range fc, fr |
8-Pole
Butterworth
2.0” x 2.0” x 0.5”
1.0 Hz to 102.4 kHz |
8-Pole, 6 zero
Elliptic
2.0” x 2.0” x 0.5”
1.0 Hz to 102.4 kHz |
8-Pole, 6 zero
Elliptic
2.0” x 2.0” x 0.5”
1.0 Hz to 102.4 kHz |
8-Pole, 6 zero
Elliptic
2.0” x 2.0” x 0.5”
1.0 Hz to 102.4 kHz |
Theoretical Transfer
Characteristics |
Click to view
|
Click to view
|
Click to view
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Click to view
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Passband Ripple
(theoretical) |
0.0 dB |
± 0.035 dB |
-0.05 dB |
-0.05 dB |
Voltage Gain
(non-inverting) |
0 ± 0.2 dB to 100 kHz
0 ± 0.5 dB to 120 kHz |
0 ± 0.2 dB to 100 kHz
0 ± 0.5 dB to 120 kHz |
0 ± 0.2 dB to 100 kHz
0 ± 0.5 dB to 120 kHz |
0 ± 0.2 dB to 100 kHz
0 ± 0.5 dB to 120 kHz |
| Power Bandwidth |
120 kHz |
120 kHz |
120 kHz |
120 kHz |
Small Signal
Bandwidth |
(-6 dB) 1 MHz |
(-6 dB) 1 MHz |
(-6 dB) 1 MHz |
(-6 dB) 1 MHz |
Stopband
Attenuation Rate |
48 dB/octave |
80 dB min. |
80 dB min. |
100 dB min. |
Cutoff Frequency
Stability
Amplitude
Phase |
fc ± 2% max.
± 0.01% /°c
-3 dB
-360° |
fr ± 2% max.
± 0.01% /°c
-0.035 dB
-323.5° |
fr ± 2% max.
± 0.01% /°c
-0.05 dB
-414° |
fr ± 2% max.
± 0.01% /°c
-0.05 dB
-419° |
Filter Attenuation
(theoretical) |
80 dB 0.31 fc
60.0 dB 0.42 fc
3.01 dB 1.00 fc
0.00 dB 2.00 fc |
80 dB 0.56 fr
60.0 dB 0.60 fr
3.01 dB 0.88 fr
0.03 dB 1.00 fr
0.00 dB 2.00 fr |
80 dB 0.64 fr
60.0 dB 0.69 fr
3.01 dB 0.95 fr
0.03 dB 1.00 fr
0.00 dB 2.00 fr |
100 dB 0.50 fr
80.0 dB 0.55 fr
3.01 dB 0.94 fr
0.03 dB 1.00 fr
0.00 dB 2.00 fr |
| Phase Match1 |
- fc - 100 kHz
- ± 3° max.
± 1.5° typ.
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- fr - 1.25 fr
- ± 4° max.
± 2° typ.
- 1.25 fr-100 kHz
- ± 2° max.
± 1° typ.
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- fr - 1.25 fr
- ± 4° max.
± 2° typ.
- 1.25 fr-100 kHz
- ± 2° max.
± 1° typ.
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- fr - 1.25 fr
- ± 4° max.
± 2° typ.
- 1.25 fr-100 kHz
- ± 3° max.
± 1.5° typ.
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Amplitude Accuracy
(theoretical) |
- fc-1.25 fc
- ± 0.3 dB max.
± 0.15 dB typ.
- 1.25 fc-100kHz
- ± 0.2 dB max.
± 0.1 dB typ.
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- fr-1.25 fr
- ± 0.3 dB max.
± 0.15 dB typ.
- 1.25 fr-100kHz
- ± 0.2 dB max.
± 0.1 dB typ.
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- fr-1.25 fr
- ± 0.5 dB max.
± 0.25 dB typ.
- 1.25 fr-100kHz
- ± 0.2 dB max.
± 0.1 dB typ.
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- fr-1.25 fr
- ± 0.5 dB max.
± 0.25 dB typ.
- 1.25 fr-100kHz
- ± 0.2 dB max.
± 0.1 dB typ.
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Total Harmonic
Distortion @ 1 kHz |
< - 100 dB typ. |
< - 88 dB typ. |
< - 88 dB typ. |
< - 88 dB typ. |
Wide Band Noise
(5 Hz - 2 MHz) |
400 µVrms typ. |
400 µVrms typ. |
500 µVrms typ. |
500 µVrms typ. |
Narrow Band Noise
(5 Hz - 100 kHz) |
100 µVrms typ. |
100 µVrms typ. |
150 µVrms typ. |
150 µVrms typ. |
Filter Mounting
Assembly |
FMA-02A |
FMA-02A |
FMA-02A |
FMA-02A |
1. Unit to unit match for the same transfer function, set to the same frequency and operating configuration, and from the same manufacturing lot. |
Specifications
(@ 25°C and Vs ±15 Vdc)
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Analog Input Characteristics 1
- Impedance: 10 kΩ min.
- Voltage Range: ± 10 Vpeak
- Max. Safe Voltage: ± Vs
Analog Output Characteristics
- Impedance(Closed Loop):
1 Ω typ.
10 Ω max.
- Linear Operating Range: ± 10 V
- Maximum Current2: ± 2 mA
- Offset Voltage3:
2 mV typ.
20 mV max.
- Offset Temp. Coeff.: 50 µV / °C
Notes:
- Input and output signal voltage referenced to supply common.
- Output is short circuit protected to common. DO NOT CONNECT TO ±Vs.
- Adjustable to zero.
- Units operate with or without offset pin connected.
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Power Supply (±Vs)
- Rated Voltage: ± 15 Vdc
- Operating Range: ± 12 to ± 18 Vdc
- Maximum Safe Voltage: ± 18 Vdc
- Quiescent Current (8 pole):
±25 mA typ.
±40 mA max.
Temperature
- Operating: 0 to + 70°C
- Storage: -25 to+85°C
See note 4
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Pin-Out and Package Data
Filter Mounting Assembly-See FMA-02A
Ordering Information
Power Sequence & ESD
Programmable Filters Modules
- Scope
The following precautions are necessary when handling and installing Frequency Devices programmable filter modules.
- Digital Circuit Description
The digital input pins connect directly to 4000 series CMOS logic, such as the 4053 analog switch. The power supply (Vss) for the digital logic on the module comes directly from the +15 Volt pin on the module. This sets the threshold voltage at 11.0 V minimum to 15.0 V maximum for a "1" (High) level and 0.0 V minimum to 4.0 V maximum for a "0" (Low) level. Applying a voltage between 4.0 and 11.0 V will produce unpredictable operation. Connecting 5 Volt or 3.3 V logic devices directly to the filter module without using a voltage translator will result in erratic operation of the filter.
- (VERY IMPORTANT) 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. The proper power-up and power-down sequence is:
- Connect filter module ground.
- Connect filter module +15 V.
- Connect filter module -15 V.
- Connect the input signal.
All four of the above steps can also occur simultaneously. Power-down should occur in the reverse order.
- ESD Issues
Like most modern electronic equipment, the modules can be damaged by electrostatic discharge (ESD). The modules are shipped from the factory in sealed, anti-static packaging and should be kept in the sealed package prior to mounting on a circuit board. The following additional rules should also be observed when handling the modules after they are removed from the factory packaging:
- Only a person wearing a properly grounded wrist strap should handle the modules.
- Any work surface that the modules are placed on must be properly ESD grounded.
- Any insulating materials capable of generating static charge (such as paper) should be kept away from the modules.
We hope the information given here will be helpful. The information is based on data and our best knowledge, and we consider the information to be true and accurate. Please read all statements, recommendations or suggestions herein in conjunction with our conditions of sale which apply to all goods supplied by us. We assume no responsibility for the use of these statements, recommendations or suggestions, nor do we intend them as a recommendation for any use which would infringe any patent or copyright.
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