828 Series
1.0 Hz to 102.4 kHz
8-Bit Programmable
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.
2" x 2"
8-Pole Filters
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.
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:
. . . . . . . . . . . . . . . . . .
828L8B
8-pole Butterworth . . . . . . . . . . . . . . . . . 3
828L8E
8-pole, 6 zero elliptic, 1.77 (-80dB) . . . . 3
828L8EX
8-pole, 6 zero elliptic, 1.56 (-80dB) . . . . 3
828L8EY
8-pole, 6 zero elliptic, 2.00 (-100dB) . . . 3
828L8L
8-pole Bessel. . . . . . . . . . . . . . . . . . . . . 4
828L8D60
8-pole constant delay (-60dB) . . . . . . . . 4
828L8D80
8-pole constant delay (-80dB) . . . . . . . . 4
828L8D10
8-pole constant delay (-100dB) . . . . . . . . 4
Available High-Pass Models:
. . . . . . . . . . . . . . . . . .
828H8B
8-pole Butterworth . . . . . . . . . . . . . . . . . 5
828H8E
8-pole, 6 zero elliptic, 1.77 (-80dB) . . . . . 5
828H8EX
8-pole, 6 zero elliptic, 1.56 (-80dB) . . . . . 5
828H8EY
8-pole, 6 zero elliptic, 2.00 (-100dB) . . . . 5
General Specifications:
Ordering information . . . . . . . . . . . . . . . . . . . . . . . . 6
Pin-out/package data . . . . . . . . . . . . . . . . . . . . . . . . 6
25 Locust St, Haverhill, Massachusetts 01830 • Tel: 800/252-7074, 978/374-0761 • FAX: 978/521-1839
e-mail: sales@freqdev.com • Web Address: http://www.freqdev.com
828 Series
8-Bit Programmable Filters
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 (D
0
- D
7
).
Filter tuning follows the tuning equation given below:
f
c
= ( f
max
/256 ) [ 1 + D
7
x 2 + D
6
x 2 + D
5
x 2 + D
4
x 2 +
D
3
x 2 + D
2
x 2 + D
1
x 2 + D
0
x 2 ]
where D
1
- D
7
= "0" or "1", and
f
max
= Maximum tuning frequency;
f
c
= corner frequency;
Minimum tunable frequency = f
max
/256 (D
0
thru D
7
= 0);
Minimum frequency step (Resolution) = f
max
/256
2.00
OUT +Vs -Vs
D
7
D
6
D
5
D
4
GND
D
3
D
2
D
1
D
0
IN Os
4
3
2
1
0
7
6
5
4
Digital Tuning &
Control Characteristics
Pin-Out Key
IN
OUT
GND
+Vs
-Vs
Os
Analog Input Signal
Analog Output Signal
Power and Signal Return
Supply Voltage, Positive
Supply Voltage, Negative
Offset Adjustment
D
7
Tuning
D
6
Tuning
D
5
Tuning
D
4
Tuning
D
3
Tuning
D
2
Tuning
D
1
Tuning
D
0
Tuning
Bit
Bit
Bit
Bit
Bit
Bit
Bit
Bit
7 (MSB)
6
5
4
3
2
1
0 (LSB)
Data Input Specifications
Input Data Levels
(CMOS Logic)
4 Vdc max.
15 Vdc max.
-1
µA
max.
.
+1
µA
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
D
0
D
7
Frequency Range
- 10
µA
typ.
-5
+10
µA
typ
.
5 pF typ
-5
Bottom View
MSB
2
7
---
2
6
---
2
5
---
2
4
---
2
3
---
2
2
---
2
1
LSB
2
0
Bit
Weight
Corner
Frequency
Frequency Select Bits
Logic "1" = +Vs
Logic "0" = Gnd
(Binary-Coded)
LSB (least significant bit)
MSB (most significant bit)
256 : 1, Binary Weighted
fc
D
7
0
0
0
0
0
0
0
0
1
D
6
0
0
0
0
0
0
0
1
1
D
5
0
0
0
0
0
0
1
1
1
D
4
0
0
0
0
0
1
1
1
1
D
3
0
0
0
0
1
1
1
1
1
D
2
0
0
0
1
1
1
1
1
1
D
1
0
0
1
1
1
1
1
1
1
D
0
0
1
1
1
1
1
1
1
1
f
max
/256
f
max
/128
f
max
/64
f
max
/32
f
max
/16
f
max
/8
f
max
/4
f
max
/2
fmax
2
25 Locust St, Haverhill, Massachusetts 01830 • Tel: 800/252-7074, 978/374-0761 • FAX: 978/521-1839
e-mail: sales@freqdev.com • Web Address: http://www.freqdev.com
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