858 Series
0.1 Hz to 102.4 kHz
8-Bit Programmable
Description
2" x 4"
8-Pole Filters
The 858 Series are digitally programmable low pass
and high-pass active filters that are tunable over a
256:1 frequency range. 858 filters are available
with any one of six standard factory-set tuning
ranges up to 102.4 kHz. These units contain 8
CMOS logic inputs that can be operated in a
transparent or latching mode.
All 858 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. 858 filters operate
from non-critical ± 12 to ± 18 Vdc power supplies,
have a 10 kW (min.) input impedance, a 10
W
(max.)
output impedance and offer dc voltage offset
adjustment.
Features/Benefits:
•
Lower cost, high precision replacement for 848
and 878 series products.
• 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:
. . . . . . . . . . . . . . . . . . .
858L8B
8-pole Butterworth . . . . . . . . . . . . . . . . . 3
858L8E
8-pole, 6 zero elliptic, 1.77 (-80dB) . . . . . 3
858L8EX
8-pole, 6 zero elliptic, 1.56 (-80dB) . . . . . 3
858L8EY
8-pole, 6 zero elliptic, 2.00 (-100dB) . . . . 3
858L8L
8-pole Bessel . . . . . . . . . . . . . . . . . . . . . 4
858L8D60
8-pole constant delay (-60dB). . . . . . . . . 4
858L8D80
8-pole constant delay (-80dB). . . . . . . . . 4
858L8D10
8-pole constant delay (-100dB) . . . . . . . . 4
Available High-Pass Models:
. . . . . . . . . . . . . . . . . .
858H8B
8-pole Butterworth . . . . . . . . . . . . . . . . . . 5
858H8E
8-pole, 6 zero elliptic, 1.77 (-80dB) . . . . . 5
858H8EX
8-pole, 6 zero elliptic, 1.56 (-80dB) . . . . . 5
858H8EY
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
858 Series
8-Bit Programmable Filters
Digital Tuning Characteristics
The digital tuning interface circuits are two 4042 quad CMOS
latches which accept the following CMOS-compatible inputs:
eight tuning bits (D
0
- D
7
), a latch strobe bit (C), and a transition
polarity bit (P).
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
3
2
1
0
7
6
5
4
Digital Tuning &
Control Characteristics
Pin-Out Key
IN
OUT
GND
“P”
“C”
+Vs
-Vs
Os
Analog Input Signal
Analog Output Signal
Power and Signal Return
Transition Polarity Bit
Tuning Strobe Bit
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)
OUT +Vs -Vs
D
7
D
6
D
5
D
4
GND
D
3
D
2
D
1
D
0
IN Os
Data Input Specifications
Data Control Lines
Functions
Latch Strobe (C)
Transition Polarity (P)
frequency follows input codes
frequency latched on rising edge
frequency follows input codes
frequency latched on falling edge
Data Control Modes
Mode 1
P = 0; C = 0
P = 0; C = 0›
Mode 2
P = 1; C = 1
P = 1; C = 1fl
Bottom View
P C
MSB
Input Data Levels
(CMOS Logic)
4 Vdc max.
15 Vdc max.
-1
mA
max.
.
+1
mA
max.
7.5 pF max.
0
0
0
0
0
1
2
7
---
2
6
---
2
5
---
2
4
---
2
3
---
2
2
---
2
1
LSB
2
0
Bit
Weight
Corner
Frequency
fc
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
mA
typ.
-5
+10
mA
typ
.
5 pF typ
-5
D
7
0
0
0
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
Frequency Select Bits
Logic "1" = +Vs
Logic "0" = Gnd
(Binary-Coded)
LSB (least significant bit)
MSB (most significant bit)
256 : 1, Binary Weighted
Notes:
1. Frequency data must be present before occurrence of strobe edge.
2. Frequency data must be present after occurrence of strobe edge.
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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