R858 Series
1.0 Hz to 102.4 kHz
8-Bit Programmable
Description
2" x 4" Range Switch
8-Pole Filters
The R858 Series are digitally programmable, 8-pole
low-pass and high-pass active filters that contain a
low and a high programmable frequency range, with
each range tunable over a 256:1 ratio. R858 filters
are available with any two 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 that can be operated in a transparent or
latching mode and 1 logic input for range selection.
All R858 Series models are convenient, easy to
use, fully finished filters which require no external
components or adjustments. They feature low
harmonic distortion, and precision phase and ampli-
tude characteristics. R858 filters operate from non-
critical ±12 to ±18 Vdc power supplies, have a 10
kΩ (min.) input impedance, a 10
Ω
(max.) output im-
pedance.
Features/Benefits:
• 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
Programmable Specifications:
. . . . . . . . . . . . .
Page
Digital Tuning & Control. . . . . . . . . . . . . . . . . . . . . . 2
Available Low-Pass Models:
. . . . . . . . . . . . . . . . . . .
R858L8B
8-pole Butterworth . . . . . . . . . . . . . . . 3
R858L8E
8-pole, 6 zero elliptic, 1.77 (-80dB) . . . 3
R858L8EX
8-pole, 6 zero elliptic, 1.56 (-80dB) . . . 3
R858L8EY
8-pole, 6 zero elliptic, 2.00 (-100dB) . . 3
R858L8L
8-pole Bessel . . . . . . . . . . . . . . . . . . . 4
R858L8D60
8-pole constant delay (-60dB). . . . . . . 4
R858L8D80
8-pole constant delay (-80dB). . . . . . . 4
R858L8D10
8-pole constant delay (-100dB) . . . . . . 4
Available High-Pass Models:
. . . . . . . . . . . . . . . . . .
R858H8B
8-pole Butterworth . . . . . . . . . . . . . . . . 5
R858H8E
8-pole, 6 zero elliptic, 1.77 (-80dB) . . . 5
R858H8EX
8-pole, 6 zero elliptic, 1.56 (-80dB) . . . 5
R858H8EY
8-pole, 6 zero elliptic, 2.00 (-100dB) . . 5
General Specifications:
Ordering information . . . . . . . . . . . . . . . . . . . . . . . . . 6
Pin-out/package data . . . . . . . . . . . . . . . . . . . . . . . . 6
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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
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
R858 Series
Range Switch
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
), arrange selection bit (R), 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 (D0 thru D7 = 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
R
Analog Input Signal
Analog Output Signal
Power and Signal Return
Transition Polarity Bit
Tuning Strobe Bit
Supply Voltage, Positive
Supply Voltage, Negative
Offset Adjustment
Range Switch 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)
R
D
7
D
6
D
5
D
4
2.00
GND
D
3
D
2
D
1
D
0
IN Os
4
OUT +Vs -Vs
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
Input Data Levels
P = 1; C = 1
P = 1; C = 1⇓
Bottom View
P C
(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
Latch Response
Data Set Up Time
1
Data Hold Time
2
Strobe Pulse Width
Input Data Format
Positive Logic
Bit Weighting
D
0
D
7
Frequency Range
- 10
µA
typ.
-5
+10
µA
typ
.
5 pF typ
25nS
50 nS
80 nS min.
-5
MSB
2
7
---
2
6
---
2
5
---
2
4
---
2
3
---
2
2
---
2
1
LSB
2
0
Bit
Weight
Corner
Frequency
fc
D
7
0
0
0
0
0
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.
1
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
Test/Measurement
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