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
10 Hz - 102.4 kHz
4-Bit Programmable
428 Series
32-Pin DIP
8-Pole Filters
Description
The 428 Series are 8-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. 428 filters are factory tuned to one of ten
preset 4-bit binary ranges from 10 Hz to 102.4 kHz.
Contact the factory for custom discrete tuning
ranges, maximum span 1000:1.
All 428 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 12V to 18V power supplies.
Features/Benefits:
Low harmonic distortion and wide signal-to-noise
ratio to 16-bit resolution.
Compact 1.8"L x 0.8"W 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:
. . . . . . . . . . . . . . . . . . .
428L4B
8-pole Butterworth . . . . . . . . . . . . . . . . . . 3
428L4E
8-pole, 6 zero elliptic, 1.77 (-80dB) . . . . . . 3
428L4EX 8-pole, 6 zero elliptic, 1.56 (-80dB) . . . . . . 3
428L4EY 8-pole, 6 zero elliptic, 2.00 (-100dB) . . . . . 3
428L4L
8-pole Bessel . . . . . . . . . . . . . . . . . . . . . . 4
428L4D60 8-pole constant delay (-60dB) . . . . . . . . . . 4
428L4D80 8-pole constant delay (-80dB) . . . . . . . . . . 4
428L4D10 8-pole constant delay (-100dB) . . . . . . . . . 4
Available High-Pass Models:
. . . . . . . . . . . . . . . . . .
428H4B
8-pole Butterworth . . . . . . . . . . . . . . . . . . 5
428H4E
8-pole, 6 zero elliptic, 1.77 (-80dB) . . . . . . 5
428H4EX 8-pole, 6 zero elliptic, 1.56 (-80dB) . . . . . . 5
428H4EY 8-pole, 6 zero elliptic, 2.00 (-100dB) . . . . . 5
General Specifications:
Ordering information . . . . . . . . . . . . . . . . . . . . . . . . . 6
Pin-out/package data. . . . . . . . . . . . . . . . . . . . . . . . . 6
U.S. Selling Price (1-9)
$320.00 ea.
Orders for Export
U.S. Selling Price + 20%
Minimum Order Value $150.00
F.O.B. Haverhill, MA
Lead-Time: 2-4 weeks A.R.O.
Accept Visa, Mcard, Amex
4-Bit Programmable Filters
428 Series
Digital Tuning &
Control Characteristics
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
Digital Tuning Characteristics
The digital tuning interface circuits are a parallel set of CMOS
switches which accept CMOS compatible inputs for the four
tuning bits (D
0
- D
3
).
Binary Tuning Range
Pin-Out Key
IN
Analog Input Signal
D
3
Tuning Bit 3 (MSB)
OUT Analog Output Signal
D
2
Tuning Bit 2
GND Power and Signal Return D
1
Tuning Bit 1
+Vs
Supply Voltage, Positive
D
0
Tuning Bit 0 (LSB)
-Vs
Supply Voltage, Negative +5V Logic Power
Os
Offset Adjustment
Data Input Specifications
Input Data Levels
(+5Vdc CMOS Logic)
Input Voltage (
Vs=15 Vdc
)
Low Level In
0 Vdc min.
0.5 Vdc max.
High Level In
3.5 Vdc min.
5.0 Vdc max.
Input Current
High Level In
-0.4
A typ.
-2.0
A max.
Low Level In
+0.4
A typ.
+2.0
A max.
Input Capacitance
20 pF typ.
30 pF max.
Input Data Format
Frequency Select Bits
Positive Logic
Logic "1" = (+5Vdc)
Logic "0" = Gnd
Bit Weight
(Binary-Coded)
D
0
LSB (least significant bit)
D
3
MSB (most significant bit)
Frequency Range16:1 Binary Weighted
MSB
---
---
LSB
Bit
Weight
2
3
2
2
2
1
2
0
fc - corner
D
3
D
2
D
1
D
0
frequency
0
0
0
0
f
max
/16
0
0
0
1
f
max
/8
0
0
1
1
f
max
/4
0
1
1
1
f
max
/2
1
1
1
1
f
max
Binary Tuning Equation:
fc = (f
max
/16) [1+ D
3
x 2
3
+ D
2
x 2
2
+ D
1
x 2
1
+ D
0
x 2
0
]
where D
1
- D
3
= "0" or "1", and
f
max
= Maximum tuning frequency
fc = Corner frequency;
Minimum tunable frequency = f
max
/16 (D
0
thru D
3
= 0);
Minimum frequency step (Resolution) = f
max
/16
Discrete Frequencies
F
D
0
D
1
D
2
D
3
F
B
0
0
0
0
F
1
1
0
0
0
F
2
1
1
0
0
F
3
1
1
1
0
F
4
1
1
1
1
Discrete Tuning Equation:
fc = F
B
+ D
0
[
f
0
] + D
1
[
f
1
] + D
2
[
f
2
] + D
3
[
f
3
]
f
0
,
f
1
,
f
2
,
f
3
are the incremental frequency shifts for the data
bits D
0
, D
1
,
D
2
and D
3
. They are selected to realize the five
customer specified programming frequencies F
B
F
4
. Other
programming codes produce valid fc's between F
B
and F
4
.
Bottom View
0.70
0.80
0.00
0.10
1.00
1.50
1.30
1.10
0.50
1.80
1.60
0.30
0.00
0.80
0.90
Gnd Os
-Vs +Vs
D0
D2 D3
D1
+5V
Out
In
4
2
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