
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
1.0 Hz to 102.4 kHz
8-Bit Programmable
D824 Series
2" x 2"
Differential Input
4-Pole Filters
Description
The D824 Series are digitally programmable low
pass and high pass active filters with differential
input that are tunable over a 256:1 frequency range.
D824 filters are available with any one of five
standard factory-set tuning ranges up to 102.4 kHz.
These units contain 8 CMOS logic inputs .
All D824 Series models are convenient, low profile,
easy to use fully finished filters which require no ex-
ternal components or adjustments. They feature low
harmonic distortion, and near theoretical phase and
amplitude characteristics.  D824 filters operate from
non-critical ± 12 to ± 18 Vdc power supplies, have a
10 k
W
 (min.) input impedance, a 10 
W
 (max.) output. 
Features/Benefits:
 Compact 2" x 2" design minimizes board space
requirements.
 Digitally programmable corner frequency allows
selecting cut-off frequencies specific to each appli-
cation.
 Plug-in ready-to-use, reducing engineering de-
sign 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:
. . . . . . . . . . . . . . . . . . . 
D824L8B
4-pole Butterworth . . . . . . . . . . . . . . . . . 3
D824L8L
4-pole Bessel . . . . . . . . . . . . . . . . . . . . . 3
D824L8Y2 4-pole Cheby (0.2 dB Ripple) . . . . . . . . . 3
D824L8Y5 4-pole Cheby (0.5 dB Ripple) . . . . . . . . . 3
Available High-Pass Models:
 . . . . . . . . . . . . . . . . . . 
D824H8B
4-pole Butterworth . . . . . . . . . . . . . . . . . 4
D824H8Y2 4-pole Cheby (0.2 dB Ripple) . . . . . . . . . 4
D824H8Y5 4-pole Cheby (0.5 dB Ripple) . . . . . . . . . 4
General Specifications:
Ordering information . . . . . . . . . . . . . . . . . . . . . . . . . 5
Pin-out/package data. . . . . . . . . . . . . . . . . . . . . . . . . 5