SSM2000 Analog, SSM2000 Datasheet - Page 16

• Manufacturer Part Number: SSM2000
• Description: HUSH Stereo Noise Reduction System with Adaptive Threshold
• Manufacturer: Analog

SSM2000
VCF—minimum bandwidth) to their fully open positions. If
the VCA and VCF are fully opened then at least 1.5 seconds of
no signal is required for the VCA and VCF detectors to return
to the closed position. A series of 10 kHz pulses interspersed
with 1.5 seconds of no signal will accomplish this requirement.
The system’s attack and release times will be dominated by
VCA since the attack and release times of the VCA are slower
than the VCF’s. In addition, monitoring Pins 11 (VCF) and 12
(VCA) will ensure that the VCA and VCF are either fully
opened or fully closed.
The SSM2000 is manufactured under a license granted to Analog Devices,
Inc., by Rocktron Corp. and embodies technology covered by the following
patents: 4696044, 4893099, 5124657, 5263091, 5402498, and 5493617. For-
eign patents are pending. Rocktron Corp. grants a royalty-free license to
purchasers of the SSM2000 for use in end equipment, and no further rights
are implied. The use of the HUSH logo is encouraged on products, packaging,
0.200 (5.05)
0.125 (3.18)
0.0118 (0.30)
0.0040 (0.10)
(5.33)
0.210
MAX
24
1
0.022 (0.558)
0.014 (0.356)
PIN 1
24
1
IMPORTANT NOTICE—LICENSING
PIN 1
0.0500
(1.27)
BSC
Dimensions shown in inches and (mm).
0.6141 (15.60)
0.5985 (15.20)
OUTLINE DIMENSIONS
1.275 (32.30)
1.125 (28.60)
0.100 (2.54)
0.0192 (0.49)
0.0138 (0.35)
BSC
24-Pin Plastic DIP
24 Pin SOIC
(SOL-24)
(N-24)
–16–
0.1043 (2.65)
0.0926 (2.35)
0.070 (1.77)
0.045 (1.15)
13
12
SEATING
PLANE
As stated before, the most common cause of a failure to reduce
noise is fixed-frequency tones that are being detected by the
output. A solution for this condition is detailed in the “Precau-
tions, Limitations, and Observations” section.
In single-supply applications, ACOM should be driven with a
well regulated reference capable of both sinking and souring
current. Zener-resistor references are unacceptable, because of
their inability to sink significant amounts of current.
By following these simple suggestions, the common pitfalls to a
successful implementation of the HUSH noise reduction system
can be avoided.
promotional and descriptive literature. Rocktron Corp. reserves the right to
approve use of the HUSH logo and may require submission of a schematic
illustrating the use of the SSM2000; a physical sample of the end product may
also be required. Applications for approval of the use of the HUSH name and
logo may be obtained by contacting ADI.
13
12
0.060 (1.52)
0.015 (0.38)
0.280 (7.11)
0.240 (6.10)
0.0125 (0.32)
0.0091 (0.23)
SEATING
PLANE
0.150
(3.81)
MIN
8
0
0.325 (8.25)
0.300 (7.62)
0.0291 (0.74)
0.0098 (0.25)
0.0500 (1.27)
0.0157 (0.40)
0.015 (0.381)
0.008 (0.204)
0.195 (4.95)
0.115 (2.93)
x 45
REV. 0