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4-252
Semiconductor
Description
The HC-55536 is a CMOS integrated circuit used to convert
serial NRZ digital data to an analog (voice) signal. Conver-
sion is by delta demodulation, using the Continuously
Variable Slope (CVSD) method of demodulation.
While signals are compatible with other CVSD circuits, the
internal design is unique. The analog loop filters have been
replaced by digital filters which use very low power and
require no external timing components. This digital approach
allows inclusion of many desirable features, which otherwise
would be difficult to implement. The device is usable from
9Kbits/s to above 64kbits/s, and may be easily configured
with the HC-55564 CVSD for a complete transmit/receive
voice channel.
Ordering Information
PART
NUMBER
TEMP.
RANGE (
o
C)
PACKAGE
PKG. NO.
HC1-55536-5
0 to 75
14 Ld CERDIP
HC1-55536-9
-40 to 85
14 Ld CERDIP
HC3-55536-5
0 to 75
14 Ld PDIP
HC3-55536-9
-40 to 85
14 Ld PDIP
Features
All Digital
Requires Few External Parts
Low Power Drain: 1.5mW from Single 3V to 6V Supply
Time Constants Determined by Clock Frequency; No
Calibration or Drift Problems; Automatic Offset
Adjustment
Filter Reset by Digital Control
Automatic Overload Recovery
Automatic “Quiet” Pattern Generation
Applications
Voice Decoder for Digital Systems and Speech
Syntheses
Voicemail
Audio Manipulations; Delay Lines, Echo Generation/
Suppression, Special Effects, etc.
Pagers/Satellites
March 1993
Pinout
HC-55536
(PDIP, CERDIP)
TOP VIEW
VDD
NC
AOUT
NC
NC
NC
NC
NC
FZ
DIGITAL INPUT
NC
NC
CLOCK
DIGITAL GND
1
2
3
4
5
6
7
14
13
12
11
10
9
8
Functional Diagram
(13)
FORCE ZERO
(12)
DIGITAL IN
3 BIT
SHIFT
REGISTER
DIGITAL
MODULATOR
+1
1
6
6
SYLLABIC
DIGITAL
FILTER
4.0msec
SIGNAL
ESTIMATE
DIGITAL FILTER
1.0msec
10 BIT
DAC
CLOCK
(9)
(1)
10
DIGITAL GND
(8)
A
OUT
(3)
V
DD
Z
O
HC-55536
Continuously Variable Slope
Delta-Demodulator (CVSD)
CAUTION: These devices are sensitive to electrostatic discharge. Users should follow proper IC Handling Procedures.
Copyright
Harris Corporation 1997
File Number
2888.1
FOR NEW DESIGNS
Low Bit Rate Voiceband Encoders/Decoders