1

Semiconductor

Description

The HC-55564 is a half duplex modulator/demodulator CMOS

intergrated circuit used to convert voice signals into serial NRZ

digital data and to reconvert that data into voice. The conver-

sion is by delta-modulation, using the Continuously Variable

Slope (CVSD) method of modulation/demodulation.

While the signals are compatible with other CVSD circuits, the inter-

nal design is unique. The analog loop filters have been replaced by

very low power digital filters which require no external timing compo-

nents. This approach allows inclusion of many desirable features

which would be difficult to implement using other approaches.

The fundamental advantages of delta-modulation, along with its

simplicity and serial data format, provide an efficient (low data

rate/low memory requirements) method for voice digitization.

The HC-55564 is usable from 9kbits/s to above 64kbps. See the

Harris Military databook for a MIL-STD-883C compliant CVSD.

Application Note 607.

Ordering Information

PART

NUMBER

TEMP.

PACKAGE

PKG. NO.

HC1-55564-2

-55 to 125

14 Ld CERDIP

F14.3

HC1-55564-5

0 to 75

14 Ld CERDIP

F14.3

HC1-55564-9

-40 to 85

14 Ld CERDIP

F14.3

HC3-55564-5

0 to 75

14 Ld PDIP

E14.3

HC9P55564-5

0 to 75

16 Ld Plastic SOIC (W)

M16.3

Features

• All Digital

• Requires Few External Parts

• Low Power Drain: 1.5mW Typical From Single 4.5V

To 6V Supply

• Time Constants Determined by Clock Frequency;

No Calibration or Drift Problems: Automatic Offset

Adjustment

• Half Duplex Operation Under Digital Control

• Filter Reset Under Digital Control

• Automatic Overload Recovery

• Automatic “Quiet” Pattern Generation

• AGC Control Signal Available

Applications

• Voice Transmission Over Data Channels (Modems)

• Voice/Data Multiplexing (Pair Gain)

• Voice Encryption/Scrambling

• Voicemail

• Audio Manipulations: Delay Lines, Time Compression,

Echo Generation/Suppression, Special Effects, etc.

• Pagers/Satellites

• Data Acquisition Systems

• Voice I/O for Digital Systems and Speech Synthesis

Requiring Small Size, Low Weight, and Ease of

Reprogrammability

• Related Literature

- AN607, Delta Modulation for Voice Transmission

February 1999

Pinouts

HC-55564

(PDIP, CERDIP)

TOP VIEW

HC-55564

(SOIC)

TOP VIEW

ANALOG GND

AGC

NC

NC

DIG OUT

FZ

DIG IN

APT

ENC/DEC

CLOCK

DIG GND

1

2

3

4

5

6

7

14

13

12

11

10

9

8

14

15

16

9

13

12

11

10

1

2

3

4

5

7

6

8

ANALOG GND

AGC

AIN

NC

NC

NC

DIG OUT

DIG IN

APT

ENC/DEC

CLOCK

DIG GND

NC

FZ

CAUTION: These devices are sensitive to electrostatic discharge. Users should follow proper IC Handling Procedures.

Copyright

Low Bit Rate Voiceband Encoders/Decoder

HC-55564

Continuously Variable

Slope Delta-Modulator (CVSD)

File Number

2889.5

[ /Title

(HC-

55564

)

/Sub-

ject

(Con-

tinu-

ously

Vari-

able

Slope

Delta-

Modu-

lator

(CVS

D))

/

Autho

r ()

/Key-

words

(Har-

ris

Semi-

con-

ductor

, Tele-

com,

SLICs

,

SLAC

s,

Tele-

phone,

Tele-

phony,

OBSOLETE

PRODUCT

NO RECOMMENDED

REPLA

CEMENT

Call

Central

Applications

1-800-442-7747

or email:

centapp@harris.com