CD22204E View Datasheet(PDF) - Harris Semiconductor
Part Name
Description
Manufacturer
CD22204E Datasheet PDF : 5 Pages
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SEMICONDUCTOR
CD22204
January 1997
5V Low Power Subscriber
DTMF Receiver
Features
• No Front End Band Splitting Filters Required
• Single Low Tolerance 5V Supply
• Three-State Outputs for Microprocessor Based
Systems
• Detects all 16 Standard DTMF Digits
• Uses Inexpensive 3.579545MHz Crystal
• Excellent Speech Immunity
• Output in 4-Bit Hexadecimal Code
• Excellent Latch-Up Immunity
Ordering Information
PART
NUMBER
CD22204E
CD22204M
TEMP.
RANGE (oC)
PACKAGE
0 to 70 14 Ld PDIP
0 to 70 24 Ld Plastic SOIC
PKG. NO.
E14.3
M24.3
Description
The CD22204 complete dual tone multiple frequency (DTMF)
receiver detects a selectable group of 12 or 16 standard digits. No
front-end pre-filtering is needed. The only externally required com-
ponents are an inexpensive 3.579545MHz TV ‘‘colorburst’’ crystal
(for frequency reference) and a bias resistor. Extremely high sys-
tem density is possible through the use of the Alternate Time Base
(ATB) output of a crystal connected CD22204 receiver to drive the
time bases of up to 10 additional receivers. This is a monolithic
integrated circuit fabricated with low power, complementary sym-
metry CMOS processing. It only requires a single power supply.
The CD22204 employs state-of-the-art ‘‘switched-capacitor’’ filter
technology, resulting in approximately 40 poles of filtering and dig-
ital circuitry on the same CMOS chip. The analog input is prepro-
cessed by 60Hz reject and bandsplitting filters and then zero-cross
detected to provide AGC. Eight bandpass filters detect the individ-
ual tones. Digital processing is used to measure the tone and
pause durations and provides the correctly coded and timed digital
outputs. The outputs interface directly to standard CMOS circuitry
and are three-state enabled to facilitate bus oriented architectures.
Pinouts
CD22204 (PDIP)
TOP VIEW
D2 1
D1 2
EN 3
VDD 4
NC 5
XEN 6
ANALOG 7
IN
14 D4
13 D8
12 DV
11 ATB
10 XIN
9 XOUT
8 VSS
CD22204 (SOIC)
TOP VIEW
D2 1
D1 2
EN 3
NC 4
NC 5
VDD 6
NC 7
NC 8
NC 9
NC 10
XEN 11
AIN 12
24 D4
23 D8
22 NC
21 NC
20 DV
19 NC
18 ATB
17 NC
16 XIN
15 NC
14 XOUT
13 VSS
Functional Diagram
7
ANALOG IN
11
ATB
6
XEN
XIN
10
LOW B/P
FILTERS
HIGH B/P
FILTERS
CHIP
CLOCKS
9
XOUT
VOLTAGE
REG./REF.
4
VDD
8
VSS
NOTE: Pin numbers are for PDIP.
5
NC
12
DV
2
D1
1
D2
14
D4
13
D8
3
EN
CAUTION: These devices are sensitive to electrostatic discharge. Users should follow proper IC Handling Procedures.
Copyright © Harris Corporation 1997
4-1
File Number 1696.3
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