CALIFORNIA MICRO DEVICES
CM8888/8888-2
CMOS INTEGRATED DTMF TRANCEIVER
Fea tur es
Advanced CMOS technology for low power
consumption and increased noise immunity
Complete DTMF
Transmitter/Receiver
Standard 8051, 8086/8 microprocessor port
Central office quality and performance
Adjustable guard time
Automatic tone burst mode
Call progress mode
Single +5 volt power supply
20-pin DIP, 20-pin DIP EIAJ, 20-pin SOIC,
28-pin PLCC packages
2 MHz microprocessor port operation
Applications
Paging systems
Repeater systems/mobile radio
Interconnect dialers
PABX systems
Computer systems
Fax machines
Pay telephones
Credit card verification
Product
Description
The CAMD CM8888/8888-2 is a fully integrated DTMF Transceiver, featuring adjustable guard time, automatic tone burst
mode, call progress mode, and a fully compatible 8051, 8086/8 microprocessor interface. The CM8888/8888-2 is
manufactured using state-of-the-art advanced CMOS technology for low power consumption and precise data handling.
The CM8888/8888-2 is based on the industry standard CM8870 DTMF Receiver, while the transmitter utilizes a switched-
capacitor D/A converter for low distortion, highly accurate DTMF signaling. Internal counters provide an automatic tone
burst mode which allows tone bursts to be transmitted with precise timing. A call progress filter can be selected by an
external microprocessor for analyzing call progress tones. The CM8888-2 is electrically equivalent to the CM8888 but does
not include the call progress function.
Block Diagram
All trademarks are the property of their respective holders.
© 2000 California Micro Devices Corp. All rights reserved.
5/00
C0400798D
215 Topaz Street, Milpitas, California 95035
Tel: (408) 263-3214
Fax: (408) 263-7846
www.calmicro.com
1
CALIFORNIA MICRO DEVICES
Absolute Maximum Ratings: (See Note)
CM8888/8888-2
This device contains input protection
against damage due to high static voltages
or electric fields; however, precautions
should be taken to avoid application of
voltages higher than the maximum rating.
Note:
Exceeding these ratings may cause
permanent damage, functional
operation under these conditions is
not implied.
ABSOLUTE MAXIMUM RATINGS
Parameter
Power Supply Voltage
(V
D D
-V
S S
)
Voltage on any Pin
Current on any Pin
Operating Temperature
Storage Temperature
Symbol
V
D D
Vdc
I
D D
T
A
T
S
Value
6.0V Max
-0.3V to V
D D
+0.3V
10mA Max
-40°C to +85°C
-65°C to +150°C
DC Characteristics:
All voltages referenced to V
SS
, V
DD
= 5.0V + 5%,
fc = 3.579545 MHz, T
A
= -40°C to +85°C unless otherwise noted.
Parameter
Operating Supply Voltage
Operating Supply Current
Power Consumption
Inputs
High Level Input Voltage OSCI
Low Level Input Voltage OSCI
Input Impedance, (@ 1KHz) IN+IN-
Steering Threshold Voltage (V
DD
=5.0V)
Outputs
High Level Output Voltage (No Load) OSC2
Low Level Output Voltage (No Load) OSC2
Output Leakage Current (V
OH
=2..4V) IRQ
V
REF
Output Voltage (No Load)
V
REF
Output Resistance
D ata Bus (D O-D 3, RD , WR, RSO, CS)
Low Level Input Voltage
High Level Input Voltage
Low Level Output Voltage (I
High Level Input Voltage (I
OL
=1.6mA)
OH
=400
µ
A)
DC CHARACTE RISTICS
Symbol
Min
V
DD
4.75
I
D D
P
O
V
I HO
V
I LO
R
I N
V
Tst
V
OHO
V
OLO
I
OZ
V
R EF
R
OR
V
I L
V
I H
V
OL
V
OH
I
I Z
2.4
2.0
3.5
Typ*
5.0
10
Max
5.25
52.5
Units
V
mA
mΩ
V
V
MΩ
V
V
1.5
2.2
4.9
1.0
2.4
0.1
10.0
2.7
1
0.8
0.4
10.0
10.0
2.3
2.5
V
µA
V
KΩ
V
V
V
V
µA
Input Leakage Current (V
I N
=0.4 to 2.4V) I
Operating Characteristics - Gain Setting Amplifier:
All voltages referenced to V
SS
, V
DD
= 5.0V + 5%,
fc = 3.579545 MHz, T
A
= -40°C to +85°C unless otherwise noted.
Parameter
Input Leakage Current( V
S S
< V
I N
Input Resistance
Input Offset Voltage
Power Supply Rejection (1 KHz)
Common Mode Rejection(-3.0V < V
I N
<3.0V)
D C Open Loop Voltage Gain
Unity Gain Bandwidth
Output Voltage Swing ( R
L
> 100K
Ω
to V
S S
)
Maximum Capacitive Load (GS)
Maximum Resistive Load (GS)
Common Mode Range (No Load)
©2000 California Micro Devices Corp. All rights reserved.
OPE RATING CHARACTE RISTICS
Symbol
Min
Typ
< V
D D
)
I
I N
10 0
R
I N
V
O S
P SR R
CMRR
A
V O L
BW
V
O
C
L
R
L
Vc m
10
25
60
60
65
1.5
4.5
10 0
50
3.0
Max
Units
nA
MΩ
mV
dB
dB
dB
MHz
V
pp
pF
KΩ
V
pp
2
215 Topaz Street, Milpitas, California 95035
Tel: (408) 263-3214
Fax: (408) 263-7846
www.calmicro.com
5/00
CALIFORNIA MICRO DEVICES
AC Characteristics:
All voltages referenced to V
SS
, V
DD
= 5.0V + 5%, fc = 3.579545 MHz,
T
A
= -40°C to +85°C unless otherwise noted.
Parameter
Receive Signal Conditions
Valid Input Signal Levels
(Each Tone of Composite Signal;
Notes 1,2,3,4,5,6,9)
Positive Twist Accept (Notes 2,3,6,9)
Negative Twist Accept (Notes 2,3,6,9)
Freq. D eviation Accept Limit (Notes 2,3,5,9)
Freq. D eviation Reject Limit (Notes 2,3,5)
Third Tone Tolerance ( 2,3,4,5,9,10)
Noise Tolerance ( 2,3,4,5,7,9,10)
D ial Tone Tolerance ( 2,3,4,5,8,9,11)
Lower Frequency (@ -25 dBm) ACCEPT
Upper Frequency (@ -25 dBm) ACCEPT
Lower Frequency (@ -25 dBm) ACCEPT
Upper Frequency (@ -25 dBm) ACCEPT
Receive Timing
Tone Present D etection Time
Tone Absent D etection Time
Min Tone D uration Accept (Ref. Fig 9)
Max Tone D uration Reject (Ref. Fig 9)
Min. Interdigit Pause Accept (Ref. Fig 9)
Max. Interdigit Pause Reject (Ref. Fig 9)
Propagation D elay (St to b3)
Propagation D elay (St to RXO - RX3)
Transmit Timing
Tone Burst D uration (D TMF Mode)
Tone Pause D uration (D TMF Mode)
Tone Burst D uration
(Extended, Call Process Mode)
Tone Pause D uration
(Extended, Call Process Mode)
Tone Output
High Group Output Level (R
L
= 10K
Ω)
Low Group Output Level (R
L
= 10K
Ω)
Pre-emphasis (R
L
= 10K
Ω)
Output D istortion
(R
L
= 10K
Ω
3.4 KHz Bandwidth)
Frequency D eviation (f = 3.5795 MHz)
Output Load Resistance
AC CHARACTE RISTICS
Symbol
Min
-29
27.5
Typ
CM8888/8888-2
Max
+1
869
10
10
Units
dBm
mV
RMS
dB
dB
Nom.
Nom.
dB
dB
dB
Hz
Hz
Hz
Hz
±1.5%
±2Hz
±3.5%
-16
-16
22
320
510
290
540
5
0.5
20
40
20
13
8
50
50
10 0
10 0
52
52
10 4
10 4
11
4
14
8.5
40
F
LA
F
HA
F
LR
F
HR
t
DP
t
DA
t
REC
t
REC
t
ID
t
DO
t
PS
t
b3
t
PS
t
RX
t
BST
t
BSTE
t
PSE
t
PS
mS
mS
mS
mS
mS
µS
µS
µS
mS
mS
mS
mS
V
HOUT
V
LOUT
dB
P
TH D
f
D
R
LT
-6.1
-8.1
0
2
-25
±0.7
10
-2.1
-4.1
3
dBm
dBm
dB
dB
%
K
Ω
±1.5
50
© 2000 California Micro Devices Corp. All rights reserved.
5/00
215 Topaz Street, Milpitas, California 95035
Tel: (408) 263-3214
Fax: (408) 263-7846
www.calmicro.com
3
CALIFORNIA MICRO DEVICES
A Characteristics:
V
DD
= 5.0V + 5%, V
SS
= OV, T
A
= -40°C to +85°C
C
AC CHARACTE RISTICS
CM8888/8888-2
Parameter
Microprocessor Interface
RD , WR, Low Pulse Width
RD , WR, High Pulse Width
RD , WR, Rise and Fall
Address Hold
Address Setup
Read D ata Hold
RD to Valid D ata D elay (200 pF Load)
Write D ata Setup
Write D ata Hold
Input Capacitance D O-D 3
Output Capacitance IRQ CP
D TMF Clock
Crystal Clock Frequency
Clock Input Rise Time (External Clk.)
Clock Input Fall Time (External Clk.)
Clock Input D uty Cycle (External Clk.)
Capacitive Load OSC2
Notes:
1. dBm = decibels above or below a reference power
of 1 mW into a 600 ohm load.
2. Digit sequence consists of all 16 DTMF tones.
3. Tone duration = 40mS. Tone pause = 40 mS.
4. Nominal DTMF frequencies are used.
5. Both tones in the composite signal have
an equal amplitude.
Symbol
t
CL
t
CH
t
R ,
t
F
t
AH
t
AS
t
D H R
t
D D R
t
D SW
t
D H W
t
CIN
t
OU T
fc
t
L H CL
t
L H CL
D C
CL
C
LO
Min
200
18 0
Typ*
Max
Unit
ns
ns
ns
ns
ns
ns
ns
ns
ns
pF
pF
MHz
ns
ns
%
pF
25
10
23
22
150
45
10
5
5
3.5759
3.5795
3.5831
110
110
60
30
40
50
* Typical values are for use as design aids only, and are not guaranteed or subject to production testing.
6.
7.
8.
9.
10.
11.
The tone pair is deviate by + 1.5% + 2Hz.
Bandwidth limited (3 KHz) Gaussian Noise.
The precise dial tone frequencies are 350 and 440 Hz (+2%)
For an error date of less than 1 in 10,000.
Referenced to the lowest amplitude tone in the DTMF signal.
Referenced to the minimum valid accept level.
©2000 California Micro Devices Corp. All rights reserved.
4
215 Topaz Street, Milpitas, California 95035
Tel: (408) 263-3214
Fax: (408) 263-7846
www.calmicro.com
5/00
CALIFORNIA MICRO DEVICES
CM8888/8888-2
© 2000 California Micro Devices Corp. All rights reserved.
5/00
215 Topaz Street, Milpitas, California 95035
Tel: (408) 263-3214
Fax: (408) 263-7846
www.calmicro.com
5