MT8888C
Data Sheet
20 PIN PLASTIC DIP/SOIC
24 PIN SSOP
Figure 2 - Pin Connections
Pin Description
Pin #
20
1
2
3
4
5
6
7
24
1
2
3
4
5
6
7
28
1
2
4
6
7
8
9
Name
IN+
IN-
GS
V
Ref
V
SS
Non-inverting
op-amp input.
Inverting
op-amp input.
Gain Select.
Gives access to output of front end differential amplifier for
connection of feedback resistor.
Reference Voltage
output (V
DD
/2).
Ground (0V ).
Description
OSC1 DTMF clock/oscillator input. Connect a 4.7 MΩ resistor to VSS if crystal oscillator is
used.
OSC2
Oscillator
output. A 3.579545 MHz crystal connected between OSC1 and OSC2
completes the internal oscillator circuit. Leave open circuit when OSC1 is driven
externally.
TONE Output from internal DTMF transmitter.
WR
CS
RS0
RD
Write
microprocessor input. TTL compatible.
Chip Select
input. Active Low. This signal must be qualified externally by address
latch enable (ALE) signal, see Figure 14.
Register Select
input. Refer to Table 3 for bit interpretation. TTL compatible.
Read
microprocessor input. TTL compatible.
8
9
10
11
12
13
10
11
12
13
14
15
12
13
14
15
17
18
IRQ/CP
Interrupt Request/Call Progress
(open drain) output. In interrupt mode, this
output goes low when a valid DTMF tone burst has been transmitted or received.
In call progress mode, this pin will output a rectangular signal representative of the
input signal applied at the input op-amp. The input signal must be within the
bandwidth limits of the call progress filter, see Figure 8.
D0-D3
Microprocessor Data Bus.
High impedance when CS = 1 or RD = 1.
TTL compatible.
14-17 18-21 19-22
2
Zarlink Semiconductor Inc.
TONE
WR
CS
RSO
NC
RD
IRQ/CP
IN+
IN-
GS
VRef
VSS
OSC1
OSC2
TONE
WR
CS
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
VDD
St/GT
ESt
D3
D2
D1
D0
IRQ/CP
RD
RS0
IN+
IN-
GS
VRef
VSS
OSC1
OSC2
NC
NC
TONE
WR
CS
1
2
3
4
5
6
7
8
9
10
11
12
24
23
22
21
20
19
18
17
16
15
14
13
VDD
St/GT
ESt
D3
D2
D1
D0
NC
NC
IRQ/CP
RD
RS0
12
13
14
15
16
17
18
NC
VRef
VSS
OSC1
OSC2
NC
NC
4
3
2
1
28
27
26
GS
NC
IN-
IN+
VDD
St/GT
EST
5
6
7
8
9
10
11
•
25
24
23
22
21
20
19
NC
NC
NC
D3
D2
D1
D0
28 PIN PLCC
ZARLINK [ ZARLINK SEMICONDUCTOR INC ]
