MT8840
ISO
2
-CMOS
DET
CRx
Rxl
RxE
LOOP
VRef
TxO
TxDI
VSS
1
2
3
4
5
6
7
8
9
18
17
16
15
14
13
12
11
10
VDD
RxDO
OSC2
OSC1
CK32
ETC
MTC
TCO
FATC
18 PIN PLASTIC DIP/SOIC
Figure 2 - Pin Connections
Pin Description
Pin #
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
Name
DET
CRx
RxI
RxE
LOOP
V
Ref
TxO
TxDI
V
SS
FATC
TCO
MTC
ETC
CK32
OSC1
OSC2
RxDO
V
DD
Description
Demodulator detection level adjust input (Analog). Internal resistor divider applies
2.36V in open circuit condition. Connection of external resistor will vary detect level.
External AGC time constant adjust input (Analog). Connect external capacitor to V
SS
.
Modulated receive signal input (Analog). Biased at V
Ref
.
Receive enable input (Digital) with internal pull up. Active high.
Self-test mode select input (Digital) with internal pull down. Active high.
Internal reference supply voltage input (Analog) .
Modulated transmit carrier output (Analog).
Transmit data input (Digital).
Negative power supply.
Tone caller center frequency adjust input (Analog).
Tone caller output (Digital).
Mute tone caller input (Digital) with internal pull down. Active high.
Enable tone caller input (Digital) with internal pull down. Active high.
32 kHz data strobe output (Digital).
Clock Input
Clock Output to drive external devices.
Positive power supply.
3.579545 MHz crystal connected between
these pins completes internal oscillator.
Receive data output (Digital). Synchronized to CK32.
5-4
MITEL [ MITEL NETWORKS CORPORATION ]
