AS2520B AMSCO [austriamicrosystems AG], AS2520B Datasheet - Page 3

• Manufacturer Part Number: AS2520B
• Description: Telephone Speech Circuit with Loudhearing and Handsfree
• Manufacturer: AMSCO [austriamicrosystems AG]

Preliminary
DI:
DO:
DI/O:
Operating Modes
MODE
Idle (on-hook)
Ringing
POT
POT/pulse dialling
POT/DTMF dialling
Handsfree
Handsfree/pulse dial
Handsfree/DTMF dial
Loudhearing
Loudhearing/pulse dial
Loudhearing/DTMF dial
TAM without LSP
TAM with LSP
Melody feedback
Test mode 1
Test mode 2
Rev. 5.1
19
22
20
21
23
24
25
26
27
28
Digital Input
Digital Output
Digital Input/Output
I/O Pins
VOL
M1
M2
M4
M3
CS
V
SS
RI
LI
SS
HS
0
0
1
1
1
0
0
0
1
1
1
1
1
0
0
0
Supply
AI/O
D/AI
AO
AO
AI
AI
AI
Digital Inputs
LE
0
0
0
0
0
1
1
1
1
1
1
0
1
1
0
0
PD
Microphone Inputs
Differential inputs for handset microphone (electret).
Handsfree Microphone Inputs
These are the input pins for the handsfree microphone (electret).
Volume Control Input
Volume control for the receive signal.
AS2520: Digital control with +/– keys or from µC;
AS2521: Analogue dc control with potentiometer.
Supply Source Control Output
This N-channel open drain output controls the external high power source
transistor for supplying (V
loudhearing/handsfree mode.
Current Shunt Control Output
This N-channel open drain output controls the external high power shunt
transistor for the modulation of the line voltage and for shorting the line
during make period of pulse dialling.
Negative Power Supply
Line Input
This input is used for power extraction and line current sensing.
Receive Input
This is the input for the receive signal.
0
1
0
1
0
0
1
0
0
1
0
1
1
1
0
1
MT
Table 1: Operating Modes
0
0
0
1
1
0
1
1
0
1
1
0
0
0
1
1
Not connected
PDM signal to LO (DI)
Not connected
Not connected
DTMF to LI and RO (AI)
Not connected
Not connected
DTMF to LI and RO (AI)
Not connected
Not connected
DTMF to LI and RO (AI)
Signal to LI (AI)
Signal to LI (AI)
PDM signal to LO (DI)
Page 3
Tone Input
AI:
AO:
AI/O:
TI
PP
) the loudspeaker amplifier in off-hook
Reserved for testing
Reserved for testing
Analogue Input
Analogue Output
Analogue Input/output
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
CM
SW
‘M1/M2’
‘M3/M4’
‘M1/M2’
V
‘TI’
V
‘TI’
V
‘TI’
LI
AS2520/21/20B/21B
-
-
BE
BE
BE
Outputs
‘RI/STB’
‘RI/STB’
‘RI/STB’
‘RI/STB’
‘RI/STB’
‘RI/STB’
RO
PD
‘TI’
-
-
May 1999
‘LSI’
‘LSI’
‘LSI’
‘LSI’
‘LSI’
PD
LO
‘TI’
-
-
-
-