AS2536 austriamicrosystems, AS2536 Datasheet - Page 5

• Manufacturer Part Number: AS2536
• Description: IC MULTI-STANDARD CMOS TELEPHONE SOIC-28
• Manufacturer: austriamicrosystems

Specifications of AS2536

• Audio Control Type: Volume
• Control / Process Application: Electronic Telephonic Set
• Supply Voltage Range: 3.8V To 5V
• Operating Temperature Range: -25°C To +70°C
• Audio Ic Case Style: SOIC
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Data Sheet AS2533-36
Keyboard Connections continued
Power On Reset
The on chip power on reset circuit monitors the supply
voltage (V
approx. 1.2V, a power on reset occurs which clears the
RAM.
DC Conditions
The normal operating range is from 13 mA to 100 mA.
Operating range with reduced performance is from 5 mA to
13 mA (parallel operation). In the operating range all
functions are operational.
At line currents below 13 mA the AS253x provides an
additional slope below 4.5V in order to allow parallel
operation (see Figure 12).
The dc characteristic (excluding diode bridge) is
determined by the voltage at LI and the resistor R1 at line
currents above 13 mA as follows:
The voltage at LI is 4.5V in the normal operating range.
Revision 8.8
DD
) during off-hook. When V
R1
R2
R3
R4
VLS = VLI + ILINE × R1
P
P
P
L
L
L
M
M
M
M
M
M
M
M
M
C1
N
N
/
4
8
#
4
8
#
N
/
4
8
#
/
1
5
9
R
M
R
1
5
9
M
1
5
9
R
M
DD
rises above
Figure 4 Keyboard Connection AS2535
M
V
M
V
M
V
M
M
C2
R
M
M
R
M
M
R
O
1
5
9
O
1
5
9
O
1
5
9
1
1
1
1
2
6
1
2
6
1
L
2
6
L
L
0
0
0
M
M
M
M
M
R
C3
M
M
R
R
M
M
2
6
0
+
2
6
0
+
2
6
0
+
1
1
2
1
3
7
2
3
7
2
3
7
1
1
1
(either VOL or +/– keys)
During pulse dialing the speech circuit and other part of
the device not operating is in a power down mode to save
current. The CS pin is pulled to V
external shunt transistor on to keep a low voltage drop at
the LS pin during make periods.
AC Impedance
The ac impedance of the circuit is set by external
components. The impedance can be real or complex.
The ac impedance is determined as follows:
The dc value of Z1 should be 30 Ω to maintain correct dc
performance.
Return loss and side tone cancellation can be determined
independent of each other.
Speech Circuit
The speech circuit consists of a transmit and a receive
path with dual soft clipping, mute, line loss compensation
and sidetone cancellation.
M
M
M
M
M
C4
R
M
M
R
M
M
R
−
−
3
7
*
−
3
7
*
*
3
7
1
1
1
3
4
8
3
3
4
8
4
8
2
2
2
ZAC = 33 · Z1
austriamicrosystems
SS
in order to turn the
Page 5 of 25