AMSCO AS2523

austriamicrosystems
Telephone Line Interface and
Speakerphone Circuit
AS2523, AS2524, AS2524B
Key Features
-
Line/Speakerphone circuit on a 28-pin CMOS-IC, simple
inventory: same die for AS2523/24 and AS2523/24B
Serial I/F on AS2523, parallel I/F on AS2524
Enhanced voice switching
Background noise monitoring
Tx- and Rx-gain programmable on AS2523 only
Digital volume control of Rx signals on AS2523 only
DC characteristic programmable on AS2523 only
Dual softclipping in handset mode on AS2523 only
Dual softclipping in handsfree mode on AS2523 only
Loudspeaker amplifier for loudhearing and handsfree
Supply voltage generation for external circuitry
Automatic line loss compensation on AS2523 / 24B only
Real and complex impedance selectable by external
components
Side tone adaptation selectable by external components
Unique EMC performance
Operating range from 15mA to 100mA (down to 5mA
with reduced performance)
Few external components
PRELIMINARY DATA SHEET
General Description
AS2523/24 is a CMOS integrated circuit that incorporates
DC and AC line adaptation (DC-mask and synthesized ACimpedance of 1000Ω) as well as a speech circuit with
softclipping, line loss compensation and Rx-volume control
for handset and handsfree operation. It shall act as an a/bline powered device, which is controlled by a CPU via a
serial interface on AS2523 or a standard dialler via a
parallel interface on AS2524 and AS2524B.
Applications
Enhanced handsfree feature phones with CallerID and
extended displays. The AS2524 and AS2524B are
developed to interface with common Taiwanese dialers.
Package
Available in 28-pin SOIC or die
Block Diagram
Revision 1.12, Preliminary
Page 1 of 19
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Data Sheet AS2523, AS2524, AS2524B
Pin description
Pin #
Symbol
15
LS
Function
L ine Current S ense Input
Analog input for sensing the line current
12
LI
L ine I nput
Analog input used for power extraction and line current sensing
13
RI
R eceive I nput
Analog input for ac-separated receive signal
9
STB
S ide T one B alance Input
Analog input for side tone cancellation network
10
CS
C urrent S hunt Control Output
N-channel open drain output to control the external high power shunt transistor for
synthesizing AC- and DC-impedance, modulation of line voltage and shorting the line during
make periods of pulse dialing
16
CI
C omplex I mpedance Input
Analog input pin for the capacitor to program a complex impedance
14
SS
S upply S ource Control Output
N-channel open drain output to control the external high power source transistor for supplying
(Vpp) the loudspeaker amplifier in off-hook loudspeaking/handsfree mode
11
VSS
V oltage S ource S ource
Negative Analog Power Supply
18
VDD
V oltage D rain D rain
Positive Analog Power Supply
19
AGND
A nalog G round
Special ground for the internal amplifiers
8
M1
M icrophone Input 1
Differential input for the handset microphone (electret)
6
M2
M icrophone Input 2
Differential input for the handset microphone (electret)
7
M3
M icrophone Input 3
Differential input for the handsfree microphone (electret)
5
M4
M icrophone Input 4
Differential input for the handsfree microphone (electret)
17
RO
R eceive O utput to H andset
Output for driving a dynamic earpiece with an impedance from 150Ω to 300Ω
Revision 1.12, Preliminary
Page 2 of 19
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Data Sheet AS2523, AS2524, AS2524B
Pin #
Symbol
25
xCS
Function
C hip S elect on AS2523
Chip select input of the serial interface. Internal pull-up resistor ( 100kOhm )
/xMUTE
26
DI
Mute transmit-, receive- path and activate tone path on AS2524 and AS2524B
D ata I nput
on AS2523
Data input of the serial interface. Internal pull-up resistor ( 100kOhm )
27
/xPD
Power down mode for AS2524 and AS2524B (On-hook)
CLK
Cl oc k on AS2523
Clock input of the serial interface. Internal pull-up resistor ( 100kOhm )
/HFE
Handsfree mode operation on AS2524 and AS2524B
23
LO
L oudspeaker O utput. Output pin is for a 25Ω
2
FT1
Analog input pin for connecting a capacitor for offset cancellation.
3
TXO
Analog output of the transmit signal
4
TXV
Analog input for the transmit signal in the voice switching path
1
CBN
Analog input pin for connecting a capacitor for background noise monitoring.
20
RECI
Analog input for the handsfree receive path. Should be connected to RO via coupling
capacitor.
21
RECV
Analog input for receive voice switching path.
24
VSSA
Power supply pin for LO output amplifier.
22
VPP
Power supply pin for LO output amplifier.
28
TONEIN
Revision 1.12, Preliminary
loudspeaker
Analog input for DTMF-signals.
Page 3 of 19
Data Sheet AS2523, AS2524, AS2524B
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Detailed Block Diagram
Revision 1.12, Preliminary
Page 4 of 19
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Data Sheet AS2523, AS2524, AS2524B
Functional Description
The gain of the M3/M4 → LS is set to +46dB.
This gain can be changed by programming from +39dB to
+54dB in 1dB steps on AS2523. The input is differential
DC conditions
with an impedance of 10kΩ. The soft clip circuit limits the
output voltage at LS to 2V p . There is no LLC for this path.
The normal operating mode is from 15mA to 100mA. An
operating mode with reduced performance is from 5mA to
15mA. In the line hold range from 0mA to 5mA the device
is in a power down mode.
Receive path
The gain of the LS → RO receive path is set to +7.5dB.
This gain can be changed by programming from –7.5dB to
+7.5dB in 1dB steps (Register Rxgain). The receive input
is the differential signal of RI and STB. The soft clip circuit
limits the output voltage at RO to 1V p. It prevents harsh
distortion and acoustic shock. There is LLC for this path.
The DC characteristic is determined by the voltage at LIpin and a 30Ω resistor between LI- and LS-pin. It can be
calculated by the following equation: V LS = V LI + I Line *
30Ω. V LI can be programmed to be 3.5V or 4.5V.
2/4 wire conversion
AC-impedance
The gain of the LS → LO receive path is set to +32dB.
This gain can be changed by programming from +19dB to 34dB in 1dB steps. The user can also change the gain via
Register Handsfree receive end gain (See section
"Handsfree"). The receive input is the differential signal of
RI and STB. The soft clip circuit limits the output voltage at
LO to 1.1V p. It prevents harsh distortion and acoustic
shock. There is optional LLC for this path.
The AC-impedance of AS2523/24 is set to t.m. 1000Ω.
With the external capacitor at CI-pin it can be programmed
Line Loss Compensation (AS2523, AS2524B)
complex. With an external resistor of approx. 1.5kΩ
-
connected to the LS-pin it can be programmed to 600Ω.
-
AS2523/24 has built in two Wheatstone bridges with one
common ground. This provides a maximum of
independence of AC-impedance and side tone from each
other. One can adapt side tone without changing the ACimpedance.
programmable on AS2523
not activated at AS2524
- permanently activated at AS2524B
When it is activated, the transmit and receive gains for
both I/O’s are decreased by 6dB at line currents from
20mA to 50mA or from 45mA to 75mA.
Side Tone
A good side tone cancellation can be achieved by using the
following equation:
Z BAL /Z LINE = 10
Handsfree
The handsfree function allows voice communication without
using the handset (full 2-way speaker phone). Two voice
controlled attenuators prevent acoustic coupling between
the loudspeaker and the microphone. The voice switching
circuit has three states, namely idle, transmit or receive. In
receive mode the attenuation of the receive path and the
transmit path can be controlled by Register Handsfree
receive end gain between 0dB and -20dB. The following
table shows how voice switching is controlled
Transmit path
The gain of the M1/M2 → LS is set to +37dB. This gain
can be changed by programming on AS2523 from +30dB to
+45dB in 1dB steps (Register Txgain), on AS2524 / 24B it
is set to +37dB per default. The input is differential with an
impedance of 10kΩ. The soft clip circuit limits the output
voltage at LS to 2V p. There is LLC for this path.
voice switching circuit
TX_atten
RX
Revision 1.12, Preliminary
Voice
switching
speech
Backgnd
noise
monitor
Page 5 of 19
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Data Sheet AS2523, AS2524, AS2524B
Gmax = +9dB
Gmin = -21dB … -40dB (Vol)
LINE
+23dB
+14dB
+8dB
~
+17dB
Compress
+3dB
TXO
speech
Peak
detector
Voice
switching
TXV
RO
Compress
Compress
Offset
comp
FT1
0mV
~
100mV
Peak
detector
Peak
detector
CBN
Cmicoffset
CBckgnd
RECV
RECI
Gmax = -4dB … +16dB (Vol)
Gmin = -33dB
+9dB
Speech
Mode
Rx-gain
Tx-gain
Remark
Rx > Tx_atten
X
Receive
0db to -20dB
-50dB to -30dB
adjustable with VOL-setting
Tx_atten > Rx
NO
Idle
-25
-25
middle position
Tx_atten > Rx
YES
Transmit
-50dB
0dB
independent of VOL-setting
IDLE-mode
RX-mode
TX-mode
0dB
-10dB
TX-gain
-20dB
Vol max
Vol default
Vol min
-25dB
-30dB
-40dB
RX-gain
-50dB
Revision 1.12, Preliminary
Page 6 of 19
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Data Sheet AS2523, AS2524, AS2524B
Typical Characteristics of Line Loss Compensation (AS2523, AS2524B only)
The line-loss-compensation is programmable at the AS2523, not activated at the AS2524 and LLC high (45mA-75mA) activated
at the AS2524B.
(dB)
35
34
33
32
31
30
29
Tx Gain
No LLC (AS2523, AS2524)
LLC high
(AS2523,AS2524B)
LLC low
(AS2523)
f = 800 Hz
Ω
Z LINE = 600Ω
V LS = -10 dBm
20
DC Line
Current
30
40
50
60
70
80
(mA)
Figure 1 Typical Tx Gain Characteristics Line Loss Compensation
(dB)
+4
+3
+2
+1
0
-1
-2
Rx Gain
No LLC (AS2523, AS2524)
LLC low
(AS2523)
LLC high
(AS2523,AS2524B)
f = 800 Hz
Z LINE = 600Ω
Ω
V LS = -10 dBm
VOL = 0 dB (neutral)
20
30
DC Line
Current
40
50
60
70
80
(mA)
Figure 2 Typical Rx Gain Characteristics Line Loss Compensation
Revision 1.12, Preliminary
Page 7 of 19
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Data Sheet AS2523, AS2524, AS2524B
Serial Interface on AS2523
Registers
The settings of the AS2523 are stored in 16 registers. Each
register has 4 bit data width.
Timing
The data format for writing to a register has the following form:
xCS
CLK
A3
DI
Note:
A2
A1
A0
D3
D2
D1
D0
The pins xCS,CLK,DI have internal pull-up resistors.
Parameter
Symbol
MIN
CLK Pulse width HIGH
T6
100ns
CLK Pulse width LOW
T5
100ns
xCS to first falling CLKedge setup time
T1
50ns
DIN to CLK setup time
T3
50ns
DIN to CLK hold time
T4
50ns
t5
t1
t3
TYP
MAX
t6
t4
xCS
CLK
DIN
Revision 1.12, Preliminary
Page 8 of 19
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Data Sheet AS2523, AS2524, AS2524B
Serial interface Registers
The following table shows the content of the 16 control registers.
Address
Data
A A A A
3 2 1 0
D D D D
3 2 1 0
0
0
0
0
0
Nop
for AS2523,
AS2524HF
for AS2524 LH bond
option
na
na
na
na
0111
na
na
na
na
0111
0001
0001
1000
1000
0101
1100
1111
1011
0000
1100
16 gains
Hfs1 HFs0: Speed of voice switching
0
0
max speed
0
1
1
0
1
1
min speed
Transmit gain [16], 16 steps, 1dB stepsize
0111
0111
16 gains
Data HS-mode HF-mode
0x0
30dB
39dB
:
:
:
0xF
45dB
54dB
Receive gain [16], 16 steps, 1dB stepsize
1111
1111
0100
1000
0100
0101
0000
0001
na
na
x x
Llc0
x x
Llc1
0
1
0
1
0
Liv
0
0
1
1
0
Conf
0
0
0
0
1
Default value
after reset
Control registers AS2523
0... No Conf Tone 1... Conf Tone
Conf-Tone:
0...3.5V, 1...4.5V
LIV: Voltage at pin LI
LLC1 LLC0: Line loss compensation setting
0
0
20mA-50mA
0
1
NO Line loss compensation
1
0
45-75mA
1
1
NO Line loss compensation
CT0
CT1
Softclip-settings, Tx_comp_gain settings
Bit1 Bit0 :Tx_comp_gain
0
0
+8dB
0
1
+11dB
1
0
+14dB
1
1
+17dB
0...OFF,
SOFTRX: Softclip RX
0...OFF,
SOFTTX: Softclip TX
Soft-TX
x x
Bnon
Delay_10ms
Rxoffset Bit0
Rxoffset Bit1
0 1 1 1
1 0 0 0
0...OFF,
1...ON
BURS: Analog tone at RO
0...OFF,
1...ON
BURL: Analog tone at LS
CT1 CT0: @RO
@LS
0
0
-36dB -15dB
TONE-confidence level
0
1
-30dB
-9dB
rel. to pin LS
1
0
-24dB
-3dB
1
1
-18dB
+3dB
Soft-RX
tx_comp_gain Bit0
x x
tx_comp_gain Bit 1
0 1 1 0
Burl
Burs
0 1 0 1
16 gains
Bit1 Bit0: Rx-offset setting
0
0
0mV
0
1
12mV
1
0
40mV
1
1
100mV
0... no delay
Delay_10ms
0... BGN off
Bnon
Handsfree receive endgain
Data
0x0
:
0xF
1 0 0 1
x x
1...ON
1...ON
RXgain
-20dB
:
+0dB
TXgain
-30dB
-50dB
1... 10ms delay
1... BGN on
Min. receive volume
Max. receive volume
x x
1 0 1 0
1 0 1 1
Hfs0
Hfs1
off0
off1
off1 off0: BGN-offset
0
0
120mV
0
1
180mV
1
0
240mV
1
1
300mV
Data
0x0
:
0xF
Tone
Mute
LH
Hf
HF-mode
19dB
:
34dB
0... fg=200Hz
HP_on :
0... Rxcomp=AGND
rec_on :
0... No mute
Mute
:
0... Tx-signal path
Tone
:
Mask, Lh, Hf, Hook Switch
0... No mask
Mask:
His
0
1
1
1
1
HF
x
0
0
1
1
LH:
x
0
1
0
1
1...
1...
1...
1...
fg=2000Hz
Rxcomp=RECV
Tx-path muted
Ton in signal path
1... Mask acitivated
Hook functions
Power down
Handset
not allowed
Handsfree
Loudhearing
x
x x
slow_rec
Test2
x x
Test3
1 1 1 1
x x
x x
Krat5
1 1 1 0
His
x x
Mask
1 1 0 1
Rec_on
HP_on
1 1 0 0
HS-mode
-6dB
:
+9dB
slow_rec: fast change to TX, slow change to RX, no IDLE
Krat5,Test3,Test2: For factory test only !
x
Reset to defaults
For a detailed description of the commands see Application note AN523/24.
Revision 1.12, Preliminary
Page 9 of 19
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Data Sheet AS2523, AS2524, AS2524B
Programming Guidelines for the AS2523
Additional settings in Handsfree mode
The AS2523 is programmed by means of a serial 8-bit shift
register. MSB is clocked in first, LSB last.
The first four bits (7,6,5,4) are the addresses of the
registers, the last four bits (3,2,1,0) are the data bits.
Note: change the default settings only if necessary:
Each register has a default setting (see data sheet), which
is set after power-up of the chip.
b) Change the Tx comparator preamplifier gain in register 6
Default = 14dB
The internal registers are RAM-cells. When the AS2523
loses VDD (as in on-hook state) it also loses the register
contents.
c) Change the Receive DC offset and Background noise
monitoring in Register 7
default = 0mV offset (higher val. puts more weight on Rx)
switching delay default = on
Background Noise Monitoring = on
It is therefore necessary to re-write the affected registers
after each hook event. The register contents cannot be
read, they can only be written.
d) Set the speaker amplifier volume in register 8
Default = 0B
Registers need to be re-written after each power-up and
after each hook event (handset / handsfree / on-hook).
It is recommended to always initialize the chip with a “reset
to defaults command” (Fx) first and then write the
appropriate registers that need to be changed from the
default setting.
Alternatively, all registers (4 to 16) may be re-written in a
bulk at each power-up and hook event (handset /
handsfree / on-hook).
This guarantees safe operation in case of unexpected loss
of power during normal operation. Re-writing all registers
also eases later software updates, as only register
contents need to be changed, but no additional command
lines need to be inserted.
Example of a typical power-up sequence
A typical power-up sequence will require the following
programming.
a) determine the cause of power-up (handset / handsfree
mode) and set register D accordingly.
Default = handset mode
b) Set the LI voltage to 3.5V or 4.5V (default = 4.5V) and
Line Loss Compensation (default = off) in register 4
c) Set the Confidence Tone level (e.g. the DTMF level
which is audible in the handset) and path in register 5
Default = off
d) Set the required Tx and Rx gains in Registers A and B
Default = 37dB Tx gain, 1dB Rx gain
Revision 1.12, Preliminary
a) A click-free startup can be achieved by starting up in
handset mode (=default) and then switching to
handsfree, once the chip has stabilized.
e) Set the handsfree voice switching speed and
Background Noise monitoring offset in register 9:
default voice switching speed = 1ms/6dB (fastest)
default BGN monitoring offset = 240mV (determines the
Tx level required to switch from idle to Transmit)
Additional settings during Flash
During a Flash, the AS2523 should be powered down to
avoid discharge of VDD:
Set the MASK bit (bit3 in register D) to 1
After the line current is restored, the MASK bit must be
cleared again. Other settings do not need to be re-written,
as VDD has not discharged. As a safety margin however, it
is recommended to re-write all registers after a flash
Additional settings during line breaks
If a line-break-detection (brief interruption of the line while
in off-hook state) is implemented, the same rules apply as
for a Flash: set the MASK bit to 1 to avoid discharge of
VDD. It is recommended to re-write all registers after a
line-break, as a line break may take long enough to
discharge VDD, even when the MASK bit was set.
General Rules
The serial interface may be programmed at any time, it
does not affect the speech quality, e.g. if a register is
overwritten with the same value.
It is also possible to re-write all registers periodically. The
register is static, therefore it can be clocked at any speed
up to 5MHz.
However, electromagnetic pulses on the clock and data
lines may cause unwanted programming of the chip. It is
therefore recommended to keep these lines short, filter
them by a discrete lowpass filter and reduce the clock
speed accordingly.
Page 10 of 19
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Data Sheet AS2523, AS2524, AS2524B
Parallel Interface on AS2524 and AS2524B
Input Signal on Pin
XPD
xMute
HF
0
0
0
Power down
Mode
0
0
1
Power down
0
1
0
Power down
0
1
1
Power down
1
0
0
Tone mode
1
0
1
Tone mode
1
1
0
Handset mode
1
1
1
Handsfree mode
Power down mode
For low power consumption the analog part is turned off during activated power down mode. The Power down mode is used
during Flash and Pulse dialing and for On-hook operation.
Handset mode
Speech mode is Handset mode (M1-M2, RO active; LO deactivated)
Parameter
AS2524
AS2524B
4.5V
4.5V
LLC
No LLC
LLC high (45mA to 75mA)
TX-Gain
+37dB
+43dB
RX-Gain
+7.5dB
+7.5dB
Rx-Softclip
Off
Off
Tx-Softclip
Off
Off
Tone
Off
Off
LI Voltage
Handsfree mode
Speech mode is Handsfree mode (M3-M4, RO active; LO active)
Parameter
AS2524
AS2524B
4.5V
4.5V
LLC
No LLC
LLC high (45mA to 75mA)
HF TX-Gain
+46dB
+52dB
HF RX-Gain
+34dB
+34dB
Rx-Softclip
Off
Off
Tx-Softclip
Off
Off
Tone
Off
Off
BNM
On
On
LI Voltage
Revision 1.12, Preliminary
Page 11 of 19
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Data Sheet AS2523, AS2524, AS2524B
Tone mode
This mode is used to send DTMF and FSK data to the line.
Speech mode is Tone mode (M1-M2;M3-M4 muted, Rx path muted, RO and LO active)
Parameter
AS2524
AS2524B
4.5V
4.5V
LLC
No LLC
LLC high (45mA to 75mA)
Tone TX-Gain
+14dB
+14dB
[email protected] [email protected]
relative to Pin LS
[email protected] [email protected]
relative to Pin LS
LI Voltage
Confidence tone
level
Loudhearing AS2524 and AS2524B (feature only available as DIE)
Speech mode is Loudhearing (M3-M4, RO active; LO activated).
Loudhearing can be activated via a bond-option (see document “AS2523/24 Delivery as Dice”).
Parameter
AS2524
AS2524B
4.5V
4.5V
LLC
No LLC
LLC high (45mA to 75mA)
TX-Gain
+37dB
+43dB
RX-Gain
+7.5dB
+7.5dB
Tone
Off
Off
Slow_rec
On
On
RECV pin
Deactivated
Deactivated
Highpass
2000kHz (10nF from TXO->TXV)
2000kHz (10nF from TXO->TXV)
120ms/6dB
120ms/6dB
300mV
300mV
LI Voltage
Voice switching speed
RX-Offset
Electrical characteristics
Electrical characteristics are measured with the Test Circuit
application. Typical mean values will not be tested.
Absolute maximum ratings
Positive Supply Voltage
Input Current
Input Voltage (LS)
Input Voltage (LI, CS)
Input Voltage (STB, RI)
Digital Input Voltage
Electrostatic Discharge (HBM 1.5kΩ-100pF)
Storage Temperature
-0.3V <= V DD <= 7V
+/- 25mA
-0.3V <= V in <= 12V
-0.3V <= V in <= 8V
-2V <= V in <= V DD +0.3V
-0.3V <= V in <= V DD +0.3V
+/- 1000V
-65°C to +125°C
Recommended operating conditions
Supply Voltage (generated internally)
Operating Temperature
Revision 1.12, Preliminary
3V <= V DD <= 5V
-25°C to +70°C
Page 12 of 19
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Data Sheet AS2523, AS2524, AS2524B
DC characteristics
I Line =15mA w/o operation of any additional external
circuitry, unless other specified
Symbol
Parameter
Conditions
Min
Type
Max
Units
Test
I DDS
Operating Current
Speech Mode
3
6
mA
Y
I DDH
Operating Current
Handsfree Mode
7
10
mA
Y
V LI
Line Voltage LIVolt=0
Line Voltage LIVolt=1
15mA<=ILINE<=100mA
3.5
4.5
3.8
4.8
V
V
Y
Y
I OL
Output Current, Sink
CS,SS
mA
N
3.2
4.2
VOL=0.4V
1
Transmit characteristics
I Line =15mA f=800Hz, default settings unless other specified
Symbol
A M1/2TX
A M3/4TX
A tone TX
Parameter
Conditions
Transmit Gain M1/M2 → LS
AS2524
AS2524B
Z AC(syn)= 1000Ω
Transmit Gain M3/M4 → LS
AS2524
AS2524B
Z AC(syn) =1000Ω
Transmit Gain
Z AC(syn) =1000Ω
Min
Type
Max
Units
Test
35
39
+36.5
+42.5
38
44
dB
dB
Y
Y
43
49
+45.0
+51
47
53
dB
dB
Y
Y
12
+14dB
16
dB
Y
Tone → LS
∆ A TX
Variation with frequency
f = 500Hz … 3.4kHz
±0.8
dB
N
A VRM12
Control range
16 steps
-7/+8
dBr
N
16 steps
-7/+8
dBr
N
%
Y
2
VP
N
2
VP
N
M1/M2 → LS
A VRM34
Control range
M2/M4 → LS
THD
Distortion
V AGC1
Soft Clip Level
V LS =0.25VRMS
2
M1/M2 → LS at LS
V AGC2
Soft Clip Level
M3/M4 → LS at LS
A SCO
Soft Clip Overdrive
M1/M2 - M3/M4
20
dB
N
t attack
Attack time
70
us/6dB
N
t decay
Decay time
100
ms/6dB
N
Revision 1.12, Preliminary
Page 13 of 19
austriamicrosystems
Data Sheet AS2523, AS2524, AS2524B
Symbol
Parameter
Conditions
Min
Type
Max
Units
Test
Z IN-M1/2
Input Impedance
M1/M2
10
kΩ
N
Z IN-M3/4
Input Impedance
M3/M4
10
kΩ
N
V INmax
Input Voltage Range
M1/2 - M3/4
differential
±1
Vp
N
V NO
Noise Output Voltage
LS
T AMP =25°C
dBmp
Y
Mute Attenuation
Mute activated
dB
Y
A MUTE
-72
Handset mode
Gain = 36.5dB
60
Receive characteristics
I Line =15mA f=800Hz, default settings unless other specified
Symbol
A RO
Parameter
Conditions
Min
Type
Max
Units
Test
6
+7.5
9
dB
Y
+32.0
+34
+36.0
dB
Y
Receive Gain
Z AC(syn) =1000Ω
LS → RO
Vol default
Receive Gain
LS → LO
Z AC(syn) =1000Ω
Vol maximum
∆ A RX
Variation with frequency
f=500Hz to 3.4kHz
±0.8
dB
N
A VRRO
Control range
16 steps
-7/+8
dBr
N
16 steps
-7/+8
dBr
N
A LO12
LS → RO
A VRLS
Control range
LS → LO
THD LS
Distortion LO
V LS =0.25VRMS
5
%
Y
THD RO
Distortion RO
V LS =0.25VRMS
2
%
Y
V UFC
Unwanted Freq. Cmp.
f = 200 … 20kHz
-60
dBm
Y
1
VP
N
V AGCRO Soft Clip Level
RO
V AGCLS
Soft Clip Level
LO
1.1
VP
N
A SCLS
Soft Clip Overdrive
LO
10
dB
N
T attack
Attack time
70
us/6dB
N
T decay
Decay time
100
ms/6dB
N
Revision 1.12, Preliminary
Page 14 of 19
austriamicrosystems
Data Sheet AS2523, AS2524, AS2524B
Symbol
V NO
Parameter
Conditions
Min
Type
T AMP =25°C
Noise Output Voltage
RO
Max
Units
Test
-68
dBmp
Y
Gain = 7.5dB
Z IN-RI
V INmax
Input Imp. RI
Input Voltage Range RI
8
±2
kΩ
Vp
N
Z IN-STB
V INmax
Input Imp. STB
Input Volt. Range STB
80
±2
kΩ
Vp
N
ST
Side tone
V RI <=0.25VRMS
26
dB
Y
RL
∆ Z AC/°C
Return Loss
Temp. Variation
Z AC(syn) =1000Ω
18
dB
Y
0.5
Ω/°C
Test circuit
U2
15
C1
100uF
C2
I1
Idc
10uF
R1
30R
13
12
D1
10V
R1
300R C2
R1
600R
VSS
TONE IN
RI
M3
LI
M4
1uF
9
VSS
Vac
LS
R1
6k
10
VSS
16
VSS
Q1
BC327
11
24
VSS
M1
28
C6
100nF
7
C6
100nF
5
C6
Vac
100nF
8
C6
100nF
6
C6
Vac
100nF
STB
M2
CS
RO
CI
AS2523/24
VSS
VSSA
RECI
RECV
Vac
V3
17
C2
10uF
20
C4
100nF
21
C6
VSS
R3
R4
10k
14
BC327
22
C2
47uF
LO
SS
xCS / xMUTE
DI / xPD
CLK / HFI
VPP
25
26
27
100uF
R2
VSS
32R
R5
10k
VSS
3
2
1
1
C2
1uF
TXV
TXO
FT 1
VDD
C7
VSS
4
3
1uF2
C2
22uF 19
C2
18
100uF
C2
D1
5V1
AGND
CBN
VSS
23
VSS
100nF
VSS
Q1
150R
C3
1n
VSS
Revision 1.12, Preliminary
Page 15 of 19
Data Sheet AS2523, AS2524, AS2524B
austriamicrosystems
Typical application AS2523
Revision 1.12, Preliminary
Page 16 of 19
Data Sheet AS2523, AS2524, AS2524B
austriamicrosystems
Typical application AS2524 and AS2524B
Revision 1.12, Preliminary
Page 17 of 19
austriamicrosystems
Data Sheet AS2523, AS2524, AS2524B
Packaging
28-pin plastic SOIC
For exact mechanical package dimensions please see
austriamicrosystems AG packaging information.
Pin-out, Marking
CBN 1
28 TONE IN
FT 1 2
27 CLK / HF I
TXO 3
26 DI / xPD
TXV 4
25 xCS / xMUTE
24 VSSA
YYWWAAA
AS252X
M4 5
M2 6
M3 7
M1 8
ST B 9
23 LO
22 VPP
21 RECV
20 RECI
CS 10
19 AGND
VSS 11
18 VDD
LI 12
17 RO
RI 13
16 CI
SS 14
15 LS
Devices sold by austriamicrosystems AG are covered by
the warranty and patent identification provisions appearing
in its Term of Sale. austriamicrosystems AG makes no
warranty, express, statutory, implied, or by description
regarding the information set forth herein or regarding the
freedom of the described devices from patent infringement.
austriamicrosystems AG reserves the right to change
specifications and prices at any time and without notice.
Therefore, prior to designing this product into a system, it
is necessary to check with austriamicrosystems AG for
current information. This product is intended for use in
normal commercial applications. Applications requiring
extended temperature range, unusual environmental
requirements, or high reliability applications, such as
military, medical life-support or life-sustaining equipment
are specifically not recommended without additional
processing by austriamicrosystems AG for each
application.
Copyright
YY
WW
AAA
year of production
calendar week of production
austriamicrosystems AG assembly ID
X
3 … AS2523 Version
4 … AS2524 Version
4B .. AS2524B Version
Ordering Information
Number
Package
Description
AS2523 T
SOIC28
plastic surface mounted
package – 28 leads
AS2524 T
SOIC28
Plastic surface mounted
package – 28 leads
AS2524B T
SOIC28
Plastic surface mounted
package – 28 leads
AS2523 F
DOF
Dice-on-Foil
AS2524 F
DOF
Dice-on-Foil
AS2524B F
DOF
Dice-on-Foil
Revision 1.12, Preliminary
Copyright © 1997-2002, austriamicrosystems AG, Schloss
Premstaetten, A8141 Unterpremstaetten, Austria-Europe.
Trademarks Registered ®. All rights reserved. The material
herein may not be reproduced, adapted, merged,
translated, stored, or used without the prior written consent
of the copyright owner.
The information furnished here by austriamicrosystems AG
is believed to be correct and accurate. However,
austriamicrosystems AG shall not be liable to recipient or
any third party for any damages, including but not limited
to personal injury, property damage, loss of profits, loss of
use, interruption of business or indirect, special, incidental
or consequential damages, of any kind, in connection with
or arising out of the furnishing, performance or use of the
technical data herein. No obligation or liability to recipient
or any third party shall arise or flow out of
austriamicrosystems AG rendering of technical or other
services.
Page 18 of 19
austriamicrosystems
Data Sheet AS2523, AS2524, AS2524B
Contact
Headquarters
austriamicrosystems AG
Communications Business Unit
A8141 Schloss Premstaetten, Austria
T. +43 (0) 3136 500-0
F. +43 (0) 3136 500-5692
www.austriamicrosystems.com
Sales Offices
Germany
austriamicrosystems Germany GmbH
Tegernseer Landstrasse 85
D-81539 München, Germany
Phone: +49/89/693643-0
Fax: +49/89/693643-66
France
austriamicrosystems France S.a.r.l.
124, Avenue de Paris
F-94300 Vincennes, France
Phone: +33/1/43 74 00 90
Fax: +33/1/43 74 20 98
Italy
austriamicrosystems Italy S.r.l.
Via Leone Tolstoi, 64
I-20146 Milano, Italy
Phone: +39/0242/36713
Fax: +39/0242/290889
USA (east)
austriamicrosystems USA, Inc.
Suite 400, 8601 Six Forks Road
Raleigh, NC 27615, USA
Phone: +1/919/676 5292
Fax: +1/919/676 5305
United Kingdom
austriamicrosystems UK, Ltd.
Coliseum Business Centre, Watchmoor Park
Camberley, Surrey, GU15 3YL, UK
Phone: +44/1276/23 3 99
Fax: +44/1276/29 3 53
Japan
austriamicrosystems AG
Shin Yokohama Daini, Center Bldg. 10F
3-19-5, Shin Yokohama
Kohoku-ku, Yokohama 222-0033, Japan
Phone: +81/45/474 0962
Fax: +81/45/472 9845
Switzerland
austriamicrosystems Switzerland AG
Rietstrasse 4
CH-8640 Rapperswil, Switzerland
Phone: +41/55/220 9000
Fax: +41/55/220 9001
Distributors & Representatives
USA (west)
Spain, Israel, Korea, Hong-Kong, Taiwan, Malaysia,
Singapore, India, Brazil
austriamicrosystems USA, Inc.
Suite 116, 4030 Moorpark Ave,
San Jose, CA 95117, USA
Phone: +1/408/345 1790
Fax: +1/408/345 1795
Revision 1.12, Preliminary
austriamicrosystems AG is represented by distributors in
the following countries. Please contact your nearest
regional sales office for the distributor address:
Application Support
Please contact your local sales office or your distributor.
Page 19 of 19