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FEATURES
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SA541, SA54L1
PULSE/DTMF SWITCHABLE DIALLERS
Selectable Loop-Disconnect (Pulse)
or DTMF (Tone) dialling modes
32 Digit Last Number Redial (LNR)
Selectable Interdigit Pause (IDP)
500ms or 800ms
Operates with inexpensive single con-
tact keypad
On-chip Darlington transistor pair for
DTMF tone filtering
Low power CMOS technology enables
direct operation from Telephone line
Optional use of external capacitor for
oscillator
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Keypad switchable Loop-Disconnect to
DTMF during a call
Selectable Break:Make Ratios 2:1 or
3:2
Uses inexpensive 560KHz ceramic
resonator
Earth Loop Recall and Timed Break
Recall (Timed Flash)
Low on-hook Supply Current options
SA5413 - 5µA @ 2.5V
SA5416 - 1µA @ 2.5V
SA5419 - 1µA @ 3.0V
Call, barring/locking feature available
on the SA54L1
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s
s
s
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PIN CONNECTIONS:
SA541
PIN CONNECTIONS:
SA54L1
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M57-1529
PDS039-SA541-001
REV. B
02-09-94
SA541
ABSOLUTE MAXIMUM RATINGS *
Parameter
Min
Typ
Max
6,5
V
DD
+0,3
1
0,1
0
70
125
Unit
V
V
V
mA
mA
mA
°C
°C
Notes
Supply Voltage V
DD
- V
SS
-0,3
Voltage on any pin (except HSW)
V
SS
-0,3
Voltage on pin HSW
V
SS
-0,3
Current at any pin
-1
(except HSW, FILTOUT and FILTIN)
Current at pin FILTOUT
0
Current at pin FILTIN
-5
Operating Temperature
-25
Storage Temperature
-55
See Note 1
* Stresses above those listed under "Absolute Maximum Ratings" may cause permanent
damage to the device. This a stress rating only. Functional operation of the device at
these or any other condition above those indicated in the operation sections of this
specification, is not implied. Exposure to Absolute Maximum Ratings for extended
periods may affect device reliability.
Note 1:
A diode is internally connected between this pin and V
DD
. Provided current is
externally limited to 300µA max, no damage will occur.
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SA541
DC ELECTRICAL CHARACTERISTICS
(V
DD
= 2,5V at 25°C, unless otherwise specified)
Condition
Supply voltage:
Min
Typ
Max
Unit
V
V
Notes
For memory retention
on-hook
1,8
5,7
off-hook
2,4
5,7
Hookswitch input: on-hook
0,2 V
DD
off-hook
0,8 V
DD
Supply Current: on-hook
SA5413
<0.2
5
SA5416
<0.2
1
Sa5419
<0.2
1
off-hook
1,5
MF tone sending
1,0
LD impulsing
200
Output High Voltage
2,2
(MASK, MUTE and IMP Outputs)
Output Low Voltage
0,3
(MASK, MUTE and IMP Outputs)
MF OUT d.c. Level During Tone Sending
0,9V
DD
MF OUT Output Resistance
'Key Pressed' Resistance
'Key Not Pressed' Resistance
Darlington Pair Current Gain
3
2
500
600
50,000
µA
µA
µA
µA If MF
mA
µA
V
V
V
kΩ
kΩ
kΩ
V
DD
= 2.5V
V
DD
= 2.5V
V
DD
= 3.0V
OUT is low
I = -1mA
I = +1mA
2,5V<V
DD
<5,7V
2,5V<V
DD
<5,7V
I
e
=100µA,V
ce
=2V
AC ELECTRICAL CHARACTERISTICS
(V
DD
= 2,5V at 25°C, unless otherwise specified)
Condition
Oscillating Frequency
Tone Output: Low Group
High Group
High-to-Low Group Amplitude Ratio
Total harmonic Distortion: 0-4KHz
0-10KHz
0-50KHz
0-200KHz
Min
68
1,5
Typ
560
77
97
2
1,5
2,5
5,0
6,5
Max
Unit
kHz
mVrms
mVrms
dB
%
%
%
%
Notes
No Load
No Load
At MF Out
109
2,5
10
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SA541
Keypad
R1
R2
R3
R4
C1
C2
C3
Nominal frequency (Hz)
697
770
852
941
1209 1336 1477
Deviation from nominal (%)
-,07
-,10
+,19 -,15
-,17
-,20
-,22
There will be an additional error due to a deviation in the oscillator frequency from 560
kHz.
FUNCTIONAL OVERVIEW
The SAMES SA54X1 is a family of keypad switchable Loop Disconnect (LD)/Dual Tone
multi-Frequency (DTMF) dialler devices for use in low-cost, dual dialling mode telephone
instruments.
The devices feature automatic storage of a single telephone number of up to 32 digits
for Last Number Redial (LNR) purposes. The low current consumption of the SA54X1
ensures memory retention while powered from the line.
Two modes of operation are available. The first is a LD/DTMF mode which operates
normally in LD mode, but can be switched temporarily via the keypad to DTMF mode
during a call. This mode is intended for applications such as home banking, credit-card
verification and other applications requiring low speed data communications. The
second mode allows DTMF dialling only.
The Lock function will be described in the Functional Description.
The SA54X1 is pin compatible with SAMES' SA54X5 family of diallers.
Ordering Information
SA54X1X
Lock Option
L:
with (22 pin package)
Blank: without (20 pin package)
On-Hook Current Option
3
5µA @ 2.5V
6
1µA @ 2.5V
9
1µA @ 3V
4
1µA @ 3V (and TBR Period = 300 mSec)
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SA541
Block Diagram
Figure 1 depicts the SA54X1 block diagram, while Table 1 lists the respective pin
functions.
Figure 1: SA54X1 Block Diagram
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