LS7503 Datasheet PDF - LSI

www.Datasheet-PDF.com

LS7503
LSI

Part Number LS7503
Description TONE ACTIVATED TELEPHONE LINE SWITCH CONTROLLERS
Page 4 Pages


LS7503 datasheet pdf
Download PDF
LS7503 pdf
View PDF for Mobile

No Preview Available !

LSI/CSI
LS7501-7510
U
®
L
LSI Computer Systems, Inc. 1235 Walt Whitman Road, Melville, NY 11747 (516) 271-0400 FAX (516) 271-0405
A3800
TONE ACTIVATED TELEPHONE LINE SWITCH CONTROLLERS
FEATURES:
• Circuit activated by Tone with specific Frequency and
Time Duration.
• Frequency and Time Duration values are mask
programmable.
• Small Signal (as low as - 30 DBM) and Digital Level
Tone signals accommodated.
• On-chip active oscillator network and 32,768 Hz
Crystal generates timing.
• Low power consumption.
• +4.0V to +6V operation (VDD - VSS).
APPLICATIONS:
• Remote telephone line testing
• Remote meter reading
• Security system dialers.
Nov. 1993
CONNECTION DIAGRAM - TOP VIEW
STANDARD 16 PIN PLASTIC DIP
DTO 1
TIME BASE 2
VF OUT 3
VI OUT 4
FDEN 5
DTEN INPUT 6
16 V DD (+V)
15 X2
14 X1
13 DIGITAL TONE
12 AMP IN
11 AMP OUT
GENERAL DESCRIPTION:
The LS7501 - LS7510 are CMOS frequency discriminator
circuits designed to respond to a specific frequency
TONE signal when that frequency is maintained within
+10Hz during a continuous 4.5 second Sample Interval
Time. When a valid TONE occurs the Set Relay Level
output goes high for 20 seconds.
A typical application will use the Set Relay Level output
to temporarily switch the telephone line connection.
Valid Frequencies are mask programmable from 11Hz to
4095 Hz, in 1 Hz steps. Valid Sample Interval Times are
mask-programmable from 0.5 seconds to 8.0 seconds, in
0.5 second steps. Table 1 shows mask programmable
options for the available LS7501 - LS7510 part numbers.
Table 1. MASK PROGRAMMED OPTIONS
Part # Frequency (Hz) Part # Frequency (Hz)
LS7501
LS7502
LS7503
LS7504
LS7505
2683
2713
2743
2773
2833
LS7506
LS7507
LS7508
LS7509
LS7510
2863
2893
2923
2953
2983
NOTE: All Part Numbers are programmed with a Sample
Interval Time of 4.5 seconds. Referring to the LS75XX
Block Diagram (Figure 2) each Part Number has the Set
Relay Level option on Pin 8. The 32 KHz option is on Pin
2 with one exception. LS7502 has the 8Hz option.
SET RELAY PULSE 7
10 RESET
SET RELAY LEVEL 8
9 V SS (-V)
FIGURE 1
CIRCUIT OPERATION:
Referencing Figure 2, an external C is used to generate a
Power-On Reset pulse at Pin 10. When the Frequency Dis-
criminator samples a valid frequency at Pin 13 for an entire
0.5 second sample period, Pin 3 goes high and the Sample
Interval Timer begins timing. If the Pin 13 frequency is not
valid during any subsequent sample period, Pin 3 goes low
and resets the Sample Interval Timer. When Pin 13 fre-
quency is valid for the programmed period of the Sample In-
terval Timer, a high-going pulse occurs at Pin 4. Normally,
Pin 4 externally connects to Pin 6 and the pulse will cause
the Frequency Discriminator to be disabled, enable the Dis-
connect Timer and bring Set Relay Level high at Pin 8.
When the Disconnect Timer times out (20 seconds) a high-
going pulseoccurs at Pin 1. Normally, Pin 1 externally con-
nects to Pin 5 and the pulse will cause the Frequency Dis-
criminator to be enabled, disable the Disconnect Timer and
bring Set Relay Level low at Pin 8. The circuit operating se-
quence begins again.
A digital level Tone signal connects to Pin 13. A small-signal
Tone frequency should be AC coupled to Pin 12 with Pin 11
externally connected to Pin 13. The 32,768 Hz crystal con-
nects between Pin 14 and Pin 15. Pin 10 has an internal
pull-down resistor.



No Preview Available !

INPUT/OUTPUT DESCRIPTION:
Pin 8 (SET RELAY LEVEL) or (RESET RELAY PULSE):
Pin 1 (DTO) : A 500ms positive output pulse occurring
when Disconnect Timer times out.
A normally low output which goes high when Pin 6 transitions
high and goes low again when Pin 5 transitions high. IfRESET
RELAY PULSE is mask programmed, this signal will be a 3.9
Pin 2 (TIME BASE) : 32,768Hz or 8Hz pulses. (Mask- ms pulse occurring when Pin 5 transitions high.
programmable selection).
Pin 9 (VSS): Supply Voltage negative terminal.
Pin 3 (VF): A normally low output which goes high
whena Valid Frequency is detected.
Pin 10 (RESET): A logic high applied to this pin will reset the
circuit. This input has an internal pull-down resistor.
Pin 4 (VI): A 125ms positive output pulse occurring when
the Sample Interval Timer times out.
Pin 11 (AMP OUT): Output of amplifier.
Pin5 (FDEN): A high-going transition input will cause the Pin 12 (AMP IN): Input of amplifier.
Frequency Discriminator to be enabled.
Pin 6 (DTEN ): A high-going transition input will cause
theDisconnect Timer to be enabled.
Pin 13 (DIGITAL TONE): Digital level frequency input to the
Frequency Discriminator.
Pin 7 (SET RELAY PULSE ): A 3.9 ms positive output
pulse occuring when Pin 6 transitions high.
Pin 14 (X1): Input terminal of active oscillator network.
Pin 15 (X2): Output terminal of active oscillator network.
Pin 16 (VDD ): Supply Voltage positive terminal.
ABSOLUTE MAXIMUM RATINGS:
PARAMETER
Voltage at any input
Operating Temperature
Storage Temperature
SYMBOL
VIN
TA
TSTG
VALUE
VSS-.5 to VDD+.5
-25 to +70
-65 to +150
DC ELECTRICAL CHARACTERISTICS:
(All voltages referenced to VSS, TA = -25°C to + 70°C)
PARAMETER
Supply Voltage
Supply Current
SYMBOL
VDD
IDD
MIN
4.0
-
MAX
6.0
30
UNIT
V
µA
Input Voltage:
(except AMP IN)
High
VIH
3.50
-
V
Low
VIL - 1.50
V
Output Current:
(except AMP OUT)
Source
IOH
1000
-
µA
Sink
IOL - 500
µA
NOTE: Reset input has internal pull-down resistor of about 100K ohms.
AC ELECTRICAL CHARACTERISTICS:
PARAMETER
SYMBOL
MIN
MAX
AMP IN Sensitivity*
AIs
-20
-
* Amplifier Input is AC coupled from a 300source impedance.
Output Switching:
(except AMP OUT)
Rise time
TR - 500
Fall time
TF - 125
UNIT
DBM
ns
ns
UNIT
Volts
°C
°C
CONDITION
-
VDD = +5.0V
VDD = +5.0V
VDD = +5.0V
Vo = 0.7V, VDD = 5.0V
Vo = 0.25V, VDD = 5.0V
CONDITION
VDD = +5.0V
VDD = +5.0V, CL = 50pF
VDD = +5.0V, CL = 50pF



No Preview Available !

TONE 13
X1 14
X2 15
RESET 10
AMP OUT 11
AMP IN 12
VDD 16
VSS 9
* NOTE: MASK PROGRAMMABLE OPTION
*
FREQUENCY
DISCRIMINATOR
R EN
CLK3
CLOCK
GENERATOR
R
2Hz
8Hz
256H
32zKHz
CLK3
CLK
2
CLK
1
CLK
0
*
SAMPLE INTERVAL
TIMER
EN R
CLK
3
EN
CLK
2
DISCONNECT
TIMER
R
RESET RELAY PULSE
*
SET RELAY LEVEL
CLK
1
3.9ms
ONE
SHOT
R
CLK
1
CLK
2
CLK 3.9ms
1 ONE
SHOT
+V R
*
-V
3 VALID
FREQUENCY
VALID
4 INTERVAL
TIMEOUT
DISCONNECT
1 TIMER
TIMEOUT
8
SET RELAY
LEVEL
FREQUENCY
5 DISCRIMINATOR
ENABLE
7 SET RELAY
PULSE
6
DISCONNECT
TIMER ENABLE
2
TIME
BASE
FIGURE 2. LS75XX BLOCK DIAGRAM



No Preview Available !

TIP
RING
FIGURE 3.
TELEPHONE LINE INTERROGATOR
NETWORK
The information included herein is believed to be
accurate and reliable. However, LSI Computer Systems,
Inc. assumes no responsibilities for inaccuracies, nor for
any infringements of patent rights of others which may
result from its use.
R1
Q1
R4
D1 D2
R2
R3
XTAL
D4 D3
POWER SUPPLY
16 14
VDD X1
15
X2
10
RESET
+
C3
-
C1 R5
DIFFERENTIAL AMP
AND
C2 R6 BAND PASS FILTER
8
SET RELAY
13 LEVEL
TONE
R7
LS7502
4
VI
5
FDEN
TONE
BACK
OSCILLATOR
CIRCUIT
+
6
DTEN
VSS
AMP IN
C4
-
9 12
R1 = 50k, 1/4W
R2 = 15k, 1/4W
R3 = 10k, 1/4W
R4 = 1k, 1/4W
R5,R6 =100k, 1/4W
R7 = 200k, 1/4W
C1,C2 =.001µF, 400V D1-D4 = IN4002
C3 = 2.2µF,10V
Q1 = MPSA42
C4 =10µF, 10V
XTAL = 32,768Hz
DESCRIPTION:
This application shows a method for interrogating a tele-
phone line to detect a 2713Hz (+10Hz) tone for a minimum
of 4.5 seconds. (The LS7502 Circuit.)
At the end of the 4.5 second sample period, an oscillator is
energized and generates a tone back signal which mod-
ulates the Tip/Ring telephone line.
As shown in Figure 3, the differential op-amp is connected
to the telephone lines through .001µF coupling capacitors.
This eliminates the DC component and acts as the first filter
for 60Hz. The differential amplifier stage is followed by a
band pass filter centered around 2713Hz. This filter should
be designed for high Q's (Q > 10) and yet utilize current
efficient op-amps.
The band pass output is then squared up and connected
to the Digital Tone input (Pin 13). The input signal is sam-
pled by the digital discrimination section of the LS7502. If
2713Hz (+10Hz) is present for 4.5 seconds, a 125 milli-
second pulse at Pin 4 is applied to the DTEN input (Pin 6)
causing an internal flip-flop to set and the Set Relay Level
output (Pin 8) to go high, activating the tone back os-
cillator.
As the 10µF capacitor (C4) builds up stored charge, it bi-
ases the FDEN input (Pin 5) through R7, until it is sufficient
to reset the internal flip-flop and bring the circuit back to its
idle state and turn the tone back oscillator off. By varying
the R7-C4 network, the time constant for the tone back du-
ration can be varied.



LS7503 datasheet pdf
Download PDF
LS7503 pdf
View PDF for Mobile


Related : Start with LS750 Part Numbers by
LS7501 TONE ACTIVATED TELEPHONE LINE SWITCH CONTROLLERS LS7501
LSI
LS7501 pdf
LS7502 TONE ACTIVATED TELEPHONE LINE SWITCH CONTROLLERS LS7502
LSI
LS7502 pdf
LS7503 TONE ACTIVATED TELEPHONE LINE SWITCH CONTROLLERS LS7503
LSI
LS7503 pdf
LS7504 TONE ACTIVATED TELEPHONE LINE SWITCH CONTROLLERS LS7504
LSI
LS7504 pdf
LS7505 TONE ACTIVATED TELEPHONE LINE SWITCH CONTROLLERS LS7505
LSI
LS7505 pdf
LS7506 TONE ACTIVATED TELEPHONE LINE SWITCH CONTROLLERS LS7506
LSI
LS7506 pdf
LS7507 TONE ACTIVATED TELEPHONE LINE SWITCH CONTROLLERS LS7507
LSI
LS7507 pdf
LS7508 TONE ACTIVATED TELEPHONE LINE SWITCH CONTROLLERS LS7508
LSI
LS7508 pdf

Index :   0   1   2   3   4   5   6   7   8   9   A   B   C   D   E   F   G   H   I   J   K   L   M   N   O   P   Q   R   S   T   U   V   W   X   Y   Z   

This is a individually operated, non profit site. If this site is good enough to show, please introduce this site to others.
Since 2010   ::   HOME   ::   Contact