CLARE CPC7582BB-TR Line card access switch Datasheet

CPC7582
Line Card Access Switch
Description
The CPC7582 is a monolithic solid state switch in a 16
pin surface mount SOIC package. It provides the necessary functions to replace two 2-Form-C electromechanical relays on analog line cards found in
Central Office, Access and PBX equipment. The
device contains solid state switches for tip and ring line
break, ring injection/ring return and line test access.
The CPC7582 requires only a +5V supply and offers
“break-before-make” or “make-before-break” switch
operation using simple logic level input control. There
are two versions of the CPC7582, the CPC7582BA
and the CPC7582BB. The “BA” version has a protection SCR which provides protection to the SLIC device
and subsequent circuitry during fault conditions.
Features
• Small 16 pin surface mount SOIC package
• Monolithic IC reliability
• Low matched RDSON
• Eliminates the need for zero cross switching
• Flexible switch timing to transition from ringing mode
to idle/talk mode.
• Clean, bounce free switching
• Tertiary protection consisting of integrated current
limiting, thermal shutdown and SLIC protection
• 5V operation with power consumption <10mW
• Intelligent battery monitor
• Latched logic level inputs, no drive circuitry
• Pin to pin compatible to the Lucent 7582 family
Applications
• Central office (CO)
• Digital Loop Carrier (DLC)
• PBX Systems
• Digitally Added Main Line (DAML)
• Hybrid Fiber Coax (HFC)
• Fiber in the Loop (FITL)
• Pair Gain System
• Channel Banks
Ordering Information
Part #
CPC7582BA
CPC7582BB
CPC7582BA-TR
CPC7582BB-TR
Description
6 Pole with protection SCR
6 Pole without protection SCR
Tape & Reel Version
Tape & Reel Version
Block Diagram
TIP
TLINE
R1
SW5
Line Test
Access
VBAT
Reference (16)
TRING(4)
TACCESS(5)
SW3
Ringing
Return
(3)
TBAT (2)
SW1
Break
Secondary
Protection
Ring
SCR
and Trip
Circuit
SLIC
R2
RLINE
(14)
SW6
Line Test
Access
SW4
Ringing
Access
SW2
Break
CPC7582BA
RBAT(15)
Ring Generator
RACCESS (12)
RRING (13)
DS-CPC7582-R1.0
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+
Battery
1
CPC7582
Absolute Maximum Ratings (@ 25˚ C)
Parameter
Min
Operating Temperature Range
-40
Storage Temperature Range
-40
Relative Humidity Range
5
Pin Soldering Temperature
(t=10 s max)
+5V Power Supply
Battery Supply
Logic Input Voltage
Logic Input to Switch Output Isolation
Switch Isolation (SW1, SW2, SW3, SW5, SW6) Switch Isolation (SW4)
-
Max Units
+110
˚C
+150
˚C
95
%
+260
˚C
7
-85
7
330
330
480
V
V
V
V
V
V
Electrical Characteristics TA = -40oC to +85oC
(unless otherwise specified)
Minimum and maximum values are production testing
requirements. Typical values are characteristic of the
device and are the result of engineering evaluations.
Typical values are provided for information purposes
only and are not part of the testing requirements.
Absolute Maximum Ratings are stress ratings. Stresses in
excess of these ratings can cause permanent damage to
the device. Functional operation of the device at these or
any other conditions beyond those indicated in the operational sections of this data sheet is not implied. Exposure of
the device to the absolute maximum ratings for an extended period may degrade the device and effect its reliability.
Power Supply Specifications
Supply
VDD
VBAT1
Min
+4.5
-19
Typ
+5.0
-
Max
+5.5
-72
Unit
V
V
1V
BAT is used only as a reference for internal protection circuitry.
If VBAT rises above -10V, the device will enter an all off state and will remain in the all off state
until the battery voltage drops below -15V.
ESD Rating (HBM)
1000V
Table 1. Break Switch, SW1 and SW2
Parameters
Conditions
Off-state Leakage Current:
+25˚C
Vsw (differential)= -320V to Gnd
Vsw (differential)= -60V to +260V
+85˚C
Vsw (differential)= -330V to Gnd
Vsw (differential)= -60V to +270V
-40˚C
Vsw (differential)= -310V to Gnd
Vsw (differential)= -60V to +250V
RDSON (SW1,SW2):
+25˚C
TLINE= +/-10 mA, +/-40mA, TBAT= -2V
+85˚C
TLINE= +/-10 mA, +/-40mA, TBAT= -2V
-40˚C
TLINE= +/-10 mA, +/-40mA, TBAT= -2V
RDSON Match
Per ON-resistance Test Condition of
SW1, SW2RON SW1-RONSW2
dc Current Limit:
+25˚C
Vsw (on) = +/- 10V
+85˚C
Vsw (on) = +/- 10V
-40˚C
Vsw (on) = +/- 10V
Dynamic Current Limit:
Break switches in ON state, Ringing
(t=<0.5µs)
access switches OFF, Apply +/- 1000V
at 10/1000ms pulse, Appropriate
secondary protection in place.
2
Symbol
Min
Typ
Max
Units
Isw
-
0.1
1
µA
Isw
-
0.3
1
µA
Isw
-
0.1
1
µA
∆V
∆V
∆V
Magnitude
-
14.5
20.5
10.5
0.15
28
0.8
Ω
Ω
Ω
Ω
lsw
lsw
lsw
Isw
80
-
300
160
400
2.5
425
-
mA
mA
mA
A
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Rev. 1.0
CPC7582
Table 1. Break Switch, SW1 and SW2 (Continued)
Parameters
Conditions
Logic Input to Switch Output Isolation:
+25˚C
Vsw (TLINE, RLINE) = +/-320V
Logic Inputs = Gnd
+85˚C
Vsw (TLINE, RLINE) = +/-330V
Logic Inputs = Gnd
-40˚C
Vsw (TLINE, RLINE) = +/-310V
Logic Inputs = Gnd
dv/dt Sensitivity1
1
Symbol
Min
Typ
Max
Units
Isw
-
0.1
1
µA
Isw
-
0.3
1
µA
Isw
-
0.1
1
µA
-
-
200
-
V/µs
Symbol
Min
Typ
Max
Units
Isw
-
0.1
1
µA
Isw
-
0.3
1
µA
Isw
-
0.1
1
µA
Isw
Isw
Isw
Isw
-
135
85
210
2.5
-
mA
mA
mA
A
∆V
∆V
∆V
-
60
85
45
100
-
Ω
Ω
Ω
Isw
-
0.1
1
µA
Isw
-
0.3
1
µA
Isw
-
0.1
1
µA
Applied voltage is 100 Vp-p square wave at 100Hz.
Table 2. Ring Return Switch, SW3
Parameters
Off-state Leakage Current
+25˚C
+85˚C
-40˚C
dc Current Limit:
+25˚C
+85˚C
-40˚C
Dynamic Current Limit:
(t=<0.5ms)
Conditions
Vsw (differential)= -320V to Gnd
Vsw (differential)= -60V to +260V
Vsw (differential)= -330V to Gnd
Vsw (differential)= -60V to +270V
Vsw (differential)= -310V to Gnd
Vsw (differential)= -60V to +250V
Vsw (on) = +/- 10V
Vsw (on) = +/- 10V
Vsw (on) = +/- 10V
Break switches in ON state, Ringing
access switches OFF, Apply +/- 1000V
at 10/1000ms pulse, Appropriate
secondary protection in place.
RDSON
+25˚C
Isw (on) = +/-0mA, +/-10mA
+85˚C
Isw (on) = +/-0mA, +/-10mA
-40˚C
Isw (on) = +/-0mA, +/-10mA
Logic Input to Switch Output Isolation
+25˚C
Vsw (TRING, TLINE) = +/-320V
Logic Inputs = Gnd
+85˚C
Vsw (TRING, TLINE) = +/-330V
Logic Inputs = Gnd
-40˚C
Vsw (TRING, TLINE) = +/-310V
Logic Inputs = Gnd
Rev. 1.0
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3
CPC7582
Table 3. Ringing Access Switch, SW4
Parameters
Off-state Leakage Current
+25˚C
+85˚C
-40˚C
Conditions
Vsw (differential)= -255V to +210V
Vsw (differential)= +255V to -210V
Vsw (differential)= -270V to +210V
Vsw (differential)= +270V to -210V
Vsw (differential)= -245V to +210V
Vsw (differential)= +245V to -210V
Isw (on) = +/- 1mA
Vcc = 5V, INaccess = 0
ON Voltage
Ring Generator Current
During Ring
Surge Current
Release Current
RDSON
Isw (on) = +/-70mA, +/-80mA
Logic Input to Switch Output Isolation:
+25˚C
Vsw (RRING, RLINE) = +/-320V
Logic Inputs = Gnd
+85˚C
Vsw (RRING, RLINE) = +/-330V
Logic Inputs = Gnd
-40˚C
Vsw (RRING, RLINE) = +/-310V
Logic Inputs = Gnd
Symbol
Min
Typ
Max
Units
Isw
-
0.05
1
µA
Isw
-
0.1
1
µA
Isw
-
.05
1
µA
IR
-
1.5
0.1
3
0.25
V
mA
∆V
-
300
8.5
2
12
A
µA
Ω
Isw
-
.05
1
µA
Isw
-
0.1
1
µA
Isw
-
.05
1
µA
Symbol
Min
Typ
Max
Units
Table 4. Loop Access Switches, SW5 and SW6
Parameters
Off-state Leakage Current
+25˚C
+85˚C
-40˚C
DC Current Limit:
+25˚C
+85˚C
-40˚C
Dynamic Current Limit:
(t=<0.5µs)
Conditions
Vsw (differential)= -320V to Gnd
Vsw (differential)= -60V to +260V
Vsw (differential)= -330V to Gnd
Vsw (differential)= -60V to +270V
Vsw (differential)= -310 to Gnd
Vsw (differential)= -60V to +250V
Isw
-
0.1
1
µA
Isw
-
0.3
1
µA
Isw
-
0.1
1
µA
Vsw (on) = +/- 10V
Vsw (on) = +/- 10V
Vsw (on) = +/- 10V
Break switches in ON state, Ringing
access switches OFF, Apply +/- 1000V
at 10/1000ms pulse, Appropriate
secondary protection in place.
Isw
Isw
Isw
Isw
80
-
175
110
210
2.5
250
-
mA
mA
mA
A
∆V
∆V
∆V
-
38
46
28
70
-
Ω
Ω
Ω
Isw
-
0.1
1
µA
Isw
-
0.3
1
µA
Isw
-
0.1
1
µA
RDSON:
+25˚C
Isw (on) = +/-10 mA, +/-40mA
+85˚C
Isw (on) = +/-10 mA, +/-40mA
-40˚C
Isw (on) = +/-10 mA, +/-40mA
Logic Input to Switch Output Isolation:
+25˚C
Vsw (TACCESS, TLINE) = +/-320V
Logic Inputs = Gnd
+85˚C
Vsw (TACCESS, TLINE) = +/-330V
Logic Inputs = Gnd
-40˚C
Vsw (TACCESS, TLINE) = +/-310V
Logic Inputs = Gnd
4
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Rev. 1.0
CPC7582
Table 5. Additional Electrical Characteristics
Parameters
Digital Input Characteristics
Input Low Voltage
Input High Voltage
Input Leakage Current (High)
Input Leakage Current (Low)
Conditions
Symbol
Min
Typ
Max
Units
Ilog
3.5
-
0.1
1.5
1
V
V
µA
Ilog
-
0.1
1
µA
IDD, IBAT
IDD
-
5.5
6.5
7.5
10
mW
mW
IDD
IDD
-
1.1
1.3
1.5
1.9
mA
mA
IBAT
IBAT
-
0.1
0.1
10
10
µA
µA
-
110
10
125
-
150
25
˚C
˚C
-
-
VDD = 5.5V, VBAT = -75V,
Vlog = 5V
VDD = 5.5V, VBAT = -75V,
Vlog = 0V
Power Requirements
Power Dissipation
VDD = 5V, VBAT = -48V,
Idle/Talk State or All Off State
Ringing State or Access State
VDD Current
VDD = 5V,
Idle/Talk State or All Off State
Ringing State or Access State
VBAT Current
VBAT = -48V,
Idle/Talk State or All Off State
Ringing State or Access State
Temperature Shutdown Requirements1
Shutdown Activation Temperature
Shutdown Circuit Hysteresis
1
Temperature shutdown flag (TSD) will be high during normal operation and low during temperature shutdown state.
Table 6. Make-Before-Break Operation (Ringing to Idle/Talk Transition)
Access Input
0V
5V
0V
0V
0V
Rev. 1.0
0V
TSD
Float
Float
State
Ringing
Make-before-break
Float
Idle / Talk
Break
Switches
Timing
1&2
Open
SW4 waiting for next zero current Closed
crossing to turn off. Maximum
time is one half of ringing. In this
transition state, current that is
limited to the dc break switch
current limit value will be sourced
from the ring node of the SLIC
Zero cross current has occurred
Closed
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Ring
Return
Switch
3
Closed
Open
Ring
Access
Switch
4
Closed
Closed
Line Access
Switches
5&6
Open
Open
Open
Open
Open
5
CPC7582
Table 7. Break-Before-Make Operation (Ringing to Idle/Talk Transition)
Access Input
0V
5V
5V
5V
TSD
Float
Float
State
Ringing
All Off
All Off
SW4 has opened.
Idle/Talk
5V
5V
Float
0V
0V
Float
Timing
Hold this state for <= 25ms.
SW4 waiting for zero current to
turn off.
Zero current has occurred.
Release Break Switches
Ring
Ring
Access Line Access
Switch
Switches
4
5&6
Closed
Open
Closed
Open
Break
Switches
1&2
Open
Open
Return
Switch
3
Closed
Open
Open
Open
Open
Open
Closed
Open
Open
Open
Alternate “Break-Before-Make” Operation
Note that the “break-before-make” operation can also be achieved using TSD as an input. In lines 2 & 3 of Table 7,
instead of using the logic input pins to force the “all off” state, force TSD to ground. This will override the logic inputs
and also force the all off state. Hold this state for 25 ms. During this 25 ms all off state, toggle the inputs from the
ringing state (Input=5V, Access=0V) to the idle/talk state (Input=0V, Access=0V). After 25 ms, release TSD to return
switch control to the input pins which will set the idle talk state.
When using the CPC7582 in this mode, forcing TSD to ground will override the INPUT pins and force an all off state.
Setting TSD to +5V will allow switch control via the logic INPUT pins. However, setting TSD to +5V will also disable
the thermal shutdown mechanism. This is not recommended. Therefore, to allow switch control via the logic INPUT
pins, allow TSD to float.
Thus when using TSD as an input, the two recommended states are 0 (overrides logic input pins and forces all off
state) and float (allows switch control via logic input pins and thermal shutdown mechanism is active). This may
require use of an open collector buffer.
Table 8. Electrical Specifications, Protection Circuitry
Parameters
Conditions
Parameters Related to Diodes
(in Diode Bridge)
Voltage Drop @ Continuous
Apply +/-dc current limit of break
Current (50/60 Hz)
switches
Voltage Drop @ Surge
Apply +/-dynamic current limit of
Current
break switches
Parameters Related to
Protection SCR1
Surge Current
Trigger Current (+25˚C)
Hold Current (+25˚C)
Trigger Current (+85˚C)
Hold Current (+85˚C)
Gate Trigger Voltage
Trigger Current
Reverse Leakage Current
VBAT
ON State Voltage1
0.5A t = 0.5 ms
2.0A t = 0.5 ms
Symbol
Min
Typ
Max
Units
Forward
Voltage
Forward
Voltage
-
2.1
3
V
-
5
-
V
-
60
VBAT - 4
-
60
100
35
70
-3
-5
*
-
A
mA
mA
mA
mA
V
µA
V
V
ITRIG
IHOLD
ITRIG
IHOLD
Von
-
VBAT - 2
1.0
-
1 Only for the CPC7581BA.
* Passes GR1089 & ITU-T K.20 with appropriate secondary protection in place.
6
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Rev. 1.0
CPC7582
Table 9. Truth Table
Input
Access
TSD
Tip Break
Switch
0V
5V
0V
5V
Don’t
Care
0V
0V
5V
5V
Don’t
Care
5V/Float5
5V/Float5
5V/Float5
5V/Float5
0V6
On
Off
Off
Off
Off
1
Idle/Talk State
2
Power Ringing State
3
Test out message waiting state.
4
All OFF State
5
If TSD = 5V, the thermal shutdown mechanism is disabled.
If TSD if floating, the thermal shutdown mechanism is active.
6
Forcing TSD to ground overrides the logic input pins and forces an all off state.
Ring
Break
Switch
On
Off
Off
Off
Off
Ringing
Return
Switch
Off
On
Off
Off
Off
Ring
Switch
Off
On
Off
Off
Off
Tip
Access
Switch
Off
Off
On
Off
Off
Ring
Access
Switch
Off1
Off2
On3
Off4
Off4
Package Pinout
CPC7582
TBAT
2
TLINE 3
TRING
TACCESS
VDD
TSD
DGND
16
SCR
and
Trip
Circuit
SW1
15
SW2
5
6
14
VBAT
RBAT
RLINE
13 R
RING
4
SW3
SW4
SW5
SW6
7
8
Control Logic
FGND
1
12
11
10
9
RACCESS
LATCH
Pin
Name
1
FGND
Fault ground
2
TBAT
Connect to TIP on SLIC side
3
TLINE
Connect to TIP on line side
4
TRING
Connect to return ground for ringing
generator
5
TACCESS
Test access
6
VDD
+5V supply
7
TSD
Temperature shutdown pin. Can be
used as a logic level input or output.
See Tables 6, 7 and 9 for more
details. As an output, will read +5V
when device is in its operational mode
and 0V in the thermal shutdown mode.
To disable the thermal shutdown
mechanism, tie this pin to +5V
(NOT Recommended).
8
DGND
Digital ground
9
INACCESS
10
INRING
Logic level input switch control
11
LATCH
Data latch control, active high,
transparent low
12
RACCESS
Test access
13
RRING
Connect to ringing generator
14
RLINE
Connect to RING on line side
15
RBAT
Connect to RING on SLIC side
16
VBAT
Battery voltage. Used as a reference
for protection circuit
INRING
INACCESS
* Only the CPC7582BA contains the protection SCR.
Rev. 1.0
Function
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Logic level switch control
7
CPC7582
Functional Description
Introduction
The CPC7582 has four states:
• Idle/talk state (line break switches SW1, and SW2
closed, ringing switches SW3, SW4 open and loop
access switches SW5, SW6 open),
• Ringing state (line break switches SW1, and SW2
open, ringing switches SW3, SW4 closed and loop
access switches SW5, SW6 open)
• Loop access (line break switches SW1, and SW2
open, ringing switches SW3, SW4 open and loop
access switches SW5, SW6 closed)
• All Off state (line break switches SW1, and SW2
open, ringing switches SW3, SW4 open and loop
access switches SW5, SW6 open)
The CPC7582 offers break-before-make and makebefore-break switching with simple logic level input control. Solid state switch construction means no impulse
noise is generated when switching during ring cadence
or ring trip, thus eliminating the need for external “zero
cross” switching circuitry. State control is via logic level
input so no additional driver circuitry is required. The
line break switches SW1 and SW2 are linear switches
that have exceptionally low RDSON and excellent
matching characteristics. The ringing access switch
SW4 has a breakdown voltage rating of >480V which is
sufficiently high, with proper protection, to prevent
breakdown in the presence of a transient fault condition
(i.e., passing the transient on to the ring generator).
Integrated into the CPC7582 is a diode bridge/SCR
clamping circuit, current limiting and thermal shutdown mechanism to provide protection to the SLIC
device during a fault condition. Positive and negative
surges are reduced by the current limiting circuitry and
steered to ground via diodes and the integrated SCR.
Power cross transients are also reduced by the current limiting and thermal shutdown circuits. Please
note that only the CPC7582BA has the integrated protection SCR.
To protect the CPC7582 from an overvoltage fault
condition, use of a secondary protector is required.
The secondary protector must limit the voltage seen at
the tip and ring terminals to a level below the max
breakdown voltage of the switches. To minimize the
stress on the solid-state contacts, use of a foldback or
crowbar type secondary protector is recommended.
With proper selection of the secondary protector, a
line card using the CPC7582 will meet all relevant
ITU, LSSGR, FCC or UL protection requirements.
dissipation and allows use with virtually any range of
battery voltage. A battery voltage is also used by the
CPC7582 as a reference for the integrated protection
circuit. In the event of a loss of battery voltage, the
CPC7582 will enter an “all off” state.
Switch Timing
The CPC7582 provides, when switching from the ringing state to the idle/talk state, the ability to control the
timing when the ringing access switches SW3 and
SW4 are released relative to the state of the line break
switches SW1 and SW2 using simple logic level input.
This is referred to a “make before break” or “break
before make” operation. When the line break switch
contacts (SW1, SW2) are closed (or made) before the
ringing access switch contact (SW3, SW4) is opened
(or broken), this is referred to a ‘make-before-break’
operation. Break-before-make operation occurs when
the ringing access contact (SW3, SW4) is opened
(broken) before the line break switch contacts (SW1,
SW2) are closed (made). With the CPC7582 the
“make before break” and “break before make” operations can easily be selected by applying logic level
inputs to pins 9 and 10 (INring and INaccess) of the
device.
The logic sequences for either mode of operation are
given in Tables 6 and 7. Logic states and explanations
are given in Table 9.
Break-before make operation can also be achieved
using pin 7 (TSD) as an input. In table 7 lines 2 and 3
it is possible to induce the switches to “all off” by
grounding pin 7 (TSD) instead of apply logic input to
the pins. This has the effect of overriding the logic
inputs and forcing the device to the “all off” state. Hold
this input state for 25ms. During this hold period, toggle the inputs from the ringing state (10) to the idle/talk
state (00). After the 25ms release pin 7 (TSD) to return
the switch control to the input pins 9 and 10 and reset
the device to the idle/talk state.
Setting TSD to +5V will allow switch control using the
logic pins 9 and 10. This setting, however, will also disable the thermal shutdown circuit and is therefore not
recommended. When using logic controls via the input
pins 9 and 10, pin 7 (TSD) should be allowed to float.
As a result the two recommended states when using
pin 7 (TSD) as a control are 0 which forces the device
to the “all of state” or float which allows logic inputs to
pins 9 and 10 to remain active. This may require use
of an open collector buffer.
The CPC7582 operates from a +5V supply only. This
gives the device extremely low idle and active power
8
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Rev. 1.0
CPC7582
Ring Access Switch Zero Cross Current Turn Off
After the application of a logic input to turn SW4 off,
the ring access switch is designed to delay the change
in state until the next zero crossing. Once on, the
switch requires a zero current cross to turn off and
therefore should not be used to switch a pure DC signal. The switch will remain in the on state no matter
what logic input until the next zero crossing. For proper operation, pin 13 (RRing) should be connected using
proper impedance to a ring generator or other ac
source. These switching characteristics will reduce
and possibly eliminate overall system impulse noise
normally associated with ringing access switches. The
attributes of ringing access switch SW4 may make it
possible to eliminate the need for a zero cross switching scheme. A minimum impedence of 300Ω in series
with the ring generator is recommended.
Power Supplies
Both a +5V supply and battery voltage are connected
to the CPC7582. CPC7582 switch state control is
powered exclusively by the +5V supply. As a result,
the CPC7582 exhibits extremely low power dissipation during both active and idle states.
The battery voltage is not used for switch control but
rather as a reference by the integrated secondary protection circuitry. The integrated SCR is designed to
trigger when pin 2 (TBAT) or pin 15 (RBAT) drops 2 to 4V
below the battery. This trigger prevents a fault induced
overvoltage event at the TBAT or RBAT nodes.
Battery Voltage Monitor
The CPC7582 also uses the voltage reference to monitor battery voltage. If battery voltage is lost, the
CPC7582 will immediately enter the “all off” state and
remain in this state until the battery voltage is restored.
The device will also enter the “all off” state if the battery
voltage rises above –10V and will remain there until the
battery voltage drops below –15V. This battery monitor
feature draws a small current from the battery (<1µA
typ.) and will add slightly to the device’s overall power
dissipation.
positive transient condition, the fault current is conducted through the diode bridge to ground. Voltage is
clamped to the diode drop above ground. During a
negative transient of 2 - 4 volts more negative than the
battery, the SCR conducts and faults are shunted to
ground via the SCR and diode bridge.
Also, in order for the SCR to crowbar or foldback, the
on voltage (see Table 8) of the SCR must be less negative than the battery reference voltage. If the battery
voltage is less negative the SCR on voltage, the SCR
will not crowbar, however it will conduct fault currents to
ground.
For power induction or power cross fault conditions,
the positive cycle of the transient is clamped to the
diode drop above ground and the fault current directed to ground. The negative cycle of the transient will
cause the SCR to conduct when the voltage exceeds
the battery reference voltage by two to four volts,
steering the current to ground.
Current Limiting function
If a lightning strike transient occurs when the device in
the talk/idle state, the current is passed along the line
to the integrated protection circuitry and limited by the
dynamic current limit response of break switches SW1
and SW2. When a 1000V 10x1000 pulse (LSSGR
lightning) is applied to the line though a properly
clamped external protector, the current seen at pins 2
(TBAT) and pin 15 (RBAT) will be a pulse with a typical
magnitude and duration of 2.5A and < 0.5ms.
If a power cross fault occurs with device in the talk/idle
state, the current is passed though the break switches
SW1 and SW2 on to the integrated protection circuit
and is limited by the dynamic DC current limit
response of the two break switches. The DC current
limit, specified over temperature, is between 80mA
and 425mA and the circuitry has a negative temperature coefficient. As a result, if the device is subjected
to extended heating due to power cross fault, the
measured current at pin 2 (TBAT) and pin 15 (RBAT) will
decrease as the device temperature increases. If the
device temperature rises sufficiently, the temperature
shutdown mechanism will activate and the device will
default to the “all off” state.
Protection
Diode Bridge/SCR
Temperature Shutdown
The CPC7582 uses a combination of current limited
break switches, a diode bridge/SCR clamping circuit
and a thermal shutdown mechanism to protect the
SLIC device or other associated circuitry from damage
during line transient events such as lightning. During a
The thermal shutdown mechanism will activate when
the device temperature reaches a minimum of 110°C
placing the device in the “all off” state regardless of
logic input. During this thermal shutdown mode, pin 7
(TSD) will read 0V. Normal output of TSD is +VDD
Rev. 1.0
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9
CPC7582
If presented with a short duration transient such as a
lightning event, the thermal shutdown feature will not
typically activate. But in an extended power cross
transient, the device temperature will rise and the thermal shutdown will activate forcing the switches to an
“all off” state. At this point the current measured at pin
2 (TBAT) and pin 15 (RBAT) will drop to zero. Once the
device enters thermal shutdown it will remain in the
“all off” state until the temperature of the device drops
below the activation level of the thermal shutdown circuit. This will return the device to the state prior to
thermal shutdown. If the transient has not passed,
current will flow at the value allowed by the dynamic
DC current limiting of the switches and heating will
begin again, reactivating the thermal shutdown mechanism. This cycle of entering and exiting the thermal
shutdown mode will continue as long as the fault condition persists. If the magnitude of the fault condition is
great enough, the external secondary protector could
activate and shunt all current to ground.
state. The switches will remain in the position they
were in when the LATCH changed from logic 0 to logic
1 and will not respond to changes in input as long as
the latch is at logic 1. In addition, TSD input is not tied
to the data latch. Therefore, TSD is not affected by
the LATCH input and TSD input will override state
control via pin 10 (INRING) and pin 9 (INACCESS) and the
LATCH.
The thermal shutdown mechanism of the CPC7582
can be disable by applying +VDD to pin 7 (TSD)
External Protection Elements
The CPC7582 requires only one overvoltage secondary protector on the loop side of the device. The integrated protection feature described above negates the
need for protection on the line side. The purpose of
the secondary protector is to limit voltage transients to
levels that do not exceed the breakdown voltage or
input-output isolation barrier of the CPC7582. A foldback or crowbar type protector is recommended to
minimize stresses on the device.
Consult Clare’s application note, AN-100, “Designing
Surge and Power Fault Protection Circuits for Solid
State Subscriber Line Interfaces” for equations related
to the specifications of external secondary protectors,
fused resistors and PTCs.
Data Latch
The CPC7582 has an integrated data latch. The latch
operation is controlled by logic level input pin 11
(LATCH). The data input of the latch is pin 10 (INRING)
and pin 9 (INACCESS) of the device while the output of
the data latch is an internal node used for state control. When LATCH control pin is at logic 0, the data
latch is transparent and data control signals flow
directly through to state control. A change in input will
be reflected in a change is switch state. When LATCH
control pin is at logic 1, the data latch is now active
and a change in input control will not affect switch
10
www.clare.com
Rev. 1.0
CPC7582
MECHANICAL DIMENSIONS
16 Pin SOIC (JEDEC Package)
10.11 MIN / 10.31 MAX
(.398 MIN / .406 MAX)
1.27
(.050)
0.23 MIN / 0.32 MAX
(.0091 MIN / .0125 MAX)
2.44 MIN / 2.64 MAX
(.096 MIN / .104 MAX)
7.40 MIN /
(.291 MIN /
0.51 MIN / 1.01 MAX
(.020 MIN / .040 MAX)
32 MAX
125 MAX)
7.40 MIN / 7.60 MAX
(.291 MIN / .299 MAX)
10.11 MIN / 10.51 MAX
(.398 MIN / .414 MAX)
0.36 MIN / 0.46 MAX
(.014 MIN / .018 MAX)
PC Board Pattern
(Top View)
1.270
(.050)
9.728 ± .051
(.383 ± .002)
1.193
(.047)
.787
(.031)
Dimensions
mm
(Inches)
Rev. 1.0
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11
For additional information please visit our website at: www.clare.com
Clare, Inc. makes no representations or warranties with respect to the accuracy or completeness of the contents of this publication and reserves the right to make changes to specifications and product descriptions
at any time without notice. Neither circuit patent licenses nor indemnity are expressed or implied. Except as set forth in Clare’s Standard Terms and Conditions of Sale, Clare, Inc. assumes no liability whatsoever, and
disclaims any express or implied warranty, relating to its products including, but not limited to, the implied warranty of merchantability, fitness for a particular purpose, or infringement of any intellectual property right.
The products described in this document are not designed, intended, authorized or warranted for use as components in systems intended for surgical implant into the body, or in other applications intended to support or sustain life, or where malfunction of Clare’s product may result in direct physical harm, injury, or death to a person or severe property or environmental damage. Clare, Inc. reserves the right to discontinue or
make changes to its products at any time without notice.
Specification: DS-CPC7582BA-R1.0
©Copyright 2001, Clare, Inc.
All rights reserved. Printed in USA.
9/20/01
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