STMICROELECTRONICS SMP75-8

SMP75-8

TRISILTM
FEATURES
Bidirectional surge arrestor.
Very low stand-off voltage : VRM = 8 V.
High repetitive surge capability :
IPP = 75 A (10/1000µs).
Very low capacitance : C < 75 pF
Low leakage current : < 2 µA
DESCRIPTION
The SMP75-8 is a very low voltage transient surge
arrestor especially designed to protect sensitive
telecommunication equipment against lightning
strikes and other transients.
SMB
(JEDEC DO-214AA)
SCHEMATIC DIAGRAM
MAIN APPLICATION
XDSL TRANSMISSION EQUIPMENT
BENEFITS
Protection against high energy surges.
Very low breakover voltage : VBO < 15 V, thus
avoiding saturationof transformer.
No signal distortion thanks to very low capacitance.
COMPLIESWITHTHE FOLLOWINGSTANDARDS :
- BELLCORE TR-NWT
-000974:
- CCITT K20:
- VDE 0433:
- VDE 0878:
10/1000 µs
10/1000 µs
10/700 µs
5/310 µs
10/700 µs
5/310 µs
1.2/50 µs
1/20 µs
1 kV
75A *
4 kV
100A
4 kV
100A
4 kV
100A
* with series resistor or PTC.
January 1998 - Ed : 2
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SMP75-8
ABSOLUTE MAXIMUM RATINGS (Tamb = 25°C)
Symbol
Ipp
Parameter
Value
Unit
10/1000µs
8/20µs
75
250
A
A
Non repetitive surge peak on-state current
One cycle
50Hz
60Hz
35
37
A
A
Non repetitive surge peak on-state current
F = 50Hz
0.2s
2s
14
6
A
A
260
°C
- 55 to + 150
150
°C
°C
Value
Unit
Peak pulse current
ITSM
Maximum lead temperature for soldering during 10s
TI
Tstg
Tj
Storage temperature range
Maximum junction temperature
THERMAL RESISTANCES
Symbol
Parameter
Rth(j-I)
Junction to leads
20
°C/W
Rth(j-a)
Junction to ambient on printed circuit
(with standard footprint dimensions)
100
°C/W
Note 1: Pulse waveform
10 / 1000 µs
8 / 20 µs
5 / 310 µs
1 / 20 µs
2 / 10 µs
% IPP
tr = 10 µs
tr = 8 µs
tr = 5 µs
tr = 1 µs
tr = 2 µs
tp = 1000 µs
tp = 20 µs
tp = 310 µs
tp = 20 µs
tp = 10 µs
ELECTRICAL CHARACTERISTICS (Tamb = 25°C)
Symbol
Parameter
VRM
Stand-off voltage
IRM
VR
Leakage current at stand-off voltage
VBR
Breakdown voltage
VBO
IH
Breakover voltage
Holding current
IBO
Breakover current
IPP
C
Peak pulse current
Capacitance
Continuous Reverse voltage
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
100
50
0
tr
tp
SMP75-8
STATIC PARAMETERS
Type
IR @ VR
max.
note 1
IRM @ VRM
max.
SMP75-8
VBO @ IBO
max.
note 2
IH
typ.
note 3
C
max.
note 4
µA
V
µA
V
V
mA
mA
pF
2
6
50
8
15
800
50
75
Type
Max.
Unit
SMP75-8
20
V
Note 1 : IR measured at VR guarantees VBR>VR
Note 2 : Measured at 50Hz, see test circuit 1. In any case VBOmin ≥ VBR
Note 3 : See functional holding current test circuit 2.
Note 4 : VR=1V bias, VRMS=1V, F=1MHz.
DYNAMIC PARAMETERS
Symbol
Test conditions (see note 5)
Test conditions 1
VRISE = 100 V/µs, di/dt < 10 A/µs, IPP = 75 A
VBO
Test conditions 2
VRISE = 1 kV/µs, di/dt < 10 A/µs, IPP = 10 A
Note 5 : VBO parameters are given by a KeyTek ’System 2’ generator with PN246I module.
See test circuits (3) for VBO dynamic parameters.
TEST CIRCUIT 1 FOR IBO and VBO parameters:
tp = 20ms
Auto
Transformer
220V/2A
R1
static
relay.
140
R2
240
K
220V
Vout
IBO
measure
D.U.T
V BO
measure
Transformer
220V/800V
5A
TEST PROCEDURE :
Pulse Test duration (tp = 20ms):
- For Bidirectional devices = Switch K is closed
- For Unidirectional devices = Switch K is open.
VOUT Selection
- Device with VBO < 200 Volt
- VOUT = 250 VRMS, R1 = 140 Ω.
- Device with VBO ≥ 200 Volt
- VOUT = 480 VRMS, R2 = 240 Ω.
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
SMP75-8
FUNCTIONAL HOLDING CURRENT (IH ) TEST CIRCUIT 2: GO-NO GO TEST
R
- VP
D.U.T.
VBAT = - 6 V
Surge generator
This is a GO-NO GO test which allows to confirm the holdingcurrent (IH) level in a functionaltest circuit.
TEST PROCEDURE :
- Adjust the current level at the I H value by short circuiting the D.U.T.
- Fire the D.U.T. with a surge current : Ipp = 10A, 10/1000 µs.
- The D.U.T. will come back to the OFF-state within a duration of 50 ms max.
TEST CIRCUITS 3 FOR VBO DYNAMIC PARAMETERS
100 V / µs,Ipp = 75A
2Ω
U
83 Ω
45 Ω
10 µF
66 Ω
0.36 nF
470 Ω
KeyTek ’System 2’ generator with PN246I module
1 kV / µs,Ipp = 10 A
26 µH
U
60 µF
250 Ω
47 Ω
12 Ω
KeyTek ’System 2’ generator with PN246I module
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
46 µH
46 µH
SMP75-8
TYPICAL APPLICATION : T1 / E1 protection
DA108S1
+Vcc
5V
RTIP
RX LINE
+Vcc
0V
RRING
SMP75-8
IC
+Vcc
SM6T6V8A
TTIP
+Vcc
TX LINE
TRING
SMP75-8
The above schematic shows a T1 / E1 application
circuit. This type of line protection may be used in
premises equipment or telephone company
equipment on ports directly connected to metallic
plant lines.
During the lightning surge, the low voltage Trisil
SMP75-8 provides an efficient crowbar protection
on the primary side of the transformer.
The SMP75-8 has a maximum peak pulse current
of 75A (10/1000µs pulse) and a maximum
breakover voltage of 15V. This low voltage
prevents the transformer to be satured when a
surge occurs on the line. Additionally, the low
capacitance (65pF) is required to avoid significant
signal degradation in the case of high speed digital
pulses.
additional voltage protection is recommended on
the line input / output pins of the IC. The diode
array DA108S1 connected between +Vcc and
GND is then used to limit the remaining
overvoltage within a safe level.
The DA108S1 is especially dedicated to this
application because. Its fast response time and
low forward voltage drop enable it to clamp any
surge before the IC line interface internal
protection fails. Additionally, the low capacitance
(30pF) is required to prevent signal degradation of
the high speed datd.
The DA108S1 is a fully integrated (1 chip) device
and results from the ST ASDTM(Application
Specific Discretes) technology. ASDsTM combine
the functions of several components into a single
monolithic device that is tailored to meet the exact
requirement of a specific application, allowing
higher density and improved reliability.
To protect the IC line interface from the remaining
energy which is coupled through the transformer,
ORDER CODE
SMP
75 - 8
SURFACE MOUNT
VOLTAGE
TRISIL 75 A
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
SMP75-8
Non repetitive surge peak current versus overload
duration.
MARKING
Package
ITSM (A)
Type
Marking
50
SMB
F=50Hz
Tj initial=25°C
45
SMP75-8
L08
40
35
30
25
20
15
10
5
0
1E-2
t(s)
1E-1
1E+0
1E+1
1E+2
1E+3
PACKAGE MECHANICAL DATA
SMB (JEDEC DO-214AA)(Plastic)
DIMENSIONS
E1
REF.
Millimeters
Inches
Min. Typ. Max. Min. Typ. Max.
A1
A2
b
D
c
E
A1
c
A2
L
b
1.90 2.15 2.45 0.075 0.085 0.096
0.05 0.15 0.20 0.002 0.006 0.008
1.95
2.20 0.077
0.087
0.15
0.41 0.006
0.016
E
E1
5.10 5.40 5.60 0.201 0.213 0.220
4.05 4.30 4.60 0.159 0.169 0.181
D
3.30 3.60 3.95 0.130 0.142 0.156
L
0.75 1.15 1.60 0.030 0.045 0.063
FOOT PRINT (in millimeters)
Packaging : tape and reel
Weight : 0.12g
2.3
1.52
2.75
1.52
Information furnished is believed to be accurate and reliable. However, SGS-THOMSON Microelectronics assumes no responsibility for the
consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No
license is granted by implication or otherwise under any patent or patent rights of SGS-THOMSON Microelectronics. Specifications mentioned
in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied.
SGS-THOMSON Microelectronics products are not authorized for use as critical components in life support devices or systems without express
written approval of SGS-THOMSON Microelectronics.
 1998 SGS-THOMSON Microelectronics - Printed in Italy - All rights reserved.
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