Transcript SDP Product Series Introduction

Introduction to
Tertiary Telecom
Protection
Outline
 Tertiary Telecom Protection
–
–
–
–
–
–
Primary / Secondary / Tertiary
Transformer Coupled Applications
Tertiary Protection Requirements
Differential vs Rail Clamp Diode Array Protection
Driver Voltages & Vdrm vs Vs
Low Capacitance / Flat Capacitance
 Littelfuse Tertiary Protection Products
–
–
–
–
–
–
P0080SAMC Family
SDP0242Q12F
SP03 Family
SP300x Family
SP3050
Selection Table
2
2
Version01_100407
Primary / Secondary / Tertiary Protection
Protection is a coordinated layering of protection technologies
Outdoor
Cabling
Primary
Protection
Secondary
Protection
• OVP ~ 1000V
• Thermal Overload
• GR-974
• OVP ~ 300V
• OCP ~ Fuse / PTC
• GR-1089
• UL 60950
• ITU K.20 / K.21
Building Entrance
Tertiary
Protection
• OVP ~ 30V
• No Regulatory Need
Line Card
Tertiary protection is unique in that the performance requirements
are dictated only by the customer’s perceived need.
3
3
Version01_100407
Transformer Coupled Applications
Tertiary protection
circuits are
separated from the
secondary protection
circuits by a
transformer:
T1 / E1
xDSL
Tertiary protection is used to protect the signal driver circuitry.
• T1/E1 circuits call this the transceiver.
• xDSL circuits use line drivers.
• Ethernet uses a PHY.
Ethernet
4
4
Version01_100407
Tertiary Protection Requirements
 Tertiary protection requirements come from four
considerations:
– The nature of the threats to the protection scheme.
 ESD only? Or AC Power Cross? Lightning Exposure?
– The amount of energy coupled through the transformer.
 Primary / Secondary Technology & Topology.
– The protection requirements of the protected driver circuitry.
 Operating Voltages / Damaging Voltages
– The nature of the datastream being protected.
 The Protection Scheme Must NOT Interfere!
5
5
Version01_100407
Differential vs Rail Clamp Protection
Two Basic Strategies for Protection
– Absorb Energy Differentially
– Dump Energy Into Power Supply Rails
+V
Power Supply
Line Drivers
Digital
Circuitry
Transceiver
Surge Energy
PHY
-V
Littelfuse offers several circuit configurations designed to
maximize effectiveness and flexibility:
– Pure Differential Devices
– Rail Clamp Diode Arrays that combine Steering and TVS diodes
6
6
Version01_100407
Driver Voltages & Protection Voltages
There are a variety of supply
voltages for drivers:
Driver Type
Typical Power Rail
Voltage
Ethernet PHY
2.8, 3.3, 5.0
T1 / E1 / T3
5.0
xDSL
(CPE End)
6, 7, 12
xDSL
(CO End)
6, 12, 16, 20, 24
Two KEY Points…
• Protection VDRM or VRWM
must be higher than the
driver voltage.
• Relative protection
effectiveness comes from
comparing VC or VS on
identical test waveforms.
7
7
Version01_100407
Capacitance Issues
 High Capacitance will rob
power from the signal.
 Capacitance gains in
importance as the data rate
of the signal increases.
There is a natural trade-off between surge
capability, capacitance and clamp voltage:
High Surge  High Capacitance  Low Clamp Voltage
– Non-Issue for Voice, T1/E1
– Minor Issue for T3, ADSL
– Major Issue for VDSL,
Ethernet
– Use steering diodes
– Use devices in series
90
P0080SAMC
P0080SCMC
80
P0300SAMC
70
P0300SCMC
P0640SCMC
60
pF
 Higher capacitance devices
should minimize how much
their capacitance varies with
applied voltage.
SIDACtor Capacitance vs Line Voltage
100
P2600SCMC
P3100SCMC
50
P3100D
40
P3500SCMC
30
20
10
0
0.1
1
Line Voltage
10
100
8
8
Version01_100407
Outline
 Tertiary Telecom Protection
–
–
–
–
–
–
Primary / Secondary / Tertiary
Transformer Coupled Applications
Tertiary Protection Requirements
Differential vs Rail Clamp Diode Array Protection
Driver Voltages & Vdrm vs Vs
Low Capacitance / Flat Capacitance
 Littelfuse Tertiary Protection Products
–
–
–
–
–
–
P0080SAMC Family
SDP0242Q12F
SP03 Family
SP300x Family
SP3050
Selection Table
9
9
Version01_100407
P0080SAMC





Relatively high capacitance  Low speed apps
Very high surge capability
Low voltage drivers only
Pure differential protection
SMB, QFN or TO-92 Packaging
10
10
Version01_100407
SDP0242Q12F



The only Littelfuse solution for drivers above 5V
Pure differential protection
Designed for VDSL applications
11
11
Version01_100407
SP03 Family




Available in 3.3V and 6V VRWM
Differential Protection
Grounded Bridge Option
SO-8 Packaging
12
12
Version01_100407
SP300x Family




Rail Clamp or Differential Protection
Variety of SMT Packaging
Ultra-Low Capacitance
Limited Surge Capability
13
13
Version01_100407
SP3050
 Rail Clamp or Differential Protection
 Good Parameter Balance:
– Mid-Capacitance
– Mid-Surge
 SOT23-6 Packaging
14
14
Version01_100407
Tertiary Protection Selection
Driver
Voltage
P0080
Family
0 - 6V
SP300x
0 - 6V
SP3050
0 - 6V
SP03-3.3
SP03-6
0 - 3.3V
0 - 6V
SDP0242Q12F
0 - 24V
Clamp
Voltage
25V
(100V/uS)
10.6 – 11.8V
(2A 8x20)
13.2V
(8A 8x20)
18V / 20V
(100A 8x20)
43V
(100V/uS)
Surge
Withstand
(0V)
Circuit
Configuration
150A
53pF
Differential
2.5 – 4.5A
0.35 – 0.50 pF
Rail Clamp
Diode Array
10A
1.2pF
Rail Clamp
Diode Array
150A
8pF
Grounded Diode
Array
80A
15pF
Differential
(8x20)
Capacitance
15
15
Version01_100407
Tertiary Telecom Protection
Thank You!
16
16
Version01_100407