APRIL 2001 REVISED JULY 2008
Specifications are subject to change without notice.
Customers should verify actual device performance in their specific applications.
TISP61521 SLIC Protector
TISP61521
DUAL FORWARD-CONDUCTING P-GATE THYRISTORS
PROGRAMMABLE OVERVOLTAGE PROTECTORS
Device Symbol
Overvoltage Protection for High Voltage Negative Rail
Ringing SLICs
Dual Voltage-Programmable Protectors
- Supports Battery Voltages Down to -150 V
- Low 3 mA max. Gate Triggering Current
- High 150 mA min. Holding Current
Rated for International Surge Wave Shapes
How To Order
D Package (Top View)
Vo ltage
Waveshape Standard ITSP
A
2/10 GR-1089-CORE 170
1.2/50 ITU-T K.22
VDE 0878 50
1.2/50 IEC 61000-4-5 100
10/160 FCC Part 68 Type A 50
0.5/700 I3124 40
10/700
ITU-T K.20,
VDE 0433
IEC 61000-4-5
40
9/720 FCC Part 68 Type B 40
10/560 FCC Part 68 Type A 35
10/1000 GR-1089-CORE 30
Functional Replacements for
Device Type Package Type Functional
Replacement
LCP1511D,
LCP1521 8-pin Small-Outline TISP61521DR-S
MD6XANB
NC - No internal connection
Terminal typical application names shown in
parenthesis
1
2
3
45
6
7
8K1
A
A
K2
G
K1
K2
NC
(Tip)
(Ground)
(Ground)
(Ring)
(Gate)
(Tip)
(Ring)
SD6XAEB
K1
K2
A
AG
K1
K2
Terminals K1, K2 and A correspond to the alternative
line designators of T, R and G or A, B and C. The
negative protection voltage is controlled by the
voltage, VGG, applied to the G terminal.
Description
The TISP61521 is a dual forward-conducting buffered p-gate overvoltage protector. It is designed to protect monolithic SLICs (Subscriber Line
Interface Circuits) against overvoltages on the telephone line caused by lightning, a.c. power contact and induction. The TISP61521 limits
voltages that exceed the SLIC supply rail voltage. The TISP61521 parameters are specified to allow equipment compliance with Bellcore
GR-1089-CORE, Issue 1 and ITU-T recommendation K.20.
............................................ UL Recognized Components
*RoHS Directive 2002/95/EC Jan 27 2003 including Annex
*RoHS COMPLIANT
Device Package Carrier
TISP61521 D (8-pin Small-Outline) Embossed Tape Reeled TISP61521DR-S
Order As
APRIL 2001 REVISED JULY 2008
Specifications are subject to change without notice.
Customers should verify actual device performance in their specific applications.
Absolute Maximum Ratings, TJ = 25 °C (Unless Otherwise Noted)
TISP61521 SLIC Protector
Description (continued)
The SLIC line driver section is typically powered from 0 V (ground) and a negative voltage in the region of -20 V to -150 V. The protector gate is
connected to this negative supply. This references the protection (clipping) voltage to the negative supply voltage. The protection voltage will
then track the negative supply voltage and the overvoltage stress on the SLIC is minimized.
Positive overvoltages are clipped to ground by diode forward conduction. Negative overvoltages are initially clipped close to the SLIC negative
supply rail value. If sufficient current is available from the overvoltage, then the protector will switch into a low voltage on-state condition. As
the overvoltage subsides, the high holding current of TISP61521 crowbar helps prevent d.c. latchup.
These monolithic protection devices are fabricated in ion-implanted planar vertical power structures for high reliability and in normal system
operation they are virtually transparent. The TISP61521 buffered gate design reduces the loading on the SLIC supply during overvoltages
caused by power cross and induction. The TISP61521 is available in an 8-pin plastic small-outline surface mount package.
NOTES: 1. These voltage ratings are set by the -150 V maximum supply voltage plus the 12 V diode overshoot (VGKRM) and the 25 V SCR
overshoot (VDRM).
2. Initially, the protector must be in thermal equilibrium. The surge may be repeated after the device returns to its initial conditions. The
rated current values may be applied either to the Ring to Ground or to the Tip to Ground terminal pairs. Additionally, both terminal
pairs may have their rated current values applied simultaneously (in this case, the Ground terminal current will be twice the rated
current value of an individual terminal pair).
3. Values for VGG = -48 V. For values at other voltages, see Figure 2.
Rating Symbol Value Unit
Repetitive peak off-state voltage, VGK =0, -40°C≤TJ≤85 °C (see Note 1) V
DRM -175 V
Repetitive peak gate-cathode voltage, VKA =0, -40°C≤TJ≤85 °C (see Note 1) V
GKRM -162 V
Non-repetitive peak on-state pulse current (see Note 2)
ITSP A
2/10 µs (GR-1089-CORE, 2/10 µs voltage waveshape) 170
1/20 µs (K.22, VDE0878, 1.2/50 voltage waveshape) 50
8/20 µs (IEC 61000-4-5, combination wave generator, 1.2/50 voltage, 8/20 current) 100
10/160 µs (FCC Part 68, 10/160 µs voltage waveshape) 50
0.2/310 µs (I3124, 0.5/700 µs voltage waveshape) 40
5/310 µs (VDE 0433, 10/700 µs voltage waveshape) 40
5/310 µs (ITU-T K.20/21, K.44 10/700 µs voltage wave shape) 40
5/320 µs (FCC Part 68, 9/720 µs voltage waveshape) 40
10/560 µs (FCC Part 68, 10/560 µs voltage waveshape) 35
10/1000 µs (GR-1089-CORE, 10/1000 µs voltage waveshape) 30
Non-repetitive peak on-state current, 50 Hz (see Notes 2 and 3)
ITSM A0.01 s 15
1s 5
Non-repetitive peak gate current, 10 ms half-sine wave, cathodes commoned (see Notes 1 and
2) IGSM +2 A
Junction temperature TJ-40 to +150 °C
C
Storage temperature range Tstg -65 to +150 °
APRIL 2001 REVISED JULY 2008
Specifications are subject to change without notice.
Customers should verify actual device performance in their specific applications.
Electrical Characteristics, TJ = 25 °C (Unless Otherwise Noted)
TISP61521 SLIC Protector
Recommended Operating Conditions
Component Min Typ Max Unit
C1 Gate decoupling capacitor 100 220 nF
RS
series resistor for GR-1089-CORE, 2/10, 10/360 and 10/1000 first-level surge survival 25 Ω
series resistor for GR-1089-CORE, 2/10, 10/360 and 10/1000 first-level and 2/10 second-level
surge survival 40 Ω
series resistor for K.20, K.21 and K.45 coordination with a 400 V primary protector 10 Ω
series resistor for K.44 4 kV 10/700 surge survival 60 Ω
series resistor for FCC Part 68 Type A 10/160 and 10/560 surge survival 20 Ω
series resistor for FCC Part 68 Type B 9/720 surge survival 0 Ω
series resistor for VDE 0433 2 kV 10/700 surge survival 10 Ω
series resistor for VDE 0878 2 kV 1.2/50 surge survival 0 Ω
series resistor for IEC 6100-4-5 4 kV, 10/700, class 5, long distance balanced circuits surge
survival with a 400 V primary protector 10 Ω
series resistor for IEC 6100-4-5 1.2/50-8/20 combination generator, classes 0 to 5 (500 V to
4 kV maximum), short distance balanced circuits surge survival. 0Ω
Parameter Test Conditions Min Typ Max Unit
IDOff-state current V D=V
DRM , VGK =0 TJ= 25 °C-5µA
TJ=85°C-50µA
VGK(BO) Gate-cathode impulse
breakover voltage
VGG =-48V, C
G= 220 nF
10/700, ITM =-30A, R
S=10Ω
1.2/50, ITM =-30A, R
S=10Ω
2/10, ITM =-38A, R
S=62Ω,
7
10
25
V
VFForward voltage IF=5A, t
w= 500 µs2V
VFRM Peak forward recovery
voltage
10/700, IF=30A, R
S=10Ω
1.2/50, IF=30A, R
S=10Ω
2/10, IF=38A, R
S=62Ω,
5
7
12
V
IHHolding current IT= -1 A, di/dt = 1A/ms, V GG = -100 V -150 mA
IGKS Gate reverse current VGG =V
GK =V
GKRM, VKA =0 TJ= 25 °C-5µA
TJ=85 °C-50µA
IGT Gate trigger current IT=-3A, t
p(g) ≥20 µs, VGG = -100 V 3.0 mA
VGT Gate-cathode trigger
voltage IT=-3A, t
p(g) ≥20 µs, VGG = -100 V 2.0 V
CKA Cathode-anode off-
state capacitance f=1MHz, V
d=1V, I
G= 0, (see Note 4) VD= -3 V 100 pF
VD=-48V 50 pF
NOTE 4: These capacitance measurements employ a three terminal capacitance bridge incorporating a guard circuit. The unmeasured
device terminals are a.c. connected to the guard terminal of the bridge.
APRIL 2001 REVISED JULY 2008
Specifications are subject to change without notice.
Customers should verify actual device performance in their specific applications.
Parameter Measurement Information
TISP61521 SLIC Protector
Thermal Characteristics
Figure 1. Voltage-Current Characteristic
Unless Otherwise Noted, All Voltages are Referenced to the Anode
-v
IS
VS
VGG VD
IH
IT
VT
ITSM
ITSP
V(BO)
I(BO)
ID
Quadrant I
Forward
Conduction
Characteristic
+v
+i
IF
VF
IFSM (= |ITSM|)
IFSP (= |
I
TSP|)
-i
Quadrant III
Switching
Characteristic PM6XAAA
VGK(BO)
Parameter Test Conditions Min Typ Max Unit
RθJA Junction to free air thermal resistance TA = 25 °C, EIA/JESD51-3 PCB, EIA/JESD51-
2 environment, PTOT = 1.7 W170 °C/W
APRIL 2001 REVISED JULY 2008
Specifications are subject to change without notice.
Customers should verify actual device performance in their specific applications.
TISP61521 SLIC Protector
Thermal Information
Figure 2. Non-Repetitive Peak On-State Current against Duration
PEAK NON-RECURRING AC
vs
CURRENT DURATION
t — Current Duration — s
0.01 0.1 1 10 100 1000
I
TSM
— Peak Non-Recurrent 50 Hz Current — A
0.5
0.6
0.7
0.8
1.5
2
3
4
5
6
7
8
15
20
1
10
V
GG
= -60 V
V
GG
= -80 V
V
GG
= -100 V
V
GG
= -120 V
RING AND TIP TERMINALS:
Equal I
TSM
values applied
simultaneously
GROUND TERMINAL:
Current twice I
TSM
value
EIA / JEDSD51
Environment and
PCB, T
A
= 25 C°
TI61AF
APRIL 2001 REVISED JULY 2008
Specifications are subject to change without notice.
Customers should verify actual device performance in their specific applications.
TISP61521 SLIC Protector
Gated Protectors
This section covers three topics. First, it is explained why gated protectors are needed. Second, the voltage limiting action of the protector is
described. Third, an example application circuit is described.
Purpose of Gated Protectors
Fixed voltage thyristor overvoltage protectors have been used since the early 1980s to protect monolithic SLICs (Subscriber Line Interface
Circuits) against overvoltages on the telephone line caused by lightning, a.c. power contact and induction. As the SLIC was usually powered
from a fixed voltage negative supply rail, the limiting voltage of the protector could also be a fixed value. The TISP1072F3 is a typical example
of a fixed voltage SLIC protector.
SLICs have become more sophisticated. To minimize power consumption, some designs automatically adjust the driver supply voltage to a
value that is just sufficient to drive the required line current. For short lines, the supply voltage would be set low, but for long lines, a higher
supply voltage would be generated to drive sufficient line current. The optimum protection for this type of SLIC would be given by a protection
voltage which tracks the SLIC supply voltage. This can be achieved by connecting the protection thyristor gate to the SLIC VBATH supply,
Figure 3. This gated (programmable) protection arrangement minimizes the voltage stress on the SLIC, no matter what value of supply voltage.
APPLICATIONS INFORMATION
Figure 3. Negative Overvoltage Condition
C1
220 nF
IG
Th5
SLIC
VBAT
SLIC
PROTECTOR
TISP
61521
IK
AI6XABA
Th5
SLIC
VBAT
SLIC
PROTECTOR
TISP
61521
C1
220 nF
IF
AI6XACA
Figure 4. Positive Overvoltage Condition
Operation of Gated Protectors
Figure 3 and Figure 4 show how the TISP61521 limits negative and positive overvoltages. Positive overvoltages (Figure 4) are clipped by the
antiparallel diode of Th5 and the resulting current is diverted to ground. Negative overvoltages (Figure 3) are initially clipped close to the SLIC
negative supply rail value (VBATH). If sufficient current is available from the overvoltage, then Th5 will switch into a low voltage on-state
condition. As the overvoltage subsides, the high holding current of Th5 prevents d.c. latchup. The protection voltage will be the sum of the
gate supply (VBATH) and the peak gate-cathode voltage (VGK(BO)). The protection voltage will be increased if there is a long connection
between the gate decoupling capacitor, C1, and the gate terminal. During the initial rise of a fast impulse, the gate current (IG) is the same as
the cathode current (IK). Rates of 70 A/µs can cause inductive voltages of 0.7 V in 2.5 cm of printed wiring track. To minimize this inductive
voltage increase of protection voltage, the length of the capacitor to gate terminal tracking should be minimized. Inductive voltages in the
protector cathode wiring will also increase the protection voltage. These voltages can be minimized by routing the SLIC connection through
the protector as shown in Figure 6.
Figure 5, which has a 10 A/µs rate of impulse current rise, shows a positive gate charge (QGS) of about 0.1 µC. With the 0.1 µF gate
decoupling capacitor used, the increase in gate supply is about 1 V (= QGS/C1). This change is just visible on the -72 V gate voltage, VBATH.
But the voltage increase does not directly add to the protection voltage, as the supply voltage change reaches a maximum at 0.4 µs, when the
gate current reverses polarity, and the protection voltage peaks earlier at 0.3 µs. In Figure 5, the peak clamping voltage (V(BO)) is -77.5 V, an
increase of 5.5 V on the nominal gate supply voltage. This 5.5 V increase is the sum of the supply rail increase at that time, (0.5 V), and the
protection circuit’s cathode diode to supply rail breakover voltage (5 V). In practice, use of the recommended 220 nF gate decoupling capacitor
would give a supply rail increase of about 0.3 V and a V(BO) value of about -77.3 V.
APRIL 2001 REVISED JULY 2008
Specifications are subject to change without notice.
Customers should verify actual device performance in their specific applications.
TISP61521 SLIC Protector
Application Circuit
Figure 6 shows a typical TISP61521 SLIC card protection circuit. The incoming line conductors, Ring (R) and Tip (T), connect to the relay
matrix via the series overcurrent protection. Fusible resistors, fuses and positive temperature coefficient (PTC) resistors can be used for
overcurrent protection. Resistors will reduce the prospective current from the surge generator for both the TISP61521 and the ring/test
protector. The TISP7xxxF3 protector has the same protection voltage for any terminal pair. This protector is used when the ring generator
configuration may be ground or battery-backed. For dedicated ground-backed ringing generators, the TISP3xxxF3 gives better protection as
its inter-conductor protection voltage is twice the conductor to ground value.
Relay contacts 3a and 3b connect the line conductors to the SLIC via the TISP61521 protector. The protector gate reference voltage comes
from the SLIC negative supply (VBATH). A 220 nF gate capacitor sources the high gate current pulses caused by fast rising impulses.
Figure 5. Protector Fast Impulse Clamping and Switching Waveforms
Time - µs
0.0 0.5 1.0 1.5
Voltage - V
-80
-60
-40
-20
0
VK
Time - µs
0.0 0.5 1.0 1.5
Current - A
- A
-5
-4
-3
-2
-1
0
1
IK
IG
QGS
VBATH
AI6XDE
APRIL 2001 REVISED JULY 2008
Specifications are subject to change without notice.
Customers should verify actual device performance in their specific applications.
TISP61521 SLIC Protector
Figure 6. Typical Application Circuit
TEST
RELAY RING
RELAY SLIC
RELAY
TEST
EQUIP-
MENT RING
GENERATOR
S1a
S1b
RSA
RSB
RING
WIRE
TIP
WIRE Th1
Th2
Th3
Th4
Th5
SLIC
SLIC
PROTECTOR
RING/TEST
PROTECTION
OVER-
CURRENT
PROTECTION
S2a
S2b
TISP
61521
TISP
3xxxF3
OR
7xxxF3
S3a
S3b
VBAT
C1
220 n F
AI6XAA B
APRIL 2001 REVISED JULY 2008
Specifications are subject to change without notice.
Customers should verify actual device performance in their specific applications.
Devices will be coded as follows:
MECHANICAL DATA
TISP61521 SLIC Protector
Device Symbolization Code
Device Symbolization
Code
TISP61521DR-S 61521
“TISP” is a trademark of Bourns, Ltd., a Bourns Company, and is Registered in U.S. Patent and Trademark Office.
“Bourns” is a registered trademark of Bourns, Inc. in the U.S. and other countries.
