Page 1
L3121B
ApplicationSpecific Discretes
A.S.D.
FEATURES
BIDIRECTIONALFUNCTIONWITH VOLTAGE
PROGRAMMABILITYIN BOTH POSITIVEAND
NEGATIVEPOLARITIES.
PROGRAMMABLE BREAKDOWN VOLTAGE
UP TO100 V.
HOLDINGCURRENT = 150mA min.
HIGHSURGE CURRENTCAPABILITY.
IPP= 100A, 10/1000µs
DESCRIPTION
This device has been especially designed to protect a subscriber line interface circuit (SLIC) with
anintegratedring generator.
Used with the recommended application circuit,
eachline(TIPand RING)is protectedagainstpositive and negative surges. In the positive polarity,
the breakdownvoltage is referenced to the + VB ,
andinthe negativepolarity,the breakdownvoltage
isreferencedto the -Vbat .
TM
PROGRAMMABLE TRANSIENT VOLTAGE
SUPPRESSORFOR SLIC PROTECTION
SIP4
SCHEMATIC DIAGRAM
Line
Gate P
Gate N
Itshigh surgecurrentcapabilitymakesthe L3121B
areliableprotectiondevicefor veryexposedequipment,or when series resistorsare very low.
May 1999 - Ed:4A
GND
CONNECTION DIAGRAM
1/7
Page 2
L3121B
COMPLIESWITHTHE
Peak Surge
FOLLOWING STANDARDS:
ITU-T K20
VDE0433
VDE0878
IEC1000-4-5
FCC Part 68, lightning surge
type A
FCC Part 68, lightning surge
type B
BELLCORE TR-NWT-001089
First level
BELLCORE TR-NWT-001089
Second level
ABSOLUTE MAXIMUM RATINGS
Voltage
(V)
4000 10/700 5/310 100 4000 10/700 5/310 100 4000 1.2/50 1/20 100 -
level4
level4
1500
800
1000 9/720 5/320 25 2500
1000
5000 2/10 2/10 250 10
(Tamb= 25°C)
Voltage
Waveform
(µs)
10/700
1.2/50
10/160
10/560
2/10
10/1000
Current
Waveform
(µs)
5/310
8/20
10/160
10/560
2/10
10/1000
Admissible
Ipp
(A)
100
100
200
100
250
100
Necessary
Resistor
(Ω)
Symbol Parameter Value Unit
I
PP
I
TSM
V
MLG
V
MGL
T
stg
T
j
T
L
Top
Note 1: Variation ofelectrical parameters is given by curves.
Peak pulse current
Non repetitive surge peak on-state
current
Maximum voltage LINE/GND.
Maximum voltage GATE/LINE.
Storage temperature range
Maximum operating junction temperature
Maximum lead temperature for soldering during 10s
Operating temperature range (see note 1)
10/1000µs
2/10µs
100
250
tp = 10 ms 50 A
100
80
- 40 to +150
+ 150
260 °C
-40to+85 °C
-
-
-
-
-
-
A
V
V
°
C
°C
Pulsewaveform10/1000µs
%I
PP
100
50
0
t
r
t
p
THERMAL RESISTANCE
Symbol Parameter Value Unit
Junction-to-ambient
2/7
R
th (j-a)
t
80 °C/W
Page 3
L3121B
ELECTRICALCHARACTERISTICS
Symbol Parameter
V
RM
I
RM
V
BR
V
BO
I
H
I
BO
I
PP
V
GN
I
GN,IGP
C
Stand-off voltage
Reverseleakagecurrent
Breakdown voltage
Breakover voltage
Holding current
Breakover current
Peak pulse current
Gate voltage
Triggeringgate current
Capacitance
1- OPERATIONWITHOUT GATE
I
RM
Type
max. min. max. typ. max. min. max.
(T
@V
amb
RM
=25°C)
VBR@I
R
I
IPP
I
BO
IH
V
BO
@I
BO
I
note1 note 1 note2
VRM
VBO
VBR
H
C
µA V V mA V mA mA mA pF
L3121B
5
8
60
90
2- OPERATIONWITH GATE
@IGN= 200mA IGN@VAC= 60V IGP@VAC= 60V
V
GN
Type
min. max. min. max. max.
V V mA mA mA
L3121B
Note 1 :
See the reference testcircuits for IH,IBOand VBOparameters.
Note 2 :VR= 5 V, F = 1MHz.
0.6 1.8 80 200 180
100 1 180 200 500 150 200
3/7
Page 4
L3121B
REFERENCETEST CIRCUIT FOR IBOand VBOparameters:
tp=20ms
Auto
Transformer
220V/2A
220V
Transformer
220V/800V
5A
TESTPROCEDURE:
PulseTest duration (tp = 20ms):
- For Bidirectionaldevices= SwitchK is closed
- For Unidirectionaldevices= SwitchK isopen.
V
Selection
OUT
- Device with V
-V
- Devicewith V
-V
BO
OUT
BO
OUT
< 200 Volt
= 250V
≥
200 Volt
=480 V
,R1=140 Ω.
RMS
RMS,R2
static
relay.
V
out
= 240 Ω.
K
I,I
BO H
measure
R1
140
R2
240
D.U.T
V
BO
measure
FUNCTIONALHOLDING CURRENT (IH) TEST CIRCUIT= GO- NOGOTEST.
R
D.U.T.
V
= - 48 V
BAT
This isa GO-NOGO Test which allows to confirm the holding current (IH)level in a functionaltest circuit.
This testcan be performed ifthe referencetest circuitcan’t be implemented.
TEST PROCEDURE :
1) Adjust the currentlevel at the IH value by short circuiting the line andGND pinsof the D.U.T.
2) Fire the D.U.T with a surgeCurrent : Ipp = 10A , 10/1000µs.
3) The D.U.T will come back to the OFF-State within a duration of 50 ms max.
-V
P
Surge generator
4/7
Page 5
L3121B
Fig. 1:
Surge peak current versus overload
duration(typicalvalues).
I (A)TSM
40
35
30
25
20
15
10
5
0
1E-2 1E-1 1E+0 1E+1 1E+2 1E+3
Fig. 3:
t(s)
Typical relative variation of breakdown
F=50H z
Tj initial=25°C
voltageversusambient temperature.
V[T]
BR amb
BR amb
V[T =25°C]
2.04
I=1mAR
2.00
Fig. 2:
Typical relative variation of holding current
versusambienttemperature.
H amb
I[T ]
H amb
I[T =25°C]
1.45
1.30
1.15
1.0
0.85
T(°C)amb
0.70
-40 -20 0 20 40 60 80 85
Fig. 4:
Junction capacitance versus reverse
appliedvoltage.
1.06
1.02
0.98
0.94
0.90
Fig.5:
-40 -20 0 20 40 60 80
Typicalrelative variationof leakagecurrent
T(°C)amb
versusambienttemperature.
IR[Tj] / IR [Tj=25°C]
1E+5
1E+4
1E+3
1E+2
1E+1
Tj(°C)
1E+0
25 50 75 100 125
85
Fig. 6:
Typical relative variation of peak pulse
current(10/1000µs) versusambient temperature.
Ipp[Tamb] / Ipp [25°C]
1.10
1.05
1.00
0.95
Tamb(°C)
0.90
-40 -30 -20 -10 0 10 20 30 40 50 60 70 80
5/7
Page 6
L3121B
TypicalSlic ProtectionConcept.
LINE
-Vbat
LINE
R1
GND
R2
G
G
N
N
L3121B
L3121B
G
G
P
P
R3
220nF
220nF
R4
+VB
-Vbat
TIP
SLIC
L3000N
RING
GND
+VB
ORDERCODE
L3121B
DEVICECODE
MARKING : Logo, Date Code, PartNumber
6/7
Page 7
PACKAGEMECHANICAL DATA
SIP4(Plastic)
REF.
L3121B
DIMENSIONS
Millimetres Inches
B
C
Min. Typ. Max. Min. Typ. Max.
A 7.10 0.280
a1 2.80 0.110
I
A
B 10.15 0.400
b1 0.50 0.020
a1
b1
b2
Z
e
L
c1
c2
e3
b2 1.35 1.75 0.053 0.069
C 3.18 3.43 0.125 0.135
c1 0.38 0.50 0.015 0.020
c2 1.30 0.051
e 2.54 0.100
e3 7.62 0.200
I 10.50 0.413
L 3.30 0.130
Z 1.50 0.059
Ordrecode Marking Package Weight Base qty Deliverymode
L3121B SIP4 0.55g
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