L3121B Datasheet, PDF (4/7 Pages) STMicroelectronics – PROGRAMMABLE TRANSIENT VOLTAGE SUPPRESSOR FOR SLIC PROTECTION

L3121B
REFERENCE TEST CIRCUIT FOR IBO and VBO parameters:
Auto
Transformer
2 2 0 V/ 2 A
t p = 20ms
R1
static
140
relay.
R2
240
Vout
K
IBO , IH
measure
D.U.T
V _BO
measure
Tr an s fo rm er
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.
FUNCTIONAL HOLDING CURRENT (I_H) TEST CIRCUIT = GO - NOGO TEST.
R
V_BAT = - 48 V
D.U.T.
- V_P
Surge generator
This is a GO-NOGO Test which allows to confirm the holding current (IH) level in a functional test circuit.
This test can be performed if the reference test circuit can’t be implemented.
TEST PROCEDURE :
1) Adjust the current level at the IH value by short circuiting the line and GND pins of the D.U.T.
2) Fire the D.U.T with a surge Current : Ipp = 10A , 10/1000 µs.
3) The D.U.T will come back to the OFF-State within a duration of 50 ms max.
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