CLT3-4B Datasheet, PDF (4/13 Pages) STMicroelectronics – Current limited over-voltage protected quad digital termination

Characteristics
CLT3-4B
Table 5.
Symbol
CLT3 System electromagnetic compatibility ratings,
R_I = 1.8 kΩ, R_C = 4.7 kΩ (unless otherwise specified)
Node
Parameter name and conditions
Value Unit
ESD protection, IEC 61000-4-2, per input, in air
±8
kV
ESD protection, IEC 61000-4-2, per input, in contact
V_PP
IN
ESD protection, IEC 61000-4-2, per input, in air, R_I = 0 Ω
±6
kV
±3
kV
ESD protection, IEC 61000-4-2, per input, in contact, R_I = 0 Ω ± 3
kV
V_PPB
V_PP
V_PP
V_I
Total Peak Pulse Voltage Burst, IEC 61000-4-4
C_IN = 100 pF, C_OUT = 22 nF, F = 5 kHz ⁽¹⁾
V_I Peak Pulse Voltage Surge, IEC 61000-4-5, R = 42 Ω ⁽²⁾
V_CC Peak Pulse Voltage Surge, IEC 61000-4-5, R = 2 Ω ⁽²⁾
±4
kV
±1
kV
±1
kV
1. Refer to Application note AN2527 for test conditions.
2. See test circuit in Figure 12.
Figure 3.
Typical junction to ambient thermal resistance versus copper surface
under common pad (FR4 epoxy, copper thickness is 35 µm)
Rth(j-a)(° C/W)
160
140
120
100
80
60
40
20
S(cm²)
0
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
1.1
Functional description
The CLT3-4 is a quadruple input digital termination device designed for 24 V DC automation
applications. It provides the front-end circuitry of a digital input module (I/O) in industrial
automation, and drives an isolating opto-coupler.
Available in a four channels configuration, it offers a high-density termination by minimizing
the external components count. It is housed in a TSSOP20 surface mount package to
reduce the printed board size.
Made of an input voltage protection, a serial current limiting circuit and an opto-coupler
driver, each channel circuit terminates the connection between the logic input and the
associated high side sensor or switch.
The CLT3-4 is a 3 mA quad channel device compatible the type 1 and 3 characteristics of
the IEC 61131-2 standard.
Each input voltage clamping block protects the module input against electromagnetic
interferences such as those described in the IEC 61131-2 standard and IEC 61000-4-2
(ESD), 4-4 (transient burst), 4-5 (voltage surge) standards. The supply input is also
designed with such a protection structure.
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