CLT3-4B datasheet(5/13 Pages) STMICROELECTRONICS

5 / 13 page

CLT3-4B

Characteristics

5/13

The current limiting circuit connected between the input and the output pins is compensated

all over the temperature range. Thanks to its low tolerance, the current limitation allows

reducing drastically the dissipation of the input compared to a resistive input: the overall

module requires less cooling capability and becomes smaller.

The output block of each termination channel controls the operation of an opto-coupler that

is enabled by a Light Emitting Diode.

When the input current is less than 1.5 mA, this output circuit derivates the input current to

maintain the opto-coupler off.

The original structure of the CLT limiter allows its activation threshold to be low and

insensitive to the output voltage up to a maximum value of 2.0 V.

When the CLT input voltage VIN is higher than 5 V, or the module input voltage Vi higher

than 11 V and a series resistor RI = 1.2 kΩ, the output current that is a share of the input

current (3/4) is higher than 1.5 mA. The whole termination channel including the opto-

coupler is on.

Depending on the input type operation that is described by the IEC 61131-2 standard, the

input resistance RI can be adjusted because of the different on-state threshold VON MIN.

This document describes operation and characteristics for type 3 operation with

VON MIN = 11 V and RI = 1.2 kΩ.

In type 1 operation the on state threshold VON MIN is 12.34 V instead, and the input resistor

RI is set 2.2 kΩ.

1.2

Input characteristics of CLT3-4

Figure 4.

Typical input characteristics of each CLT3-4 channel

3.7

0.5

1.5

2.5

3.5

V (V)

I (mA)

Off-state

On-state

CLT3-4B 数据表(PDF) 5 Page - STMicroelectronics

CLT3-4B 数据表(HTML) 5 Page - STMicroelectronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13

数据表下载