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.

Features
■ 4 channel topology
■ Wide range input dc Voltage:
    – VI= - 0.3 to 30 V with RI = 0
    – VI = - 30 to 30 V with RI = 1.8 kΩ
    – Low side configuration with common ground
■ Current limiter:
    – IGEN = 3 mA
    – Input current limiter activation voltage < 5 V
    – Temperature compensated operation
■ Opto-coupler drive:
    – No coupler activation below 1.5 mA input current
■ Input protection (RI = 1.2 kΩ):
    – IEC 61000-4-2 electrostatic discharge ESD, Class 3
        In contact, ± 6 kV; in air, ± 8 kV
        Level B: temporary disruption; no change of opto-coupler state
    – IEC 61000-4-5 voltage surge, Class 3
        ± 1000 V with 42 Ω serial resistor in differential mode
        Level B: temporary disruption
    – IEC 61000-4-4 transient burst immunity
        ± 4 kV peak voltage; 5 kHz repetitive rate
        Level A: fully functional
■ Operating ambient temperature: - 25 to 85° C

Benefits
■ Reduced overall dissipation
■ Compact with high integration
■ Enables input to meet type 1 and 3 characteristic of IEC 61131-2 standard
■ Compatible operation with 2 and 3 wires proximity sensor according EN60947-5-2 standard
■ Insensitive to the on state sensor impedance
■ Surface mount package for highly automated assembly
■ Enhanced functional reliability

Applications
■ Industrial automation
■ Programmable logic controller
■ Communication field bus nodes
■ Peripheral input / output modules
■ Machine tool interface