This application note investigates the possibility of using a TDE1708DFT switch for the physical layer transmitter realization of 3-wire IO-Link sensors. The TDE1708DFT is an integrated power switch especially dedicated to proximity detectors. It can deliver up to 250 mA, enables high-side and low-side configurations and includes a number of protections. According to the IO-Link Communication Specification (see Section 8: References -3. and for the TDE1708DFT features - see Section 8: References - 1.) two basic slave transmitter configurations were tested (see Figure 1): p-switching (high-side) driver p-switching driver with an additional n-switching (low-side) driver (push-pull operation). Figure 1. P-switching slave drive and p-switching with n-switching slave drive In the following test arrangements the input load current (ILLM) is fixed to 10 mA which represents the average master current sink value specified for a 3-wire system. The master (CQM), slave (CQL), and line capacitances are set together at 4.7 nF, corresponding to the maximum parasitic capacitance of the system.
This document investigates the feasibility of using the TDE1708DFT integrated power switch for the physical layer transmitter realization of 3-wire IO-Link sensors. The TDE1708DFT is an integrated power switch especially dedicated to proximity detectors that can deliver up to 250 mA and includes various protection features.
The note details test arrangements for two basic slave transmitter configurations: p-switching (high-side) driver and p-switching with an additional n-switching (low-side) driver (push-pull operation). It analyzes performance characteristics, including dynamic information and temperature effects, and provides alternative driving schematics to manage propagation time drift in push-pull configurations.
The TDE1708DFT can deliver up to 250 mA.
The device supports COM1 (4.8 kBaud) for p-switching and up to COM2 (38.4 kBaud) for push-pull configurations.