february 2011 doc id 14923 rev 1 1/25 AN2813 application note tde1708dft in io-link applications 1 introduction 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 (ill m ) is fixed to 10 ma which represents the average master current sink value specified for a 3-wire system. the master (cq m ), slave (cq l ), and line capacitances are set together at 4.7 nf, corresponding to the maximum parasitic capacitance of the system. s l a v e m a s t e r l i n e o n o f f , , n # 1 ! - # 1 3 # 1 3 # 1 - # 1 - ) , , - ) , , - s l a v e m a s t e r l i n e , , n # 1 o n o f f o n o f f p
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contents AN2813 2/25 doc id 14923 rev 1 contents 1 introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2 tde1708dft in high-side configuration . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.1 high-side configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.2 high-side configuration with a capacitive load . . . . . . . . . . . . . . . . . . . . . . 7 3 tde1708dft in low-side configuration . . . . . . . . . . . . . . . . . . . . . . . . . . 9 3.1 low-side configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 3.2 low-side configuration with a capacitive load . . . . . . . . . . . . . . . . . . . . . 11 4 push-pull configuration with tde1708dft . . . . . . . . . . . . . . . . . . . . . . 13 5 performance characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 5.1 dynamic information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 5.2 temperature characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 6 alternative driving . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 6.1 temperature characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 7 conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 8 references . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 9 revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
AN2813 list of tables doc id 14923 rev 1 3/25 list of tables table 1. push-pull configuration dynamic information (v cc = 24 v; t j = 25 c; c l = 4.7 nf) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 table 2. dynamic information (v cc = 24 v; t j = 25 c; i l = 10 ma) . . . . . . . . . . . . . . . . . . . . . . . . 18 table 3. document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
list of figures AN2813 4/25 doc id 14923 rev 1 list of figures figure 1. p-switching slave drive and p-switching with n-switching slave drive. . . . . . . . . . . . . . . . . . 1 figure 2. high-side switch test configuration schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 figure 3. high-side switch configuration turn-on behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 figure 4. high-side switch configuration turn-off behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 figure 5. high-side switch test configuration schematic with a capacitive load . . . . . . . . . . . . . . . . . . 7 figure 6. high-side switch configuration with a capacitive load turn-on behavior . . . . . . . . . . . . . . . . 8 figure 7. high-side switch configuration with a capacitive load turn-off behavior . . . . . . . . . . . . . . . . 8 figure 8. low-side switch test configuration schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 figure 9. low-side switch configuration turn-on behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 figure 10. low-side switch configuration turn-off behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 figure 11. low-side switch test configuration schematic with a capacitive load . . . . . . . . . . . . . . . . . 11 figure 12. low-side switch configuration with a capacitive load turn-on behavior . . . . . . . . . . . . . . . 12 figure 13. low-side switch configuration with capacitive load turn-off behavior . . . . . . . . . . . . . . . . . 12 figure 14. push-pull test configuration schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 figure 15. push-pull configuration with capacitive load rising edge . . . . . . . . . . . . . . . . . . . . . . . . . . 15 figure 16. push-pull configuration with capacitive load falling edge . . . . . . . . . . . . . . . . . . . . . . . . . . 16 figure 17. software timing example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 figure 18. propagation turn-on time vs. temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 figure 19. propagation turn-off time vs. temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 8 figure 20. alternative driving schematics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 figure 21. alternative driving timings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 figure 22. delay propagation turn-on time vs. temperature (h. s. configuration) . . . . . . . . . . . . . . . . 22 figure 23. delay propagation turn-on time vs. temperature (l. s. configuration) . . . . . . . . . . . . . . . . 22 figure 24. propagation turn-off time vs. temperature (h. s. configuration) . . . . . . . . . . . . . . . . . . . . . 23 figure 25. propagation turn-off time vs. temperature (l. s. configuration) . . . . . . . . . . . . . . . . . . . . . 23
AN2813 tde1708dft in high-side configuration doc id 14923 rev 1 5/25 2 tde1708dft in high-side configuration 2.1 high-side configuration figure 2. high-side switch test configuration schematic , % $ $ 2 ) 6 % 2 ( 3 / 5 4 $ % , ! 9 ' . $ ) . 6 2 % ' 6 6 s , 3 / 5 4 5 4 $ % $ & |