TIDUEB8C July   2018  – March 2021 TPS274160

 

  1.   Description
  2.   Resources
  3.   Features
  4.   Applications
  5.   5
  6. 1System Description
    1. 1.1 Key System Specifications
  7. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Highlighted Products
      1. 2.2.1 LM5165
      2. 2.2.2 TLC59282
      3. 2.2.3 TPS4H160-Q1
      4. 2.2.4 INA253
      5. 2.2.5 TIOL111
    3. 2.3 System Design Theory
      1. 2.3.1 IO-Link PHY
      2. 2.3.2 Current Sink
      3. 2.3.3 Power Supply for L+
      4. 2.3.4 Power Supply
      5. 2.3.5 Pinouts
    4. 2.4 Software Frame Handler
      1. 2.4.1 PRU-ICSS IO-Link Frame-Handler
        1. 2.4.1.1 Performance Advantages and Benefits
        2. 2.4.1.2 Principle of Operation
  8. 3Hardware, Software, Testing Requirements, and Test Results
    1. 3.1 Required Hardware and Software
      1. 3.1.1 Hardware
      2. 3.1.2 Software
    2. 3.2 Testing and Results
      1. 3.2.1 Test Setup
      2. 3.2.2 Test Results
        1. 3.2.2.1 IO-Link Wake-Up Pulse
        2. 3.2.2.2 L+ Turnon Behavior
        3. 3.2.2.3 Current Sink on CQ
        4. 3.2.2.4 Residue Voltage
        5. 3.2.2.5 IO-Link Physical Layer Test Summary
        6. 3.2.2.6 Current Sense on Each Port
        7. 3.2.2.7 TPS4H160 Thermal Behavior
  9. 4Design Files
    1. 4.1 Schematics
    2. 4.2 Bill of Materials
    3. 4.3 PCB Layout Recommendations
      1. 4.3.1 Layout Prints
    4. 4.4 Altium Project
    5. 4.5 Gerber Files
    6. 4.6 Assembly Drawings
  10. 5Software Files
  11. 6Related Documentation
    1. 6.1 Trademarks
  12. 7About the Author
  13. 8Revision History

2.3.1 IO-Link PHY

The TIOL111 device used here has the main purpose to shift levels between the 3.3-V logic side and the 24-V interface. The optional internal LDO, the wake up detection and overcurrent detection is not used.

However, the TIOL111 device in master configuration has to be able to drive an IO-Link conform wake-up pulse. IO-Link devices start up in SIO mode and have to be configured to IO-Link prior to communication. So, the output is either on a low (around 0 V) or high level (around 24 V) and is driven. To switch the mode, the master has to send a pulse of 80-µs length and must be able to drive 500 mA during this pulse and still reach a certain voltage. The device will switch to IO-Link mode after detection of this pulse and communication can begin.

The exact parameters for testing this are listed in the IO-Link® Test Specification, Version 1.1.2, see Table 2-1 and Table 2-2. Both parts of the specification have to be met to be compliant.

Table 2-1 Wake-Up Pulse Test Specification High Pulse
TEST CASE ATTRIBUTESIDENTIFICATION, REFERENCE
Identification (ID)SDCI_TC_0021
NameTCM_PHYL_INTF_IQWUH
Purpose (short)Driver capability of the wake-up pulse – high-side driver
Equipment under test (EUT)Master and Legacy Master
Test case version1.0
Category, typeMaster protocol test; test to pass (positive testing)
Specification (clause)See Section 5.3.3.3, Table 9 of IO-Link Interface and System Specification Version 1.1.22
Configuration, setup  –
TEST CASECONDITIONS, PERFORMANCE
Purpose (detailed)The Master shall drive the resistive load above the threshold high level of a receiver. Measure pulse voltage at Master C/Q port with Master configured for SDCI. The pulse voltage is measured with a resistive load applied between C/Q and L–.
PreconditionMaster configured to SDCI mode
Procedure  a) Apply minimum supply voltage (VSM = 20 V) to Master
  b) Apply resistive load Rload between C/Q and L–:
      Rload = VTHHMmax / IQPKHMmin = 26 Ohm (51 Ohm shunted by 51 Ohm) 
  c) Trigger on wake-up request
  d) Measure voltage at C/Q port during wake-up request 
  e) Check if VIM is exceeding VTHHMmax 
  f) Repeat test with maximum supply voltage (VSM = 30 V)
Input parameter  –
Post condition  –
TEST CASE RESULTSCHECK, REACTION
Evaluation  –
Test passedLevel at C/Q during wake-up request greater than or equal VTHHMmax
Test failed (examples)Level at C/Q during wake-up request less thanl VTHHMmax
ResultsVIM@WURQ (VSM = 18 V): <value>
VIM@WURQ (VSM = 30 V): <value>
Table 2-2 Wake-Up Pulse Test Specification Low Pulse
TEST CASE ATTRIBUTESIDENTIFICATION, REFERENCE
Identification (ID)SDCI_TC_0023
NameTCM_PHYL_INTF_IQWUL
Purpose (short)Driver capability of the wake-up pulse – low-side driver
Equipment under test (EUT)Master and Legacy Master
Test case version1.0
Category, typeMaster protocol test; test to pass (positive testing)
Specification (clause)See Section 5.3.3.3, Table 9 of IO-Link Interface and System Specification Version 1.1.22
Configuration, setup  –
TEST CASECONDITIONS, PERFORMANCE
Purpose (detailed)The Master shall drive the resistive load below the threshold low level of a receiver. Measure pulse voltage at Master C/Q port with Master configured for SDCI. The pulse voltage is measured with a resistive load applied between C/Q and L+.
PreconditionMaster configured to SDCI mode
Procedure  a) Apply minimum supply voltage (VSM = 20 V) to Master
  b) Apply resistive load Rload between C/Q and L+:
      Rload = (VSM – VTHLMmin) / IQPKLMmin = 24 Ohm (47 Ohm shunted by 51 Ohm) 
  c) Trigger on wake-up request
  d) Measure voltage at C/Q port during wake-up request 
  e) Check if VIM is below VTHLMmin 
  f) Repeat test with maximum supply voltage (VSM = 30 V) to Master:
     Rload = 44 Ohm (82 Ohm shunted by 100 Ohm)
Input parameter  –
Post condition  –
TEST CASE RESULTSCHECK, REACTION
Evaluation  –
Test passedLevel at C/Q during wake-up request less than or equal VTHLMmin
Test failed (examples)Level at C/Q during wake-up request greater thanl VTHLMmin
ResultsVIM@WURQ (VSM = 20 V): <value>
VIM@WURQ (VSM = 30 V): <value>

Prior to design, it is verified that the TIOL111 device can generate the wake-up pulse. In Figure 2-7 one of the four test options is shown. In this case, the high-side driver is tested with VCC at 30 V. CQ is loaded with a 26-Ω resistor, here the CQ line reaches almost 30 V and the CQ current is larger than 500 mA. So this meets the requirements.

GUID-B61BC7A8-CA92-4474-952C-CAB4F92B94ED-low.pngFigure 2-7 Test Results of TIOL111 Device Wake-Up Pulse

By design, the TIOL111 device is able to deliver the current necessary for the wake-up pulse, so it can be used as a master PHY.