AP32146
TC1782 Scalable Pads
Timing and Electromagnetic Emission
Table of Contents
1Preface ................................................................................................................................................5
2Introduction ........................................................................................................................................6
2.1 Pad driver scaling in detail...................................................................................................................6
2.2 Physical basics.....................................................................................................................................7
2.2.1 Load charging.......................................................................................................................................7
2.2.2 Signal integrity......................................................................................................................................8
2.2.3 Power integrity / Electromagnetic emission.......................................................................................12
3TC1782 test configuration...............................................................................................................14
4Specified timings .............................................................................................................................16
5Measured timings.............................................................................................................................17
5.1 Measurement conditions and naming conventions............................................................................17
5.2 Measured rise/fall times for Class A1 drivers.....................................................................................20
5.3 Measured rise/fall times for Class A1+ drivers...................................................................................21
5.4 Measured rise/fall times for Class A2 drivers.....................................................................................23
5.5 Rise/fall time diagrams for Class A1 drivers......................................................................................26
5.6 Rise/fall time diagrams for Class A1+ drivers....................................................................................27
5.7 Rise/fall time diagrams for Class A2 drivers......................................................................................29
5.8 Rise/fall time diagrams for increased capacitive loads......................................................................33
6Measured electromagnetic emission.............................................................................................37
6.1 Microcontroller operation mode..........................................................................................................37
6.2 Description of test equipment.............................................................................................................41
6.2.1 Conducted emission test configuration..............................................................................................41
6.2.2 Radiated emission test configuration.................................................................................................41
6.2.3 Measurement settings........................................................................................................................42
6.3 Emission test result discussion..........................................................................................................43
7Recommended pad driver settings................................................................................................51
7.1 Signal categories................................................................................................................................51
7.2 Decision tables and diagrams............................................................................................................52
7.2.1 Decision table for pad class A2..........................................................................................................55
7.2.2 Decision table for pad class A1+........................................................................................................57
7.2.3 Decision table for pad class A1..........................................................................................................59
7.2.4 Decision diagrams for pad class A2...................................................................................................60
7.2.5 Decision diagrams for pad class A1+.................................................................................................65
7.2.6 Decision diagrams for pad class A1...................................................................................................70
7.2.7 Decision diagrams for weak driver at high capacitive load................................................................75
7.2.8 Decision diagrams for medium driver at high capacitive load............................................................80
8Pad Scaling Calculator (PASTOR)..................................................................................................85
8.1 Scope of the software ........................................................................................................................85
8.2 How to use PASTOR .........................................................................................................................85
8.3 PASTOR screenshots........................................................................................................................86
Annex A: Measured rise/fall waveforms............................................................................................................90
Annex B: Glossary.............................................................................................................................................150
Application Note 4 V1.0, 2010-01
