Contents
1.
Introduction ...................................................................................................................................................................................................2
Key Points for Optimal Layout .............................................................................................................................................................2
2.
Tx Power Circuits .........................................................................................................................................................................................3
Resonance Capacitors ........................................................................................................................................................................8
Sensitive Circuits ...............................................................................................................................................................................10
5V Step Down Switching Regulator ...................................................................................................................................................12
Flash Circuit .......................................................................................................................................................................................13
3.
PCB Footprint Design .................................................................................................................................................................................14
4.
Audible Noise Suppression ........................................................................................................................................................................15
5.
6.
Revision History ..........................................................................................................................................................................................22
List of Figures
Figure 7. Resonance Capacitors ........................................................................................................................................................................8
Figure 12. Flash Circuit .......................................................................................................................................................................................13
Figure 14. Application Schematic .......................................................................................................................................................................16
Figure 15. Silkscreen - Top of Board .................................................................................................................................................................19
Figure 16. Copper - Top Layer ...........................................................................................................................................................................19
Figure 17. Copper L1 Layer ................................................................................................................................................................................20
Figure 18. Copper L2 Layer ................................................................................................................................................................................20
Figure 19. Copper Bottom ..................................................................................................................................................................................21
© 2019 Integrated Device Technology, Inc.
P9235A-RB Layout Guide
1
March 19, 2019