P9235A-RB Layout Guide
© 2019 Integrated Device Technology, Inc.
1
March 19, 2019
Contents
1.
Introduction ...................................................................................................................................................................................................2
Key Points for Optimal Layout .............................................................................................................................................................2
2.
Tx Power Circuits .........................................................................................................................................................................................3
Resonance Capacitors ........................................................................................................................................................................8
VCC5V V
IN
, VCC5V, LDO33, LDO18, VBRG_IN, PE Circuit and DRV_VIN Pin Capacitors ...............................................................9
Sensitive Circuits ...............................................................................................................................................................................10
Boost Capacitors and Gate Drive Lines.............................................................................................................................................11
5V Step Down Switching Regulator ...................................................................................................................................................12
Flash Circuit .......................................................................................................................................................................................13
3.
PCB Footprint Design .................................................................................................................................................................................14
4.
Audible Noise Suppression ........................................................................................................................................................................15
5.
Schematics, Bill of Materials (BOM), and Board Layout .............................................................................................................................16
6.
Revision History ..........................................................................................................................................................................................22
List of Figures
Figure 1.
Schematic with Main Power Path (Orange) and Main (Noisy) AC Power Loops (Red) .......................................................................3
Figure 2.
Recommended Orientation for the P9235A-RB and Generic Placement Guide for Select Critical Components ................................4
Figure 3.
Actual Placement for the P9235A-RB EVK. Select Critical Components are circled in Yellow ...........................................................5
Figure 4.
P9235A-RB Physical Layout from P9235A-RB-EVK Evaluation Board (2nd Layer (L1)) ....................................................................6
Figure 5.
P9235A-RB Physical Layout from P9235A-RB-EVK Evaluation Board (3rd Layer (L2)) .....................................................................6
Figure 6.
P9235A-RB Physical Layout from Demo PCB of Bottom Layer ..........................................................................................................7
Figure 7.
Resonance Capacitors ........................................................................................................................................................................8
Figure 8.
V
IN
, VCC5V, LDO33, LDO18, VBRG_IN, and DRV_VIN Pin Capacitors Placed Close to P9235A-RB with 0.1µF Placed Closest ..9
Figure 9.
P9235A-RB Typical GND Noise Areas and Sensitive Circuit Placement ..........................................................................................10
Figure 10.
Boost Capacitors and Gate Drive Lines.............................................................................................................................................11
Figure 11.
5V Step Down Switching Regulator ...................................................................................................................................................12
Figure 12.
Flash Circuit .......................................................................................................................................................................................13
Figure 13.
P9235A-RB Recommended PCB Land Pattern Drawing ..................................................................................................................14
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
