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Texas Instruments APA100 manual PCB Layout, 2.1.1Split Ground Plane

Models: APA100

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2.1 PCB Layout

PCB Layout

2.1 PCB Layout

The critical part of the design lies particularly in the layout process. The EVM layout should be followed exactly for optimal performance. The main concern is the placement of components and the proper routing of signals. Place the bypass/decoupling capacitors as close as possible to the pins; properly separate the linear and switching signals from each other. Because of its importance, carefully consider the ground plane in the layout process. A split ground plane is ideally preferred.

2.1.1Split Ground Plane

The split plane used in the EVM separates the ground plane for the H−bridge and a separate plane for everything else. The ground plane plays an important role in controlling the noise and other effects that contribute to distortion and noise on the output. To ensure that the return currents are handled properly, route the appropriate signals only in their respective sections; this means that the analog traces should only lay directly above or below the analog ground section and the H-bridge traces in the H-bridge ground section. Minimize the length of the traces. Figure 2−1 shows the top layer labeled with Analog Section and H-Bridge Section to demonstrate how the board is split. The bottom layer is split along the same line, as shown in Figure 2−2.

Figure 2−1. APA100 Split Plane Top Layout

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Texas Instruments APA100 manual PCB Layout, 2.1.1Split Ground Plane

Contents

Audio Power Amplifiers User’s GuideAPA100 AugustIMPORTANT NOTICE ProductsApplications How to Use This Manual Read This FirstAbout This Manual Information About Cautions and WarningsRelated Documentation From Texas Instruments FCC WarningData Sheets This is an example of a warning statementContents Figures TablesEVM Overview ChapterPage Topic1.1 Features 1.2 Power Requirements1.2.1Supply Voltage 1.3 EVM Basic Function/Block Diagram EVM Basic Function/Block DiagramEVM Overview EVM Basic Function/Block Diagram FeedbackIntegrator TLV2464PCB Design SchematicChapter Page2.1 PCB Layout 2.1.1Split Ground Plane2.1.2H-BridgeLayout 2.1.3Analog Section LayoutFigure 2−2. APA100 Split Plane Bottom Layout 2.1.4PCB Layers Figure 2−3. Top Copper and SilkscreenFigure 2−4. Bottom Copper and Silkscreen Figure 2−5. Drill DrawingPCB Layout PCB Design2.2 Bill of Materials Table 2−1. Parts ListBill of Materials 2.3 Schematic SchematicPCB Design Page EVM Operation ChapterPage Topic3.1 Quick Start Figure 3−1. Quick Start Module Map3.2 Power−Up/Down Sequence 3.3 Reset Button/Mute3.4 Error Signals Table 3−1. TAS5111 Error Decoding3.5 Changing the Gain Technical Information ChapterPage Topic4.1 Feedback System Design Figure 4−1. APA100 Block DiagramPhase Margin + 180 Phase at Fc Figure 4−4. APA100 Integrator Design Closed−loop gain + 1.5 0 C10 V1 1 0 4.2 TPA2001D1 Class-DModulator Figure 4−7. TPA2001D1 Block Diagram TPA2001D1 Class-DModulatorCh1: 3V/Div Ch2: 3V/Div Ch3: 3V/Div Ch4: 1V/Div t − Time −4.4 TLV2464A Gain Setting and Feedback 4.3 TAS5111 H-Bridge4.5 LC Filter Figure 4−9. APA100 Output Filter4.6 Thermal Table 4−1. TAS5111 Thermal TableAs an indication of the importance of keeping the thermal grease layer thin, if the thermal grease layer increases to 0.002 inch thick, the required heatsink thermal resistance changes to 2.4C/W Measured Results ChapterPage Topic5.1 Total Harmonic Distortion + Noise Total Harmonic Distortion + NoiseTotal Harmonic Distortion + Noise Measured Results5.2 Output Power Output Power5.3 Efficiency EfficiencyMeasured Results 5.4 Gain and Phase Response 5.5 Signal-to-NoiseRatio SNRGain and Phase Response 5.6 Supply Ripple Rejection Supply Ripple RejectionMeasured Results