LM4865

SNAS035G – DECEMBER 1999 – REVISED MAY 2013

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RECOMMENDED PRINTED CIRCUIT BOARD LAYOUT

Figure 31 through Figure 33 show the recommended two-layer PC board layout that is optimized for the SOIC-8

packaged LM4865 and associated external components. Figure 34 through Figure 38 show the recommended

four-layer PC board layout for the micro SMD packaged LM4865. A four-layer board is recommended when

using the micro SMD packaged LM4865: the two inner layers, one connected to the GND pin, the other to the

VDD pin, provide heatsinking. Both layouts are designed for use with an external 5V supply, 8Ω speakers, and

32

Ω headphones. The schematic for both recommended PC board layouts is Figure 3.

Both circuit boards are easy to use. Apply a 5V supply voltage and ground to the board's VDD and GND pads,

respectively. Connect a speaker with an 8

Ω minimum impedance between the board's -OUT and +OUT pads.

For headphone use, the layout has provisions for a headphone jack, J1. When a jack is connected as shown,

inserting a headphone plug automatically switches off the external speaker.

Figure 31. Recommended SOIC PC Board Layout:

Component Side Silkscreen

Figure 32. Recommended SOIC PC Board Layout:

Component Side Layout

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