PAM8406 EVB User Guide

Transcription

1 EV Board User Guide AE Department. Revision Information PAM8406 Date Revision Description Comment 0//5 V.0 Initial Release. EV Board Schematic J5 + C C R C6 R C7 C FB FB C0 SP J4 C5 VREF 8 INL 7 6 MUTE 5 P-L 4 PAM8406 -OUT-L PGND-L +OUT-L U C9 9 MODE 0 INR GND SHDN PR 4 -OUT-R 5 PGND-R 6 +OUT-R FB C C R C4 C8 FB4 C SP J J J Figure Demo Board Schematic

2 . PAM8406 Demo Board Description PAM8406 demo board is design for PAM8406 demo and evaluation, targeted to be used in providing a simple and convenient evaluation environment for the PAM8406. Requires parts, potentiometer for standard RCA jacks for audio inputs, pin jacks for power supply and signal outputs, low-pass RC output filter for each channel, etc. on the board make it easy to be evaluated. 4. EV Board View Power in:.5v to 5.5V L- Channels Output Audio Input R- Channels Output Class D /Class AB Select Select Jump Shutdown Select Jump EV Board Operational Sequence : Figure Demo Board Top View a. Preset the power supply to between.5v and 5.5V. b. Connect power supply to EV board power. c. Connect audio input from audio input jack. d. Connect the SPKs to the output jack. e. Turn on the power supply and verify that the sound quality of speaker.

3 EV Board BOM List Item Value Type Rating Description C7,C8 0µF Ceramic/0805 P main decoupling CAP C,C4 µf P coupling CAP C6 µf decoupling CAP C5 µf Vref bypass CAP C,C, µf Input coupling CAP R,R 0K 0805 % Input Resistor R4 0Ω % Separate AVCC from P C 0µF Electrolytic DC coupling CAP FB,FB,FB,FB4 A/0Ω 0805 For EMI C9,C0,C,C, 0pF 5. External Components Selection Power Supply decoupling Caps (C, C4, C6, C7, C8) () Low ESR for good THD, PSRR () C,C4 and C6,.0µF ceramic for higher frequency transients, spikes () C7 and C8, Additional 0uF or greater for low frequency noise filtering and serves as a local storage capacitor for supplying current during large signal transients on the amplifier outputs. (4) Need place very closed to the IC Input Capacitors (C, C) () Form a high pass filter with Ri, and the cut off frequency is fc=/ Ri*Ci () Low leakage current needed, ceramic recommend Input Resistors (R, R) () Limit the closed-loop gain () Form a high pass filter with Ci, and the cut off frequency is fc=/*π*ri*ci () % tolerance needed for resistor matching to improve CMRR, PSRR VREF Bypass Capacitor (C5) (). µf ceramic recommend (). Need place very closely to the pin for good THD, PSRR EMI Eliminate Filter (FB, FB, FB and FB4) () High impedance at high frequency and very low impedance at low frequency () The current rating is higher than A

4 6. PCB Layout Guidelines Grounding () Use plane grounding or separate grounds () Do not use one line connecting power GND and analog GND () Output noise grounds must tie to system ground at the power in exclusively. (4) Signal currents for the inputs need to be returned to quite ground. This ground only ties to the signal components and the GND pin. Others () The power supply de coupling capacitors need to place very close to the PAM8406 s pins. () The output route should be far away from audio input route. 7. PCB Layout Example Top Layer Figure

5 Bottom Layer Figure 4