PAM8302A EVB User Guide PAM8302A-EV Board User Guide AE Department 1. Revision Information Date 2008/06/12 2008/11/14 Revision V1.0 V2.0 Description Initial Release PCB Change Comment 2. EV Board Schematic Figure 1 Demo Board Schematic This application note contains new product information. Diodes, Inc. reserves the right to modify the product specification without notice. No liability isassumed as a result of the use of this product. No rights under any patent accompany the sale of the product. PAM8302A EVB User Guide 3. PAM8302A EB85AA Description PAM8302A CB81AS is design for PAM8302A demo and evaluation, targeted to be used in providing a simple and convenient evaluation environment for the PAM8302A. 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 Test Point (Sine-Wave Class-D BTL Output Power In: 2.5V to 5.5V Shutdown Jump Differential/ Single-Ended Input Selection Audio Input Figure 2 Demo Board Top View EV Board Operational Sequence: a. Preset the power supply to between 2.5V 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 BTL output jack, 8ohm speaker recommend. e. Turn on the power supply and verify that the sound quality of speaker. This application note contains new product information. Diodes, Inc. reserves the right to modify the product specification without notice. No liability isassumed as a result of the use of this product. No rights under any patent accompany the sale of the product. PAM8302A EVB User Guide EV Board BOM List Item Value Type Rating Description C3, C5 100nF X5R/X7R, Ceramic/0603 10V Input CAP C1 10µF X5R/X7R, Ceramic/1210 10V VDD coupling CAP C2 1µF X5R/X7R, Ceramic/0603 10V VDD coupling CAP R1, R2 Bead1/2 C4, C6 10K 120Ω/1A 220pF 1% Input Resistor EMI EMI 0603 X5R/X7R, Ceramic/0603 10V Vender and Part Number Murata GRM21R71C104B Murata GRM21R71C106B Murata GRM21R71C105B 5. External Components Selection Input Capacitors (C3, C5) (1) Form a high pass filter with Ri, and the cut off frequency is fc=1/2ΠRi*Ci. (2) Have a tolerance of 10% or better for matching: any mismatch in capacitance causes an importance mismatch at the corner frequency. (3) Low leakage current needed 0.1µF. Input Resistors (R1, R2) (1) Limit the closed-loop gain. (2) Form a high pass filter with Ci, and the cut off frequency is fc=1/2*Π*Ri*Ci. (3) 1% tolerance needed for resistor matching to improve CMRR, PSRR. Power Supply decoupling Caps (C1, C2) (1). Low ESR for good THD, PSRR. (2) C2, 1.0µF ceramic for higher frequency transients, spikes. (3) C1, Additional 10uF 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. This application note contains new product information. Diodes, Inc. reserves the right to modify the product specification without notice. No liability isassumed as a result of the use of this product. No rights under any patent accompany the sale of the product. PAM8302A EVB User Guide 6. PCB Layout Guidelines Grounding (1) Use plane grounding or separate grounds (2) Do not use one line connecting power GND and analog GND (3) 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 (1) The power supply de coupling capacitors (C1, C2) need to place very close to the PAM8302A’s pins. (2) The output route should be far away from audio input route. 7. PCB Layout Example Top Layer Bottom Layer Figure 3 Figure 4 This application note contains new product information. Diodes, Inc. reserves the right to modify the product specification without notice. No liability isassumed as a result of the use of this product. No rights under any patent accompany the sale of the product.