PAM8008 EVB User Guide PAM8008-EV Board User Guide AE Department 1. Revision Information Date 2012/06/28 Revision V1.0 Description Initial Release Comment 2. PAM8008 General Description The PAM8008 is a 2.4W, class-D audio amplifier. Advanced 64-step DC volume control minimizes external components and allows speaker volume control. Integrated power limit technology which suppress the output signal clip automatically due to the over level input signal. It offers low THD+N, to produce high-quality sound reproduction. PAM8008 has an additional noise reduction circuit which achieve 6dB noise attenuation. This circuit may help eliminate external filtering, thereby saving the board space and components cost. 3. Key Features 2.4W Output at 1% THD with a 4Ω Load and 5V Power Supply 6dB Effective Noise Reduction Superior Low Noise: 60µV Filter less , Low Quiescent Current and Low EMI Minimize Pop/Clip Noise Low THD+N High Efficiency up to 90% Power Limit Function to Protect Speaker when Auto Recovery Short Circuit Protection Occuring large Input 64-step DC Volume Control from -80dB to 20dB Thermal Shutdown Pb-Free Package 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. PAM8008 EVB User Guide 4. EV Board Schematic C9 TP1 R5 FB1 IC1 SD 1 Vin 2 SD 3 2 C4 Vin C1 Rin R1 R3 C2 1 Vin 2 MUTE 3 4 R4 MUTE 1 C3 Lin R2 Volume 5 6 7 3 MUTE 8 SD ROUTP BYPASS VDD RINN PL GND LINN VOLUME MUTE ROUTN PAM8008 SD GND GND LOUTN VDD LOUTP 16 RoutP RoutP FB2 15 14 Vin RoutN C5 C6 12 C7 1 R6 C10 C8 2 1 C14 C11 TP3 R7 FB3 LoutN 10 9 2 TP2 13 11 RoutN C13 Rout Vin LoutP FB4 LoutP LoutN R8 C12 C15 Lout 2 1 2 1 C16 TP4 Figure 1 5. PAM8008 EVB TB21AA Description PAM8008 TB21AA is an evaluation board for the PAM8008, a stereo class-D audio power amplifier. The board is targeted to be used in providing a simple and convenient evaluation environment for the PAM8008. Requires parts, the standard RCA jacks for audio inputs, pin jacks for power supply and signal outputs etc. on the board make it easy to be evaluated. 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. PAM8008 EVB User Guide 6. EV Board View and Jack Description SD Control Power Supply Top View R-CH Output Audio Input L-CH Output Volume Control Mute Control EV Board Operational Sequence: a) Connect SD to a high for normal operation b) Connect audio input from audio input jack c) Connect the loading(speaker or power resistor) to the output jack d) Power on: 2.5V to 5.5V DC power supply 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. PAM8008 EVB User Guide 7. EV Board BOM List Item C1,C2 C5,C7 C6,C8 C3 C4 R1, R2 R3, R4 VR1 FB1,FB2,FB3,FB4 C13,C14,C15,C16 Value 0.1µF 1µF 10µF 1µF 1µF 0 0Ω 50kΩ 200Ω 220pF Type X5R/X7R, Ceramic/0603 X5R/X7R, Ceramic/0603 X5R/X7R, Ceramic/0805 X5R/X7R, Ceramic/0603 X5R/X7R, Ceramic/0603 0805 Rating 10V 25V 10V 16V 16V 1% 5% 0805 0603 2A 25V Description Input coupling CAP PVDD coupling CAP, PVDD main coupling CAP, BYPASS CAP Decoupling CAP Input Resistor PL select resistor Volume setting For EMI eliminate components form a FB-CAP filter Vender and port LMK063BJ104KP-F TMK107B7105KA-T LMK107BBJ106MALT EMK107B7105KA-T EMK107B7105KA-T 8. External Components Selection Input Capacitors (C1, C2) (1) Form a high pass filter with Ri, and the cut off frequency is fc = 1/2*Π*Ri*Ci (2) Have a tolerance of 10% or better for matching : any mismatch in capacitance causes an importance mismatch at the corner frequency and below (3) Low leakage current needed, 0.1µF, X5R/X7R ceramic recommend 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 (C5, C6, C7, C8 ) (1) Low ESR for good THD, PSRR (2) 1uF ceramic for higher frequency transients, spikes, or digital hash on the line of PVDD/AVCC (3) Additional 10µF 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 Bias Voltage Capacitor (C3) (1) Internal power supply for pre-amplifier, (2) 1uF, X5R/X7R ceramic recommend (3) Place very closed to the device EMI Eliminate Filter (FB1, FB2, FB3 and FB4) (1) High impedance at high frequency and very low impedance at low frequency (2) The current rating is higher than 2A 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. PAM8008 EVB User Guide 9. 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. Power Supply Others (1). The power supply capacitors (C5, C6, C7, C8, ) need to place very close to the PAM8008’s pins. (2). Input capacitors (C1, C2) place closed to input pin as near as possible 10. PCB Layout Example Top Layer 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. PAM8008 EVB User Guide Bottom Layer 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.