19-1921; Rev 0; 1/01 MAX4297 Evaluation Kit Features ♦ 2W/Channel Output Power at +5V 0.7W/Channel Output Power at +3V ♦ Programmable PWM Oscillator Frequency Selection (125kHz, 250kHz, 500kHz, 1MHz) ♦ Low 0.4% THD+N (RL = 4Ω, fIN = 1kHz, fOSC = 250kHz) ♦ +2.7V to +5.5V Input Range ♦ Volume Control ♦ Fully Assembled and Tested Surface-Mount Board Ordering Information Component List DESIGNATION QTY BAT1 1 Battery holder (3AA) C1, C7, C14 3 0.1µF, 16V X7R ceramic capacitors Taiyo Yuden EMK107BJ104KA or Murata GRM39X7R104K016 C2, C15 2 150pF, 50V NPO ceramic capacitors C3, C16 2 5pF, 50V NPO ceramic capacitors C4, C5, C8, C10–C13, C17, C18 9 1µF, 10V X7R ceramic capacitors Taiyo Yuden LMK212BJ105KG or Murata GRM40X7R105K010 C6, C19, C20 0 Not installed FAX 2 330µF, 6.3V POSCAPs Sanyo 6TPB330M PHONE C9, C23 Coilcraft 847-639-6400 847-639-1469 J1 1 3.5mm stereo jack Coiltronics 561-241-7876 561-241-9339 2-position terminal blocks for speakers Murata 814-237-1431 814-238-0490 Panasonic 201-392-7522 201-392-4441 619-661-6835 619-661-1055 408-573-4150 408-573-4159 J2, J3 2 DESCRIPTION PART MAX4297EVKIT TEMP. RANGE IC PACKAGE 0°C to +70°C 24 SSOP Component Suppliers SUPPLIER JU1–JU4 4 3-pin jumpers Sanyo 4 15µH inductors Coilcraft DO3316P153 or Coiltronics UP2B-150 Taiyo Yuden L1–L4 R1 1 10kΩ, thumbwheel potentiometer Panasonic EVU-TU5B32B14 R2, R3, R5, R6 4 51kΩ ±5% resistors R4, R7 2 100kΩ ±5% resistors U1 1 MAX4297EAG ________________________________________________________________ Maxim Integrated Products 1 For price, delivery, and to place orders, please contact Maxim Distribution at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. Evaluates: MAX4297 General Description The MAX4297 is a stereo, switch-mode (Class-D) audio power amplifier intended for multimedia and generalpurpose high-power applications. It has greater than 83% efficiency and is capable of delivering 2W maximum continuous power to a 4Ω load. The MAX4297 evaluation kit (EV kit) is a fully assembled and tested surface-mount board. The EV kit is designed to be driven by the lineout or headphone jack of a CD player or directly connected to any audio source. It can be powered by either three AA batteries or an external power supply. The EV kit includes a volume control and two terminal blocks for quick speaker connection. Evaluates: MAX4297 MAX4297 Evaluation Kit Quick Start Required Equipment • Two 4Ω/8Ω speakers • Either three AA batteries or a DC power supply capable of supplying +2.7V to +5.5V at 1.5A. The MAX4297 EV kit is fully assembled and tested. Follow the steps below to verify board operation. Do not turn on the power supply until all connections are completed: 1) Connect the speakers to terminal blocks J2 and J3. 2) Connect an audio source, such as a CD player, to stereo jack J1 or the pads labeled INPUTL, INPUTR, and AUDIO-GND. 3) Set jumper JU2 to position 1–2 for battery power or 2–3 for a DC power supply. 4) Set the remaining jumpers to the following positions: JU1: 2–3 (MAX4297 enabled) JU3: 2–3 (FS2 = low) fOSC = 250kHz JU4: 1–2 (FS1 = high) Jumper Selection Jumper JU1 controls the shutdown pin (SHDN) on the MAX4297. See Table 1 for shunt positions. Jumper JU2 selects between an external power supply or the on-board battery pack. See Table 1 for shunt positions. Jumpers JU3 and JU4 control frequency select pins FS1 and FS2. See Tables 1 and 2 for the shunt positions. Note: The MAX4297 EV kit is optimized for a 250kHz switching frequency. Inductors L1–L4 and capacitors C4, C5, C17, and C18 may need to be optimized for other switching frequencies. Refer to the MAX4295/MAX4297 data sheet for selecting the values. Table 1. Jumper Selection JUMPER } 5) Either insert three AA batteries into the battery holder, or connect a DC power supply to the VSUPPLY and GND pads. JUMPER POSITION 1–2 SHDN = low. MAX4297 disabled. 2–3* SHDN = high. MAX4297 enabled. Open Drive pad SHDN with an external signal. 1–2 Power is supplied by the battery pack. 2–3* Power is supplied by an external power supply connected to VSUPPLY and GND pads. 1–2 Frequency select pin FS2 = VCC. 2–3* Frequency select pin FS2 = GND. JU1 6) Turn on the audio source. 7) Adjust the volume control if necessary. Detailed Description The MAX4297 EV kit is a stereo, switch-mode (Class-D) audio power amplifier. The EV kit is designed to be driven by the lineout or headphone jack of a CD player or directly connected to any audio source. It can be powered by either three AA batteries or an external power supply. A thumbwheel potentiometer mounted to the board is provided to control volume. The EV kit is shipped with the components selected for driving 4Ω speakers with the MAX4297 set to unity gain. The gain can be increased by changing resistors R4 and R7. See the equations below for determining values: Left channel: Gain = -R4 / (R2 + R3) = -R4 / 102kΩ Right channel: Gain = -R7 / (R5 + R6) = -R7 / 102kΩ JU2 JU3 JU4 FUNCTION 1–2* Frequency select pin FS1 = VCC. 2–3 Frequency select pin FS1 = GND. *Default position. Table 2. Frequency Selection JU3 (FS2) JU4 (FS1) 2–3 (GND) 2–3 (GND) 125kHz 2–3 (GND) 1–2 (VCC) 250kHz 1–2 (VCC) 2–3 (GND) 500kHz 1–2 (VCC) 1–2 (VCC) 1MHz To drive speakers other than 4Ω, replace inductors L1–L4 and capacitors C4, C5, C17, and C18. Refer to the MAX4295/MAX4297 data sheet for selecting the values. 2 _______________________________________________________________________________________ FREQUENCY MAX4297 Evaluation Kit Evaluates: MAX4297 VSUPPLY LEFT J2 L1 15µH C4 1µF J1 R2 51kΩ C6 OPEN BAT1 24 R4 100kΩ VCC 2 3 INPUTL 1 C5 1µF 1 C3 5pF C2 150pF VCC L2 15µH JU2 GND R3 51kΩ AOUTL C1 0.1µF 3 2 INPUTR C13 1µF C8 1µF C9 330µF C10 1µF MAX4297 INL VCC VCC SHDN PVCC VCC 3 2 22 OUT+ L OUT-L PGND PGND 7 8 PGND OUT+R OUT-R 9 10 PVCC FS2 JU1 C23 330µF 20 19 PGND 18 17 PVCC GND SHDN 1 21 PVCC 6 C12 1µF VCC 23 C11 1µF 5 AUDIO-GND C7 0.1µF SS VCC 4 R1 10kΩ U1 VCC 16 1 2 15 JU3 VCC 3 R5 51kΩ C14 0.1µF R6 51kΩ 11 C16 5pF R7 100kΩ 12 C15 150pF INR FS1 VCM AOUTR 1 2 14 JU4 3 13 C20 OPEN C19 OPEN L3 15µH L4 15µH C17 1µF J3 RIGHT C18 1µF Figure 1. MAX4297 EV Kit Schematic _______________________________________________________________________________________ 3 Evaluates: MAX4297 MAX4297 Evaluation Kit 1.0" 1.0" Figure 2. MAX4297 EV Kit Component Placement Guide— Component Side 1.0" Figure 3. MAX4297 EV Kit Component Placement Guide— Solder Side 1.0" Figure 4. MAX4297 EV Kit PC Board Layout—Component Side Figure 5. MAX4297 EV Kit PC Board Layout—Soldier Side Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 4 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2001 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.