19-0662; Rev 0; 11/06 MAX9723D Evaluation Kit/Evaluation System The MAX9723D evaluation kit (EV kit) is a fully assembled and tested PCB that evaluates the MAX9723 stereo DirectDrive TM headphone amplifier with BassMax, volume control, and I2C. The MAX9723D EV kit operates from a single 1.8V to 3.6V power supply, and is capable of delivering 60mW into a 16Ω load. The MAX9723D evaluation system (EV system) includes a MAX9723D EV kit, Windows 98SE/2000/XP-compatible software, and a Maxim system command module. The software’s graphical user interface (GUI) allows easy control of the MAX9723D’s I2C interface, adjusting settings such as BassMax and volume. Order the complete EV system (MAX9723DEVCMODU+ or MAX9723DEVCMOD2+) for a comprehensive evaluation of the MAX9723A/MAX9723B/ MAX9723C/MAX9723D using a PC. Order the EV kit (MAX9723DEVKIT+) if the CMODUSB+ or CMOD232+ system command module has already been purchased with a previous Maxim EV system, or for custom use in other microcontroller-based (µC) systems. The EV kit comes with the MAX9723DETE+ installed. Contact the factory for free samples of the pin-compatible MAX9723A/MAX9723B/MAX9723C to evaluate these parts. Windows is a registered trademark of Microsoft Corp. Features Single 1.8V to 3.6V Power-Supply Operation 60mW Stereo DirectDrive Headphone Outputs Ω, VDD = 3V) (16Ω System Command Module: USB Interface (CMODUSB+) or Serial Interface (CMOD232+) Windows® 98SE/2000/XP-Compatible Evaluation Software Evaluates the MAX9723A/MAX9723B/MAX9723C (with IC replacement) Fully Assembled and Tested Ordering Information PART TYPE INTERFACE EV kit User-supplied I2C interface MAX9723DEVCMODU+ EV system CMODUSB+ USB interface board MAX9723DEVCMOD2+ EV system CMOD232+ RS-232 serial-interface board MAX9723DEVKIT+ +Denotes a lead-free and RoHS-compliant EV kit. Note: The MAX9723D EV kit software is included with the MAX9723D EV kit, but is designed for use with the complete EV system. The EV system includes a Maxim system command module (CMODUSB+ or CMOD232+) and the EV kit. If the Windows software will not be used, the EV kit board can be purchased without the Maxim system command module. Component List MAX9723DEVCMODU+ PART MAX9723DEVKIT+ CMODUSB+ QTY DESCRIPTION 1 MAX9723D EV kit 1 System command module (USB serial interface) MAX9723DEVKIT+ DESIGNATION C1, C9, C10 QTY 3 0.1µF ±10%, 16V X7R ceramic capacitors (0603) TDK C1608X7R1C104K Murata GRM188R71C104K 3 1µF ±10%, 10V X7R ceramic capacitors (0603) TDK C1608X7R1A105K TDK C1608X7R1C105K Murata GRM188R61A105K 2 0.47µF ±10%, X7R ceramic capacitors (0603) TDK C1608X7R1A474K (10V) Murata GRM188R71E474KA12D (25V) Murata GRM188R71C747KA88 (16V) Kemet C0603C474K9RAC7867 (6.3V) MAX9723DEVCMOD2+ PART QTY DESCRIPTION MAX9723DEVKIT+ 1 MAX9723D EV kit CMOD232+ 1 System command module (RS-232 serial interface) C2, C3, C6 C4, C5 DESCRIPTION ________________________________________________________________ Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. 1 Evaluate: MAX9723A/MAX9723B/MAX9723C/MAX9723D General Description Evaluate: MAX9723A/MAX9723B/MAX9723C/MAX9723D MAX9723D Evaluation Kit/Evaluation System Component List (continued) MAX9723DEVKIT+ DESIGNATION QTY J1 1 JU1, JU2, JU3 3 DESCRIPTION SUPPLIER PHONE WEBSITE Keystone 800-221-5510 www.keyelco.com 2 x 10 right-angle receptacle Murata 770-436-1300 www.murata.com 3-pin headers TDK 847-703-6100 www.component.tdk.com PJ1 1 3.5mm stereo jack (SMT, lead free, and RoHS) CUI Inc. SJ-3523-SMT R1, R2 2 10kΩ ±1% resistors (0603) lead free R3, R6 2 22.1kΩ ±1% resistors (0603) lead free R4, R5 2 47.5kΩ ±1% resistors (0603) lead free U1 1 MAX9723DETE+ (16-pin TQFN) Stereo DirectDrive headphone amplifier — 3 Shunts — 1 MAX9723D EV kit PCB Quick Start Recommended Equipment • DC power supply (3.3V @ 0.5A) • Stereo audio source (e.g., CD player, MP3 player, etc.) • 32Ω or 16Ω headphones • MAX9723D EV system MAX9723D EV kit Maxim CMODUSB+ or CMOD232+ system command module • Component Suppliers A user-supplied Windows 98SE/2000/XP PC Note: In the following sections, software-related items are identified by bolding. Text in bold refers to items directly from the EV kit software. Text in bold and underlined refers to items from the Windows 98SE/ 2000/XP operating system. Procedure Follow the steps below to verify board operation. Caution: Do not turn on the power supply until all connections are complete. 1) Visit the Maxim website (www.maxim-ic.com/evkitsoftware) to download the most recent version of the EV kit software, 9723RXX.ZIP. Save the EV kit software to a temporary folder and uncompress the ZIP file. Note: Indicate that you are using the MAX9723D when contacting these component suppliers. MAX9723D EV Kit Files FILE DESCRIPTION INSTALL.EXE Installs the EV kit files on your computer MAX9723V03.EXE TROUBLESHOOTING_USB. PDF Application program USB driver installation help file FTD2XX.INF USB device driver file UNINST.INI Uninstall the EV kit software 2) Install the MAX9723D EV kit software on your computer by running the INSTALL.EXE program inside the temporary folder. The program files are copied and icons are created in the Windows Start | Programs menu. 3) Carefully connect the system command module to the EV kit by aligning the 20-pin connector of the MAX9723D EV kit with the 20-pin header of the Maxim system command module interface board. 4) Enable the pullup resistors on the system command module by making sure the SDA switch and SCL switch (both on SW1) are thrown on. 5) If using Maxim’s serial-interface board (CMOD232+), connect a 9-pin male-to-female cable from the computer’s serial port to CMOD232+. CMOD232+ requires a 9V power supply to P1 (DC IN). For regulated 3.3V output voltage, install a shunt across pins 1-2 of J1 on the CMOD232+. If using Maxim’s USB interface board (CMODUSB+), connect the A-to-B USB cable from the computer’s USB port to CMODUSB+. CMODUSB+ requires no external power as it is powered from the PC USB port. For regulated 3.3V output, install a shunt across pins 2-3 of J1 on the CMODUSB+. 6) Ensure that a shunt is placed across pins 1-2 of JU3 on the MAX9723D EV kit board. 2 ________________________________________________________________________________________ _______________________________________________________________________________________ MAX9723D Evaluation Kit/Evaluation System 8) Ensure that the input audio source is turned off. 9) Connect the stereo audio source to the pads labeled RIN, LIN, and GND on the MAX9723D EV kit board. 10) Plug the headphones into the 3.5mm headphone jack on the MAX9723D EV kit board. 11) Turn on the DC power supply. 12) Enable the audio source. 13) Start the MAX9723 program by opening its icon in the Windows Start menu. Select the device slave address from the device pulldown menu. See Table 1. Detailed Description of Software Device Selection and Slave Address The MAX9723 has an I 2C-compatible interface that allows serial communication between the MAX9723 and a microcontroller. The MAX9723 is available with one of two preset slave addresses (see Table 1). The MAX9723D EV kit ships with the MAX9723D. Change IC U1 to evaluate other devices. Samples of other MAX9723 devices are available through Maxim’s website at www.maxim-ic.com. The Device pulldown menu allows the user to select the device slave address. Select the slave address of the device being evaluated at startup. See Figure 2 for details. Table 1. MAX9723 Slave Address VERSION MAX9723 SLAVE ADDRESS A6 A5 A4 A3 A2 A1 A0 R/W MAX9723A 1 0 0 1 1 0 0 X X MAX9723B 1 0 0 1 1 0 1 MAX9723C 1 0 0 1 1 0 0 X MAX9723D* 1 0 0 1 1 0 1 X *EV kit IC version. Figure 1. MAX9723D EV Kit Software GUI Window Figure 2. Device Selection and Slave Address _______________________________________________________________________________________ 3 Evaluate: MAX9723A/MAX9723B/MAX9723C/MAX9723D 7) Connect a 3.3V power supply between the pads labeled V DD and GND on the MAX9723D EV kit board. Evaluate: MAX9723A/MAX9723B/MAX9723C/MAX9723D MAX9723D Evaluation Kit/Evaluation System Gain Range and Gain Settings The MAX9723 offers two options for the maximum volume setting (AV_VOL). The MAX9723A/MAX9723B have selectable maximum gains of -5dB or 0dB, while the MAX9723C and MAX9723D have selectable maximum gains of +1dB or +6dB. The Gain Range checkbox (Figure 3) allows the user to select between the two maximum gain ranges. See Table 2 for the corresponding gain range of each IC version. Figure 4. MAX9723 Bass-Boost Feature Checking the Bass Boost Select checkbox (Figure 4) enables bass boost. The output has additional gain (AV_BOOST) on top of the overall gain (AV_VOL). The default AV_BOOST is +8.8dB for bass frequencies. The absolute gain at low frequencies is equal to: AV_TOTAL = AV_VOL + AV_BOOST Powered Up Checkbox and Close Button Figure 3. Gain Range Checkbox and Gain Setting Slide Bar for MAX9723 Gain Adjustments Table 2. MAX9723 Gain Range VERSION GAIN RANGE (dB) MAX9723A -5 or 0 MAX9723B -5 or 0 MAX9723C +1 or +6 MAX9723D* *EV kit IC version. +1 or +6 Uncheck the Powered Up checkbox (Figure 5), while SHDN is pulled high, to shut down the MAX9723. The EV kit software powers up in the state shown in Figure 5. Clearing the Powered Up checkbox does not reset the internal registers. Press the Close button (Figure 5) to quit the MAX9723D EV kit software. The MAX9723 also includes a 32-level volume control that adjusts the overall gain (A V_VOL) of the output amplifiers. Use the Gain Setting slide bar to adjust AV_VOL. Bass Boost Select The MAX9723 includes a bass-boost feature that compensates for the headphone’s poor bass response by increasing the amplifier gain at low frequencies (AV_BOOST). The bass-boost setting is customized by adjusting R5, R6, and C9 for the left channel and R4, R6, and C10 for the right channel. See the Detailed Description of Hardware section. 4 Figure 5. Powered Up Checkbox and Close Button _______________________________________________________________________________________ MAX9723D Evaluation Kit/Evaluation System R MAX9723D R AUDIO INPUT Table 3. BassMax Gain Examples—R5 (R4) = 47kΩ OUT_ R5 (R4) R6 (R3) (kΩ) AV GAIN (dB) 39 20.6 33 15.1 27 11.3 22 8.8 15 5.7 BB_ BASSMAX ENABLE R6 (R3) C9 (C10) *REFERENCE DESIGNATORS IN PARENTHESIS INDICATE RIGHT-CHANNEL COMPONENTS. Figure 6. Bass Boost External Components for Left Channel Detailed Description of Hardware BassMax Component Selection PCB components R5, R6, and C9 set the bass boost for the left channel, while components R4, R3, and C10 set the bass boost for the right channel (see Figure 6). The default bass boost is +8.8dB. Changing the components listed above modifies the bass-boost gain and frequency response. For example, when bass boost is enabled, the ratio of R5 and R6 sets the left-channel bass boost gain (AV_BOOST_) that is calculated using the following equation. Adjust resistors R4 and R3 to set the right-channel bass boost. 10 3.7 Note: Reference designators in parenthesis indicate rightchannel components. The low-frequency boost attained by the BassMax circuit is added to the gain realized by the volume setting. Select the BassMax gain so that the output signal remains within the dynamic range of the MAX9723. Output signal clipping occurs at low frequencies if the BassMax gain boost is excessively large (refer to the Output Dynamic Range section in the MAX9723 data sheet). GAIN PROFILE WITH AND WITHOUT BASSMAX 16 R6 R5 + R6 must not exceed 1/2 (a ratio of 1/3 is recommended). The switch that shorts BB_ to SGND, when BassMax is disabled, can have an on-resistance as high as 300Ω. Choose a value for R5 (R3) greater than 40kΩ to ensure 12 fZERO 10 AV_TOTAL (dB) To maintain circuit stability, the ratio: fPOLE 14 ⎛ R5 + R6 ⎞ A V _ BOOSTL = 20 × log ⎜ ⎟ ⎝ R5 − R6 ⎠ 8 WITH BASSMAX 6 4 WITHOUT BASSMAX 2 MAX9723D R5(R3) = 47kΩ R6 (R4) = 22.1kΩ C9 (C10) = 0.1µF AV_VOL = +6dB 0 -2 -4 10 100 1000 10,000 100,000 FREQUENCY (Hz) Figure 7. BassMax, Gain Profile Example for AV_VOL = +6dB _______________________________________________________________________________________ 5 Evaluate: MAX9723A/MAX9723B/MAX9723C/MAX9723D that positive feedback is negligible when BassMax is disabled. Table 3 contains a list of R6 (R3) values, with R5 (R4) = 47kΩ, and the corresponding low-frequency gain. Evaluate: MAX9723A/MAX9723B/MAX9723C/MAX9723D MAX9723D Evaluation Kit/Evaluation System For the left channel, capacitor C9 creates a pole and a zero according to the following equations: R5 − R6 fPOLE = 2π × C9 × R5 × R6 R5 + R6 fZERO = 2π × C9 × R5 × R6 CMODUSB+ and CMOD232+ Command Module The CMODUSB+ and CMOD232+ use a proprietary design to provide SPI- and I2C-compatible interfaces to demonstrate various Maxim devices. Maxim reserves the right to change the implementation of this module at any time with no advance notice. fPOLE is the frequency that the gain boost begins to roll off. fZERO is the frequency that the bass-boost gain no longer affects the transfer function and the volume-control gain dominates. Table 4 lists capacitor values and the corresponding poles and zeros for a given DC gain. See Figure 7 for an example of a gain profile using BassMax. Set the right-channel frequency response by adjusting R4, R3, and C10. CMODUSB+ Power Supply The CMODUSB+ board uses a MAX1658 linear regulator. Jumper J1 selects between the 5VDC voltage that comes from the USB connector and the MAX1658’s regulated 3.3V output voltage. Set the CMODUSB+ jumper J1 at position 2-3 to have 3.3V output voltage to evaluate the MAX9723D EV kit. Table 4. BassMax Pole and Zero Examples for a Gain Boost of 8.8dB—R5 (R4) = 47kΩ and R6 (R3) = 22kΩ CMOD232+ Power Supply The CMOD232+ board uses a MAX1659 linear regulator. Jumper J1 selects either the MAX1659’s 5V default output voltage or 3.3V output voltage. Set the CMOD232+ jumper J1 at position 1-2 to have 3.3V output voltage to evaluate the MAX9723D EV kit. C9 (C10) (nF) fPOLE (Hz) fZERO (Hz) 100 38 106 MAX9723D EV Kit Stand-Alone Operation The MAX9723D EV kit operates without the system command module, but the functions are limited to power-on reset-default settings listed below: • BassMax enabled 82 47 130 68 56 156 56 68 190 47 81 230 22 174 490 10 384 1060 Note: Reference designators in parenthesis indicate rightchannel components. Simply substitute R4 for R5, R3 for R6, and C10 for C9 for right-channel equations. • Maximum gain range: 0dB for MAX9723A/MAX9723B or +6dB for MAX9723C/MAX9723D • Maximum gain setting • Device enabled MAX9723D EV System Input Mode The MAX9723D EV system (MAX9723DEVCMODU+ or MAX9723DEVCMOD2+) is a complete stereo DirectDrive headphone amplifier system consisting of the MAX9723D EV kit and Maxim’s system command module (CMODUSB+ or CMOD232+). The audio input terminals on the MAX9723D EV kit accept stereo single-ended inputs (INR and INL). The MAX9723D EV kit provides a proven layout for evaluating the MAX9723 and comes with the MAX9723DETE+ installed. MAX9723 I2C Address The MAX9723 device is an I2C/SMBus™ slave and is write only. Versions A and C have a fixed slave address of 1001100X, and versions B and D have a fixed slave address of 1001101X. See Table 1 for details. SMBus is a trademark of Intel Corp. 6 _______________________________________________________________________________________ MAX9723D Evaluation Kit/Evaluation System Hardware- or Software-Shutdown Control The MAX9723 features a shutdown mode to reduce power consumption and extend battery life. Shutdown can be either hardware- or software-controlled. The software-controlled shutdown maintains the configuration set by the user (see the Powered Up Checkbox and Close Button section). Jumper JU3 controls the hardware-shutdown function of the MAX9723D EV kit. Move jumper JU3 to position 2-3 to shut down the entire MAX9723 and reset all the registers to their power-on defaults. See Table 5 for shutdown shunt positions. Table 5. Hardware Shutdown Selection JU3 FUNCTION 1-2* Normal operation 2-3 Power-down mode *Default position. User-Supplied I2C Interface Connect SDA, SCL, and GND lines from the user-supplied I2C interface to the corresponding pads on the MAX9723D EV kit board. Install shunts across pins 1-2 of JU1 and JU2 to pull up the SDA and SCL lines. Remove the jumpers if the bus is already pulled up. _______________________________________________________________________________________ 7 Evaluate: MAX9723A/MAX9723B/MAX9723C/MAX9723D Power Supply The MAX9723D EV kit board is powered from a usersupplied +1.8V to +3.6VDC power supply between the VDD and GND pads. Evaluate: MAX9723A/MAX9723B/MAX9723C/MAX9723D MAX9723D Evaluation Kit/Evaluation System LEFT PJ1 GND R5 47.5kΩ 1% R6 22.1kΩ 1% 16 C1 0.1µF J1 20-PIN HEADER J1-2 J1-1 J1-4 J1-3 J1-6 J1-5 J1-8 J1-7 J1-10 J1-9 J1-12 J1-11 J1-14 J1-13 15 BBL 1 C3 1µF R4 47.5kΩ 1% 13 C9 0.1µF VDD C2 1µF RIGHT 14 OUTL OUTR BBR VDD 2 SVSS U1 C1P INR MAX9723D 3 PGND 4 INL SGND C1N R3 22.1kΩ 1% C10 0.1µF SCL PVSS SDA SHDN 5 6 7 8 12 11 C5 0.47µF INL 10 9 INR C4 0.47µF SDA SCL VDD 1 2 3 JU1 R1 10kΩ VDD 1% 1 2 3 JU2 R2 10kΩ 1% VDD 1 2 JU3 SHDN 3 J1-16 J1-15 J1-18 J1-17 J1-20 J1-19 Figure 8. MAX9723D EV Kit Schematic 8 _______________________________________________________________________________________ C6 1µF MAX9723D Evaluation Kit/Evaluation System Evaluate: MAX9723A/MAX9723B/MAX9723C/MAX9723D Figure 9. MAX9723D EV Kit Component Placement Guide— Component Side Figure 10. MAX9723D EV Kit PCB Layout—Component Side _______________________________________________________________________________________ 9 Evaluate: MAX9723A/MAX9723B/MAX9723C/MAX9723D MAX9723D Evaluation Kit/Evaluation System Figure 11. MAX9723D EV Kit Component Placement Guide— Solder Side Figure 12. MAX9723D EV Kit PCB Layout—Solder 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. 10 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2006 Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc.