AUDIOMAX LX1701SPK EVAL USER’S GUIDE LX1701 / LX1701SPK AUDIOMAX EVALUATION KIT USER’S GUIDE ® TM Copyright © 2004 Rev. 1.1, 2003-05-28 Microsemi Integrated Products 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 1 AUDIOMAX LX1701SPK EVAL USER’S GUIDE LX1701 Evaluation Board Quick Start Guide The LX1701 Evaluation Board is a fully functional filterless mono class-D amplifier. Connection to a single power supply, even two AA batteries, one speaker, and an audio source like portable player or computer is all that is required to begin evaluating the amplifier. The amplifier will support continuous output power levels up to 2W into 4 Ω load (<10% THD+N). Board Setting 1. Power and Ground Connections: The terminal J3 is for the power supply connection. VBAT is connected to the positive polarity of the power supply or battery (+1.8V ~ +5V); the GND is connected to the negative polarity of the power supply or battery. Please make sure your power supply polarity connection and supply voltage is correct before you start to evaluate the board. 2. Speakers Connection: J4 is the speaker output. Connect speaker “+” and “-“ to “OUT+/OUT+”. This evaluation board is designed for > 4 Ω speaker loads. 3. Audio Input Connection: J1 is the audio input connection. The positive audio inputs are connected to IN+ pin, while the negative inputs are connected to IN- pin. For single-ended audio input, the audio signal is connected to IN+ and ground connected to IN-. 4. “Enable/Disable” Jumper Setting: JP2 is the jumper for “Enable/Disable”. Enable jumper must be closed for normal system operation. 5. “BW_SEL” (Bandwidth Selection) Jumper Setting: JP3 is for low frequency cut off corner frequency selection. There are two choices: one is 20Hz if “20Hz” position is closed; another one is 300Hz if “300Hz” position is closed. 6. “Gain” Jumper Setting: JP1 is the jumper for system gain selection. There are also two choices: 14dB if “14dB” position is closed; 8dB if “8dB” position is closed. 7. Output Selection Jumper Setting: JP4 & JP5 is the jumpers for LC filter or filterless output selection. Default setting is filterless output, which “filterless+” and “filterless-“ positions are closed. L1/L2, C6/C7 are optional components for LC filter output when “LC+” and “LC-“ positions are closed. L1/L2 could be inductors, or Ferrite Beads for long speaker wires output to speaker. 8. Test Set Up: R1/R2/R3/R4/R5 & C2/C3/C4/C5 are components for test purpose (refer to next page schematic), they are not necessary for the real application circuit. They make a second order RC filter cutting off the high switching frequency, to measure the audio signal more precisely. R1 is an on-board load, can be 4~16Ω, 2W resistor, you also can connect a resistor load off the board through the output terminal without on-board load. The probes just touch “TESTOUT+” and “TESTOUT-“ test points, you can measure audio performance of the board Actually this evaluation board is added a lot of optional components, or for test purpose, also some headers, terminals for input and output, they are not necessary for the real application. The real component for this system is only one: C1, for the power supply ripple. Another application board we made only has this one component on the board except for the IC, you can find the schematic and picture in the page? It is sold separately. Copyright © 2004 Rev. 1.1, 2003-05-28 Microsemi Integrated Products 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 2 J2 J1 C1 47uF VBAT THERMAL INDICATOR AUDIO_IN VBAT + 2 1 1 2 JP1 2 1 Integrated Products 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Microsemi U1 TOVL VINP VINN JP2 OUTP LX1701 OUTN PVDD PVDD 1 2 3 4 VBAT 470 470 C4 4700PF R5 22uH * OPERATION 22uH R3 470 R4 L2 4/2W R1 L1 470 R2 C2 4700PF LX1701 2W class-D Audio Amplifier Evaluation Module J3 VBAT GND 12 11 10 9 GAIN T ABV 7 41 L EL3 JP3 6 51 SSV 8 L ES_ WB DDV 31 T ABV 5 E N SV S SVP S Copyright © 2004 Rev. 1.1, 2003-05-28 61 SSVP JP5 JP4 TP2 2 1 TP1 * FOR TEST PURPOSE C5 2200PF C7 470nF C6 470nF C3 2200PF * FOR TEST PURPOSE J4 AUDIOMAX LX1701SPK EVAL USER’S GUIDE APPLICATION SCHEMATIC FIGURE 1 - LX1701 SCHEMATIC Page 3 AUDIOMAX LX1701SPK EVAL USER’S GUIDE BOARD LAYOUT COMPONENT LAYER Solder Layer Components placement FIGURE 2 - LX1701 PCB LAYOUT Copyright © 2004 Rev. 1.1, 2003-05-28 Microsemi Integrated Products 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 4 AUDIOMAX LX1701SPK EVAL USER’S GUIDE TEST PROCEDURES GND VBAT + Power Supply C1 OutputAudio Precision System One IN- Output+ IN+ 2nd Order RC LPF TP+ OUT+ LX1701 On-Board Resistor Load OUT- Input+ Audio Precision System One GND 2nd Order RC LPF TP- Input- LX1701 Evaluation Kit FIGURE 3 - LX1701 TEST SYSTEM SETUP ¾ Default Settings: Equipments: Audio Precision SYSTEM 1, Oscilloscope, Power Supply ~+5V; Supply Voltage: 1.8V/3.3V/5.0V 3 corner voltages On-Board passive LPF: 40KHz cut off frequency (-3dB) On-Board resistor load: 4/8 Ω, 2W AP settings: 10Hz ~ 22KHz BPF Copyright © 2004 Rev. 1.1, 2003-05-28 Microsemi Integrated Products 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 5 AUDIOMAX LX1701SPK EVAL USER’S GUIDE TEST PROCEDURES(CONT.) ¾ THD+N vs. Output Power Tested signal frequency f=1KHz, through On-Board PC LPF to minimize the switching noise, keep measuring accuracy ¾ THD+N vs. Frequency Tested signal level Po=100mW, sweep input signal frequency from 20Hz to 20KHz, through OnBoard PC LPF to minimize the switching noise, keep measuring accuracy ¾ Frequency response Tested signal level Po=100mW, sweep input signal frequency from 20Hz to 20KHz, not through On-Board PC LPF, directly test it from OUT+ and OUTChange JP3, the BandWidth selection jumper to change the HPF cutoff frequency, then measure it ¾ Signal-to-Noise Ratio (SNR) Input short, output through TP1 and TP2 into AP input, AP is set up with FFT digital analyzer function, A-weighted filter, 0dB as maximum output power with 1%THD+N ¾ Efficiency Output power vs. power supply power, since resistor is acting as a load even at high switching frequency, the On-Board load resistor is removed and the output through OUT+/OUT- into a speaker load because the speaker can act as an inductor to cut off the higher switching frequency to keep measuring accuracy. Tested signal is f=1KHz sine wave. ¾ GAIN Same procedure with frequency response, set 0dB as input signal level Change JP1, the gain selection jumper to change its gain, and measure it Copyright © 2004 Rev. 1.1, 2003-05-28 Microsemi Integrated Products 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 6 AUDIOMAX LX1701SPK EVAL USER’S GUIDE APPLICATIONS LX1701SPK* is evaluation/application module; it has very compact size (22mm x 13mm). On the board, there are only two components, one is LX1701, and another is a surface mount CAP 4.7uF. It is easy for users to directly embed this module into speaker, connect to the audio source and 2 or 3 “AA” size batteries, and then plug-play. * - It is sold separately. 5 PVSS 6 VSS EN PVDD U1 LX1701 VINP PVDD TOVL OUTN 14 13 VDD 12 VINN 4 OUT+ 3 VBAT 2 1 OUT- PVSS 11 OUTP VSS IN+ GAIN S1 SPK+ S2 SPK- 16 10 3LEL IN- 15 Audio IN- 8 9 VBAT Audio IN+ C1 47uF BW_SEL + 7 VBAT VBAT FIGURE 4 - LX1701SPK EVALUATION/APPLICATION MODULE . Example of LX1701’s size: Copyright © 2004 Rev. 1.1, 2003-05-28 Microsemi Integrated Products 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 7 AUDIOMAX LX1701SPK EVAL USER’S GUIDE BILL OF MATERIAL MISCELLANEOUS COMPONENTS Line Item Part Description Manufacturer & Part # Case 1 2 3 IC, Class-D Audio Controller PC Test Points, .125”, White Connector Headers, .100” Center, 2POS Microsemi Keystone Amp LX1701CLQ 5007-White 87220-2 SM TH TH 4 Connector Headers, .100” Center, 3POS Amp 87220-3 TH 5 Shorting Jumpers, Opren Top, Black Sullen STC02SYAN TH 6 7 Terminal Block, 2POS 5mm PCB, Microsemi, LXE1701-X2 Block Master Microsemi 301-021-1000 LXE1701 TH PCB Reference Designators U1 TP1, TP2 J1, J2 JP1, JP2, JP3, JP4, JP5 JP1, JP2, JP3 JP4, JP5 J3, J4 Reev> X2 Qty 1 2 2 5 5 2 1 CAPACITORS Line Item 1 2 3 Part Description Capacitor, X7R, .47µF, 16V, 20% Capacitor, COG, 2.2nF, 16V, 5% Capacitor, COG, 4.7nF, 16V, 5% Part Description AVX TDK TDK 1206YC474MAT2A C2012COG1C222J C2012COG1C472J Case Reference Designators Qty 1206 0805 0805 C1 C3, C5 C2, C4 1 2 2 Case Reference Designators Qty 0805 R2, R3, R4, R5 4 RESISTORS Line Item 1 Part Description Resistor, 470 Ohm, 5% 1/8W Copyright © 2004 Rev. 1.1, 2003-05-28 Part Description ASJ CR21J471T Microsemi Integrated Products 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 8