MAX8678EVKIT+

µ 19-4084; Rev 0; 3/08 MAX8678 Evaluation Kit The MAX8678 evaluation kit (EV kit) is a fully assembled and tested printed-circuit board (PCB) for evaluating the MAX8678 white LED charge pump with mono class AB audio amplifier. The MAX8678 EV kit drives up to four LEDs for backlighting. In addition, the EV kit is able to drive a combined loudspeaker/earpiece speaker for the mono audio amplifier. An on-board pulse generator provides an easy way to evaluate the MAX8678’s amplifier gain adjustment and LED dimming. Features ♦ High-Efficiency White LED Charge Pump Individual Adaptive Supply for Each LED 24mA to 0.1mA Dimming Range Low 50µA (typ) Quiescent Current ♦ Mono Class AB Loudspeaker Amplifier 1.1W RMS Mono Output (8Ω, VIN = 5V) Low 0.004% THD+N at 1kHz High 90dB PSRR at 1kHz Fully Differential Inputs -9dB to +18dB Gain Settings in 3dB Steps Low Quiescent Current ♦ 2.7V to 5.5V Supply Voltage Range ♦ Thermal Shutdown, Open- and Short-Circuit Protections ♦ Fully Assembled and Tested ♦ 16-Pin, 3mm x 3mm Thin QFN IC Package Ordering Information PART TYPE MAX8678EVKIT+ EV Kit +Denotes lead-free and RoHS-compliant. Component List DESIGNATION QTY DESCRIPTION DESIGNATION QTY DESCRIPTION 470kΩ ±5% resistors (0402) 1µF ±10%, 6.3V X5R ceramic capacitors (0402) Murata GRM155R60J105K TDK C1005X5R0J105K R1, R2 2 R3, R4 2 220Ω ±5% resistors (0402) R5 1 10kΩ ±5% resistor (0402) 0.1µF ±10%, 10V X5R ceramic capacitors (0402) TDK C1005X5R1A104K S1–S5 5 3 Momentary pushbutton switches Panasonic EVQ-PHP03T U1 1 1 4.7µF ±10%, 6.3V X5R ceramic capacitor (0603) Murata GRM188R60J475K TDK C1608X5R0J475K White LED charge pump with mono Class AB audio amplifier (16 thin QFN) Maxim MAX8678ETE+ (Top Mark: AFF) 1 2 10pF ±5%, 50V C0G ceramic capacitors (0402) TDK C1005C0G1H100D U2 Maxim low-power LCD microcontroller (68 QFN) MAXQ2000-RAX+ D1–D4 4 White LEDs Nichia NSCW215T U3 1 D5, D6 2 Green LEDs (0603) Panasonic LNJ308G8TRA Maxim ultra-low-noise LDO linear regulator (5 SC70) MAX8511EXK25+ (Top Mark: ADV) J1 0 Not installed, 10-pin (2 x 5) header, 0.1in spacing Y1 1 JU1, JU7 2 3-pin headers 16MHz crystal Citizen HC49US16.000MABJ-U ECS ECS-160-20-4X Vishay XT9S20ANA16M JU2–JU5 4 2-pin headers Y2 0 Not installed, 32.768kHz crystal (1206) JU6 0 Not installed, PCB short — 6 Shunts, 2 position — 1 PCB: MAX8678 Evaluation Kit+ C1, C2, C4, C5, C12, C13 6 C3, C7, C8 C6 C9, C11 ________________________________________________________________ Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim Direct 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. Evaluates: MAX8678 General Description Evaluates: MAX8678 MAX8678 Evaluation Kit Component Suppliers SUPPLIER PHONE Kamaya, Inc. WEBSITE 260-489-1533 www.kamaya.com Murata Electronics 814-237-1431 www.murata-northamerica.com North America, Inc. 3) Turn off the audio source. 4) Verify that shunts on JU2–JU5 are installed (if the audio source does not have a bias voltage compatible with the MAX8678, remove the shunts from JU2 and JU3 to use the input filter capacitors). See Table 1 for jumper positions. 5) Connect the speaker across OUT+ and OUT- output pads on MAX8678 EV kit. Nichia Corp. 248-352-6575 www.nichia.com Panasonic Corp. 800-405-0652 www.panasonic.com TDK Corp. 847-803-6100 www.component.tdk.com Vishay 402-563-6866 www.vishay.com Note: Indicate that you are using the MAX8678 when contacting these component suppliers. Quick Start Recommended Equipment Before beginning, the following equipment is needed: • 2.7V to 5.5V power supply or battery able to deliver 1.5A 6) Connect the audio source to IN+/IN- for differential audio source and to IN+ for single-ended audio input source. 7) Set JU1 to select a differential or single-ended input (JU2 and JU3 must be removed when using a single-ended input). 8) Set JU7 to IN1. 9) Connect the power-supply positive terminal to the IN1 pad. • Audio source (e.g., CD player, MP3 player, etc.) 10) Connect the power-supply negative terminal to the GND1 pad. • 4Ω/8Ω speaker 11) Turn on the power supply and the audio source. Procedure 12) Press switch S2 once. The MAX8678 EV kit is fully assembled and tested. Follow the steps below to verify board operation. Caution: Do not turn on the power supply until all connections are completed. 13) Verify that the white LEDs are dimly lit. 1) Preset the power supply to between 2.7V and 5.5V. 16) Press switch S4 to turn on the audio amp to the minimum volume. 2) Turn off the power supply. Do not turn on the power supply until all connections are completed. 14) Repeatedly press switch S2 to increase the LED brightness. 15) Press switch S1 to run the LED demo. 17) Repeatedly press switch S4 to increase the volume in 3dB steps. Table 1. Jumper Positions JUMPER POSITIONS OPEN 2-3 Single-ended audio input JU1 — Differential audio input JU2 IN- input filter capacitor is used IN- input filter capacitor is not used — JU3 IN+ input filter capacitor is used IN+ input filter capacitor is not used — JU4 An external pulse generator controls the dimming The on-board pulse generator controls the dimming — JU5 An external pulse generator controls the amplifier gain The on-board pulse generator controls the gain — The pulse generator is not powered The pulse generator is powered from IN1 JU6 JU7 2 1-2 JU6 connects the input supply to the LEDs The pulse generator is powered from IN2 _______________________________________________________________________________________ MAX8678 Evaluation Kit On-Board Pulse Generator The on-board pulse generator provides an easy way to evaluate the LED dimming and amplifier gain adjustment. The pulse generator outputs the serial-pulse signals for ENLED and ENAMP. LED D6 indicates when the LED driver is active and LED D5 indicates when the audio amplifier is active. Five pushbutton switches (S1–S5) are used to set the LED brightness and amplifier gain, as shown in Table 2. The pulse generator is powered from either IN1 or IN2. To power from IN1, connect pins 1-2 of JU7. This powers the EV kit from the same supply as the MAX8678, allowing the EV kit to operate from a single supply. To power the pulse generator from a separate supply, connect pins 2-3 of JU7 and connect the supply from IN2 to GND2. This is useful when evaluating the quiescent current of the MAX8678. Using External Pulse Generators To use external pulse generators to control ENLED and ENAMP, disconnect ENLED and ENAMP from the onboard pulse generator by removing the shunts from JU4 and JU5. Remove the shunt from JU7 to disconnect power from the on-board pulse generator. The signals from the external pulse generators are connected to the pads labeled ENLED and ENAMP. For information on the required serial-pulse signal, refer to the MAX8678 IC data sheet. LED Driver Using the on-board pulse generator, press S2 to increase LED brightness or press S3 to decrease brightness. There are 31 brightness settings and an off setting. Refer to the MAX8678 IC data sheet for details. Pressing S1 starts the LED demo, which cycles through a preset sequence of dimming and flashing. Press S2 or S3 to cancel the demo. The power-up default setting is off. Note that the LEDs might flash briefly when power is first applied, due to the pulse-generator circuit powering up. Evaluating with Fewer than Four LEDs To use fewer than four LEDs, connect the square pad next to any unused LEDs to the IN1 pad. Using External LEDs To connect external LEDs to the MAX8678 EV kit, cut the trace shorting JU6. Connect the anodes of all the external LEDs to the IN1 pad. Connect each cathode to one of the LED outputs (square pads next to D1–D4). If fewer than four LEDs are used, connect any unused LED output to IN1. Audio Amplifier Using the on-board pulse generator, press S4 to increase the amplifier gain or S5 to reduce the gain. The gain up/down buttons cycle through off and -9dB to +18dB in 3dB steps. The power-up default setting is off. Input Filter Capacitors The EV kit has 1µF input filter capacitors installed. To evaluate without the filter capacitors, short the pins of JU2 and JU3. If the input bias voltage is out of the MAX8678’s common-mode input-voltage range, these jumpers must be open. Differential or Single-Ended Input JU1 selects between differential or single-ended inputs. For a differential input, connect the input to the IN+ and IN- pads. For a single-ended input, connect the input to IN+ with the signal ground connected to GND1. When using a single-ended input, the input filter capacitors must be used (JU2 and JU3 are open). Speaker Output The MAX8678 EV kit is capable of driving a speaker with 4Ω or greater impedance. Connect the speaker across the OUT+ and OUT- pads. Table 2. Pulse-Generator Controls PUSHBUTTON FUNCTION S1 Used to activate the LED demo. The MAX8678 EV kit changes the brightness of LED1–LED4 in a predefined sequence. Press S2 or S3 to stop the demo. S2 Used to increase the brightness of LED1–LED4. When maximum brightness is reached, an additional press of S2 forces the MAX8678 to enter power-down mode for the LEDs. S3 Used to decrease the brightness of LED1–LED4. When minimum brightness is reached, an additional press of S3 turns off the MAX8678 LEDs. Pressing S3 when the LEDs are off turns the LEDs on at full brightness. S4 Used to increase gain of the audio amplifier. When maximum gain is reached, an additional press of S4 turns off the audio amplifier. Pressing S4 when the audio amplifier is off turns the amplifier on at minimum gain. S5 Used to decrease gain of the audio amplifier. When minimum gain is reached, an additional press of S3 turns off the audio amplifier. Pressing S5 when the audio amplifier is off turns the amplifier on at maximum gain. _______________________________________________________________________________________ 3 Evaluates: MAX8678 Detailed Description Evaluates: MAX8678 MAX8678 Evaluation Kit JU6 C5 1μF 15 C4 1μF 14 C+ NEG C- TP1 IN ENLED GND1 NEG LED1 IN1 1 C6 4.7μF 2 TP2 IN LED2 GND 16 ENLED D1 9 U1 MAX8678 D2 10 TP3 JU4 ENLED NEG 13 LED3 D3 11 TP4 R1 470kΩ ENAMP 5 JU5 ENAMP IN+ 8 R2 470kΩ C3 0.1μF A+ OUT+ JU3 4 D4 12 ENAMP BIAS 3 C2 1μF LED4 OUT- 6 7 OUT+ OUT+ AEP C1 1μF JU2 NEG IN1 2 3 JU1 Figure 1. MAX8678 EV Kit Schematic (MAX8678) 4 _______________________________________________________________________________________ MAX8678 Evaluation Kit Evaluates: MAX8678 VIO_2V5 C7 0.1μF C8 0.1μF S1 18 DEMO 27 54 55 56 VDDIO VLCD VLCD1 VLCD2 49 SEG28/P3.4/INT4 19 UP 20 SEG29/P3.5/INT5 SEG30/P3.6/INT6 S4 21 UP SEG31/P3.7/INT7 S5 GAIN 62 DOWN 64 D5 GAIN 60 R4 220Ω VIO_2V5 D6 LED 65 R3 220Ω 61 66 67 68 1 2 3 4 5 6 C11 10pF J1 JTAG Y1 16MHz C9 10pF J1-2 51 50 J1-10 34 J1-8 J1-4 VIO_2V5 35 J1-9 J1-5 J1-3 J1-6 IN2 SEG6/P0.6/INT2 SEG7/P0.7/INT3 SEG2/P0.2 P5.2/RX1/INT10 P5.3/TX1/INT11 P6.4/TOB/WKOUT0 P6.5/TO/WKOUT1 P7.0/TXO/INT14 P7.1/RX0/INT15 U2 MAXQ2000 P5.4/SS P5.5/MOSI P5.6/SCLK P5.7/MISO HFXIN HFXOUT 32KIN P6.0/T1B/INT12 P6.1/T1/INT13 SEG5/P0.5/INT1 SEG0/P0.0 SEG1/P0.1 Y2 32.768kHz J1-7 J1-1 SEG4/P0.4/INT0 SEG3/P0.3 SEG8/P1.0 SEG9/P1.1 SEG10/P1.2 SEG11/P1.3 SEG12/P1.4 SEG13/P1.5 SEG14/P1.6 SEG15/P1.7 SEG16/P2.0 TCK 29 TDI 30 TMS 31 TDO 32 RESET 33 VADJ SEG18/P2.2 SEG19/P2.3 SEG20/P2.4 SEG21/P2.5 SEG22/P2.6 SEG23/P2.7 SEG24/P3.0 SEG25/P3.1 SEG26/P3.2 SEG27/P3.3 SEG32 SEG33/COM3 SEG34/COM2 SEG35/COM1 COM0 S3 DOWN 57 SEG17/P2.1 S2 LED VDD 32KOUT 7 8 9 10 11 12 13 14 15 16 17 22 23 24 25 26 ENAMP ENLED 36 37 47 48 52 53 38 39 40 41 43 44 63 58 59 P4.0/TCK/INT8 P6.2/T2B/OW_OUT P6.3/T2/OW_IN P4.1/TDI/INT9 45 46 P4.2/TMS P4.3/TDO RESET EP GND 42 GND 28 IN2 3 2 1 GND2 JU7 1 C13 1μF 2 IN R5 10kΩ 3 IN U3 OUT 5 VIO_2V5 C12 1μF MAX8511 GND SHDN N.C. 4 Figure 2. MAX8678 EV Kit Schematic (Pulse Generator) _______________________________________________________________________________________ 5 Evaluates: MAX8678 MAX8678 Evaluation Kit Figure 3. MAX8678 EV Kit Component Placement Guide—Component Side 6 _______________________________________________________________________________________ MAX8678 Evaluation Kit Evaluates: MAX8678 Figure 4. MAX8678 EV Kit PCB Layout—Component Side _______________________________________________________________________________________ 7 Evaluates: MAX8678 MAX8678 Evaluation Kit Figure 5. MAX8678 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. 8 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2008 Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc.