19-5995; Rev 0; 8/11 MAX14579E Evaluation Kit Evaluates: MAX14579E/MAX14579AE General Description Features The MAX14579E evaluation kit (EV kit) provides a proven design to evaluate the MAX14579E headset detection IC. The EV kit is designed to demonstrate the IC’s headset insertion detection, SEND/END detection, and microphone low-power features. The EV kit requires a single power source using an active USB port. S USB Powered or External Power Supplies The EV kit PCB comes with a MAX14579EETA in an 8-pin TDFN package with an exposed pad installed and can also be used to evaluate the MAX14579AE. S Headset SEND/END Detection S Low-Power Microphone Mode S Low-Noise Microphone Bias Generator S Configurable for Headsets with Normally Open Detection Switches S Proven PCB Layout S Fully Assembled and Tested Ordering Information appears at end of data sheet. Component List DESIGNATION QTY DESCRIPTION DESIGNATION QTY J4 0 Not installed, jack DESCRIPTION JU1, JU2 2 3-pin headers JU3 1 2-pin header L1 1 Ferrite bead (0603) Murata BLM18SG700TN1 1 1FF Q10%, 16V X5R ceramic capacitor (0603) Murata GRM188R61C105k 0 Not installed, ceramic capacitor (0603) MIC 1 Red test point C3 1 0.22FF Q10%, 25V X7R ceramic capacitor (0603) TDK C1608X7R1E224K P1 1 USB type-B right-angle PC-mount receptacle 2 1MI Q5% resistors (0603) 2 0.1FF Q10%, 50V X5R ceramic capacitors (0603) Murata GRM188R61H104K R1, R2 C4, C5 R3 1 2.2kI Q5% resistor (0603) R4 1 10kI Q5% resistor (0603) GND 2 Black test points J1 1 3.5mm audio jack U1 1 J2 1 3.5mm, 4-pole jack KSD Co. KJA-PH-00176 Headset jack detection IC (8 TDFN-EP) Maxim MAX14579EETA+ — 3 Shunts 1 3.5mm, 4-pole jack INCHANG Electronics IJAN-97 — 1 PCB: MAX14579E EVALUATION KIT C1 C2 J3 Component Suppliers SUPPLIER PHONE WEBSITE INCHANG Electronics 82-31-4688181 www.inchange.en.ec21.com KSD Co. 82-31-3719955 www.ksdigital.en.ec21.com Murata Electronics North America, Inc. 770-436-1300 www.murata-northamerica.com TDK Corp. 847-803-6100 www.component.tdk.com Note: Indicate that you are using the MAX14579E when contacting these component suppliers. __________________________________________________________________ Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. MAX14579E Evaluation Kit Evaluates: MAX14579E/MAX14579AE Quick Start Required Equipment • MAX14579E EV kit • User-supplied PC with a spare USB port • 3-channel oscilloscope • Audio input source (optional) • USB cable • 3.5mm headset or microphone input source Procedure The EV kit if fully assembled and tested. Follow the steps below to verify board operation: 1) Verify that shunts are installed on pins 1-2 on jumpers JU1 and JU2. 2) Verify that a shunt is installed on jumper JU3. 3) Connect the USB cable to the USB connector (P1) on the EV kit. 4) Connect the other end of the USB cable to an active USB port. 5) Connect the oscilloscope to the DETIN, DET, and SWD PCB pads. 6) Verify that DETIN, DET, and SWD amplitudes are approximately 5V. 7) Insert a headset with a normally open detection switch to the audio line at J2. 8) Verify that DETIN and DET are low. 9) Press and hold the headset microphone pushbutton. Verify that SWD is low. 10) Release the headset microphone pushbutton and verify that SWD goes high. Detailed Description of Hardware The MAX14579E EV kit provides a proven design to evaluate the MAX14579E insertion jack detection, microphone bias generator, and SEND/END button-press detection IC. The EV kit requires an active USB port or an external 2.5V to 5.5V supply for operation The MAX14579E/MAX14579AE devices manage headsets by integrating a jack insertion detection circuit, microphone bias generation, and SEND/END button-press detection. The devices feature a low-power microphone mode to reduce the high bias current required for microphone operation when the microphone is not in use. The EV kit circuit provides two 3.5mm headset jacks (J2 and J3) for quick evaluation of the devices. The EV kit also provides a 3.5mm audio jack (J1) for routing audio signals to J2 and J3. The audio signals can also be applied at the AUDIO_L and AUDIO_R PCB pads. The MAX14579E and MAX14579AE have 350ms (typ) and 1s (typ) DETIN to DET debounce delays, respectively. The EV kit provides PCB pads for monitoring the SWD, DET, DETIN, and MIC_OUT signals in addition to a test point for monitoring the MIC voltage. The EV kit can also be used to evaluate the MAX14579AE with IC replacement of U1. External Power Supply The EV kit derives it power from the USB port (P1) or an external voltage applied at the VCC and GND PCB pads. A 2.5V to 5.5V external supply can be applied at the VCC and GND PCB pads. When operating the EV kit using an external supply, verify that P1 is not connected to an active USB port. Power-Mode Selection (JU1) Jumper JU1 configures the IC power mode. Install a shunt on pins 1-2 to enter call mode. In call mode, the internal 2.2V (typ) LDO turns on immediately and generates the microphone bias voltage (VBIAS) when a plug is inserted at J2 or J3. The LDO is connected to the MIC through bias resistor R3. The bias voltage can be monitored at the MIC test point. Install a shunt on pins 2-3 on JU1 to place the IC in standby mode. The microphone bias connection either turns off permanently if a headset is inserted at J2, or J3 enters microphone low-power mode (MPLP). In MPLP mode, the MIC output is pulsed high every 8ms (typ) with a peak amplitude equivalent to VBIAS. See Table 1 for JU1 configuration. The MODE input is compatible with 1.8V logic and can be set using VCC or a 1.8V to 5.5V external supply at the VLOGIC and GND PCB pads Refer to the MODE Control Input section in the MAX14579E/MAX14579AE IC data sheet for a detailed description of the IC power-mode states. Table 1. Power-Mode Selection (JU1) SHUNT POSITION MODE PIN 1-2 Connected to VLOGIC Call 2-3 Connected to ground Standby POWER MODE __________________________________________________________________ Maxim Integrated Products 2 MAX14579E Evaluation Kit Evaluates: MAX14579E/MAX14579AE Headset Detection/Insertion The EV kit circuit detects a headset insertion/removal event by monitoring the DETIN input on the IC. Jumper JU2 configures the EV kit for headsets with normally open insertion detection switches. Insert a shunt on pins 1-2 for evaluating a headset with a normally open detection switch to the audio line connected at J2. Install a shunt on pins 2-3 to evaluate a headset with a normally open detection switch to ground at J3. When a valid headset is inserted at the connectors, DETIN is pulled low and DET is low after the IC DETIN-to-DET debounce period. Headset SEND/END Detection The IC SEND/END detection circuitry is active when DETIN is low. The EV kit circuit detects a SEND/END button-press event by monitoring the MIC input. When pressing the headset MIC pushbutton, the SEND/END open-drain logic output (SWD) goes low after the 30ms (typ) debounce period. The SWD output can be monitored using the SWD PCB pad. Digital Supply Selection (JU3) The EV kit provides DETIN and DET PCB pads for monitoring the input and output signals, respectively. See Table 2 for proper JU2 configuration when operating the EV kit using a headset at J2 or J3. Jumper JU3 selects the EV kit digital supply voltage. Install a shunt on jumper JU3 to select VCC as the digital supply voltage. Remove the shunt on JU3 and apply a user-supplied 1.8V to 5.5V DC power supply at the VLOGIC and GND PCB pads. See Table 3 for proper jumper configuration for setting the EV kit digital supply voltage. Table 2. Headset Configuration (JU2) Table 3. Digital Voltage Configuration (JU3) SHUNT POSITION HEADSET CONNECTED AT HEADSET SWITCH CONFIGURATION 1-2 J2 Normally open to audio line 2-3 J3 Normally open to GND SHUNT POSITION DIGITAL VOLTAGE SUPPLY Installed VCC Not installed User-supplied 1.8V to 5.5V power source applied at VLOGIC and GND PCB pads __________________________________________________________________ Maxim Integrated Products 3 MAX14579E Evaluation Kit Evaluates: MAX14579E/MAX14579AE Figure 1. MAX14579E EV Kit Schematic __________________________________________________________________ Maxim Integrated Products 4 MAX14579E Evaluation Kit Evaluates: MAX14579E/MAX14579AE 1.0” Figure 2. MAX14579E EV Kit Component Placement Guide— Component Side 1.0” Figure 3. MAX14579E EV Kit PCB Layout—Component Side 1.0” Figure 4. MAX14579E EV Kit PCB Layout—Solder Side __________________________________________________________________ Maxim Integrated Products 5 MAX14579E Evaluation Kit Evaluates: MAX14579E/MAX14579AE Ordering Information PART TYPE MAX14579EEVKIT# #Denotes RoHS compliant. EV Kit __________________________________________________________________ Maxim Integrated Products 6 MAX14579E Evaluation Kit Evaluates: MAX14579E/MAX14579AE Revision History REVISION NUMBER REVISION DATE 0 8/11 DESCRIPTION Initial release PAGES CHANGED — 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. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2011 Maxim Integrated Products 7 Maxim is a registered trademark of Maxim Integrated Products, Inc.