19-5964; Rev 0; 06/11
TION KIT EVALUA BLE ILA AVA
Low-Power Headset Detectors with SEND/END Button Support
Features
S 3.5mm Jack Insertion Detection S Simple Interface: One Input/Two Open-Drain Outputs S Low-Power Microphone Mode S Low-Noise, High-PSRR Microphone Bias Generator S Click-and-Pop Suppression S High-ESD Protection on MIC and DETIN Inputs ±15kV Human Body Model (HBM)
General Description
The MAX14579E/MAX14579AE provide a simple solution for detecting the insertion and managing the operation of a 3.5mm stereo headset with a microphone. These devices integrate all circuitry required to detect SEND/ END button press events and generate required microphone bias voltages. The devices are managed with only three GPIOs from the host controller to select between call mode and standby mode, and monitor the SEND/END and jack insertion status. In call mode, the low-noise LDO is enabled to provide DC bias to the externally preamplified microphone. In standby mode, microphone low-power pulsing is enabled to reduce supply current while waiting for a SEND/END button press event. Two open-drain outputs signal the host controller when an insertion/removal or SEND/END button press event occurs. The MAX14579E/MAX14579AE manage jack insertion detection by monitoring a 3.5mm socket with a normally open jack insertion switch. The devices are available in an 8-pin TDFN package, and are fully specified over the -40NC to +85NC extended temperature range.
MAX14579E/MAX14579AE
Applications
Cell Phones e-Readers Tablet PCs
Ordering Information
PART MAX14579EETA+ MAX14579AEETA+** TEMP RANGE -40NC to +85NC -40NC to +85NC PIN-PACKAGE 8 TDFN-EP* 8 TDFN-EP*
+Denotes a lead(Pb)-free/RoHS compliant package. *EP = Exposed pad. **Future product—contact factory for availablity.
Typical Operating Circuit
ADC 1µF 3.3V 3.5mm SOCKET MODE VCC CAP 0.22µF
3.3V PROCESSOR
1MΩ
SWD 3.3V
MAX14579E
RES
2.2kΩ
DETIN DET EP/GND MIC
10kΩ
1MΩ
AUDIO AMPLIFIER MICROPHONE AMPLIFIER 0.1µF
_______________________________________________________________ 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.
Low-Power Headset Detectors with SEND/END Button Support MAX14579E/MAX14579AE
ABSOLUTE MAXIMUM RATINGS
(Voltages referenced to ground.) VCC, MODE, SWD, DET .......................................... -0.3V to +6V CAP, MIC, DETIN, RES ............................ -0.3V to (VCC + 0.3V) Continuous Current into Any Terminal .......................... Q100mA Continuous Power Dissipation (TA = +70NC) TDFN (derate 11.9mW/NC above +70NC) ................. 953.5mW Operating Temperature Range .......................... -40NC to +85NC Junction Temperature .....................................................+150NC Storage Temperature Range............................ -65NC to +150NC Lead Temperature (soldering, 10s) ...............................+300NC Soldering Temperature (reflow) ......................................+260NC
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
PACKAGE THERMAL CHARACTERISTICS (Note 1)
TDFN Junction-to-Ambient Thermal Resistance (BJA) ........ 83.9NC/W Junction-to-Case Thermal Resistance (BJC)................ 37NC/W Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a fourlayer board. For detailed information on package thermal considerations, refer to www.maxim-ic.com/thermal-tutorial.
ELECTRICAL CHARACTERISTICS
(VCC = 2.5V to 5.5V, CDETIN < 100pF, TA = -40NC to +85NC, unless otherwise noted. Typical values are at VCC = 3.6V, TA = +25NC.) (Note 2) PARAMETER DC CHARACTERISTICS Supply Voltage Range VCC Undervoltage-Lockout Threshold VCC VCCUVLO VCC rising MODE = low, DETIN = high VCC Supply Current ICC VCC = 2.8V MODE = low, DETIN = low, IMIC = 300FA MODE = high, DETIN = low, IMIC = 300FA DETIN Pullup Resistance Internal Microphone Bias Voltage MIC SEND/END Detection Threshold DETIN Detection Threshold Falling edge RDETIN VBIAS MODE = low MODE = high, DETIN = low 0.20 O VBIAS 1/3 O VCC 2.5 0.9 1.7 0.8 8 500 1000 VCC 2.2 0.22 O VBIAS 1/2 O VCC 0.24 O VBIAS 2/3 O VCC 5.5 2.45 1.3 11 800 kI V V V FA V V SYMBOL CONDITIONS MIN TYP MAX UNITS
2
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Low-Power Headset Detectors with SEND/END Button Support
ELECTRICAL CHARACTERISTICS (continued)
(VCC = 2.5V to 5.5V, CDETIN < 100pF, TA = -40NC to +85NC, unless otherwise noted. Typical values are at VCC = 3.6V, TA = +25NC.) (Note 2) PARAMETER LINEAR REGULATOR (CAP) Minimum Bypass Capacitance Output Current Limit Output Voltage LDO PSRR COUT ICAP VLDO PSRRLDO VCAP < VLDO VCC = 2.8V Noise from VCC to CAP, f = 217Hz, VCC = 2.8V Q0.1V, ICAP = 300FA, MODE = high VCC = 2.8V, IMIC = 300FA, f = 100Hz to 4000Hz VCC = 2.8V, RL = 2kI, VCAP from 90% to 10% 1.4 0.4 -1 Output voltage = 5V ISINK = 1mA RMIC = 5kI, MPLP RMIC = 5kI, MPLP Falling edge MAX14579E MAX14579AE 120 8 300 1000 28 Human Body Model Human Body Model Q15 Q2 +1 1 0.4 0.22 4 2.0 2.2 100 2.45 FF mA V dB SYMBOL CONDITIONS MIN TYP MAX UNITS
MAX14579E/MAX14579AE
LDO Noise LDO Turn-Off Time
NLDO tOFF
11 120
FVRMS Fs
DIGITAL SIGNALS (MODE, SWD, DET) Input-Voltage High Input-Voltage Low Input Leakage Current Output Logic-High Leakage Current (Open Drain) Output Logic-Low DYNAMIC CHARACTERISTICS MIC Low-Power Mode On-Time MIC Low-Power Mode Period DETIN Debounce Time SEND/END Debounce Time ESD PROTECTION MIC, DETIN All Other Pins kV kV tMICLPO tMICLPP tDETINDEB tSEDEB Fs ms ms ms VIH VIL IINLEAK IOH_LKG VOL V V FA FA V
Note 2: All units are production tested at TA = +25NC. Specifications over temperature are guaranteed by design.
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Low-Power Headset Detectors with SEND/END Button Support MAX14579E/MAX14579AE
Typical Operating Characteristics
(MAX14579E, VCC = 3.3V, TA = +25NC, CDETIN < 100pF, unless otherwise noted.)
VCC SUPPLY CURRENT vs. VOLTAGE
MAX14579E toc01
VCC SUPPLY CURRENT vs. VOLTAGE
MPLP MODE IMIC = 0µA TA = +85°C TA = +25°C
6 4 2 0
MAX14579E toc02
4.5 4.0 3.5 3.0 ICC (µA) 2.5 2.0 1.5 1.0 0.5 0
SHUTDOWN MODE
12 10 8
TA = -40°C
ICC (µA)
TA = +25°C TA = +85°C
2.5 3.5 VCC (V) 4.5 5.5
TA = -40°C
2.5
3.5 VCC (V)
4.5
5.5
VCC SUPPLY CURRENT vs. VOLTAGE
MAX14579E toc03
CAP VOLTAGE vs. VCC
ICAP = 0mA
MAX14579E toc04
200 180 160
CALL MODE IMIC = 0µA
TA = +85°C
3.0 2.5 2.0 VCAP (V) 1.5 1.0 0.5 0
ICC (µA)
140 120 100 80 60 2.5 3.5 VCC (V) 4.5 5.5
TA = +25°C TA = -40°C
2.5
3.5 VCC (V)
4.5
5.5
CAP VOLTAGE vs. CURRENT
MAX14579E toc05
CAP VOLTAGE vs. TEMPERATURE
VCC = 2.8V ICAP = 0mA
MAX14579E toc06
3.0 2.5 2.0 VCAP (V) 1.5 1.0 0.5 0 0
VCC = 3.3V
3.0 2.5 2.0 VCAP (V) 1.5 1.0 0.5 0
1
2
3
4
5
6
7
-40
-15
10 TA (°C)
35
60
85
ICAP (mA)
4
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Low-Power Headset Detectors with SEND/END Button Support
Typical Operating Characteristics (continued)
(MAX14579E, VCC = 3.3V, TA = +25NC, CDETIN < 100pF, unless otherwise noted.)
CAP POWER-SUPPLY REJECTION RATIO vs. FREQUENCY
VCC = 2.8V ± 0.1V
MAX14579E toc08
MAX14579E/MAX14579AE
CAP DROPOUT VOLTAGE vs. CAP CURRENT
TA = -40°C
DROPOUT VOLTAGE (mV) 2000
MAX14579E toc07
2500
0 -20 PSRR TO CAP (dB) -40 -60 -80 -100 -120
TA = +25°C
1500
TA = +85°C
1000 500 0 0 1 2 3 4 5 6 7 ICAP (mA)
10
100
1000 FREQUENCY (Hz)
10,000
100,000
CAP NOISE DENSITY vs. FREQUENCY
NOISE SPECTRAL DENSITY (µV/√Hz) 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 100 1000 FREQUENCY (Hz) 10,000
MAX14579E toc09
MICROPHONE LOW-POWER MODE OPERATION
MAX14579E toc10
1.0
3.3V VMIC 1V/div 0V
1ms/div
DETIN DEBOUNCE TIMING (MODE = LOW)
MAX14579E toc11
SWD DEBOUNCE TIMING
3.3V VDETIN 1V/div 0V 3.3V VRES 2V/div 0V
MAX14579E toc12
3.3V VMIC 1V/div 0V 3.3V VSWD 2V/div 0V
40ms/div
100ms/div
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Low-Power Headset Detectors with SEND/END Button Support MAX14579E/MAX14579AE
Pin Configuration
TOP VIEW
MIC 8 DETIN 7 VCC 6 CAP 5
+
1 RES
MAX14579E MAX14579AE *EP/GND
2 MODE
3 SWD
4 DET
TDFN
*CONNECT THE EXPOSED PAD (EP/GND) TO THE GROUND PLANE.
Pin Description
PIN 1 2 3 4 5 6 7 8 — NAME RES MODE SWD DET CAP VCC DETIN MIC EP FUNCTION Resistor Connection. Connect an external 2.2kI resistor from RES to MIC for microphone biasing. Microphone Mode Control Input. MODE selects the operating mode. See the MODE Control Input section for more information. SEND/END Button Detection Output. SWD asserts when a SEND/END button press event occurs. SWD is an active-low, open-drain output. Jack Insertion Detection Open-Drain Output. DET is asserted when there is a 3.5mm jack inserted into the socket. DET is an active-low output. Internal LDO Output. Connect a 0.22FF ceramic (X5R, X7R, or better) capacitor between CAP and ground. Supply Voltage. Bypass VCC to ground with a 1FF ceramic capacitor. Jack Insertion Detection Input. An internal comparator monitors DETIN for jack insertion/ removal events. Microphone Connection. During audio operation, a 2.2V bias voltage is supplied to MIC through RES. An internal comparator monitors MIC for SEND/END button press events. Exposed Pad. The exposed pad is the ground connection for the device. Connect EP/GND to the ground plane.
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Low-Power Headset Detectors with SEND/END Button Support
Functional Diagram
VCC VBIAS
MAX14579E/MAX14579AE
MAX14579E MAX14579AE
LOW-NOISE 2.2V LDO
CAP
MODE
CONTROL
RES
DEBOUNCE
SWD MIC
DEBOUNCE
0.22VBIAS
DET
VCC
LM
DETIN 0.5VCC
Detailed Description
The MAX14579E/MAX14579AE manage headsets by integrating 3.5mm jack insertion detection, microphone bias generation, and SEND/END button press detection. These devices feature a low-power microphone mode to reduce the high bias current required for microphone operation while it is not in use. The devices require only a single MODE input to select between call mode and low-power mode. See the Jack Insertion Detection section for details about the differences among the devices. The devices feature an internal low-noise, low-dropout regulator (LDO) for biasing the microphone connected to MIC. The LDO’s output voltage is set at 2.2V. The LDO is enabled and enters low-noise mode when the MODE input is logic-high and a jack is detected. Pull the MODE input low to put the LDO in low-power shutdown mode.
An externally preamplified microphone is connected to MIC. Connect MIC to RES through an external 2.2kI resistor to bias the microphone. All the devices generate a bias voltage (VBIAS) at RES. VBIAS is generated either by the internal 2.2V (typ) LDO when the MODE input is logic-high or by VCC when the MODE input is logic-low.
Microphone Operation and Bias Voltage Generation
Internal LDO Regulator
A microphone draws a large amount of current due to the required bias resistor when it is connected. This current is dissipated even while the microphone is not in use. The ICs feature internal circuitry to reduce this current while simultaneously detecting SEND/END button press events.
Microphone Low-Power Mode (MPLP)
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Low-Power Headset Detectors with SEND/END Button Support MAX14579E/MAX14579AE
When microphone low-power mode (MPLP) is entered by pulling the MODE input low, the bias voltage is disconnected from the RES output and is reconnected for a short duration every 8ms (typ) to check for a SEND/END button press event. MPLP is exited when the MODE input transitions to logic-high. Note that VBIAS is permanently disconnected from RES when no jack is inserted and microphone low-power mode is not entered. The MAX14579E/MAX14579AE detect jack insertion/ removal events by monitoring the DETIN input. Debounce circuitry ensures that transient voltages do not force the device to enter or exit MPLP due to false jack insertion/ removal detection. MAX14579E Detection The MAX14579E/MAX14579AEs' DETIN input has an internal 1MI pullup resistor to VCC. DETIN monitors a normally open insertion detection switch connected between DETIN and an audio line. DETIN is pulled high by the resistor, and DET is logic-high when no jack is inserted into the socket. DETIN is pulled low by the switch, and DET is logic-low when a jack is inserted. Ensure that the total capacitance on DETIN is less than 100pF. The MAX14579E/MAX14579AE detect SEND/END button press events by monitoring the MIC input. A SEND/ END button press is detected if the voltage at MIC falls below the MIC SEND/END detection threshold (0.22 O VBIAS (typ)) for longer than the debounce time (typ). The SWD output is logic-low for the duration of the SEND/ END button press event following the debounce period. The SEND/END detection circuitry is active whenever a jack is inserted. The debounce period built into the SEND/END button press detection allows the mechanical SEND/END button to reach steady-state before applying the microphone bias. This mitigates click-and-pop noise. An external host processor controls the MODE input. Table 1 shows the behavior of the device based on the MODE input and jack insertion status. The device enters call mode when MODE is logic-high and a jack is detected, enabling the LDO immediately in low-noise mode (LNM). The 2.2V (typ) LDO output powers VBIAS and is connected to the microphone through an external 2.2kI bias resistor. Pull MODE low to put the device in standby mode. In standby mode, VCC powers VBIAS, the LDO enters shutdown mode (SDM), and the microphone bias connection either turns off permanently if no jack is inserted or enters MPLP if a jack is inserted. The MODE input is compatible with 1.8V logic with VCC voltages up to 5.5V.
MODE Control Input
Jack Insertion Detection
Applications Information
There are two typical 3.5mm jacks: tip-ring-ring-sleeve (TRRS) with four conductors (Figure 1a) and tip-ringsleeve (TRS) with three conductors (Figure 1b). The most common configuration of the TRRS jack is to use rings 1 and 2 for audio signals, ring 3 for ground, and ring 4 for a microphone. The TRS jack typically uses rings 1 and 2 for audio signals and rings 3 and 4 as ground.
Typical Connections for 3.5mm Jacks
SEND/END Button Press Detection
Table 1. Operating Modes
MODE DETIN/MIC INSERTED LDO Mode MIC Bias Mode MPLP LOW SDM Off 2.2kI LOW HIGH LOW SDM Off HIGH HIGH
1
2
3 (a)
4
1
2
3 (b)
4
Figure 1. Typical 3.5mm Jacks
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Low-Power Headset Detectors with SEND/END Button Support
The devices support all standard configurations of headsets with a microphone and SEND/END button on a TRS or TRRS 3.5mm jack. Figure 2 shows the supported connections of the speakers, SEND/END button, and microphone to the jack. Headset with No Microphone When the 3.5mm jack in Figure 2a is inserted, the MIC input is pulled low permanently by the ground connection on the sleeve and the SWD output is logic-low permanently. This type of headset is supported by implementing a timeout period in software to recognize that the permanent logic-low is not due to a very long SEND/ END button press event. Headset with Microphone and Normally Open SEND/END Button in Parallel When the 3.5mm jack in Figure 2b is inserted, the MIC input is pulled below the threshold only during a SEND/ END button press event. The SWD output is logic-high when the SEND/END button is pressed for more than the debounce time. Headset with Normally Open SEND/END Button and Resistive Remote Control The devices support the 3.5mm jack with a microphone and two buttons in Figure 2c that is the standard Windows Mobile™ configuration. The threshold is set to detect a button press, regardless of which button is pressed. Electrostatic discharge (ESD)-protection structures are incorporated on all pins to protect against electrostatic discharges up to Q2kV Human Body Model (HBM) encountered during handling and assembly. DETIN and MIC are further protected against ESD up to Q15kV (HBM) without damage. After an ESD event, all the devices continue to function without latchup.
1 2
Supported Accessories
MAX14579E/MAX14579AE
1
2
3
4
SPEAKER
SPEAKER (a)
1
2
3
4
SPEAKER
MICROPHONE SEND/ END
SPEAKER (b)
3
4
SPEAKER
SEND/ END
600Ω
200Ω
MICROPHONE
SPEAKER (c)
High-ESD Protection
Figure 2. Supported 3.5mm Accessory Configurations
Windows Mobile is a registered trademark of Microsoft Corporation. _______________________________________________________________________________________ 9
Low-Power Headset Detectors with SEND/END Button Support MAX14579E/MAX14579AE
RC 1MΩ CHARGE-CURRENT LIMIT RESISTOR HIGHVOLTAGE DC SOURCE RD 1.5kΩ DISCHARGE RESISTANCE DEVICE UNDER TEST IP 100% 90% AMPS 36.8% 10% 0 Ir PEAK-TO-PEAK RINGING (NOT DRAWN TO SCALE)
CS 100pF
STORAGE CAPACITOR
0
tRL
TIME tDL CURRENT WAVEFORM
Figure 3. Human Body ESD Test Model
Figure 4. Human Body Current Waveform
ESD performance depends on a variety of conditions. Contact Maxim for a reliability report that documents test methodology, and results. Figure 3 shows the Human Body Model. Figure 4 shows the current waveform it generates when discharged into a low impedance. This model consists of a 100pF capacitor charged to the ESD voltage of interest that is then discharged into the device through a 1.5kI resistor.
ESD Test Conditions
Chip Information
PROCESS: BiCMOS
Human Body Model
Package Information
For the latest package outline information and land patterns (footprints), go to www.maxim-ic.com/packages. Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. PACKAGE TYPE 8 TDFN-EP PACKAGE CODE T822+2 OUTLINE NO. 21-0168 LAND PATTERN NO. 90-0065
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Low-Power Headset Detectors with SEND/END Button Support
Revision History
REVISION NUMBER 0 REVISION DATE 6/11 Initial release DESCRIPTION PAGES CHANGED —
MAX14579E/MAX14579AE
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.
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©
11
2011 Maxim Integrated Products
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