19-6310; Rev 0; 5/12
E V A L U A T I O N K I T A V A I L A B L E
MAX14627/MAX14628
Low-Power Headset Detectors with
SEND/END Button Support
General Description
Benefits and Features
The MAX14627/MAX14628 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 needed to detect SEND/END button
press events and generate required microphone bias volt-
ages, and are fully compatible with Windows Mobile 7.
The devices need only three GPIOs from the host control-
ler 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 sup-
ply 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. If a 3P headset without a microphone is
inserted, the low-power pulsing can be disabled by setting
the MODE input to high impedance.
The MAX14627 operates from a 2.5V to 5.5V input voltage
supply and features an internal 2.2V LDO output, while the
MAX14628 operates from a 3.1V to 5.5V voltage supply
and features an internal 2.8V LDO output voltage. Both
devices control jack insertion detection by monitoring a
3.5mm socket with a normally open jack insertion switch.
Additionally, the MAX14628 features open microphone
detection.
S Versatile Jack Detection and Control
MODE Three-State Microphone Bias Control
MIC Switch Ground Detection (MAX14627)
MIC Switch Open and Ground Detection
(MAX14628)
S Compatible with Windows Mobile 7 and Google
Android
Microphone Button Press Detection
S High-Performance MIC Bias and Power Savings
No Pop-Up Noises
Ultra-Low Noise, High-PSRR MIC Bias
Low-Power MIC Idle Mode
Automatic Ultra-Low-Power Mode When
Microphone Is Disabled
S PCB Space and Cost Savings
Integrated 1ꢀkV ESD Protection (HBM) on
DETIN and MIC Input Terminals
Small 8-Pin (2mm x 2mm) TDFN Package
Applications
Cell Phones
Portable Media Players
Tablet/Laptop PCs
Ordering Information appears at end of data sheet.
For related parts and recommended products to use with this part,
refer to www.maxim-ic.com/MAX14627.related.
Windows Mobile is a registered trademark of Microsoft Corporation.
The MAX14627/MAX14628 are available in an 8-pin TDFN
package, and are fully specified over the -40NC to +85NC
extended temperature range.
Typical Operating Circuits
V
CC
Typical Operating Circuits continued
at end of data sheet.
MIC
AUDIO DIRECT
DRIVE
1µF
V
CC
MODE
SWD
CAP
RES
1µF
V
V
IO
IO
1MI
1MI
MAX14628
2.2kI
PROCESSOR
MIC
LEFT
DET
MIC
MICROPHONE
SEND/
END
DET
DETIN
RIGHT
GND
EP/GND
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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.