AS3421-EQFP-500

AS3421-EQFP-500 Datasheet

AS3421 AS3422

Part	Datasheet
AS3421-EQFP-500	AS3421-EQFP-500 (pdf)

Related Parts	Information
AS3421-EQFP	AS3421-EQFP
AS3421	AS3421
AS3422-EQFP-500	AS3422-EQFP-500
AS3422	AS3422
AS3422 EK-ST	AS3422 EK-ST

PDF Datasheet Preview
Datasheet AS3421 AS3422 Low Power Ambient Noise-Cancelling Speaker Driver 1 General Description The AS3421/22 are speaker driver with Ambient Noise Cancelling function for headsets, headphones or ear pieces. It is intended to improve quality of e.g. music listening, a phone conversation etc. by reducing background ambient noise. The fully analog implementation allows the lowest power consumption, lowest system BOM cost and most natural received voice enhancement otherwise difficult to achieve with DSP implementations. The device is designed to be easily applied to existing architectures. An internal OTP-ROM can be optionally used to store the microphone gain calibration settings as well as all application specific settings. The AS3421/22 can be used in different configurations for best trade-off of noise cancellation, required filtering functions and mechanical designs. The simpler feed-forward topology is used to effectively reduce frequencies typically up to 2-3kHz. The feed-back topology with either 1 or 2 filtering stages has it strengths especially at very low frequencies. The typical bandwidth for feedback system is from 20Hz up to 1kHz which is a little bit lower than with feed forward systems. The filter loop for both systems is determined by measurements, for each specific headset individually, and depends very much on mechanical designs. The gain and phase compensation filter network is implemented with cheap resistors and capacitors for lowest system costs. AS3421/22 features also an audio playback only mode which allows the user to easily switch between ANC on and off mode. In ANC off mode unused blocks are automatically switch off to guaranty lowest power consumption in each operating mode. 2 Key Features Microphone Input 128 gain steps 0.375dB and MUTE with AGC Differential, low noise microphone amplifier Single ended or differential mode Improved supply for electret microphone MIC gain OTP programmable High Efficiency Headphone Amplifier 2x23mW, THD+N 1.5V supply, 100dB SNR Bridged mode for e.g. loads Click and pop less start-up and mode switching Line Input Volume control via serial interface or push buttons 64 steps 0.75dB and MUTE, pop-free gain setting Fully differential stereo line inputs ANC processing Feed-forward cancellation Feed-back cancellation with filter loop transfer function definable via simple RC components Simple in production SW calibration 12-30dB noise reduction headset dependent 10-3000Hz wide frequency active noise attenuation headset dependent Monitor Function For assisted hearing, i.e. to monitor announcements Fixed OTP prog. ambient sound amplification to compensate headphone passive attenuation Incremental Functions ANC with or without music on the receiving path Music Playback mode for lowest power consumption OTP ROM for automatic trimming during production 4 times programmable Performance Parameter 7mA 1.5V stereo ANC <1µA quiescent Extended PSRR for 217Hz Increased TDMA noise immunity Interfaces 2-wire serial control mode & volume inputs Calibration via Line-In or 2-wire serial interface Fixed 1.0-1.8V supply with internal CP Package AS3421 QFN24 [4x4mm] 0.5mm pitch AS3422 QFN32 [5x5mm] 0.5mm pitch 3 Applications The devices are ideal for wireless devices like stereo Bluetooth headsets as well as stereo wireless headsets. 1 - 61 AS3421 AS3422 Datasheet - Applications Figure AS3421 Feed Forward ANC Block Diagram Figure AS3422 Feed-Back Block Diagram 2 - 61 AS3421 AS3422 Datasheet - Contents 4 Contents 1 General Description 1 2 Key 1 3 1 4 3 5 Pin Assignments 4 Pin 5 6 Absolute Maximum Ratings 6 7 Electrical 7 8 Typical Operating Characteristics 8 9 Detailed Description Audio Line Input 11 Microphone Input 12 Headphone Output 14 Operational Amplifier 15 SYSTEM 17 VNEG Charge Pump 20 OTP Memory & Internal Registers 20 2-Wire-Serial Control Interface 23 10 Register Description 27 11 Application Information 43 AS3422 Feedback Application Examples 43 AS3421 Feed Forward Application Examples 47 Layout Recommendation 51 Bill of Materials 52 PCB Footprint Recommendation 53 12 Package Drawings and Marking Ordering Information 3 - 61 AS3421 AS3422 Datasheet - Pin Assignments 5 Pin Assignments Note Pin assignment may change in preliminary data sheets. Figure Pin Assignments Top View CAUTION Exposed pad must be connect to VNEG or left unconnected. Exposed pad must NOT be connected to GND or AGND! 4 - 61 AS3421 AS3422 Datasheet - Pin Assignments Pin Descriptions Note Pin description may change in preliminary data sheets. Table Pin Description for AS3421 AS3422 Pin Number Pin Name Type AS3421 AS3422 IOP1L ANA IN QLINL ANA OUT QMICL ANA OUT AGND ANA IN LINL_N ANA IN LINL_P ANA IN LINR_P ANA IN LINR_N ANA IN ANC_CSDA MIXED IO MODE_CSCL DIG IN MICL MICS MICR QMICR QLINR IOP1R QOP1R IOP2R QOP2R VSS HPL HPVSS HPR HPVDD VBAT CPP GND CPN VNEG QOP2L IOP2L QOP1L VNEG ANA IN ANA OUT ANA IN Datasheet - Ordering Information 13 Ordering Information The devices are available as the standard products shown in Table Table Ordering Information Ordering Code AS3421-EQFP Low Power Ambient Noise-Cancelling Speaker Driver AS3421-EQFP-500 Low Power Ambient Noise-Cancelling Speaker Driver AS3422-EQFP Low Power Ambient Noise-Cancelling Speaker Driver AS3422-EQFP-500 Low Power Ambient Noise-Cancelling Speaker Driver Delivery Form Package Tape & Reel dry pack QFN 24 [4.0x4.0x0.85mm] 0.5mm pitch Tape & Reel dry pack QFN 24 [4.0x4.0x0.85mm] 0.5mm pitch Tape & Reel dry pack QFN 32 [5.0x5.0x0.85mm] 0.5mm pitch Tape & Reel dry pack QFN 32 [5.0x5.0x0.85mm] 0.5mm pitch Note All products are RoHS compliant and austriamicrosystems green. Buy our products or get free samples online at ICdirect: For further information and requests, please contact us or find your local distributor at 60 - 61 AS3421 AS3422 Datasheet - Copyrights Copyrights Copyright 1997-2012, austriamicrosystems AG, Tobelbaderstrasse 30, 8141 Unterpremstaetten, Austria-Europe. Trademarks Registered All rights reserved. The material herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. All products and companies mentioned are trademarks or registered trademarks of their respective companies. Disclaimer Devices sold by austriamicrosystems AG are covered by the warranty and patent indemnification provisions appearing in its Term of Sale. austriamicrosystems AG makes no warranty, express, statutory, implied, or by description regarding the information set forth herein or regarding the freedom of the described devices from patent infringement. austriamicrosystems AG reserves the right to change specifications and prices at any time and without notice. Therefore, prior to designing this product into a system, it is necessary to check with austriamicrosystems AG for current information. This product is intended for use in normal commercial applications. Applications requiring extended temperature range, unusual environmental requirements, or high reliability applications, such as military, medical life-support or life-sustaining equipment are specifically not recommended without additional processing by austriamicrosystems AG for each application. For shipments of less than 100 parts the manufacturing flow might show deviations from the standard production flow, such as test flow or test location. The information furnished here by austriamicrosystems AG is believed to be correct and accurate. However, austriamicrosystems AG shall not be liable to recipient or any third party for any damages, including but not limited to personal injury, property damage, loss of profits, loss of use, interruption of business or indirect, special, incidental or consequential damages, of any kind, in connection with or arising out of the furnishing, performance or use of the technical data herein. No obligation or liability to recipient or any third party shall arise or flow out of austriamicrosystems AG rendering of technical or other services. Contact Information Headquarters austriamicrosystems AG Tobelbaderstrasse 30 A-8141 Unterpremstaetten, Austria Tel +43 0 3136 500 0 Fax +43 0 3136 525 01 For Sales Offices, Distributors and Representatives, please visit: 61 - 61

PDF Datasheet Preview

Datasheet

AS3421 AS3422

Low Power Ambient Noise-Cancelling Speaker Driver
1 General Description

The AS3421/22 are speaker driver with Ambient Noise Cancelling function for headsets, headphones or ear pieces. It is intended to improve quality of e.g. music listening, a phone conversation etc. by reducing background ambient noise.

The fully analog implementation allows the lowest power consumption, lowest system BOM cost and most natural received voice enhancement otherwise difficult to achieve with DSP implementations. The device is designed to be easily applied to existing architectures.

An internal OTP-ROM can be optionally used to store the microphone gain calibration settings as well as all application specific settings.

The AS3421/22 can be used in different configurations for best trade-off of noise cancellation, required filtering functions and mechanical designs.

The simpler feed-forward topology is used to effectively reduce frequencies typically up to 2-3kHz. The feed-back topology with either 1 or 2 filtering stages has it strengths especially at very low frequencies. The typical bandwidth for feedback system is from 20Hz up to 1kHz which is a little bit lower than with feed forward systems.

The filter loop for both systems is determined by measurements, for each specific headset individually, and depends very much on mechanical designs. The gain and phase compensation filter network is implemented with cheap resistors and capacitors for lowest system costs.

AS3421/22 features also an audio playback only mode which allows the user to easily switch between ANC on and off mode. In ANC off mode unused blocks are automatically switch off to guaranty lowest power consumption in each operating mode.
2 Key Features

Microphone Input 128 gain steps 0.375dB and MUTE with AGC

Differential, low noise microphone amplifier

Single ended or differential mode

Improved supply for electret microphone

MIC gain OTP programmable

High Efficiency Headphone Amplifier 2x23mW, THD+N 1.5V supply, 100dB SNR

Bridged mode for e.g. loads

Click and pop less start-up and mode switching

Line Input Volume control via serial interface or push buttons 64 steps 0.75dB and MUTE, pop-free gain setting Fully differential stereo line inputs

ANC processing Feed-forward cancellation Feed-back cancellation with filter loop transfer function definable via simple RC components Simple in production SW calibration 12-30dB noise reduction headset dependent 10-3000Hz wide frequency active noise attenuation headset dependent

Monitor Function For assisted hearing, i.e. to monitor announcements Fixed OTP prog. ambient sound amplification to compensate headphone passive attenuation

Incremental Functions ANC with or without music on the receiving path Music Playback mode for lowest power consumption OTP ROM for automatic trimming during production 4 times programmable

Performance Parameter 7mA 1.5V stereo ANC <1µA quiescent Extended PSRR for 217Hz Increased TDMA noise immunity

Interfaces 2-wire serial control mode & volume inputs Calibration via Line-In or 2-wire serial interface Fixed 1.0-1.8V supply with internal CP

Package AS3421 QFN24 [4x4mm] 0.5mm pitch AS3422 QFN32 [5x5mm] 0.5mm pitch
3 Applications

The devices are ideal for wireless devices like stereo Bluetooth headsets as well as stereo wireless headsets.
1 - 61

AS3421 AS3422

Datasheet - Applications

Figure AS3421 Feed Forward ANC Block Diagram

Figure AS3422 Feed-Back Block Diagram
2 - 61

AS3421 AS3422

Datasheet - Contents
4 Contents
1 General Description 1 2 Key 1 3 1 4 3 5 Pin Assignments 4

Pin 5 6 Absolute Maximum Ratings 6 7 Electrical 7 8 Typical Operating Characteristics 8 9 Detailed Description
Audio Line Input 11 Microphone Input 12 Headphone Output 14 Operational Amplifier 15 SYSTEM 17 VNEG Charge Pump 20 OTP Memory & Internal Registers 20 2-Wire-Serial Control Interface 23 10 Register Description 27 11 Application Information 43 AS3422 Feedback Application Examples 43 AS3421 Feed Forward Application Examples 47 Layout Recommendation 51 Bill of Materials 52 PCB Footprint Recommendation 53 12 Package Drawings and Marking Ordering Information
3 - 61

AS3421 AS3422

Datasheet - Pin Assignments
5 Pin Assignments

Note Pin assignment may change in preliminary data sheets. Figure Pin Assignments Top View

CAUTION Exposed pad must be connect to VNEG or left unconnected. Exposed pad must NOT be connected to GND or AGND!
4 - 61

AS3421 AS3422

Datasheet - Pin Assignments

Pin Descriptions

Note Pin description may change in preliminary data sheets.

Table Pin Description for AS3421 AS3422

Pin Number

Pin Name

Type

AS3421 AS3422

IOP1L

ANA IN

QLINL

ANA OUT

QMICL

ANA OUT

AGND

ANA IN

LINL_N

ANA IN

LINL_P

ANA IN

LINR_P

ANA IN

LINR_N

ANA IN

ANC_CSDA

MIXED IO

MODE_CSCL

DIG IN

MICL MICS MICR QMICR QLINR IOP1R QOP1R IOP2R QOP2R VSS HPL HPVSS HPR HPVDD VBAT CPP GND CPN VNEG QOP2L IOP2L QOP1L VNEG

ANA IN

ANA OUT

ANA IN
Datasheet - Ordering Information
13 Ordering Information

The devices are available as the standard products shown in Table
Table Ordering Information
Ordering Code

AS3421-EQFP

Low Power Ambient Noise-Cancelling Speaker Driver

AS3421-EQFP-500

Low Power Ambient Noise-Cancelling Speaker Driver

AS3422-EQFP

Low Power Ambient Noise-Cancelling Speaker Driver

AS3422-EQFP-500

Low Power Ambient Noise-Cancelling Speaker Driver

Delivery Form

Package

Tape & Reel dry pack

QFN 24 [4.0x4.0x0.85mm] 0.5mm pitch

Tape & Reel dry pack

QFN 24 [4.0x4.0x0.85mm] 0.5mm pitch

Tape & Reel dry pack

QFN 32 [5.0x5.0x0.85mm] 0.5mm pitch

Tape & Reel dry pack

QFN 32 [5.0x5.0x0.85mm] 0.5mm pitch

Note All products are RoHS compliant and austriamicrosystems green. Buy our products or get free samples online at ICdirect:

For further information and requests, please contact us or find your local distributor at
60 - 61

AS3421 AS3422

Datasheet - Copyrights

Copyrights

Copyright 1997-2012, austriamicrosystems AG, Tobelbaderstrasse 30, 8141 Unterpremstaetten, Austria-Europe. Trademarks Registered All rights reserved. The material herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. All products and companies mentioned are trademarks or registered trademarks of their respective companies.

Disclaimer

Devices sold by austriamicrosystems AG are covered by the warranty and patent indemnification provisions appearing in its Term of Sale. austriamicrosystems AG makes no warranty, express, statutory, implied, or by description regarding the information set forth herein or regarding the freedom of the described devices from patent infringement. austriamicrosystems AG reserves the right to change specifications and prices at any time and without notice. Therefore, prior to designing this product into a system, it is necessary to check with austriamicrosystems AG for current information. This product is intended for use in normal commercial applications. Applications requiring extended temperature range, unusual environmental requirements, or high reliability applications, such as military, medical life-support or life-sustaining equipment are specifically not recommended without additional processing by austriamicrosystems AG for each application. For shipments of less than 100 parts the manufacturing flow might show deviations from the standard production flow, such as test flow or test location. The information furnished here by austriamicrosystems AG is believed to be correct and accurate. However, austriamicrosystems AG shall not be liable to recipient or any third party for any damages, including but not limited to personal injury, property damage, loss of profits, loss of use, interruption of business or indirect, special, incidental or consequential damages, of any kind, in connection with or arising out of the furnishing, performance or use of the technical data herein. No obligation or liability to recipient or any third party shall arise or flow out of austriamicrosystems AG rendering of technical or other services.

Contact Information

Headquarters austriamicrosystems AG Tobelbaderstrasse 30 A-8141 Unterpremstaetten, Austria Tel +43 0 3136 500 0 Fax +43 0 3136 525 01

For Sales Offices, Distributors and Representatives, please visit:
61 - 61

More datasheets: 3GD-201 | 3GC-201 | 1799 | DUALCON-3 | ADNS-3150-001 | 44211 | AS3421-EQFP | AS3421 | AS3422-EQFP-500 | AS3422

Notice: we do not provide any warranties that information, datasheets, application notes, circuit diagrams, or software stored on this website are up-to-date or error free. The archived AS3421-EQFP-500 Datasheet file may be downloaded here without warranties.

Datasheet ID: AS3421-EQFP-500 519678