LM4935 - Audio Sub-System with Dual-Mode Stereo Headphone & Mono High Efficiency Loudspeaker Amplifiers and Multi-Purpose ADC

LM4935

Audio Sub-System with Dual-Mode Stereo Headphone & Mono High Efficiency Loudspeaker Amplifiers and Multi-Purpose ADC

Overview

Diagrams

Parametrics

Documents

Order

Boards

Packaging

Tools

Reliability

Obsolete

Features

• 18-bit stereo DAC

• 16-bit mono ADC

• 12-bit 4 input multipurpose SAR ADC

• 8 kHz to 48 kHz stereo audio playback

• 8 kHz to 48 kHz mono recording

• 1 Hz to 13.888 kHz sample rate on all 4 SAR channels

• Bidirectional PCM/I²S compatible audio interface

• Sigma-Delta PLL for operation from any clock at any sample rate

• Low power clock network operation if 12 MHz system clock is available

• Read/write I²C or SPI compatible control interface

• 33mW stereo headphone amplifier at 3.3V

• OCL or AC-coupled headphone operation

• Automatic headphone & microphone detection

• Support for internal and external microphones

• Automatic gain control for microphone input

• High efficiency BTL 8 amplifier, 600 mW @ 3.3V

• 115 mW earpiece amplifier at 3.3V

• Differential audio I/O for external cellphone module

• Mono differential auxiliary output

• Stereo auxiliary inputs

• Differential microphone input for internal microphone

• Flexible audio routing from input to output

• 32 Step volume control for mixers with 1.5 dB steps

• 16 Step volume control for microphone in 2 dB steps

• Programmable sidetone attenuation in 3 dB steps

• DC Volume Control

• Two configurable GPIO ports

• Programmable voltage triggers on SAR channels

• Multi-function IRQ output

• Micro-power shutdown mode

• Available in the 4 x 4 mm 49 bump micro SMDxt package

Description
The LM4935 is an integrated audio subsystem that supports both analog and digital audio functions. The LM4935 includes a high quality stereo DAC, a mono ADC, a multi-purpose SAR ADC, a stereo headphone amplifier, which supports output cap-less (OCL) or AC-coupled (SE)modes of operation, a mono earpiece amplifier and a mono high efficiency loudspeaker amplifier. It is designed for demanding applications in mobile phones and other portable devices.

The LM4935 features a bi-directional I²S serial interface for full range audio and an I²C or SPI compatible interface for control. The stereo DAC path features an SNR of 88 dB with an 18-bit 48 kHz input. In SE mode the headphone amplifier delivers at least 33 mW_RMS to a 32 single-ended stereo load with less than 1% distortion (THD+N) when A_V_DD = 3.3V. The mono earpiece amplifier delivers at least 115 mW_RMS to a 32 bridged-tied load with less than 1% distortion (THD+N) when A_V_DD = 3.3V. The mono speaker amplifier delivers up to 600 mW into an 8 load with less than 1% distortion when LS_V_DD = 3.3V and up to 1.3W when LS_V_DD = 5.0V. The LM4935 also contains a general purpose SAR ADC for housekeeping duties such as battery and temperature monitoring. This can also be used for analog volume control of the output stages and can trigger interrupt events.

The LM4935 employs advanced techniques to reduce power consumption, to reduce controller overhead to speed development time and to eliminate click and pop. Boomer audio power amplifiers were designed specifically to provide high quality output power with a minimal amount of external components. It is therefore ideally suited for mobile phone and other low voltage applications where minimal power consumption, PCB area and cost are primary requirements.

Key Specification

P_{HP (AC-COUP)} @ A_V_DD = 3.3V, 32, 1% THD

33 mW

P_{HP (OCL)} @ A_V_DD = 3.3V, 32, 1% THD

31 mW

P_LS @ LS_V_DD = 5V, 8, 1% THD

1.3 W

P_LS @ LS_V_DD = 4.2V, 8, 1% THD

900 mW

P_LS @ LS_V_DD = 3.3V, 8, 1% THD

600 mW

Supply Voltage Range BB_V_DD = 1.8V to 4.5V, D_V_DD & PLL_V_DD = 2.7V to 4.5V LS_V_DD& A_V_DD = 2.7V to 5.5V

Shutdown Current

1.1 µA

PSRR @ 217 Hz, A_V_DD = 3.3V, (Headphone)

60 dB

SNR (Stereo DAC to AUXOUT)

88 dB (typ)

SNR (Mono ADC from Cell Phone In)

90 dB (typ)

SNR (Aux In to Headphones)

98 dB (typ)

Applications

• Smartphones

• Mobile Phones and Multimedia Terminals

• PDAs, Internet Appliances and Portable Gaming

• Portable DVD/CD/AAC/MP3 Players

• Digital Cameras/Camcorders

MY BRIEFCASE

Click any "Briefcase" icon to add an item

Typical Application click for larger image

Connection Diagram click for larger image

Typical Performance *click for larger image

Parameters Values

Power@ 8Ohms, 1% THD 0.6 Watt

THD 0.4 %

PSRR 54 dB

SNR 76 dB

Channels 4 Channels

THD Conditions 8ohms, Pout=400mW

PSRR Conditions Aux inputs terminated, CB=1uF, Vripple=200mVpp, fripple=217Hz

SNR Conditions From 0dB Analog Aux input at 1kHz, A-weighted

User Supply 3.3 Volt

Audio Mux Yes

Capless Headphone No

ClassD Driver Yes

Interface I2C, SPI, I2S

Stereo Inputs 1 analog + I2S

National 3D No

Digital Volume Control Max 12 dB

Digital Volume Control Min -45.6 dB

Output Modes 1000

Supply Range +2.7 - +5.5 V

Mono Inputs 1 analog + I2S

Temperature Min -40 deg C

Temperature Max 85 deg C

Loudspeaker Type Class D

Headphone Type Virtual Ground

Loudspeaker Outputs 3

A/D Channels 2 Channels

D/A Channels 2

Datasheet
Title Size Date Other
Language

LM4935 Boomer ® Audio Power Amplifier Series Audio Sub-System with Dual-Mode Stereo Headphone & Mono High Efficiency Loudspeaker Amplifiers and Multi-Purpose ADC 5013
Kbytes 29-Mar-06

Featured Application Notes
Title Size Date Other
Language

AN-1432: Application Note 1432 The LM4935 Headset/Push-Button Detection Guide 464
Kbytes 24-Apr-06 中文

AN-1451: Application Note 1451 LM4935 Automatic Gain Control (AGC) Guide 550
Kbytes 24-Apr-06 中文

More Application Notes
Title Size Date Other
Language

AN-1492: Application Note 1492 LM4934 I2C/SPI Interface Software Manual v1.0 1527
Kbytes 25-May-06 中文

Part Number(s)
(NSID)

Top View

Availability

Current Reported Stock

Budgetary Pricing

Standard Pack Size

LM4935RL/NOPB

RoHS

Full production
Lead Time: 6 weeks

Distributor	Region	Qty
ARROW	Worldwide	250
DIGIKEY	Worldwide	728
FUTURE	Worldwide	250

$3.95 each at 1K+ pcs

reel
of
250

LM4935RLX/NOPB

RoHS

Full production
Lead Time: 6 weeks

Distributor		Region	Qty
DIGIKEY		Worldwide	0

$3.95 each at 1K+ pcs

reel
of
1000

Obsolete Versions

Obsolete Part Alternate Part or Supplier Source Last Time Buy Date

LM4935WL
LM4935RL
NATIONAL SEMICONDUCTOR
06 Mar 2007

LM4935WLX
LM4935RLX
NATIONAL SEMICONDUCTOR
06 Mar 2007

Part Number(s)
(NSID)

Description

Availability

Current Reported Stock

Budgetary Pricing

Standard Pack Size

LM4935RLEVAL

Audio Sub-System with Dual-Mode Stereo Headphone & Mono High Efficiency Loudspeaker Amplifiers and Multi-Purpose ADC

Full production

Distributor		Region	Qty
NATIONAL		Worldwide	40

$1000.00 each

The LM4935 is an integrated audio subsystem that supports both analog and digital audio functions. The LM4935 includes a high quality stereo DAC, a mono ADC, a multipurpose SAR ADC, a stereo headphone amplifier, which supports output cap-less (OCL) or AC-coupled modes of operation, a mono earpiece amplifier and a mono high efficiency loudspeaker amplifier. It is designed for demanding applications in mobile phones and other portable Devices.

This LM4935RLEVAL is an evaluation kit designed to ease the evaluation and effort during the development of a circuit using the LM4935RL.

Features:

Available in the 4 x 4 mm 49 bump microfil package
18-bit stereo DAC
16-bit mono ADC
12-bit 4 input multipurpose SAR ADC
8 kHz to 48 kHz stereo audio playback
8 kHz to 48 kHz mono recording
1 Hz to 13.888 kHz sample rate on all 4 SAR channels
Bidirectional PCM/I2S compatible audio interface
Sigma-Delta PLL for operation from any clock at any sample rate
Low power clock network operation if 12 MHz system clock is available
Read/write I2C or SPI compatible control interface
30mW stereo headphone amplifier at 3.3V
OCL or AC-coupled headphone operation
Automatic headphone & microphone detection
Support for internal and external microphones
Automatic gain control for microphone input
High efficiency BTL 8W amplifier, 600 mW @ 3.3V
115 mW earpiece amplifier at 3.3V
Differential audio I/O for external cellphone module
Mono differential auxiliary output
Stereo auxiliary inputs
Differential microphone input for internal microphone
Flexible audio routing from input to output
32 Step volume control for mixers with 1.5 dB steps
16 Step volume control for microphone in 2 dB steps
Programmable sidetone attenuation in 3 dB steps
DC Volume Control
Two configurable GPIO ports
Programmable voltage triggers on SAR channels
Multi-function IRQ output
Micro-power shutdown mode

Part Number(s) (NSID)	Top View	Type	Pins	MSL Rating	Peak Reflow	RoHS	CAD Symbols	Models	Package Marking Format
LM4935RL/NOPB		MICRO SMDXT	49	1	260	RoHS	Download	N/A	XYTT I GG7
LM4935RLX/NOPB		MICRO SMDXT	49	1	260	RoHS	Download	N/A	XYTT I GG7

Design Tools
Title Size Date

Audio Amplifier Digital Control Interface Evaluation Board Software

Reliability Metrics

Part Number Process EFR Reject EFR Sample Size PPM LTA Rejects LTA Device Hours FITS MTTF (Hours)

LM4935RL CMOS7 0 18406 0 0 1089000 4 309006723

LM4935RLX CMOS7 0 18406 0 0 1089000 4 309006723

Note: The Early Failure Rates (EFR) were calculated as point estimate PPM based on rejects and sample size for EFR. The Long Term Failure Rates were calculated at 60% confidence using the Arrhenius equation at 0.7eV activation energy and derating the assumed stress temperature of 150°C to an application temperature of 55°C.

For more information on Reliability Metrics, please click here.

[Information as of 21-Nov-2009]