NSC WLA49VVA

LM4935
Audio Sub-System with Dual-Mode Stereo Headphone &
Mono High Efficiency Loudspeaker Amplifiers and
Multi-Purpose ADC
1.0 General Description
j Supply Voltage Range
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 (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 mWRMS to a 32Ω single-ended stereo
load with less than 1% distortion (THD+N) when A_VDD =
3.3V. The mono earpiece amplifier delivers at least 115
mWRMS to a 32Ω bridged-tied load with less than 1% distortion (THD+N) when A_VDD = 3.3V. The mono speaker amplifier delivers up to 600 mW into an 8Ω load with less than
1% distortion when LS_VDD = 3.3V and up to 1.3W when
LS_VDD = 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.
2.0 Applications
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Smartphones
Mobile Phones and Multimedia Terminals
PDAs, Internet Appliances and Portable Gaming
Portable DVD/CD/AAC/MP3 Players
Digital Cameras/Camcorders
3.0 Key Specifications
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PHP (AC-COUP) @ A_VDD = 3.3V, 32Ω, 1% THD
33 mW
PHP (OCL) @ A_VDD = 3.3V, 32Ω, 1% THD
31 mW
PLS @ LS_VDD = 5V, 8Ω, 1% THD
1.3 W
PLS @ LS_VDD = 4.2V, 8Ω, 1% THD
900 mW
PLS @ LS_VDD = 3.3V, 8Ω, 1% THD
600 mW
BB_VDD = 1.8V to 4.5V,
D_VDD & PLL_VDD = 2.7V to 4.5V
LS_VDD & A_VDD = 2.7V to 5.5V
n
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Shutdown Current
PSRR @ 217 Hz, A_VDD = 3.3V, (Headphone)
SNR (Stereo DAC to AUXOUT)
88
SNR (Mono ADC from Cell Phone In)
90
SNR (Aux In to Headphones)
98
1.1 µA
60 dB
dB (typ)
dB (typ)
dB (typ)
4.0 Features
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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 8Ω 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 microfil package
Boomer ® is a registered trademark of National Semiconductor Corporation.
© 2005 National Semiconductor Corporation
DS201341
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LM4935 Audio Sub-System with Dual-Mode Stereo Headphone & Mono High Efficiency
Loudspeaker Amplifiers and Multi-Purpose ADC
October 2005
LM4935
5.0 LM4935 Overview
20134101
FIGURE 1. Conceptual Schematic
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2
LM4935
6.0 Typical Application
20134102
FIGURE 2. Example Application in Multimedia Mobile Phone
3
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LM4935
Table of Contents
1.0 General Description ..................................................................................................................................... 1
2.0 Applications .................................................................................................................................................. 1
3.0 Key Specifications ........................................................................................................................................ 1
4.0 Features ....................................................................................................................................................... 1
5.0 LM4935 Overview ........................................................................................................................................ 2
6.0 Typical Application ........................................................................................................................................ 3
7.0 Connection Diagrams ................................................................................................................................... 6
7.1 PIN TYPE DEFINITIONS .......................................................................................................................... 7
8.0 Absolute Maximum Ratings ........................................................................................................................ 8
9.0 Operating Ratings ........................................................................................................................................ 8
10.0 Electrical Characteristics ........................................................................................................................... 8
11.0 System Control ......................................................................................................................................... 16
11.1 I2C SIGNALS ......................................................................................................................................... 16
11.2 I2C DATA VALIDITY ............................................................................................................................... 16
11.3 I2C START AND STOP CONDITIONS .................................................................................................. 16
11.4 TRANSFERRING DATA ........................................................................................................................ 16
11.5 I2C TIMING PARAMETERS ................................................................................................................. 18
12.0 Status & Control Registers ...................................................................................................................... 20
12.1 BASIC CONFIGURATION REGISTER ................................................................................................. 21
12.2 CLOCKS CONFIGURATION REGISTER ............................................................................................. 22
12.3 LM4935 CLOCK NETWORK ................................................................................................................ 23
12.4 COMMON CLOCK SETTINGS FOR THE DAC & ADC ....................................................................... 24
12.5 PLL M DIVIDER CONFIGURATION REGISTER .................................................................................. 25
12.6 PLL N DIVIDER CONFIGURATION REGISTER .................................................................................. 26
12.7 PLL P DIVIDER CONFIGURATION REGISTER .................................................................................. 27
12.8 PLL N MODULUS CONFIGURATION REGISTER ............................................................................... 28
12.9 FURTHER NOTES ON PLL PROGRAMMING ..................................................................................... 29
12.10 ADC_1 CONFIGURATION REGISTER ............................................................................................... 31
12.11 ADC_2 CONFIGURATION REGISTER ............................................................................................... 32
12.12 AGC_1 CONFIGURATION REGISTER ............................................................................................. 33
12.13 AGC_2 CONFIGURATION REGISTER ............................................................................................. 34
12.14 AGC_3 CONFIGURATION REGISTER ............................................................................................. 35
12.15 AGC OVERVIEW ................................................................................................................................. 36
12.16 MIC_1 CONFIGURATION REGISTER ............................................................................................... 37
12.17 MIC_2 CONFIGURATION REGISTER ............................................................................................... 38
12.18 SIDETONE ATTENUATION REGISTER ............................................................................................. 39
12.19 CP_INPUT CONFIGURATION REGISTER ........................................................................................ 40
12.20 AUX_LEFT CONFIGURATION REGISTER ........................................................................................ 41
12.21 AUX_RIGHT CONFIGURATION REGISTER ...................................................................................... 42
12.22 DAC CONFIGURATION REGISTER .................................................................................................. 43
12.23 CP_OUTPUT CONFIGURATION REGISTER .................................................................................... 44
12.24 AUX_OUTPUT CONFIGURATION REGISTER .................................................................................. 45
12.25 LS_OUTPUT CONFIGURATION REGISTER ..................................................................................... 46
12.26 HP_OUTPUT CONFIGURATION REGISTER .................................................................................... 47
12.27 EP_OUTPUT CONFIGURATION REGISTER .................................................................................... 48
12.28 DETECT CONFIGURATION REGISTER ............................................................................................ 49
12.29 HEADSET DETECT OVERVIEW ........................................................................................................ 50
12.30 STATUS REGISTER ........................................................................................................................... 53
12.31 AUDIO INTERFACE CONFIGURATION REGISTER ......................................................................... 54
12.32 DIGITAL AUDIO DATA FORMATS ...................................................................................................... 55
12.33 GPIO CONFIGURATION REGISTER ................................................................................................. 56
12.34 SAR CHANNELS 0 & 1 CONFIGURATION REGISTER .................................................................... 57
12.35 SAR CHANNELS 2 & 3 CONFIGURATION REGISTER .................................................................... 58
12.36 SAR DATA 0 TO 3 REGISTERS ......................................................................................................... 59
12.37 SAR OVERVIEW ................................................................................................................................. 60
12.38 DC VOLUME CONFIGURATION REGISTER .................................................................................... 62
12.39 SAR TRIGGER 1 CONFIGURATION REGISTER .............................................................................. 63
12.40 SAR TRIGGER 1 MSBs CONFIGURATION REGISTER ................................................................... 64
12.41 SAR TRIGGER 2 CONFIGURATION REGISTER .............................................................................. 65
12.42 SAR TRIGGER 2 MSBs CONFIGURATION REGISTER ................................................................... 66
12.43 DEBUG REGISTER ........................................................................................................................... 67
13.0 Typical Performance Characteristics ....................................................................................................... 68
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14.0
15.0
16.0
17.0
18.0
LM4935
Table of Contents
(Continued)
LM4935 Demonstration Board Schematic Diagram ..............................................................................
Demoboard PCB Layout ........................................................................................................................
Product Status Definitions ......................................................................................................................
Revision History ......................................................................................................................................
Physical Dimensions ..............................................................................................................................
5
104
105
110
111
112
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LM4935
7.0 Connection Diagrams
49 Bump Microfil
49 Bump Microfil Marking
201341P5
Top View
XY — Date Code
TT — Die Traceability
G — Boomer
F4 — LM4935WL/WLX
201341P3
Top View (Bump Side Down)
Order Number LM4935
See NS Package Number WLA49VVA
Pin Descriptions
Pin
Pin Name
Type
Direction
A1
EP_NEG
Analog
Output
Description
A2
A_VDD
Supply
Input
Headphone and mixer VDD
A3
INT_MIC_POS
Analog
Input
Internal microphone positive input
A4
EXT_MIC
Analog
Input
External microphone input
A5
VSAR2
Analog
Input
Input to SAR channel 2
A6
VSAR1
Analog
Input
Input to SAR channel 1
A7
PLL_VSS
Supply
Input
PLL VSS
B1
A_VSS
Supply
Input
B2
EP_POS
Analog
Output
B3
INT_MIC_NEG
Analog
Input
Internal microphone negative input
B4
BYPASS
Analog
Inout
A_VDD/2 filter point
B5
TEST_MODE/CS
Digital
Input
If SPI_MODE = 1, then this pin becomes CS. If SPI_MODE = 0,
and TEST_MODE/CS = 1, then this places the LM4935 into test mode.
B6
PLL_FILT
Analog
Inout
Filter point for PLL VCO input
B7
PLL_VDD
Supply
Input
C1
HP_R
Analog
Output
Headphone Right Output
C2
EXT_BIAS
Analog
Output
External microphone supply (2.0/2.5/2.8/3.3V)
C3
INT_BIAS
Analog
Output
2.0V/2.5V ultra-clean supply for internal microphone
C4
AUX_R
Analog
Input
Right Analog Input
C5
GPIO_2
Digital
Inout
General Purpose I/O 2
C6
SDA
Digital
Inout
Control Data, I2C_SDA or SPI_SDI
C7
SCL
Digital
Input
D1
HP_L
Analog
Output
D2
VREF_FLT
Analog
Inout
Filter point for the microphone power supply
D3
AUX_L
Analog
Input
Left Analog Input
D4
SPI_MODE
Digital
Input
Control mode select 1 = SPI, 0 = I2C (or test)
D5
GPIO_1
Digital
Inout
General Purpose I/O 1
Earpiece negative output
Headphone and mixer VSS
Earpiece positive output
PLL VDD
Control Clock, I2C_SCL or SPI_SCK
Headphone Left Output
D6
BB_VDD
Supply
Input
Baseband VDD for the digital I/Os
D7
D_VDD
Supply
Input
Digital VDD
E1
HP_VMID
Analog
Inout
Virtual Ground for Headphones in OCL mode, otherwise 1st headset detection input
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6
Pin Descriptions
LM4935
7.0 Connection Diagrams
(Continued)
(Continued)
Pin
Pin Name
Type
Direction
E2
HP_VMID_FB
Analog
Inout
VMID Feedback in OCL mode, otherwise a 2nd headset detection input
Description
E3
MIC_DET
Analog
Input
Headset insertion/removal and Microphone presence detection input
E4
CPI_NEG
Analog
Input
E5
IRQ
Digital
Output
E6
I2S_SDO
Digital
Output
E7
I2S_SDI
Digital
Input
I2S Serial Data Input
F1
LS_VDD
Supply
Input
Loudspeaker VDD
Cell Phone analog input negative
Interrupt request signal (NOT open drain)
I2S Serial Data Out
F2
LS_VDD
Supply
Input
Loudspeaker VDD
F3
CPI_POS
Analog
Input
Cell Phone analog input positive
F4
CPO_NEG
Analog
Output
Cell Phone analog output negative
F5
AUX_OUT_NEG
Analog
Output
Auxiliary analog output negative
F6
I2S_WS
Digital
Inout
F7
I2S_CLK
Digital
Inout
G1
LS_POS
Analog
Output
I2S Word Select Signal (can be master or slave)
I2S Clock Signal (can be master or slave)
Loudspeaker positive output
G2
LS_VSS
Supply
Input
G3
LS_NEG
Analog
Output
Loudspeaker negative output
G4
CPO_POS
Analog
Output
Cell Phone analog output positive
G5
AUX_OUT_POS
Analog
Output
Auxiliary analog output positive
G6
D_VSS
Supply
Input
Digital VSS
G7
MCLK
Digital
Input
Input clock from 0.5 MHz to 30 MHz
Loudspeaker VSS
7.1 PIN TYPE DEFINITIONS
Analog Input — A pin that is used by the analog and is
never driven by the device. Supplies are
part of this classification.
Digital Output —
Analog Output — A pin that is driven by the device and
should not be driven by external sources.
Analog Inout — A pin that is typically used for filtering a
DC signal within the device, Passive components can be connected to these pins.
Digital Input —
A pin that is used by the digital but is
Digital Inout —
7
never driven.
A pin that is driven by the device and
should not be driven by another device to
avoid contention.
A pin that is either open drain (I2C_SDA)
or a bidirectional CMOS in/out. In the
later case the direction is selected by a
control register within the LM4935.
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LM4935
8.0 Absolute Maximum Ratings
Thermal Resistance
θJA – WLA49 (soldered down
to PCB with 2in2 1oz. copper
plane)
(Notes 1, 2)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Analog Supply Voltage
(A_VDD & LS_VDD)
Digital Supply Voltage
(BB_VDD & D_VDD & PLL_VDD)
60˚C/W
Soldering Information
6.0V
See AN-1279 for MicrofilTM package information. Peak
reflow temperature should not exceed 235˚C.
6.0V
9.0 Operating Ratings
Storage Temperature
−65˚C to +150˚C
Power Dissipation (Note 3)
Internally Limited
ESD Susceptibility
Human Body Model (Note 4)
Machine Model (Note 5)
2500V
200V
Junction Temperature
150˚C
Temperature Range
−40˚C to +85˚C
Supply Voltage
D_VDD/PLL_VDD
BB_VDD
LS_VDD/A_VDD
2.7V to 4.5V
1.8V to 4.5V
2.7V to 5.5V
10.0 Electrical Characteristics (Notes 1, 2) Unless otherwise stated PLL_VDD = 3.3V, D_VDD = 3.3V,
BB_VDD = 1.8V, A_VDD = 3.3V, LS_VDD = 3.3V. The following specifications apply for the circuit shown in Figure 2 unless
otherwise stated. Limits apply for 25˚C.
LM4935
Symbol
Parameter
Conditions
Typical
(Note 6)
Limit
(Note 7)
Units
DC CURRENT CONSUMPTION
Chip Mode ’00’, fMCLK = 13MHz
DISD
DIST
DIDD
Digital Shutdown Current
Digital Standby Current
Digital Active Current
Chip Mode ’00’, fMCLK = 19.2MHz
0.7
0.7
µA
5
µA
(max)
Chip Mode ’01’, fMCLK = 13MHz
1.5
Chip Mode ’01’, fMCLK = 19.2MHz
2.2
Chip Mode ’10’, fMCLK = 13MHz,
DAC, ADC, SAR OFF
1.5
mA
Chip Mode ’10’, fMCLK = 19.2MHz,
DAC, ADC, SAR OFF
2.2
mA
Chip Mode ’10’, fMCLK = 13MHz
DAC, ADC, SAR ON
11.2
mA
Chip Mode ’10’, fMCLK = 19.2MHz,
DAC, ADC, SAR ON
16.2
20
mA
(max)
0.2
3
µA
(max)
3
µA
(max)
mA
3
mA
(max)
AISD
Analog Shutdown Current
Chip Mode ’00’
AIST
Analog Standby Current
Chip Mode ’01’,
No headset inserted
0.2
All Outputs OFF, SE MODE
6.1
mA
All Outputs OFF, OCL MODE
5.7
mA
All Outputs ON, SE MODE
18.3
mA
AIDD
Analog Active Current
All Outputs ON, OCL MODE
PLLIDD
ADCIDD
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PLL Active Current
ADC Active Current
18.7
28
mA
(max)
fMCLK = 13 MHz
fPLLOUT = 12 MHz, PLL ON only
4.2
mA
fMCLK = 19.2 MHz
fPLLOUT = 12 MHz, PLL ON only
6.2
mA
fMCLK = 13MHz, ADC ON only
2.5
mA
fMCLK = 19.2MHz, ADC ON only
3.6
mA
8
LM4935
10.0 Electrical Characteristics (Notes 1, 2) Unless otherwise stated PLL_VDD = 3.3V, D_VDD = 3.3V,
BB_VDD = 1.8V, A_VDD = 3.3V, LS_VDD = 3.3V. The following specifications apply for the circuit shown in Figure 2 unless
otherwise stated. Limits apply for 25˚C. (Continued)
LM4935
Symbol
Parameter
Conditions
Typical
(Note 6)
Limit
(Note 7)
Units
DC CURRENT CONSUMPTION
DACIDD
DAC Active Current
fMCLK = 13MHz, DAC ON only;
PLL OFF, fS = 48kHz
7.4
mA
fMCLK = 19.2MHz, DAC ON only
PLL OFF; fS = 48kHz
10.7
mA
fMCLK = 13MHz, SAR ON only
1.6
mA
SARIDD
SAR Active Current
LSIDD
Loudspeaker Quiescent Current
HPIDD
Headphone Quiescent Current
HP ON only, OCL MODE
3.9
mA
EPIDD
Earpiece Quiescent Current
EP ON only
4.4
mA
AUXIDD
AUXOUT Quiescent Current
AUXOUT ON only
4.8
mA
CPOUTIDD
CPOUT Quiescent Current
CPOUT ON only
4.8
mA
8Ω load, LS_VDD = 5V
1.3
W
8Ω load, LS_VDD = 4.2V
0.9
W
fMCLK = 19.2MHz, SAR ON only
2.3
mA
LS ON only
8.8
mA
HP ON only, SE MODE
3.5
mA
LOUDSPEAKER AMPLIFIER
PLS
Max Loudspeaker Power
8Ω load, LS_VDD = 3.3V
0.6
LSTHD+N
Loudspeaker Harmonic Distortion
8Ω load, LS_VDD = 3.3V,
PO = 400mW
0.4
%
LSEFF
Efficiency
0 dB Input
MCLK = 12.000 MHz
84
%
PSRRLS
Power Supply Rejection Ration
(Loudspeaker)
AUX inputs terminated
CBYPASS = 1.0 µF
VRIPPLE = 200 mVP-P
fRIPPLE = 217 Hz
54
dB
SNRLS
Signal to Noise Ratio
From 0 dB Analog AUX input at
1 kHz, A-weighted
76
dB
eN
Output Noise
A-weighted
350
µV
VOS
Offset Voltage
7
mV
0.44
W (min)
HEADPHONE AMPLIFIER
PHP
PSRRHP
Headphone Power
Power Supply Rejection Ratio
(Headphones)
32Ω load, 3.3V, SE
33
20
mW
(min)
16Ω load, 3.3V, SE
52
mW
32Ω load, 3.3V, OCL, VCM = 1.5V
31
mW
32Ω load, 3.3V, OCL, VCM = 1.2V
20
mW
16Ω load, 3.3V, OCL, VCM = 1.5V
50
mW
16Ω load, 3.3V, OCL, VCM = 1.2V
32
mW
SE Mode
60
dB
OCL Mode
VCM = 1.2V
68
dB
OCL Mode
VCM = 1.5V
65
dB
AUX inputs terminated
CBYPASS = 1.0 µF
VRIPPLE = 200 mVP-P
fRIPPLE = 217 Hz
9
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LM4935
10.0 Electrical Characteristics (Notes 1, 2) Unless otherwise stated PLL_VDD = 3.3V, D_VDD = 3.3V,
BB_VDD = 1.8V, A_VDD = 3.3V, LS_VDD = 3.3V. The following specifications apply for the circuit shown in Figure 2 unless
otherwise stated. Limits apply for 25˚C. (Continued)
LM4935
Symbol
Parameter
Conditions
Typical
(Note 6)
Limit
(Note 7)
Units
HEADPHONE AMPLIFIER
From 0dB Analog AUX input
A-weighted
SNRHP
Signal to Noise Ratio
SE Mode
98
dB
OCL Mode
VCM = 1.2V
97
dB
OCL Mode
VCM = 1.5V
96
dB
HPTHD+N
Headphone Harmonic Distortion
32Ω load, 3.3V, PO = 7.5mW
eN
Output Noise
A-weighted
∆ACH-CH
Stereo Channel-to-Channel Gain
Mismatch
XTALK
Stereo Crosstalk
0.05
%
12
µV
0.3
dB
SE Mode
61
dB
OCL Mode
63
dB
EARPIECE AMPLIFIER
PEP
Earpiece Power
16Ω load, 3.3V
150
mW
PSRREP
Power Supply Rejection Ratio
(Earpiece)
AUX inputs terminated
CBYPASS = 1.0 µF
VRIPPLE = 200 mVP-P
FRIPPLE = 217 Hz
65
dB
SNREP
Signal to Noise Ratio
From 0dB Analog AUX input,
A-weighted
98
dB
0.04
%
24
µV
15
mV
32Ω load, 3.3V
EPTHD+N
Earpiece Harmonic Distortion
32Ω load, 3.3V, PO = 50mW
eN
Output Noise
A-weighted
VOS
Offset Voltage
115
100
mW
(min)
AUXOUT AMPLIFIER
THD+N
Total Harmonic Distortion + Noise
VO = 1VRMS, 5kΩ load
0.02
%
PSRR
Power Supply Rejection Ratio
AUX inputs terminated
CBYPASS = 1.0µF
VRIPPLE = 200mVPP
fRIPPLE = 217Hz
70
dB
0.02
%
68
dB
CP_OUT AMPLIFIER
THD+N
Total Harmonic Distortion + Noise
VO = 1VRMS, 5kΩ load
PSRR
Power SUpply Rejection Ratio
CBYPASS = 1.0µF
VRIPPLE = 200mVPP
fRIPPLE = 217Hz
MONO ADC
RADC
ADC Ripple
PBADC
ADC Passband
SBAADC
ADC Stopband Attenuation
SNRADC
ADC Signal to Noise Ratio
ADCLEVEL
ADC Full Scale Input Level
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± 0.25
dB
Lower (HPF Mode 1), fS = 8 kHz
300
Hz
Upper
3470
Hz
Above Passband
60
dB
HPF Notch, 50 Hz/60 Hz (worst
case)
58
dB
From CPI, A-weighted
90
dB
1
VRMS
10
LM4935
10.0 Electrical Characteristics (Notes 1, 2) Unless otherwise stated PLL_VDD = 3.3V, D_VDD = 3.3V,
BB_VDD = 1.8V, A_VDD = 3.3V, LS_VDD = 3.3V. The following specifications apply for the circuit shown in Figure 2 unless
otherwise stated. Limits apply for 25˚C. (Continued)
LM4935
Symbol
Parameter
Conditions
Typical
(Note 6)
Limit
(Note 7)
Units
STEREO DAC
RDAC
DAC Ripple
0.1
dB
PBDAC
DAC Passband
20
kHz
SBADAC
DAC Stopband Attenuation
70
dB
SNRDAC
DAC Signal to Noise Ratio
88
dB
DRDAC
DAC Dynamic Range
96
dB
DACLEVEL
DAC Full Scale Output Level
1
VRMS
Min
0.5
MHz
Max
30
MHz
A-weighted, AUXOUT
PLL
FIN
Input Frequency Range
I2S/PCM
fI2SCLK
fPCMCLK
DCI2S_CLK
I2S CLK Frequency
PCM CLK Frequency
I2S_CLK Duty Cycle
fS = 48kHz; 16 bit mode
1.536
MHz
fS = 48kHz; 25 bit mode
2.4
MHz
fS = 8kHz; 16 bit mode
0.256
MHz
fS = 8kHz; 25 bit mode
0.4
MHz
fS = 48kHz; 16 bit mode
0.768
MHz
fS = 48kHz; 25 bit mode
1.2
MHz
fS = 8kHz; 16 bit mode
0.128
MHz
fS = 8kHz; 25 bit mode
0.2
MHz
Min
Max
DCI2S_WS
I2S_WS Duty Cycle
40
% (min)
60
%
(max)
50
%
I2C
TI2CSET
I2C Data Setup Time
Refer to Pg. 18 for more details
100
ns (min)
TI2CHOLD
I2C Data Hold Time
Refer to Pg. 18 for more details
300
ns (min)
SPI
TSPISETENB
Enable Setup Time
100
ns (min)
TSPIHOLD-ENB
Enable Hold Time
100
ns (min)
TSPISETD
Data Setup Time
100
ns (min)
TSPIHOLDD
Data Hold Time
100
ns (min)
TSPICL
Clock Low Time
500
ns (min)
TSPICH
Clock High Time
500
ns (min)
VOLUME CONTROL
Minimum Gain w/ AUX_BOOST OFF
VCRAUX
VCRDAC
VCRCPIN
AUX Volume Control Range
DAC Volume Control Range
CPIN Volume Control Range
–46.5
dB
0
dB
Minimum Gain w/ AUX_BOOST ON
–34.5
dB
Maximum Gain w/ AUX_BOOST ON
12
dB
Minimum Gain w/ DAC_BOOST OFF
–46.5
dB
0
dB
Minimum Gain w/ DAC_BOOST ON
–34.5
dB
Maximum Gain w/ DAC_BOOST ON
12
dB
Maximum Gain w/ AUX_BOOST
OFF
Maximum Gain w/ DAC_BOOST
OFF
Minimum Gain
–34.5
dB
Maximum Gain
12
dB
11
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LM4935
10.0 Electrical Characteristics (Notes 1, 2) Unless otherwise stated PLL_VDD = 3.3V, D_VDD = 3.3V,
BB_VDD = 1.8V, A_VDD = 3.3V, LS_VDD = 3.3V. The following specifications apply for the circuit shown in Figure 2 unless
otherwise stated. Limits apply for 25˚C. (Continued)
LM4935
Symbol
Parameter
Conditions
Typical
(Note 6)
Limit
(Note 7)
Units
VOLUME CONTROL
VCRMIC
MIC Volume Control Range
Minimum Gain
6
dB
Maximum Gain
36
dB
Minimum Gain
–30
dB
VCRSIDE
SIDETONE Volume Control Range
0
dB
SSAUX
AUX VCR Stepsize
1.5
dB
SSDAC
DAC VCR Stepsize
1.5
dB
SSCPIN
CPIN VCR Stepsize
1.5
dB
SSMIC
MIC VCR Stepsize
2
dB
SSSIDE
SIDETONE VCR Stepsize
3
dB
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Maximum Gain
12
LM4935
10.0 Electrical Characteristics (Notes 1, 2) Unless otherwise stated PLL_VDD = 3.3V, D_VDD = 3.3V,
BB_VDD = 1.8V, A_VDD = 3.3V, LS_VDD = 3.3V. The following specifications apply for the circuit shown in Figure 2 unless
otherwise stated. Limits apply for 25˚C. (Continued)
LM4935
Symbol
Parameter
Conditions
Typical
(Note 6)
Limit
(Note 7)
Units
AUDIO PATH GAIN W/ STEREO (bit 6 of 0x00h) ENABLED (AUX_L & AUX_R signals identical and selected onto mixer)
Loudspeaker Audio Path Gain
Minimum Gain from AUX input,
BOOST OFF
–34.5
dB
Maximum Gain from AUX input,
BOOST OFF
12
dB
–22.5
dB
Maximum Gain from CPI input
24
dB
Minimum Gain from AUX input,
BOOST OFF
–52.5
dB
Maximum Gain from AUX input,
BOOST OFF
–6
dB
Minimum Gain from CPI input
Headphone Audio Path Gain
Minimum Gain from CPI input
–40.5
dB
Maximum Gain from CPI input
6
dB
Minimum Gain from MIC input using
SIDETONE path w/ VCRMIC gain =
6dB
–30
dB
Maximum Gain from MIC input using
SIDETONE path w/ VCRMIC gain =
6dB
0
dB
Minimum Gain from AUX input,
BOOST OFF
–40.5
dB
Maximum Gain from AUX input,
BOOST OFF
6
dB
–28.5
dB
Maximum Gain from CPI input
18
dB
Minimum Gain from MIC input using
SIDETONE path w/ VCRMIC gain =
6dB
–18
dB
Maximum Gain from MIC input using
SIDETONE path w/ VCRMIC gain =
6dB
12
dB
Minimum Gain from AUX input,
BOOST OFF
–46.5
dB
Maximum Gain from AUX input,
BOOST OFF
0
dB
Minimum Gain from CPI input
Earpiece Audio Path Gain
AUXOUT Audio Path Gain
CPOUT Audio Path Gain
Minimum Gain from CPI input
–34.5
dB
Maximum Gain from CPI input
12
dB
Minimum Gain from AUX input,
BOOST OFF
–46.5
dB
Maximum Gain from AUX input,
BOOST OFF
0
dB
Minimum Gain from MIC input
6
dB
Maximum Gain from MIC input
36
dB
13
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LM4935
10.0 Electrical Characteristics (Notes 1, 2) Unless otherwise stated PLL_VDD = 3.3V, D_VDD = 3.3V,
BB_VDD = 1.8V, A_VDD = 3.3V, LS_VDD = 3.3V. The following specifications apply for the circuit shown in Figure 2 unless
otherwise stated. Limits apply for 25˚C. (Continued)
LM4935
Symbol
Parameter
Conditions
Typical
(Note 6)
Limit
(Note 7)
Units
Total DC Power Dissipation
DAC (fS = 48kHz) and HP ON
MP3 Mode Power Dissipation
fMCLK = 12MHz, PLL OFF
57
mW
fMCLK = 13MHz, PLL ON
fPLLOUT = 12MHz
63
mW
fMCLK = 19.2MHz, PLL ON
fPLLOUT = 12MHz
64
mW
24
mW
AUX Inputs selected and HP ON
FM Mode Power Dissipation
fMCLK = 12MHz, PLL OFF
fMCLK = 13MHz, PLL OFF
25
mW
fMCLK = 19.2MHz, PLL OFF
27
mW
fMCLK = 12MHz, PLL OFF
49
mW
fMCLK = 13MHz, PLL OFF
50
mW
fMCLK = 19.2MHz, PLL ON
fPLLOUT = 12MHz
56
mW
mW
PCM DAC (fS = 8kHz) + ADC (fS =
8kHz) and EP ON
VOICE CODEC Mode Power
Dissipation
CP IN selected. EP and CPOUT ON
VOICE Module Mode Power
Dissipation
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fMCLK = 12MHz, PLL OFF
30
fMCLK = 13MHz, PLL OFF
31
mW
fMCLK = 19.2MHz, PLL OFF
33
mW
14
Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is
functional but do not guarantee specific performance limits.
Characteristics state DC and AC electrical specifications under particular test conditions which guarantee specific performance limits. This assumes that the device
is within the Operating Ratings. Specifications are not guaranteed for parameters where no limit is given, however, the typical value is a good indication of device
performance.
Note 2: All voltages are measured with respect to the relevant VSS pin unless otherwise specified. All grounds should be coupled as close as possible to the device.
Note 3: The maximum power dissipation must be de-rated at elevated temperatures and is dictated by TJMAX, θJA, and the ambient temperature, TA. The maximum
allowable power dissipation is PDMAX = (TJMAX – TA)/ θJA or the number given in Absolute Maximum Ratings, whichever is lower.
Note 4: Human body model: 100pF discharged through a 1.5kΩ resistor.
Note 5: Machine model: 220pF – 240pF discharged through all pins.
Note 6: Typical values are measured at 25˚C and represent the parametric norm.
Note 7: Limits are guaranteed to Nationals AOQL (Average Outgoing Quality Level).
Note 8: Best operation is achieved by maintaining 3.0V < A_VDD < 5.0 and 3.0V < D_VDD < 3.6V and A_VDD > D_VDD.
Note 9: Digital shutdown current is measured with system clock set for PLL output while the PLL is disabled.
Note 10: Disabling or bypassing the PLL will usually result in an improvement in noise measurements.
15
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LM4935
10.0 Electrical Characteristics (Notes 1, 2) Unless otherwise stated PLL_VDD = 3.3V, D_VDD = 3.3V,
BB_VDD = 1.8V, A_VDD = 3.3V, LS_VDD = 3.3V. The following specifications apply for the circuit shown in Figure 2 unless
otherwise stated. Limits apply for 25˚C. (Continued)
LM4935
11.0 System Control
Method 1. I2C Compatible Interface
11.1 I2C SIGNALS
In I2C mode the LM4935 pin SCL is used for the I2C clock SCL and the pin SDA is used for the I2C data signal SDA. Both these
signals need a pull-up resistor according to I2C specification. The I2C slave address for LM4935 is 00110102.
11.2 I2C DATA VALIDITY
The data on SDA line must be stable during the HIGH period of the clock signal (SCL). In other words, state of the data line can
only be changed when SCL is LOW.
201341Q1
I2C Signals: Data Validity
11.3 I2C START AND STOP CONDITIONS
START and STOP bits classify the beginning and the end of the I2C session. START condition is defined as SDA signal
transitioning from HIGH to LOW while SCL line is HIGH. STOP condition is defined as the SDA transitioning from LOW to HIGH
while SCL is HIGH. The I2C master always generates START and STOP bits. The I2C bus is considered to be busy after START
condition and free after STOP condition. During data transmission, I2C master can generate repeated START conditions. First
START and repeated START conditions are equivalent, function-wise.
201341Q2
11.4 TRANSFERRING DATA
Every byte put on the SDA line must be eight bits long, with the most significant bit (MSB) being transferred first. Each byte of data
has to be followed by an acknowledge bit. The acknowledge related clock pulse is generated by the master. The transmitter
releases the SDA line (HIGH) during the acknowledge clock pulse. The receiver must pull down the SDA line during the 9th clock
pulse, signifying an acknowledge. A receiver which has been addressed must generate an acknowledge after each byte has been
received.
After the START condition, the I2C master sends a chip address. This address is seven bits long followed by an eighth bit which
is a data direction bit (R/W). The LM4935 address is 00110102. For the eighth bit, a “0” indicates a WRITE and a “1” indicates a
READ. The second byte selects the register to which the data will be written. The third byte contains data to write to the selected
register.
201341Q3
I2C Chip Address
Register changes take an effect at the SCL rising edge during the last ACK from slave.
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16
LM4935
11.0 System Control
(Continued)
201341Q5
w = write (SDA = “0”)
r = read (SDA = “1”)
ack = acknowledge (SDA pulled down by slave)
rs = repeated start
Example I2C Write Cycle
17
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LM4935
11.0 System Control
(Continued)
When a READ function is to be accomplished, a WRITE function must precede the READ function, as shown in the Read
Cycle waveform.
201341Q6
Example I2C Read Cycle
201341P9
I2C Timing Diagram
11.5 I2C TIMING PARAMETERS
Symbol
Parameter
Limit
Min
Units
Max
1
Hold Time (repeated) START Condition
0.6
2
Clock Low Time
1.3
µs
3
Clock High Time
600
ns
4
Setup Time for a Repeated START Condition
600
ns
5
Data Hold Time (Output direction, delay generated by LM4935)
300
900
ns
5
Data Hold Time (Input direction, delay generated by the Master)
0
900
ns
6
Data Setup Time
7
Rise Time of SDA and SCL
20+0.1Cb
300
8
Fall Time of SDA and SCL
15+0.1Cb
300
9
Set-up Time for STOP condition
600
ns
10
Bus Free Time between a STOP and a START Condition
1.3
µs
Cb
Capacitive Load for Each Bus Line
10
100
NOTE: Data guaranteed by design
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µs
18
ns
200
ns
ns
pF
LM4935
11.0 System Control
(Continued)
Method 2. SPI/Microwire Control/3–wire Control
The LM4935 can be controlled via a three wire interface consisting of a clock, data and an active low chip_select. To use this
control method connect SPI_MODE to BB_VDD and use TEST_MODE/CS as the chip_select as follows:
20134106
FIGURE 3. SPI Write Transaction
If the application requires read access to the register set; for example to determine the cause of an interrupt request or to read
back a SAR data field, the GPIO2 pin can be configured as an SPI format serial data output by setting the GPIO_SEL in the GPIO
configuration register (0x1Ah) to SPI_SDO. To perform a read rather than a write to a particular address the MSB of the register
address field is set to a 1, this effectively mirrors the contents of the register field to read-only locations above 0x80h:
20134107
FIGURE 4. SPI Read Transaction
Three Wire Mode Write Bus Timing
20134109
FIGURE 5. SPI Timing
19
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LM4935
12.0 Status & Control Registers
TABLE 1. Register Map
Address
Register
7
6
0x00h
BASIC
OCL
STEREO
0x01h
CLOCKS
0x02h
PLL_M
0x03h
PLL_N
0x04h
PLL_P
RSVD
0x05h
PLL_MOD
RSVD
0x06h
ADC_1
5
4
CAP_SIZE
3
2
USE_OSC
PLL_ENB
1
CHP_MODE
R_DIV
PLLINPUT
ADCLK
PLL_M
DACCLK
RSVD
PLL_N
Q_DIV
PLL_P
DITHER_LEVEL
HPF_MODE
ADC_2
0x08h
AGC_1
IF216
0x09h
AGC_2
0x0Ah
AGC_3
AGC_ATTACK
0x0Bh
MIC_1
INT_EXT
0x0Ch
MIC_2
0x0Dh
SIDETONE
RIGHT
ADC_I2SM
AGC_FRAME_TIME
NOISE_GATE_THRESHOLD
NG_ON
AGC_TIGHT
RSVD
PLL_N_MOD
SAMPLE_RATE
0x07h
LEFT
CPI
ADCMUTE COMPND
AGC_TARGET
AGC_DECAY
AGC_HOLD_TIME
SE_DIFF
MUTE
PREAMP_GAIN
BTNTYPE
MIC_BIAS_VOLTAGE
CP_INPUT
MUTE
CPI_LEVEL
AUX_LEFT
AUX_DAC
MUTE
BOOST
AUX_LEFT_LEVEL
0x10h
AUX_RIGHT
AUX_DAC
MUTE
BOOST
AUX_RIGHT_LEVEL
DACMUTE
BOOST
USAXLVL
DAC
CP_OUTPUT
0x13h
AUX OUTPUT
0x14h
LS_OUTPUT
0x15h
HP_OUTPUT
0x16h
EP_OUTPUT
0x17h
DETECT
DAC_LEVEL
MICGATE
MUTE
LEFT
RIGHT
MIC
MUTE
LEFT
RIGHT
CPI
MUTE
LEFT
RIGHT
CPI
MUTE
LEFT
RIGHT
CPI
SIDE
MUTE
LEFT
RIGHT
CPI
HS_DBNC_TIME
GPIN
STATUS
0x19h
AUDIO_IF
0x1Ah
GPIO
GPIODATA
0x1Bh
SAR_SLT0/1
SLT1ENB
0x1Ch
SAR_SLT2/3
0x1Dh
SAR_DATA_0
SLOT0_DATA
0x1Eh
SAR_DATA_1
SLOT1_DATA
0x1Fh
SAR_DATA_2
SLOT2_DATA
0x20h
SAR_DATA_3
SLOT3_DATA
0x21h
DC_VOL
TRIG_1
0x23h
TRIG_1_MSB
0x24h
TRIG_2
0x25h
TRIG_2_MSB
0x26h
DEBUG
TEMP
TEMP_INT BTN_INT
0x18h
0x22h
VCMVOLT
SIDETONE_ATTEN
0x0Fh
0x11h
U/ALAW
AGC_MAX_GAIN
BTN_DEBOUNCE_TIME
0x12h
MIC
AGC_ENB
0x0Eh
I2S_SDO_DATA
PCM_LNG
SARTRG2
SARTRG1
PCMCLMS
PCMSYMS I2SCLKMS I2SWSMS
I2S_MODE
MIC
SAR_CH_SEL
SLOT1_FS
SLT2VBB
BTN
SLT3ENB
STEREO
HEADSET
GPIO_SEL
SLT0ENB
SLOT0_FS
SLT2ENB
SLOT2_FS
TRIG_1 [3:0]
SIDE
DET_INT
AUDIO_IF_MODE
MAX_LVL
EFFECT
DCVLENB
SOURCE
DIR
ENB
SOURCE
DIR
ENB
RSVD
RSVD
TRIG_1 [11:4]
TRIG_2 [3:0]
TRIG_2 [11:4]
GPIO_TEST
_MODE
RSVD
RSVD
RSVD
SOFT
RESET
RSVD
For all registers, the default setting of data bits 7 through 0 are all set to zero.
RESERVED bits should always be set to zero.
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0
20
LM4935
12.0 Status & Control Registers
(Continued)
12.1 BASIC CONFIGURATION REGISTER
This register is used to control the basic function of the chip.
TABLE 2. BASIC (0x00h)
Bits
Field
1:0
CHIP_MODE
Description
The LM4935 can be placed in one of four modes which dictate its basic operation. When a new
mode is selected the LM4935 will change operation silently and will re-configure the power
management profile automatically. The modes are described as follows:
CHIP MODE
Audio System
Detection System
Typical Application
002
Off
Off
Power-down Mode
012
Off
On
Stand-by mode with headset event
detection
102
On
Off
Active without headset event detection
112
On
On
Active with headset event detection
2
PLL_ENABLE
3
USE_OSC
If set the power management and control circuits will assume that no external clock is available and
will resort to using an on-chip oscillator for SAR, headset detection and analog power management
functions such as click and pop.
5:4
CAP_SIZE
Programs the extra delays required to stabilize once charge/discharge is complete, based on the size
of the bypass capacitor.
6
STEREO
7
OCL
If set the PLL can be used.
CAP_SIZE
Bypass Capacitor Size
002
0.1 µF
Turn-off/on time
45 ms/75 ms
012
1 µF
45 ms/140 ms
102
2.2 µF
45 ms/260 ms
112
4.7 µF
45 ms/500 ms
If set, the mixers assume that the signals on the left and right internal busses are highly correlated
and when these signals are combined their levels are reduced by 6 dB to allow enough headroom for
them to be summed at the Loudspeaker, Earpiece, CPOUT, and AUXOUT amplifiers. For the
Headphone amplifier, if this bit is set, the left and right signal levels are routed to the corresponding
left or right headphone output; if this bit is cleared, the left and the right signals are added and routed
to both headphone outputs and their levels are reduced by 6dB to allow enough headroom.
If set the part is placed in OCL (Output Capacitor Less) mode.
For reliable headset / push button detection the following bits should be defined before enabling the headset detection system by
setting bit 0 of CHIP_MODE:
The OCL-bit (Cap / Capless headphone interface; bit 7 of this register)
The headset insert/removal debounce settings (bits 6:3 of DETECT (0x17h))
The BTN_TYPE-bit (Parallel / Series push button type; bit 3 MIC_2 register (0x0Ch))
The parallel push button debounce settings (bits 5:4 of MIC_2 register (0x0Ch))
All register fields controlling the audio system should be defined before setting bit 1 of CHIP_MODE and should not be altered
while the audio sub-system is active.
If the analog or digital levels are below −12 dB then it is not necessary to set the stereo bit allowing greater output levels to be
obtained for such signals.
21
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LM4935
12.0 Status & Control Registers
(Continued)
12.2 CLOCKS CONFIGURATION REGISTER
This register is used to control the clocks throughout the chip.
TABLE 3. CLOCKS (0x01h)
Bits
Field
0
DAC_CLK
1
ADC_CLK
Description
Selects the clock to be used by the audio DAC system.
DAC_CLK
DAC Input Source
0
PLL Input (MCLK or I2S_CLK)
1
PLL Output
Selects the clock to be used by the audio ADC system.
ADC_CLK
7:2
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R_DIV
Audio ADC Input Source
0
MCLK
1
PLL Output
Programs the R divider (divides from an expected 12.000 MHz input).
R_DIV
Divide Value
0
Bypass
1
Bypass
2
1.5
3
2
4
2.5
5
3
6
3.5
7
4
8
4.5
9
5
10
5.5
11
6
12
6.5
13 to 61
7 to 31
62
31.5
63
32
22
LM4935
12.0 Status & Control Registers
(Continued)
12.3 LM4935 CLOCK NETWORK
The audio ADC operates at 125*fs, so it requires a 1.000 MHz clock to sample at 8 kHz (at point C as marked on the following
diagram). The stereo DAC operates at 250*fs, i.e. 12.000 MHz (at point B) for 48 kHz data. It is expected that the PLL is used
to drive the audio system unless a 12.000 MHz master clock is supplied and the sample rate is always a multiple of 8 kHz, in
which case the PLL can be bypassed to reduce power, clock division instead being performed by the Q and R dividers. The PLL
can also use the I2S clock input as a source. In this case, the audio DAC uses the clock from the output of the PLL and the audio
ADC either uses the PLL output divided by 2*FSDAC/FSADC or a system clock divided by Q, this allows n*8 kHz recording and
44.1 kHz playback.
MCLK must be less than or equal to 30 MHz, the I2S clock should be an integer multiple of the DAC’s sampling frequency and
should be below 6 MHz.
When using the Class D amplifier with the DAC the Class D clock generator will assume 12 MHz at point A, if this is not the case
then the DAC and power stage may become unsynchronized and SNR performance may be reduced.
The LM4935 is designed to work from a 12.000 MHz or 11.025 MHz clock at point A. This is used to drive the power management
and control logic. Performance may not meet the electrical specifications if the frequency at this point deviates significantly
beyond this range.
20134110
FIGURE 6. LM4935 Clock Network
23
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LM4935
12.0 Status & Control Registers
(Continued)
12.4 COMMON CLOCK SETTINGS FOR THE DAC & ADC
The DAC has an over sampling rate of 125 but requires a 250*fs clock at point B. This allows a simple clocking solution as it will
work from 12.000 MHz (common in most systems with Bluetooth or USB) at 48 kHz exactly, the following table describes the clock
required at point B for various clock sample rates in the different DAC modes:
TABLE 4. Common DAC Clock Frequencies
DAC Sample Rate (kHz)
Clock Required at B (MHz)
8
2
11.025
2.75625
12
3
16
4
22.05
5.5125
24
6
32
8
44.1
11.025
48
12
The ADC has an over sampling ratio of 125 so the table below shows the required clock frequency at point C.
TABLE 5. Common ADC Clock Frequencies
ADC Sample Rate (kHz)
Clock Required at C (MHz)
8
1
11.025
1.378125
12
1.5
16
2
22.05
2.75625
24
3
Methods for producing these clock frequencies are described in the PLL Section.
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24
LM4935
12.0 Status & Control Registers
(Continued)
12.5 PLL M DIVIDER CONFIGURATION REGISTER
This register is used to control the input section of the PLL.
TABLE 6. PLL_M (0x02h)
Bits
Field
0
RSVD
6:1
PLL_M
7
PLL_INPUT
Description
RESERVED
PLL_M
Input Divider Value
0
1
1
2
2
3
3
4
4...62
5...63
63
64
Programs the PLL input multiplexer to select between:
PLL_INPUT
PLL Input Source
0
MCLK
1
I2S_CLK
The M divider should be set such that the output of the divider is between 0.5 MHz and 5 MHz.
The division of the M divider is derived from PLL_M such that:
M = PLL_M + 1
Note 11: See Further Notes on PLL Programming for more detail.
25
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LM4935
12.0 Status & Control Registers
(Continued)
12.6 PLL N DIVIDER CONFIGURATION REGISTER
This register is used to control the feedback divider of the PLL.
TABLE 7. PLL_N (0x03h)
Bits
Field
7:0
PLL_N
Description
Programs the PLL feedback divider as follows:
PLL_N
Feedback Divider Value
0 to 10
10
11
11
12
12
13
13
14
14
…
…
249
249
250 to 255
250
The N divider should be set such that the output of the divider is between 0.5 MHz and 5 MHz. (Fin/M)*N will be the target resting
VCO frequency, FVCO. The N divider should be set such that 40 MHz < (Fin/M)*N < 60 MHz. Fin/M is often referred to as Fcomp
(comparison frequency) or Fref (reference frequency), in this document Fcomp is used.
The integer division of the N divider is derived from PLL_N such that:
For 9 < PLL_N < 251: N = PLL_N
Note 12: See Further Notes on PLL Programming for further details.
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26
LM4935
12.0 Status & Control Registers
(Continued)
12.7 PLL P DIVIDER CONFIGURATION REGISTER
This register is used to control the output divider of the PLL.
TABLE 8. PLL_P (0x04h)
Bits
Field
0
RSVD
3:1
PLL_P
6:4
7
Q_DIV
RSVD
Description
RESERVED
PLL_P
Output Divider Value
0002
1
0012
2
0102
3
0112
4
1002
5
1012
6
1102
7
1112
8
Programs the Q Divider (divides from an expected 12.000 MHz input).
Q_DIV
Divide Value
0002
2
0012
3
0102
4
0112
6
1002
8
1012
10
1102
12
1112
13
RESERVED
The division of the P divider is derived from PLL_P such that:
P = PLL_P + 1
Note 13: See Further Notes on PLL Programming for more details.
27
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LM4935
12.0 Status & Control Registers
(Continued)
12.8 PLL N MODULUS CONFIGURATION REGISTER
This register is used to control the modulation applied to the feedback divider of the PLL.
TABLE 9. PLL_N_MOD (0x05h)
Bits
Field
4:0
PLL_N_MOD
6:5
DITHER_LEVEL
7
RSVD
Description
Programs the PLL N divider’s fractional component:
PLL_N_MOD
Fractional Addition
0
0/32
1
1/32
2 to 30
2/32 to 30/32
31
31/32
Allows control over the dither used by the N divider:
DITHER_LEVEL
Value
002
Medium
012
Small
102
Large
112
Off
RESERVED
The complete N divider is a fractional divider as such:
N = PLL_N + PLL_N_MOD/32
If the modulus input is zero then the N divider is simply an integer N divider. The output from the PLL is determined by the
following formula:
Fout = (Fin*N)/(M*P)
Note 14: See Further Notes on PLL Programming for more details.
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28
LM4935
12.0 Status & Control Registers
(Continued)
12.9 FURTHER NOTES ON PLL PROGRAMMING
The sigma-delta PLL is designed to drive audio circuits requiring accurate clock frequencies of up to 30 MHz with frequency errors
noise-shaped away from the audio band. The 5 bits of modulus control provide exact synchronization of 48 kHz and 44.1 kHz
sample rates from any common system clock. In systems where an isochronous I2S data stream is the source of data to the DAC
a clock synchronous to the sample rate should be used as input to the PLL (typically the I2S clock). If no isochronous source is
available then the PLL can be used to obtain a clock that is accurate to within 1 Hz of the correct sample rate although this is
highly unlikely to be a problem.
20134111
FIGURE 7. PLL Overview
TABLE 10. Example PLL Settings for 48 kHz and 44.1 kHz Sample Rates
Fin (MHz)
Fs (kHz)
M
N
P
PLL_M
PLL_N
PLL_N_MOD
PLL_P
Fout (MHz)
11
48
11
60
5
10
60
0
4
12
12.288
48
4
19.53125
5
3
19
17
4
12
13
48
13
60
5
12
60
0
4
12
14.4
48
9
37.5
5
8
37
16
4
12
16.2
48
27
100
5
26
100
0
4
12
16.8
48
14
50
5
13
50
0
4
12
19.2
48
13
40.625
5
12
40
20
4
12
19.44
48
27
100
6
26
100
0
5
12
19.68
48
21
64.03125
5
20
64
1
4
12
19.8
48
17
51.5
5
16
51
16
4
12
11
44.1
11
55.125
5
10
55
4
4
11.025
11.2896
44.1
8
39.0625
5
7
39
2
4
11.025
12
44.1
5
22.96875
5
4
22
31
4
11.025
13
44.1
13
55.125
5
12
55
4
4
11.025
14.4
44.1
12
45.9375
5
11
45
30
4
11.025
16.2
44.1
9
30.625
5
8
9
20
4
11.025
16.8
44.1
17
55.78125
5
16
30
25
4
11.025
19.2
44.1
16
45.9375
5
15
45
30
4
11.025
19.44
44.1
14
39.6875
5
13
39
22
4
11.025
19.68
44.1
21
47.0625
4
20
47
2
3
11.025
19.8
44.1
11
30.625
5
10
30
204
4
11.025
29
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LM4935
12.0 Status & Control Registers
(Continued)
These tables cover the most common applications, obtaining clocks for derivative sample rates such as 22.05 kHz should be
done by increasing the P divider value or using the R/Q dividers.
If the user needs to obtain a clock unrelated to those described above, the following method is advised. An example of obtaining
12.000 MHz from 1.536 MHz is shown below (this is typical for deriving DAC clocks from I2S datastreams).
Choose a small range of P so that the VCO frequency is swept between 40 MHz and 60 MHz. So for P = 3 to 5, sweep the M
inputs from 1 to 3. The most accurate N and N_MOD can be calculated by:
N = FLOOR(((Fout/Fin)*(P*M)),1)
N_MOD = ROUND(32*((((Fout)/Fin)*(P*M)-N),0)
This shows that setting M = 1, N = 39+1/16, P = 5 (i.e. PLL_M = 0, PLL_N = 39, PLL_N_MOD = 2, & PLL_P = 4) gives a
comparison frequency of 1.5 MHz, a VCO frequency of 60 MHz and an output frequency of 12.000 MHz. The same settings can
be used to get 11.025 from 1.4112 MHz for 44.1 kHz sample rates.
Care must be taken when synchronization of isochronous data is not possible, i.e. when the PLL has to be used but an exact
frequency match cannot be found. The I2S should be master on the LM4935 so that the data source can support appropriate SRC
as required. This method should only be used with data being read on demand to eliminate sample rate mismatch problems.
Where a system clock exists at an integer multiple of the required ADC or DAC clock rate it is preferable to use this rather than
the PLL. The LM4935 is designed to work in 8, 12, 16, 24, 48 kHz modes from a 12 MHz clock and 8, 13, 26, 52 kHz modes from
a 13 MHz clock without the use of the PLL. This saves power and reduces clock jitter which can affect SNR.
The actual ADC and DAC sample rates are set up by the PLL and internal clock dividers.
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LM4935
12.0 Status & Control Registers
(Continued)
12.10 ADC_1 CONFIGURATION REGISTER
This register is used to control the LM4935’s audio ADC.
TABLE 11. ADC_1 (0x06h)
Bits
Field
0
MIC_SELECT
If set the microphone preamp output is added to the ADC input signal.
Description
1
CPI_SELECT
If set the cell phone input is added to the ADC input signal.
2
LEFT_SELECT
3
RIGHT_SELECT
If set the left stereo bus is added to the ADC input signal.
If set the right stereo bus is added to the ADC input signal.
5:4
ADC_SAMPLE_
RATE
Programs the closest expected sample rate of the mono ADC, which is a variable required by the
AGC algorithm whenever the AGC is in use. This does not set the sample rate of the mono ADC.
ADC_SAMPLE_RATE
7:6
HPF_MODE
Sample Rate
002
8 kHz
012
12 kHz
102
16 kHz
112
24 kHz
Sets the HPF of the ADC
HPF-MODE
HPF Response
002
No HPF
012
FS = 8 kHz, −0.5 dB @ 300 Hz, Notch @ 55 Hz
FS = 12 kHz, −0.5 dB @ 450 Hz, Notch @ 82 Hz
FS = 16 kHz, −0.5 dB @ 600 Hz, Notch @ 110 Hz
102
FS = 8 kHz, −0.5 dB @ 150 Hz, Notch @ 27 Hz
FS = 12 kHz, −0.5 dB @ 225 Hz, Notch @ 41 Hz
FS = 16 kHz, −0.5 dB @ 300 Hz, Notch @ 55 Hz
112
No HPF
31
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LM4935
12.0 Status & Control Registers
(Continued)
12.11 ADC_2 CONFIGURATION REGISTER
This register is used to control the LM4935’s audio ADC.
TABLE 12. ADC_2 (0x07h)
Bits
Field
0
ULAW/ALAW
Description
If COMPAND is set then the data across the PCM interface to the DAC and from the ADC is
companded as follows:
ULAW/ALAW
Commanding Type
0
µ-law
1
A-law
1
COMPAND
If set the 16 bit PCM data from the ADC is companded before the PCM interface and the PCM
data to the DAC is treated as companded data.
2
ADC_MUTE
If set the analog inputs to the ADC are muted.
5:3
AGC_FRAME_TIME
6
ADC_I2S_M
7
AUDIO_IF_2_16BIT
This sets the frame time to be used by the AGC algorithm. In a given frame, the AGC’s peak
detector determines the peak value of the incoming microphone audio signal and compares this
value to the target value of the AGC defined by AGC_TARGET (bits [3:1] of register (0x08h)) in
order to adjust the microphone preamplifiers gain accordingly. AGC_FRAME_TIME basically sets
the sample rate of the AGC to adjust for a wide variety of speech patterns. (Note 15)
AGC_FRAME_TIME
Time (ms)
0002
96
0012
128
0102
192
0112
256
1002
384
1012
512
1102
768
1112
1000
If set the DAC clock system is enabled to drive the I2S in master mode. The Point B frequency
should be double that at Point C. This bit should be set when using the I2S interface in master
mode to read SAR information whenever both the audio ADC and DAC are inactive.
If set the PCM and I2S interfaces are 16 bits per word in master mode. The 2 last clock cycles per
word are 25% shorter to allow generation.
Note 15: Refer to the AGC overview for further detail.
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LM4935
12.0 Status & Control Registers
(Continued)
12.12 AGC_1 CONFIGURATION REGISTER
This register is used to control the LM4935’s Automatic Gain Control. (Note 16)
TABLE 13. AGC_1 (0x08h)
Bits
Field
0
AGC_ENABLE
If set the AGC controls the analog microphone preamplifier gain into the system. The microphone
input must be passed to the ADC.
Description
3:1
AGC_TARGET
Programs the target level of the AGC. This will depend on the expected transients and desired
headroom. Refer to AGC_TIGHT (bit 7 of 0x09h) for more detail.
AGC_TARGET
Target Level
0002
−6 dB
0012
−8 dB
0102
−10 dB
0112
−12 dB
1002
−14 dB
1012
−16 dB
1102
−18 dB
1112
−20 dB
4
NOISE_GATE_ON
If set, signals below the noise gate threshold are muted.The noise gate is only activated after a set
period of signal absence.
7:5
NOISE_
GATE_
THRES
This field sets the expected background noise level relative to the peak signal level. The sole
presence of signals below this level will not result in an AGC gain change of the input and will be
gated from the ADC output if the NOISE_GATE_ON is set. This level must be set even if the noise
gate is not in use as it is required by the AGC algorithm.
NOISE_GATE_THRES
Level
0002
−72 dB
0012
−66 dB
0102
−60 dB
0112
−54 dB
1002
−48 dB
1012
−42 dB
1102
−36 dB
1112
−30 dB
Note 16: See the AGC overview.
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LM4935
12.0 Status & Control Registers
(Continued)
12.13 AGC_2 CONFIGURATION REGISTER
This register is used to control the LM4935’s Automatic Gain Control.
TABLE 14. AGC_2 (0x09h)
Bits
Field
Description
3:0
AGC_MAX_GAIN
This programs the maximum gain that the AGC algorithm can apply to the microphone preamplifier.
6:4
7
AGC_DECAY
AGC_TIGHT
AGC_TIGHT = 0
AGC_TIGHT = 1
AGC_MAX_GAIN
Max Preamplifier Gain
00002
6 dB
00012
8 dB
00102
10 dB
00112
12 dB
01002 to 11002
14 dB to 30 dB
11012
32 dB
11102
34 dB
11112
36 dB
Programs the speed at which the AGC will increase gains if it detects the input level is a quiet
signal.
AGC_DECAY
Step Time (ms)
0002
32
0012
64
0102
128
0112
256
1002
512
1012
1024
1102
2048
1112
4096
If set the AGC algorithm controls the microphone preamplifier more exactly. (Note 17)
AGC_TARGET
Min Level
Max Level
0002
−6 dB
−3 dB
0012
−8 dB
−4 dB
0102
−10 dB
−5 dB
0112
−12 dB
−6 dB
1002
−14 dB
−7 dB
1012
−16 dB
−8 dB
1102
−18 dB
−9 dB
1112
−20 dB
−10 dB
0002
−6 dB
−3 dB
0012
−8 dB
−5 dB
0102
−10 dB
−7 dB
0112
−12 dB
−9 dB
1002
−14 dB
−11 dB
1012
−16 dB
−13 dB
1102
−18 dB
−15 dB
1112
−20 dB
−17 dB
Note 17: The AGC can be used to control the analog path of the microphone to the output stages or to optimize the microphone path for recording on the ADC.
When the analog path is used this bit should be set to ensure the target is tightly adhered to. If the ADC is the only destination of the microphone or the desired analog
mixer level is line level then AGC_TIGHT should be cleared, allowing greater dynamic rage of the recorded signal. For further details see the AGC overview.
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LM4935
12.0 Status & Control Registers
(Continued)
12.14 AGC_3 CONFIGURATION REGISTER
This register is used to control the LM4935’s Automatic Gain Control. (Note 18)
TABLE 15. AGC_3 (0x0Ah)
Bits
Field
4:0
AGC_HOLDTIME
7:5
AGC_ATTACK
Description
Programs the amount of delay before the AGC algorithm begins to adjust the gain of the
microphone preamplifier.
AGC_HOLDTIME
No. of speech segments
000002
0
000012
1
000102
2
000112
3
001002 to 111002
4 to 28
111012
29
111102
30
111112
31
Programs the speed at which the AGC will reduce gains if it detects the input level is too large.
AGC_ATTACK
Step Time (ms)
0002
32
0012
64
0102
128
0112
256
1002
512
1012
1024
1102
2048
1112
4096
Note 18: See the AGC overview.
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LM4935
12.0 Status & Control Registers
(Continued)
12.15 AGC OVERVIEW
The Automatic Gain Control (AGC) system can be used to optimize the dynamic range of the ADC for voice data when the level
of the source is unknown. A target level for the output is set so that any transients on the input won’t clip during normal operation.
The AGC circuit then compares the output of the ADC to this level and increases or decreases the gain of the microphone
preamplifier to compensate. If the audio from the microphone is to be output digitally through the ADC then the full dynamic range
of the ADC can be used automatically. If the output is through the analog mixer then the ADC is used to monitor the microphone
level. In this case, the analog dynamic range is less important than the absolute level, so AGC_TIGHT should be set to tie
transients closely to the target level.
To ensure that the system doesn’t reduce the quality of the speech by constantly modulating the microphone preamplifier gain,
the ADC output is passed through an envelope detector. This frames the output of the ADC into time segments roughly equal to
the phonemes found in speech (AGC_FRAME_TIME). To calculate this, the circuit must also know the sample rate of the data
from the ADC (ADC_SAMPLERATE). If after a programmable number of these segments (AGC_HOLDTIME), the level is
consistently below target, the gain will be increased at a programmable rate (AGC_DECAY). If the signal ever exceeds the target
level (AGC_TARGET) then the gain of the microphone is reduced immediately at a programmable rate (AGC_ATTACK). This is
demonstrated below:
20134112
AGC Operation Example
The signal in the above example starts with a small analog input which, after the hold time has timed out, triggers a rise in the
gain ((1) → (2)). After some time the real analog input increases and it reaches the threshold for a gain reduction which decreases
the gain at a faster rate ((2) → (3)) to allow the elimination of typical popping noises.
Only ADC outputs that are considered signal (rather than noise) are used to adjust the microphone preamplifier gain. The signal
to noise ratio of the expected input signal is set by NOISE_GATE_THRESHOLD. In some situations it is preferable to remove
audio considered to be consisting solely of background noise from the audio output; for example conference calls. This can be
done by setting NOISE_GATE_ON. This does not affect the performance of the AGC algorithm.
The AGC algorithm should not be used where very large background noise is present. If the type of input data, application and
microphone is known then the AGC will typically not be required for good performance, it is intended for use with inputs with a
large dynamic range or unknown nominal level. When setting NOISE_GATE_THRESHOLD be aware that in some mobile phone
scenarios the ADC SNR will be dictated by the microphone performance rather than the ADC or the signal. Gain changes to the
microphone are performed on zero crossings. To eliminate DC offsets, wind noise, and pop sounds from the output of the ADC,
the ADC’s HPF should always be enabled.
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LM4935
12.0 Status & Control Registers
(Continued)
12.16 MIC_1 CONFIGURATION REGISTER
This register is used to control the microphone configuration.
TABLE 16. MIC_1 (0x0Bh)
Bits
Field
3:0
PREAMP_GAIN
4
MIC_MUTE
5
INT_SE_DIFF
6
INT_EXT
Description
Programs the gain applied to the microphone preamplifier if the AGC is not in use.
PREAMP_GAIN
Gain
00002
6 dB
00012
8 dB
00102
10 dB
00112
12 dB
01002 to 11002
14 dB to 30 dB
11012
32 dB
11102
34 dB
11112
36 dB
If set the microphone preamplifier is muted.
If set the internal microphone is assumed to be single ended and the negative connection is
connected to the ADC common mode point internally. This allows a single-ended internal
microphone to be used.
If set the single ended external microphone is used and the negative microphone input is grounded
internally, otherwise internal microphone operation is assumed. (Note 19)
Note 19: On changing INT_EXT from internal to external note that the dc blocking cap will not be charged so some time should be taken (300 ms for a 1 µF cap)
between the detection of an external headset and the switching of the output stages and ADC to that input to allow the DC points on either side of this cap to stabilize.
This can be accomplished by deselecting the microphone input from the audio outputs and ADC until the DC points stabilize.
An active MIC path to CPOUT or the ADC may result in the microphone DC blocking caps causing audio pops under the following situations:
1) Switching between internal and external microphone operation while in chip modes ’10’ or ’11’.
2) Toggling in and out of powerdown/standby modes.
3) Toggling between chip modes ’10’ and ’11’ whenever external microphone operation is selected.
4) The insertion/removal of a headset while in chip modes ’10’ or ’11’ whenever external microphone operation is selected.
To avoid these potential pop issues, it is recommended to deselect the microphone input from CPOUT and ADC until the DC points stabilize.
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LM4935
12.0 Status & Control Registers
(Continued)
12.17 MIC_2 CONFIGURATION REGISTER
This register is used to control the microphone configuration.
TABLE 17. MIC_2 (0x0Ch)
Bits
Field
0
OCL_
VCM_
VOLTAGE
2:1
MIC_
BIAS_
VOLTAGE
3
BUTTON_TYPE
5:4
BUTTON_
DEBOUNCE_
TIME
Description
Selects the voltage used as virtual ground (HP_VMID pin) in OCL mode. This will depend on the
available supply and the power output requirements of the headphone amplifiers.
OCL_VCM_VOLTAGE
Voltage
0
1.2V
1
1.5V
Selects the voltage as a reference to the internal and external microphones. Only one bias pin is
driven at once depending on the INT_EXT bit setting found in the MIC_1 (0x0Bh) register.
MIC_BIAS_VOLTAGE should be set to ’11’ only if A_VDD > 3.4V. In OCL mode,
MIC_BIAS_VOLTAGE = ’00’ (EXT_BIAS = 2.0V) should not be used to generate the EXT_BIAS
supply for a cellular headset external microphone. Please refer to Table 18 for more detail.
MIC_BIAS_VOLTAGE
EXT_BIAS
INT_BIAS
002
2.0V
2.0V
012
2.5V
2.5V
102
2.8V
2.8V
112
3.3V
3.3V
If set the LM4935 assumes that the button (if used) in the headset is in series (series push button)
with the microphone, opening the circuit when pressed. The default is for the button to be in parallel
(parallel push button), shorting out the microphone when pressed.
Sets the time used for debouncing the pushing of the button on a headset with a parallel push
button.
BUTTON_DEBOUNCE_TIME
Time (ms)
002
0
012
8
102
16
112
32
In OCL mode there is a trade-off between the external microphone supply voltage (EXT_MIC_BIAS - OCL_VCM_ VOLTAGE) and
the maximum output power possible from the headphones. A lower OCL_VCM_VOLTAGE gives a higher microphone supply
voltage but a lower maximum output power from the headphone amplifiers due to the lower OCL_VCM_VOLTAGE - A_VSS.
TABLE 18. External MIC Supply Voltages in OCL Mode
Available
A_VDD
Recommended
EXT_MIC_BIAS
OCL_VCM_VOLT = 1.5V
OCL_VCM_VOLT = 1.2V
> 3.4V
3.3V
1.8V
2.1V
2.9V to 3.4V
2.8V
1.3V
1.6V
2.8V to 2.9V
2.5V
1.0V
1.3V
2.7V to 2.8V
2.5V
-
1.3V
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Supply to Microphone
38
LM4935
12.0 Status & Control Registers
(Continued)
12.18 SIDETONE ATTENUATION REGISTER
This register is used to control the analog sidetone attenuation. (Note 20)
TABLE 19. SIDETONE (0x0Dh)
Bits
Field
3:0
SIDETONE_
ATTEN
Description
Programs the attenuation applied to the microphone preamp output to produce a sidetone signal.
SIDETONE_ATTEN
Attenuation
00002
-Inf
00012
−30 dB
00102
−27 dB
00112
−24 dB
01002
−21 dB
01012 to 10102
−18 dB to −3 dB
10112 to 11112
0 dB
Note 20: An active SIDETONE path to an audio output may result in the microphone DC blocking caps causing audio pops under the following situations:
1) Switching between internal and external microphone operation while in chip modes ’10’ or ’11’.
2) Toggling in and out of powerdown/standby modes.
3) Toggling between chip modes ’10’ and ’11’ whenever external microphone operation is selected.
4) The insertion/removal of a headset while in chip modes ’10’ or ’11’ whenever external microphone operation is selected.
To avoid potential pop noises, it is recommended to set SIDETONE_ATTEN to ’0000’ until DC points have stabilized whenever the SIDETONE path is used.
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LM4935
12.0 Status & Control Registers
(Continued)
12.19 CP_INPUT CONFIGURATION REGISTER
This register is used to control the differential cell phone input.
TABLE 20. CP_INPUT (0x0Eh)
Bits
Field
4:0
CPI_LEVEL
5
CPI_MUTE
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Description
Programs the gain/attenuation applied to the cell phone input.
CPI_LEVEL
Level
000002
−34.5 dB
000012
−33 dB
000102
−31.5 dB
000112
−30 dB
00100 to 111002
−28.5 dB to +7.5 dB
111012
+9 dB
111102
+10.5 dB
111112
+12 dB
If set the CPI input is muted at source.
40
LM4935
12.0 Status & Control Registers
(Continued)
12.20 AUX_LEFT CONFIGURATION REGISTER
This register is used to control the left aux analog input.
TABLE 21. AUX_LEFT (0x0Fh)
Bits
Field
4:0
AUX_
LEFT_
LEVEL
5
AUX_
LEFT_
BOOST
6
AUX_L_MUTE
7
AUX_OR_DAC_L
Description
Programs the gain/attenuation applied to the AUX LEFT analog input to the mixer. (Note 21)
AUX_LEFT_LEVEL
Level (With Boost)
Level (Without Boost)
−46.5 dB
000002
−34.5 dB
000012
−33 dB
−45 dB
000102
−31.5 dB
−43.5 dB
000112
−30 dB
−42 dB
00100 to 111002
−28.5 dB to +7.5 dB
−40.5 dB to −4.5 dB
111012
+9 dB
−3 dB
111102
+10.5 dB
−1.5 dB
111112
+12 dB
0 dB
If set the gain of the AUX_LEFT input to the mixer is increased by 12 dB (see above).
If set the AUX LEFT input is muted.
If set the AUX LEFT input is passed to the mixer, the default is for the DAC LEFT output to be
passed to the mixer.
Note 21: The recommended mixer level is 1V RMS. The auxiliary analog inputs can be boosted by 12 dB if enough headroom is available. Clipping may occur if
the analog power supply is insufficient to cater for the required gain.
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LM4935
12.0 Status & Control Registers
(Continued)
12.21 AUX_RIGHT CONFIGURATION REGISTER
This register is used to control the right aux analog input.
TABLE 22. AUX_RIGHT (0x10h)
Bits
Field
4:0
AUX_
RIGHT_
LEVEL
5
AUX_
RIGHT_BOOST
6
AUX_R_MUTE
7
AUX_OR_DAC_R
Description
Programs the gain/attenuation applied to the AUX RIGHT analog input to the mixer. (Note 22)
AUX_RIGHT_LEVEL
Level (With Boost)
Level (Without Boost)
−46.5 dB
000002
−34.5 dB
000012
−33 dB
−45 dB
000102
−31.5 dB
−43.5 dB
000112
−30 dB
−42 dB
00100 to 111002
−28.5 dB to +7.5 dB
−40.5 dB to −4.5 dB
111012
+9 dB
−3 dB
111102
+10.5 dB
−1.5 dB
111112
+12 dB
0 dB
If set the gain of the AUX_RIGHT input to the mixer is increased by 12 dB (see above).
If set the AUX RIGHT input is muted.
If set the AUX RIGHT input is passed to the mixer, the default is for the DAC RIGHT output to be
passed to the mixer.
Note 22: The recommended mixer level is 1V RMS. The auxiliary analog inputs can be boosted by 12 dB if enough headroom is available. Clipping may occur if
the analog power supply is insufficient to cater for the required gain.
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LM4935
12.0 Status & Control Registers
(Continued)
12.22 DAC CONFIGURATION REGISTER
This register is used to control the DAC levels to the mixer.
TABLE 23. DAC (0x11h)
Bits
Field
4:0
DAC_LEVEL
5
USE_AUX_
LEVELS
6
BOOST
7
DAC_MUTE
Description
Programs the gain/attenuation applied to the DAC input to the mixer. (Note 23)
DAC_LEVEL
Level (With Boost)
Level (Without Boost)
−46.5 dB
000002
−34.5 dB
000012
−33 dB
−45 dB
000102
−31.5 dB
−43.5 dB
000112
−30 dB
−42 dB
00100 to 111002
−28.5 dB to +7.5 dB
−40.5 dB to −4.5 dB
111012
+9 dB
−3 dB
111102
+10.5 dB
−1.5 dB
111112
+12 dB
0 dB
If set the gain of the DAC inputs is controlled by the AUX_LEFT and AUX_RIGHT registers, allowing
a stereo balance to be applied.
If set the gain of the DAC inputs to the mixer is increased by 12 dB (see above).
If set the stereo DAC input is muted on the next zero crossing.
Note 23: The output from the DAC is 1V RMS for a full scale digital input. This can be boosted by 12 dB if enough headroom is available. Clipping may occur if the
analog power supply is insufficient to cater for the required gain.
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12.0 Status & Control Registers
(Continued)
12.23 CP_OUTPUT CONFIGURATION REGISTER
This register is used to control the differential cell phone output. (Note 24)
TABLE 24. CP_OUTPUT (0x12h)
Bits
Field
0
MIC_SELECT
1
RIGHT_SELECT
2
LEFT_SELECT
3
CPO_MUTE
4
MIC_NOISE_GATE
Description
If set the microphone channel of the mixer is added to the cellphone output signal.
If set the right channel of the mixer is added to the cellphone output signal.
If set the left channel of the mixer is added to the cellphone output signal.
If set the CPOUT output is muted.
If this is set and NOISE_GATE_ON (register 0x08h) is enabled, the MIC to CPO path will be
gated if the signal is determined to be noise by the AGC (that is, if the signal is below the set
noise threshold).
Note 24: The gain of cell phone output amplifier is 0 dB.
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12.0 Status & Control Registers
(Continued)
12.24 AUX_OUTPUT CONFIGURATION REGISTER
This register is used to control the differential auxiliary output. (Note 25)
TABLE 25. AUX_OUTPUT (0x13h)
Bits
Field
0
CPI_SELECT
1
RIGHT_SELECT
2
LEFT_SELECT
3
AUX_MUTE
Description
If set the cell phone input channel of the mixer is added to the aux output signal.
If set the right channel of the mixer is added to the aux output signal.
If set the left channel of the mixer is added to the aux output signal.
If set the aux output is muted.
Note 25: The gain of the auxiliary output amplifier is 0 dB. If a second (external) loudspeaker amplifier is to be used its gain should be set to 12 dB to match the
onboard loudspeaker amplifier gain.
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12.0 Status & Control Registers
(Continued)
12.25 LS_OUTPUT CONFIGURATION REGISTER
This register is used to control the loudspeaker output. (Note 26)
TABLE 26. LS_OUTPUT (0x14h)
Bits
Field
0
CPI_SELECT
1
RIGHT_SELECT
2
LEFT_SELECT
3
LS_MUTE
Description
If set the cell phone input channel of the mixer is added to the loudspeaker output signal.
If set the right channel of the mixer is added to the loudspeaker output signal.
If set the left channel of the mixer is added to the loudspeaker output signal.
If set the loudspeaker output is muted.
Note 26: The gain of the loudspeaker output amplifier is 12 dB.
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12.0 Status & Control Registers
(Continued)
12.26 HP_OUTPUT CONFIGURATION REGISTER
This register is used to control the stereo headphone output. (Note 27)
TABLE 27. HP_OUTPUT (0x15h)
Bits
Field
0
SIDETONE_SELECT
If set the sidetone channel of the mixer is added to both of the headphone output signals.
Description
1
CPI_SELECT
If set the cell phone input channel of the mixer is added to both of the headphone output
signals.
2
RIGHT_SELECT
If set the right channel of the mixer is added to the headphone output. If the STEREO bit
(0x00h) is set, the right channel is added to the right headphone output signal only. If the
STEREO bit (0x00h) is cleared, it is added to both the right and left headphone output
signals.
3
LEFT_SELECT
4
HP_MUTE
If set the left channel of the mixer is added to the headphone output. If the STEREO bit
(0x00h) is set, the left channel is added to the left headphone output signal only. If the
STEREO bit (0x00h) is cleared, it is added to both the right and left headphone output
signals.
If set the headphone output is muted.
Note 27: The gain of the headphone output amplifier is –6 dB for the cell phone input channel and sidetone channel of the mixer. When the STEREO bit (0x00h)
is set, headphone output amplifier gain is –6 dB for the left and right channel. When the STEREO bit (0x00h) is cleared, the headphone output amplifier gain is –12
dB for the left and right channel (to allow enough headroom for adding them and routing them to both headphone amplifiers).
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12.0 Status & Control Registers
(Continued)
12.27 EP_OUTPUT CONFIGURATION REGISTER
This register is used to control the mono earpiece output. (Note 28)
TABLE 28. EP_OUTPUT (0x16h)
Bits
Field
0
SIDETONE_SELECT
1
CPI_SELECT
2
RIGHT_SELECT
3
LEFT_SELECT
4
EP_MUTE
Description
If set the sidetone channel of the mixer is added to the earpiece output signal.
If set the cell phone input channel of the mixer is added to the earpiece output signal.
If set the right channel of the mixer is added to the earpiece output signal.
If set the left channel of the mixer is added to the earpiece output signal.
If set the earpiece output is muted.
Note 28: The gain of the earpiece output amplifier is 6 dB.
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12.0 Status & Control Registers
(Continued)
12.28 DETECT CONFIGURATION REGISTER
This register is used to control the headset detection system.
TABLE 29. DETECT (0x17h)
Bits
Field
0
DET_INT
If set an IRQ is raised when a change is detected in the headset status. Clearing this bit will clear
an IRQ that has been triggered by the headset detect.
Description
1
BTN_INT
If set an IRQ is raised when the headset button is pressed. Clearing this bit will clear an IRQ that
has been triggered by a button event.
2
TEMP_INT
If set an IRQ is raised during a temperature event. If cleared, the LM4935 will still automatically
cycle the power amplifiers off if the internal temperature is too high. This bit should not be set
whenever the loudspeaker amplifier is turned on. Clearing this bit will clear an IRQ that has been
triggered by a temperature event.
6:3
HS_
DBNC_TIME
Sets the time used for debouncing the analog signals from the detection inputs used to sense the
insertion/removal of a headset.
HS_DBNC_TIME
Time (ms)
00002
0
00012
8
00102
16
00112
32
01002
48
01012
64
01102
96
01112
128
10002
192
10012
256
10102
384
10112
512
11002
768
11012
1024
11102
1536
11112
2048
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12.0 Status & Control Registers
(Continued)
12.29 HEADSET DETECT OVERVIEW
The LM4935 has built in monitors to automatically detect headset insertion or removal. The detection scheme can differentiate
between mono, stereo, mono-cellular and stereo-cellular headsets. Upon detection of headset insertion or removal, the LM4935
updates read-only bit 0 - headset absence/presence, bit 1- mono/stereo headset and bit 2 - headset without mic / with mic, of the
STATUS register (0x18h). Headset insertion/removal and headset type can also be detected in standby mode; this consumes no
analog supply current when the headset is absent.
The LM4935 can be programmed to raise an interrupt (set the IRQ pin high) when headset insert/removal is sensed by setting
bit 0 of DETECT (0x17h). When headset detection is enabled in active mode and a headset is not detected, the HPL_OUT and
HPR_OUT amplifiers will be disabled (switched off for capless mode and muted for AC-coupled mode) and the EXT_BIAS pin will
be disconnected from the MIC_BIAS amplifier, irrespective of control register settings.
The LM4935 also has the capability to detect button press, when a button is present on the headset microphone. Both parallel
button-type (in parallel with the headset microphone, default value) and series button-type (in series with the headset microphone) can be detected; the button type used needs to be defined in bit 3 of MIC_2 (0x0Ch). Button press can also be detected
in stand-by mode; this consumes 10 µA of analog supply current for a series type push button and 100 µA for a parallel type push
button. Upon button press, the LM4935 updates bit 3 of STATUS (0x18h). In active OCL mode, with internal microphone selected
(INT_EXT = 0; (reg 0x0Bh)), if a parallel pushbutton headset is inserted into the system, INT_EXT must be set high before BTN
(bit 3 of STATUS (0x18h)) can be read. The LM4935 can also be programmed to raise an interrupt on the IRQ pin when button
press is sensed by setting bit 1 of DETECT.
The LM4935 provides debounce programmability for headset and button detect. Debounce programmability can be used to reject
glitches generated, and hence avoid false detection, while inserting/removing a headset or pressing a button.
Headset insert/removal debounce time is defined by HS_DBNC_TIME; bits 6:3 of DETECT (0x17h). Parallel button press
debounce time is defined by BTN_DBNC_TIME; bits 5:4 of MIC_2 (0x0Ch).
Note that since the first effect of a series button press (microphone disconnected) is indistinguishable from headset removal, the
debounce time for series button press in defined by HS_DBNC_TIME.
Headset and push button detection can be enabled by setting CHIP_MODE 0; bit 0 of BASIC (0x00h). For reliable headset / push
button detection all following bits should be defined before enabling the headset detection system:
1) the OCL-bit (AC-Coupled / Capless headphone interface (bit 7 of BASIC (0x00h))
2) the headset insert/removal debounce settings (bit 6:3 of DETECT (0x17h))
3) the BTN_TYPE-bit (Parallel / Series push button type (bit 3 of MIC_2 (0x0Ch))
4) the parallel push button debounce settings (bit 5:4 of MIC_2 (0x0Ch))
Figure 8 shows terminal connections and jack configuration for various headsets. Care should be taken to avoid any DC path from
the MIC_DET pin to ground when a headset is not inserted.
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LM4935
12.0 Status & Control Registers
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20134113
FIGURE 8. Headset Configurations Supported by the LM4935
The wiring of the headset jack to the LM4935 will depend on the intended mode of the headphone amplifier:
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LM4935
12.0 Status & Control Registers
(Continued)
20134114
FIGURE 9. Connection of Headset Jack to LM4935 Depends on the Mode of the Headphone Amplifier.
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12.0 Status & Control Registers
(Continued)
12.30 STATUS REGISTER
This register is used to report the status of the device.
TABLE 30. STATUS (0x18h)
Bits
Field
0
HEADSET
This field is high when headset presence is detected (only valid if the detection system is
enabled). (Note 29)
Description
1
STEREO_
HEADSET
This field is high when a headset with stereo speakers is detected (only valid if the detection
system is enabled). (Note 29)
2
MIC
This field is high when a headset with a microphone is detected (only valid if the detection system
is enabled). (Note 29)
3
BTN
This field is high when the button on the headset is pressed (only valid if the detection system is
enabled). IRQ is cleared when the button has been released and this register has been written
to.
4
SAR TRIG 1
If this field is high then an event has happened on SAR trigger 1 (write to this register to clear
IRQ).
5
SAR TRIG 2
If this field is high then an event has happened on SAR trigger 2 (write to this register to clear
IRQ).
6
TEMP
If this field is high then a temperature event has occurred (write to this register to clear IRQ). This
field will stay high even when the IRQ is cleared so long as the event occurs. This bit is only valid
whenever the loudspeaker amplifier is turned off.
7
GPIN
When GPIO_SEL is set to a readable configuration a digital input on GPIO1 can be read back
here.
Note 29: The detection IRQ is cleared when this register has been written to.
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12.0 Status & Control Registers
(Continued)
12.31 AUDIO INTERFACE CONFIGURATION REGISTER
This register is used to control the configuration of the audio data interfaces.
TABLE 31. AUDIO_IF (0x19h)
Bits
Field
1:0
AUDIO_IF_MODE
Description
Selects the function of the 6 audio interface IOs.
AUDIO_IF_MODE
I2S_
CLK pin
I2S_
WS pin
I2S_
SDI pin
I2S_
SDO pin
GPIO_1
pin
GPIO_2
pin
002
I 2S
CLK
I2S
WS
I 2S
SDI
I2S
SDO
GPIO
1
GPIO
2
012
PCM
CLK
PCM
SYNC
-
PCM
SDO
GPIO
1
GPIO
2
102
PCM
CLK
PCM
SYNC
PCM
SDI
PCM
SDO
GPIO
1
GPIO
2
112
I 2S
CLK
I2S
WS
I 2S
SDI
PCM
SDO
PCM
CLK
PCM
SYNC
2
I2S_WS_MS
If set the I2S_WS is produced by the LM4935 and the I2S_WS pin will be an output.
3
I2S_CLK_MS
If set the I2S_CLK is produced by the LM4935 and the I2S_CLK pin will be an output.
4
PCM_SYNC_MS
If set the PCM_SYNC is produced by the LM4935 and the relevant pin will be an output.
5
PCM_CLK_MS
If set the PCM_CLK is produced by the LM4935 and the relevant pin will be an output.
7:6
I2S_SDO_DATA
The two ADCs on the LM4935 can both be read via the isochronous I2S interface. The most recent
valid sample is output from the following source: (Please refer to the GPIO configuration register
(0x1Ah) for more information on SAR_CH_SEL)
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I2S_SDO_DATA
LEFT
RIGHT
002
AUDIO ADC
SAR_CH_SEL
012
SAR VSAR 1
SAR_CH_SEL
102
SAR VSAR 2
SAR_CH_SEL
112
A_VDD/2
SAR_CH_SEL
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12.0 Status & Control Registers
(Continued)
12.32 DIGITAL AUDIO DATA FORMATS
I2S master mode can only be used when the DAC is enabled unless the ADC_I2S_M bit is set. PCM Master mode can only be
used when the ADC is enabled. If the PCM receiver interface is operated in slave mode the clock and sync should be enabled
at the same time as the PCM receiver uses the first PCM frame to calculate the PCM interface format. This format can not be
changed unless a soft reset is issued. It is strongly recommended that the LM4935 is operated in master mode as this eliminates
the risk of sample rate mismatch between the data converters and the audio interfaces.
In master mode the I2S_CLK has a 60/40 duty cycle and a frequency of 50*fs. In slave mode the PCM and I2S receivers only
record the 1st 16 and 18 bits of the serial words respectively. The I2S format is as follows:
20134115
FIGURE 10. I2S Serial Data Format (Default Mode)
20134116
FIGURE 11. PCM Serial Data Format (16 bit Slave Example)
When SAR SDO data is passed to the I2S, it is left aligned (MSB aligned) to allow lower I2S resolutions to be used.
If the DAC is driven from the PCM interface then the left channel of the DAC is used and the right channel is inactive.
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12.0 Status & Control Registers
(Continued)
12.33 GPIO CONFIGURATION REGISTER
This register is used to control the GPIO system.
TABLE 32. GPIO (0x1Ah)
Bits
Field
2:0
GPIO_SEL
Description
This sets the function of the GPIOs when the Audio Interface is not using them.
GPIO_SEL
GPIO 1
GPIO 2
0002
0
0
0012
READABLE
SPI_SDO
0102
LS_AMP_ENABLE
SPI_SDO
0112
GPIO_DATA
SPI_SDO
1002
0
SPI_SDO
1012
READABLE
SAR_SDO
1102
LS_AMP_ENABLE
SAR_SDO
1112
GPIO_DATA
SAR_SDO
Setting GPIO_SEL = “010” with the GPIO_TEST_MODE bit (register 0X26h) set configures the
GPIOs for digital mic operation. With this setting, GPI01 will output VADC_CLK_OUT to provide a
clock for the digital mic. GPIO2 will accept digital mic data. GPIO1’s LS_AMP_ENABLE setting will
be logic high whenever the loudspeaker amplifier is enabled. This is useful for enabling an external
amplifier for stereo loudspeaker applications.
4:3
SAR_CH_SEL
This field selects the SAR output channel for the 2nd (Right) I2S channel or for SAR_SDO via
GPIO2.
SAR_CH_SEL
Selected Channel
002
VSAR_1
012
VSAR_2
102
D_VDD/2 or BB_VDD
112
A_VDD/2
5
I2S_MODE
If set the I2S operates in left justified mode (sometimes referred to as DSP mode). See example
below. (Note 30)
6
PCM_LONG
If set the PCM interface uses LONG frame sync which is essentially an inverted short frame sync.
7
GPIO_DATA
If GPIO_SEL is set to GPIO_DATA then the content of this field is passed to GPIO1 as an output.
Note 30: The left justified I2S mode is similar to normal I2S other than there is no delay between a change in WS to the MSB:
20134117
FIGURE 12. I2S Serial Data Format (Left Justified Mode)
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12.0 Status & Control Registers
(Continued)
12.34 SAR CHANNELS 0 & 1 CONFIGURATION REGISTER
This register is used to control channel 0 and 1 of the SAR system. (Note 31)
TABLE 33. SAR_SLOT01 (0x1Bh)
Bits
Field
2:0
SLOT_0_FS
3
SLOT_0_ENB
6:4
SLOT_1_FS
7
SLOT_1_ENB
Description
Programs the sampling frequency of SAR channel 0:
SLOT_0_FS
Sample Rate @ 12.000 MHz
(point A)
0002
13.888 kHz
0012
3.472 kHz
0102
0.868 kHz
0112
217 Hz
1002
54 Hz
1012
14 Hz
1102
4 Hz
1112
1 Hz
If set then VSAR 1 is sampled into SAR slot 0 which also activates the
SAR ADC.
Programs the sampling frequency of SAR channel 1:
SLOT_1_FS
Sample Rate @ 12.000 MHz
(point A)
0002
13.888 kHz
0012
3.472 kHz
0102
0.868 kHz
0112
217 Hz
1002
54 Hz
1012
14 Hz
1102
4 Hz
1112
1 Hz
If set then VSAR 2 is sampled into SAR slot 1 which also activates the
SAR ADC.
Note 31: See the section SAR Overview for more details on this register.
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(Continued)
12.35 SAR CHANNELS 2 & 3 CONFIGURATION REGISTER
This register is used to control channel 2 and 3 of the SAR system. (Note 31)
TABLE 34. SAR_SLOT23 (0x1Ch)
Bits
Field
2:0
SLOT_2_FS
Description
Programs the sampling frequency of SAR channels 2 and 3:
SLOT_2_FS
Sample Rate @ 12.000 MHz
(point A)
0002
13.888 kHz
0012
3.472 kHz
0102
0.868 kHz
0112
217 Hz
1002
54 Hz
1012
14 Hz
1102
4 Hz
1112
1 Hz
3
SLOT_2_ENB
If set then D_VDD / 2 or BB_VDD (depending on SLOT2_VBB) is sampled
into SAR slot 2 which also activates the SAR ADC.
4
SLOT_3_ENB
If set then A_VDD / 2 is sampled into SAR slot 3 which also activates the
SAR ADC.
5
SLOT_2_VBB
If set then BB_VDD input is used as input to SAR slot 2 rather than the
D_VDD.
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12.0 Status & Control Registers
(Continued)
12.36 SAR DATA 0 TO 3 REGISTERS
These registers are used to read the 8 MSBs from the 4 SAR channels.
TABLE 35. SAR_DATA_0 Register (0x1Dh)
Bits
Field
7:0
SLOT_0_DATA
Description
Latest slot 0 sample bits 11:4.
TABLE 36. SAR_DATA_1 Register (0x1Eh)
Bits
Field
7:0
SLOT_1_DATA
Description
Latest slot 1 sample bits 11:4.
TABLE 37. SAR_DATA_2 Register (0x1Fh)
Bits
Field
7:0
SLOT_2_DATA
Description
Latest slot 2 sample bits 11:4.
TABLE 38. SAR_DATA_3 Register (0x20h)
Bits
Field
7:0
SLOT_3_DATA
Description
Latest slot 3 sample bits 11:4.
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(Continued)
12.37 SAR OVERVIEW
The SAR controller works via a scheduler that allocates time slots for each of the four channels. All four channels can operate up
to the same maximum frequency. When the sampling frequency of a channel is to be reduced the time slot allocated to that
channel is simply enabled less often. For example if one slot is to work at a quarter of the frequency of the others then only one
in four of its allocated slot triggers the SAR to activate:
20134118
FIGURE 13. Internal SAR Control Signals to SAR Module
Each time slot is used to sample a single fixed input, slot 0 is used for VSAR 1, slot 1 for VSAR 2, slot 2 for either D_VDD or
BB_VDD* and slot 3 for the A_VDD. When a particular time slot is activated the correct mux, clock and enable controls to the ADC
module are produced and the output sampled when ready. If the D_VDD or the A_VDD are being sampled then a voltage divider
is used to half the input to below the full scale reference of 2.5V. As this results in a current path to ground it is only inserted while
the ADC is settling to reduce power consumption.
Using this method, samples can be taken using as little power as possible while allowing sample rates as low as 1 Hz. The data
can either be read directly or used to trigger interrupts when set voltages are passed. This reduces the baseband controllers
software overhead and IO bandwidth, further reducing system power.
The full scale digital output from the SAR is equal to 2.5V. The A_VDD and D_VDD inputs are divided by two during sampling. The
SAR ADC can be activated at any time, even while the chip is in shutdown mode (chip mode ’00’). This allows the LM4935 to
perform housekeeping duties such as voltage monitoring with minimal power consumption.
*Depending on SLOT_2_VBB in SAR_SLOT23 (0x1Ch).
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12.0 Status & Control Registers
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Only the 8 MSBS [11:4] from the 12 bits of SAR output data can be read back using the I2C interface.
The SPI interface can be used to access all 12 bits of the SAR output data. In this case, GPIO2 should be set to SAR_SDO by
setting GPIO_SEL in register (0x1Ah). The SAR channel selected by SAR_CH_SEL in the GPIO register is then output onto
GPIO2 as follows:
20134108
FIGURE 14. SPI SAR Read Transaction (GPIO2 set to SAR_SDO)
In applications where the 8 MSBS [11:4] from the SAR output data is enough resolution, GPIO2 should be set to SPI_SDO by
setting GPIO_SEL in register (0x1Ah). The SAR data is then output on GPIO2 as follows:
20134107
FIGURE 15. SPI SAR Read Transaction (GPIO2 set to SPI_SDO)
If the user performs a write to the GPIO register the changes will not take effect until the next SPI operation so SAR data can be
read while the next channel is being selected. The SAR data is sampled at the start of the SPI transaction to ensure that the data
is stable during the read operation.
All 12 bits of the SAR output data for up to 2 SAR channels can be read back simultaneously through the bi-directional I2S
interface. This is accomplished by setting I2S_SDO_DATA (bit [7:6] of (0x19h)) to the desired SAR channel(s).
As mentioned previously in the Digital Audio Data Formats section, when SAR SDO is passed to the I2S bus, the SAR SDO’s
MSB is aligned with the MSB of I2S_SDO.
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12.0 Status & Control Registers
(Continued)
12.38 DC VOLUME CONFIGURATION REGISTER
This register is used to control the DC volume control system.
TABLE 39. DC_VOLUME (0x21h)
Bits
Field
0
DC_VOL_ENB
1
DC_VOL_EFFECT
3:2
Description
MAX_LEVEL
Enables the DC volume control system to use the voltage applied on the
VSAR 1 pin to set the gain of the DC volume control. (Note 32)
Selects which volume is altered:
DC_VOL_EFFECT
Source
0
AUX/DAC
1
CPI
Programs the maximum level that can be applied by the system
MAX_LEVEL
LEVEL
002
0 dB
012
−3 dB
102
−6 dB
112
−12 dB
Note 32: The correlation between the voltage on VSAR1 to the attenuation on the AUX/DAC channel is as follows:
201341P4
FIGURE 16. DC Volume Transfer Function For AUX/DAC
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12.0 Status & Control Registers
(Continued)
12.39 SAR TRIGGER 1 CONFIGURATION REGISTER
This register is used to setup a voltage trigger on one of the SAR outputs.
TABLE 40. TRIG_1 (0x22h)
Bits
Field
0
TRIG_1_ENB
Enables the 1st SAR trigger interrupt, if cleared will clear the IRQ.
1
TRIG_1_DIR
Selects the direction the voltage should be moving:
3:2
7:4
TRIG_1_SOURCE
TRIG_1_LSB
Description
TRIG_1_DIR
Trigger if signal passes:
0
Above Threshold
1
Below Threshold
Programs the channel used by the trigger.
TRIG_1_SOURCE
Source
002
VSAR_1
012
VSAR_2
102
D_VDD/2 or BB_VDD
112
A_VDD/2
Sets bits 3:0 of the threshold used by the trigger.
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12.0 Status & Control Registers
(Continued)
12.40 SAR TRIGGER 1 MSBs CONFIGURATION REGISTER
This register is used to setup the threshold of a voltage trigger on one of the SAR outputs.
TABLE 41. TRIG_1_MSB (0x23h)
Bits
Field
7:0
TRIG_1_MSB
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Description
Sets bits 11:4 of the threshold used by the trigger.
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12.0 Status & Control Registers
(Continued)
12.41 SAR TRIGGER 2 CONFIGURATION REGISTER
This register is used to setup a voltage trigger on one of the SAR outputs.
TABLE 42. TRIG_2 (0x24h)
Bits
Field
0
TRIG_2_ENB
Enables the 2nd SAR trigger interrupt, if cleared will clear the IRQ.
1
TRIG_2_DIR
Selects the direction the voltage should be moving:
3:2
7:4
TRIG_2_SOURCE
TRIG_2_LSB
Description
TRIG_2_DIR
Trigger if signal passes:
0
Above Threshold
1
Below Threshold
Programs the channel used by the trigger
TRIG_2_SOURCE
Source
002
VSAR_1
012
VSAR_2
102
D_VDD/2 or BB_VDD
112
A_VDD/2
Sets bits 3:0 of the threshold used by the trigger.
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LM4935
12.0 Status & Control Registers
(Continued)
12.42 SAR TRIGGER 2 MSBs CONFIGURATION REGISTER
This register is used to setup the threshold of a voltage trigger on one of the SAR outputs.
TABLE 43. TRIG_2_MSB (0x25h)
Bits
Field
7:0
TRIG_2_MSB
www.national.com
Description
Sets bits 11:4 of the threshold used by the trigger.
66
LM4935
12.0 Status & Control Registers
(Continued)
12.43 DEBUG REGISTER
This register is used to set test modes within the device.
TABLE 44. DEBUG (0x26h)
Bits
Field
0
RSVD
Reserved
Description
1
RSVD
Reserved
2
RSVD
3
SOFT_RESET
4
RSVD
Reserved
5
RSVD
Reserved
6
RSVD
7
GPIO_TEST_MODE
Reserved
This field can be used to reset the chip without a power cycle.
Reserved
If set and GPIO_SEL = ’010’, then the GPIOs are configured to interface with the LMV1026
digital microphone as long as AUDIO_IF_MODE (0x19h) is not set to ’11’.
GPIO_SEL
GPIO 1
GPIO 2
RSVD
0002
RSVD
0012
RSVD
RSVD
0102
VADC_CLOCK_OUT
DIG_MIC_IN
0112
RSVD
RSVD
1002
RSVD
RSVD
1012
RSVD
RSVD
1102
RSVD
RSVD
1112
RSVD
RSVD
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LM4935
13.0 Typical Performance Characteristics
(For all performance curves AVDD refers to the voltage applied to the A_VDD and LS_VDD pins. DVDD refers to the voltage applied
to the D_VDD and PLL_VDD pins; AVDD = 3.3V and DVDD = 3.3V unless otherwise specified.
Stereo DAC Frequency Response Zoom
fS = 8kHz
Stereo DAC Frequency Response
fS = 8kHz
20134136
20134137
Stereo DAC Frequency Response Zoom
fS = 16kHz
Stereo DAC Frequency Response
fS = 16kHz
20134138
20134139
Stereo DAC Frequency Response Zoom
fS = 24kHz
Stereo DAC Frequency Response
fS = 24kHz
20134140
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20134141
68
Stereo DAC Frequency Response
fS = 32kHz
(Continued)
Stereo DAC Frequency Response Zoom
fS = 32kHz
20134142
20134143
Stereo DAC Frequency Response Zoom
fS = 48kHz
Stereo DAC Frequency Response
fS = 48kHz
20134145
20134144
THD+N vs
Stereo DAC Input Voltage
(0dB DAC, AUXOUT)
Stereo DAC Crosstalk
(0dB DAC, HP SE)
20134147
20134146
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LM4935
13.0 Typical Performance Characteristics
LM4935
13.0 Typical Performance Characteristics
MONO ADC Frequency Response
fS = 8kHz, 6dB MIC
MONO ADC Frequency Response Zoom
fS = 8kHz, 6dB MIC
20134148
20134149
MONO ADC Frequency Response Zoom
fS = 8kHz, 36dB MIC
MONO ADC Frequency Response
fS = 8kHz, 36dB MIC
20134150
20134151
MONO ADC Frequency Response Zoom
fS = 16kHz, 6dB MIC
MONO ADC Frequency Response
fS = 16kHz, 6dB MIC
20134152
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(Continued)
20134153
70
MONO ADC Frequency Response
fS = 16kHz, 36dB MIC
(Continued)
MONO ADC Frequency Response Zoom
fS = 16kHz, 36dB MIC
20134154
20134155
MONO ADC Frequency Response Zoom
fS = 24kHz, 6dB MIC
MONO ADC Frequency Response
fS = 24kHz, 6dB MIC
20134156
20134157
MONO ADC Frequency Response Zoom
fS = 24kHz, 36dB MIC
MONO ADC Frequency Response
fS = 24kHz, 36dB MIC
20134158
20134169
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LM4935
13.0 Typical Performance Characteristics
LM4935
13.0 Typical Performance Characteristics
MONO ADC Frequency Response
fS = 32kHz, 6dB MIC
MONO ADC Frequency Response Zoom
fS = 32kHz, 6dB MIC
20134159
20134160
MONO ADC Frequency Response Zoom
fS = 32kHz, 36dB MIC
MONO ADC Frequency Response
fS = 32kHz, 36dB MIC
20134161
20134162
MONO ADC HPF Frequency Response
fS = 16kHz, 36dB MIC
(from left to right: HPF_MODE ’00’, ’10’, ’01’)
MONO ADC HPF Frequency Response
fS = 8kHz, 36dB MIC
(from left to right: HPF_MODE ’00’, ’10’, ’01’)
20134163
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(Continued)
20134164
72
MONO ADC HPF Frequency Response
fS = 24kHz, 36dB MIC
(from left to right: HPF_MODE ’00’, ’10’, ’01’)
(Continued)
MONO ADC HPF Frequency Response
fS = 32kHz, 36dB MIC
(from left to right: HPF_MODE ’00’, ’10’, ’01’)
20134165
20134166
MONO ADC THD+N
vs MIC Input Voltage
(fS = 8kHz, 36dB MIC)
MONO ADC THD+N
vs MIC Input Voltage
(fS = 8kHz, 6dB MIC)
20134168
20134167
MONO ADC PSRR vs Frequency
AVDD = 5V, 6dB MIC
MONO ADC PSRR vs Frequency
AVDD = 3.3V, 6dB MIC
20134170
20134171
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LM4935
13.0 Typical Performance Characteristics
LM4935
13.0 Typical Performance Characteristics
MONO ADC PSRR vs Frequency
AVDD = 3.3V, 36dB MIC
(Continued)
MONO ADC PSRR vs Frequency
AVDD = 5V, 36dB MIC
20134172
20134173
AUXOUT PSRR vs Frequency
AVDD = 5V, 0dB AUX
(AUX inputs terminated)
AUXOUT PSRR vs Frequency
AVDD = 3.3V, 0dB AUX
(AUX inputs terminated)
20134174
20134175
AUXOUT PSRR vs Frequency
AVDD = 5V, 0dB CPI
(CPI inputs terminated)
AUXOUT PSRR vs Frequency
AVDD = 3.3V, 0dB CPI
(CPI inputs terminated)
20134176
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20134177
74
AUXOUT PSRR vs Frequency
AVDD = 3.3V, 0dB DAC
(DAC inputs selected)
LM4935
13.0 Typical Performance Characteristics
(Continued)
AUXOUT PSRR vs Frequency
AVDD = 5V, 0dB DAC
(DAC inputs selected)
20134178
20134179
CPOUT PSRR vs Frequency
AVDD = 5V, 0dB AUX
(AUX inputs terminated)
CPOUT PSRR vs Frequency
AVDD = 3.3V, 0dB AUX
(AUX inputs terminated)
20134180
20134181
CPOUT PSRR vs Frequency
AVDD = 5V, 0dB DAC
(DAC inputs selected)
CPOUT PSRR vs Frequency
AVDD = 3.3V, 0dB DAC
(DAC inputs selected)
20134182
20134183
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LM4935
13.0 Typical Performance Characteristics
CPOUT PSRR vs Frequency
AVDD = 3.3V, 36dB MIC
(EXTMIC inputs terminated, AGC on)
(Continued)
CPOUT PSRR vs Frequency
AVDD = 5V, 36dB MIC
(EXTMIC inputs terminated, AGC on)
20134185
20134187
CPOUT PSRR vs Frequency
AVDD = 3.3V, 36dB MIC, MICBIAS = 2.0V
(INTMIC DIFF inputs terminated, AGC off)
CPOUT PSRR vs Frequency
AVDD = 3.3V, 36dB MIC, MICBIAS = 2.0V
(INTMIC DIFF inputs terminated, AGC on)
20134188
20134189
CPOUT PSRR vs Frequency
AVDD = 3.3V, 36dB MIC, MICBIAS = 2.5V
(INTMIC DIFF inputs terminated, AGC off)
CPOUT PSRR vs Frequency
AVDD = 3.3V, 36dB MIC, MICBIAS = 2.5V
(INTMIC DIFF inputs terminated, AGC on)
20134190
20134191
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76
(Continued)
CPOUT PSRR vs Frequency
AVDD = 3.3V, 36dB MIC, MICBIAS = 2.8V
(INTMIC DIFF inputs terminated, AGC off)
CPOUT PSRR vs Frequency
AVDD = 3.3V, 36dB MIC, MICBIAS = 2.8V
(INTMIC DIFF inputs terminated, AGC on)
20134192
20134193
CPOUT PSRR vs Frequency
AVDD = 5V, 36dB MIC, MICBIAS = 2.0V
(INTMIC DIFF inputs terminated, AGC off)
CPOUT PSRR vs Frequency
AVDD = 5V, 36dB MIC, MICBIAS = 2.0V
(INTMIC DIFF inputs terminated, AGC on)
20134196
20134197
CPOUT PSRR vs Frequency
AVDD = 5V, 36dB MIC, MICBIAS = 2.5V
(INTMIC DIFF inputs terminated, AGC off)
CPOUT PSRR vs Frequency
AVDD = 5V, 36dB MIC, MICBIAS = 2.5V
(INTMIC DIFF inputs terminated, AGC on)
20134198
20134199
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LM4935
13.0 Typical Performance Characteristics
LM4935
13.0 Typical Performance Characteristics
(Continued)
CPOUT PSRR vs Frequency
AVDD = 5V, 36dB MIC, MICBIAS = 2.8V
(INTMIC DIFF inputs terminated, AGC off)
CPOUT PSRR vs Frequency
AVDD = 5V, 36dB MIC, MICBIAS = 2.8V
(INTMIC DIFF inputs terminated, AGC on)
201341A0
201341A1
CPOUT PSRR vs Frequency
AVDD = 5V, 36dB MIC, MICBIAS = 3.3V
(INTMIC DIFF inputs terminated, AGC off)
CPOUT PSRR vs Frequency
AVDD = 5V, 36dB MIC, MICBIAS = 3.3V
(INTMIC DIFF inputs terminated, AGC on)
201341A2
201341A3
CPOUT PSRR vs Frequency
AVDD = 5V, 36dB MIC
(INTMIC SE input terminated, AGC on)
CPOUT PSRR vs Frequency
AVDD = 3.3V, 36dB MIC
(INTMIC SE input terminated, AGC on)
201341A5
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201341A7
78
Earpiece PSRR vs Frequency
AVDD = 3.3V, 0dB AUX
(AUX inputs terminated)
LM4935
13.0 Typical Performance Characteristics
(Continued)
Earpiece PSRR vs Frequency
AVDD = 5V, 0dB AUX
(AUX inputs terminated)
201341A8
201341A9
Earpiece PSRR vs Frequency
AVDD = 5V, 0dB CPI
(CPI input terminated)
Earpiece PSRR vs Frequency
AVDD = 3.3V, 0dB CPI
(CPI input terminated)
201341B0
201341B1
Earpiece PSRR vs Frequency
AVDD = 5V, 0dB DAC
(DAC input selected)
Earpiece PSRR vs Frequency
AVDD = 3.3V, 0dB DAC
(DAC input selected)
201341B2
201341B3
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LM4935
13.0 Typical Performance Characteristics
Headphone PSRR vs Frequency
AVDD = 3.3V, 0dB AUX, OCL 1.2V
(AUX inputs terminated)
Headphone PSRR vs Frequency
AVDD = 5V, 0dB AUX, OCL 1.2V
(AUX inputs terminated)
201341B4
201341B5
Headphone PSRR vs Frequency
AVDD = 5V, 0dB CPI, OCL 1.2V
(CPI input terminated)
Headphone PSRR vs Frequency
AVDD = 3.3V, 0dB CPI, OCL 1.2V
(CPI input terminated)
201341B6
201341B7
Headphone PSRR vs Frequency
AVDD = 5V, 0dB ADC, OCL 1.2V
(DAC input selected)
Headphone PSRR vs Frequency
AVDD = 3.3V, 0dB ADC, OCL 1.2V
(DAC input selected)
201341B8
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(Continued)
201341B9
80
Headphone PSRR vs Frequency
AVDD = 3.3V, 0dB AUX, OCL 1.5V
(AUX inputs terminated)
LM4935
13.0 Typical Performance Characteristics
(Continued)
Headphone PSRR vs Frequency
AVDD = 5V, 0dB AUX, OCL 1.5V
(AUX inputs terminated)
201341C0
201341C1
Headphone PSRR vs Frequency
AVDD = 5V, 0dB CPI, OCL 1.5V
(CPI input terminated)
Headphone PSRR vs Frequency
AVDD = 3.3V, 0dB CPI, OCL 1.5V
(CPI input terminated)
201341C2
201341C3
Headphone PSRR vs Frequency
AVDD = 5V, 0dB DAC, OCL 1.5V
(DAC input selected)
Headphone PSRR vs Frequency
AVDD = 3.3V, 0dB DAC, OCL 1.5V
(DAC input selected)
201341C4
201341C5
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LM4935
13.0 Typical Performance Characteristics
Headphone PSRR vs Frequency
AVDD = 3.3V, 0dB AUX, SE
(AUX inputs terminated)
Headphone PSRR vs Frequency
AVDD = 5V, 0dB AUX, SE
(AUX inputs terminated)
201341C6
201341C7
Headphone PSRR vs Frequency
AVDD = 5V, 0dB CPI, SE
(CPI input terminated)
Headphone PSRR vs Frequency
AVDD = 3.3V, 0dB CPI, SE
(CPI input terminated)
201341C8
201341C9
Headphone PSRR vs Frequency
AVDD = 5V, 0dB DAC, SE
(DAC input selected)
Headphone PSRR vs Frequency
AVDD = 3.3V, 0dB DAC, SE
(DAC input selected)
201341D0
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(Continued)
201341D1
82
Loudspeaker PSRR vs Frequency
AVDD = 3.3V, 0dB AUX
(AUX inputs terminated)
LM4935
13.0 Typical Performance Characteristics
(Continued)
Loudspeaker PSRR vs Frequency
AVDD = 5V, 0dB AUX
(AUX inputs terminated)
201341N6
201341N7
Loudspeaker PSRR vs Frequency
AVDD = 5V, 0dB CPI
(CPI input terminated)
Loudspeaker PSRR vs Frequency
AVDD = 3.3V, 0dB CPI
(CPI input terminated)
201341N8
201341N9
Loudspeaker PSRR vs Frequency
AVDD = 5V, 0dB DAC
(DAC input selected)
Loudspeaker PSRR vs Frequency
AVDD = 3.3V, 0dB DAC
(DAC input selected)
201341O0
201341O1
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LM4935
13.0 Typical Performance Characteristics
INT/EXT MICBIAS PSRR vs Frequency
AVDD = 3.3V, MICBIAS = 2.0V
INT/EXT MICBIAS PSRR vs Frequency
AVDD = 5V, MICBIAS = 2.0V
201341D2
201341D3
INT/EXT MICBIAS PSRR vs Frequency
AVDD = 5V, MICBIAS = 2.5V
INT/EXT MICBIAS PSRR vs Frequency
AVDD = 3.3V, MICBIAS = 2.5V
201341D4
201341D5
INT/EXT MICBIAS PSRR vs Frequency
AVDD = 5V, MICBIAS = 2.8V
INT/EXT MICBIAS PSRR vs Frequency
AVDD = 3.3V, MICBIAS = 2.8V
201341D6
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(Continued)
201341D7
84
INT/EXT MICBIAS PSRR vs Frequency
AVDD = 5V, MICBIAS = 3.3V
(Continued)
AUXOUT THD+N vs Frequency
AVDD = 3.3V, 0dB, VOUT = 1VRMS, 5kΩ
201341D9
201341D8
CPOUT THD+N vs Frequency
AVDD = 3.3V, 0dB, VOUT = 1VRMS, 5kΩ
AUXOUT THD+N vs Frequency
AVDD = 5V, 0dB, VOUT = 1VRMS, 5kΩ
201341E0
201341E1
Earpiece THD+N vs Frequency
AVDD = 3.3V, 0dB, POUT = 500mW, 32Ω
CPOUT THD+N vs Frequency
AVDD = 5V, 0dB, VOUT = 1VRMS, 5kΩ
201341E2
201341E3
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LM4935
13.0 Typical Performance Characteristics
LM4935
13.0 Typical Performance Characteristics
(Continued)
Headphone THD+N vs Frequency
AVDD = 3.3V, OCL 1.5V, 0dB
POUT = 7.5mW, 32Ω
Earpiece THD+N vs Frequency
AVDD = 5V, 0dB, POUT = 50mW, 32Ω
201341E4
201341E5
Headphone THD+N vs Frequency
AVDD = 3.3V, OCL 1.2V, 0dB
POUT = 7.5mW, 32Ω
Headphone THD+N vs Frequency
AVDD = 5V, OCL 1.5V, 0dB
POUT = 10mW, 32Ω
201341E6
201341N1
Headphone THD+N vs Frequency
AVDD = 3.3V, SE, 0dB
POUT = 7.5mW, 32Ω
Headphone THD+N vs Frequency
AVDD = 5V, OCL 1.2V, 0dB
POUT = 10mW, 32Ω
201341E7
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201341E8
86
LM4935
13.0 Typical Performance Characteristics
(Continued)
Loudspeaker THD+N vs Frequency
AVDD = 3.3V, POUT = 400mW
15µH+8Ω+15µH
Headphone THD+N vs Frequency
AVDD = 5V, SE, 0dB
POUT = 10mW, 32Ω
201341E9
201341O2
Earpiece THD+N vs Output Power
AVDD = 3.3V, 0dB AUX
fOUT = 1kHz, 16Ω
Loudspeaker THD+N vs Frequency
AVDD = 5V, POUT = 400mW
15µH+8Ω+15µH
201341F0
201341O3
Earpiece THD+N vs Output Power
AVDD = 3.3V, 0dB AUX
fOUT = 1kHz, 32Ω
Earpiece THD+N vs Output Power
AVDD = 5V, 0dB AUX
fOUT = 1kHz, 16Ω
201341F1
201341F2
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LM4935
13.0 Typical Performance Characteristics
Earpiece THD+N vs Output Power
AVDD = 3.3V, 0dB CPI
fOUT = 1kHz, 16Ω
Earpiece THD+N vs Output Power
AVDD = 5V, 0dB AUX
fOUT = 1kHz, 32Ω
201341F3
201341F4
Earpiece THD+N vs Output Power
AVDD = 3.3V, 0dB CPI
fOUT = 1kHz, 32Ω
Earpiece THD+N vs Output Power
AVDD = 5V, 0dB CPI
fOUT = 1kHz, 16Ω
201341F5
201341F6
Headphone THD+N vs Output Power
AVDD = 3.3V, OCL 1.2V, 0dB DAC
fOUT = 1kHz, 16Ω
Earpiece THD+N vs Output Power
AVDD = 5V, 0dB CPI
fOUT = 1kHz, 32Ω
201341F7
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(Continued)
201341F8
88
(Continued)
Headphone THD+N vs Output Power
AVDD = 3.3V, OCL 1.2V, 0dB DAC
fOUT = 1kHz, 32Ω
Headphone THD+N vs Output Power
AVDD = 5V, OCL 1.2V, 0dB DAC
fOUT = 1kHz, 16Ω
201341F9
201341G0
Headphone THD+N vs Output Power
AVDD = 3.3V, OCL 1.2V, 12dB DAC
fOUT = 1kHz, 16Ω
Headphone THD+N vs Output Power
AVDD = 5V, OCL 1.2V, 0dB DAC
fOUT = 1kHz, 32Ω
201341G1
201341G2
Headphone THD+N vs Output Power
AVDD = 3.3V, OCL 1.2V, 12dB DAC
fOUT = 1kHz, 32Ω
Headphone THD+N vs Output Power
AVDD = 5V, OCL 1.2V, 12dB DAC
fOUT = 1kHz, 16Ω
201341G3
201341G4
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LM4935
13.0 Typical Performance Characteristics
LM4935
13.0 Typical Performance Characteristics
Headphone THD+N vs Output Power
AVDD = 3.3V, OCL 1.5V, 0dB DAC
fOUT = 1kHz, 16Ω
Headphone THD+N vs Output Power
AVDD = 5V, OCL 1.2V, 12dB DAC
fOUT = 1kHz, 32Ω
201341G5
201341G6
Headphone THD+N vs Output Power
AVDD = 3.3V, OCL 1.5V, 0dB DAC
fOUT = 1kHz, 32Ω
Headphone THD+N vs Output Power
AVDD = 5V, OCL 1.5V, 0dB DAC
fOUT = 1kHz, 16Ω
201341G7
201341G8
Headphone THD+N vs Output Power
AVDD = 3.3V, OCL 1.5V, 12dB DAC
fOUT = 1kHz, 16Ω
Headphone THD+N vs Output Power
AVDD = 5V, OCL 1.5V, 0dB DAC
fOUT = 1kHz, 32Ω
201341G9
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(Continued)
201341H0
90
(Continued)
Headphone THD+N vs Output Power
AVDD = 3.3V, OCL 1.5V, 12dB DAC
fOUT = 1kHz, 32Ω
Headphone THD+N vs Output Power
AVDD = 5V, OCL 1.5V, 12dB DAC
fOUT = 1kHz, 16Ω
201341H1
201341H2
Headphone THD+N vs Output Power
AVDD = 3.3V, SE, 0dB DAC
fOUT = 1kHz, 16Ω
Headphone THD+N vs Output Power
AVDD = 5V, OCL 1.5V, 12dB DAC
fOUT = 1kHz, 32Ω
201341H3
201341H4
Headphone THD+N vs Output Power
AVDD = 3.3V, SE, 0dB DAC
fOUT = 1kHz, 32Ω
Headphone THD+N vs Output Power
AVDD = 5V, SE, 0dB DAC
fOUT = 1kHz, 16Ω
201341H5
201341H6
91
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LM4935
13.0 Typical Performance Characteristics
LM4935
13.0 Typical Performance Characteristics
Headphone THD+N vs Output Power
AVDD = 3.3V, SE, 12dB DAC
fOUT = 1kHz, 16Ω
Headphone THD+N vs Output Power
AVDD = 5V, SE, 0dB DAC
fOUT = 1kHz, 32Ω
201341H7
201341H8
Headphone THD+N vs Output Power
AVDD = 3.3V, SE, 12dB DAC
fOUT = 1kHz, 32Ω
Headphone THD+N vs Output Power
AVDD = 5V, SE, 12dB DAC
fOUT = 1kHz, 16Ω
201341H9
201341I0
Headphone THD+N vs Output Power
AVDD = 3.3V, OCL 1.2V, 0dB AUX
fOUT = 1kHz, 16Ω
Headphone THD+N vs Output Power
AVDD = 5V, SE, 12dB DAC
fOUT = 1kHz, 32Ω
201341I1
www.national.com
(Continued)
201341I2
92
(Continued)
Headphone THD+N vs Output Power
AVDD = 5V, OCL 1.2V, 0dB AUX
fOUT = 1kHz, 16Ω
Headphone THD+N vs Output Power
AVDD = 3.3V, OCL 1.2V, 12dB AUX
fOUT = 1kHz, 16Ω
201341I3
201341I4
Headphone THD+N vs Output Power
AVDD = 3.3V, OCL 1.2V, 0dB AUX
fOUT = 1kHz, 32Ω
Headphone THD+N vs Output Power
AVDD = 5V, OCL 1.2V, 12dB AUX
fOUT = 1kHz, 16Ω
201341I5
201341I6
Headphone THD+N vs Output Power
AVDD = 5V, OCL 1.2V, 0dB AUX
fOUT = 1kHz, 32Ω
Headphone THD+N vs Output Power
AVDD = 3.3V, OCL 1.2V, 12dB AUX
fOUT = 1kHz, 32Ω
201341I7
201341I8
93
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LM4935
13.0 Typical Performance Characteristics
LM4935
13.0 Typical Performance Characteristics
Headphone THD+N vs Output Power
AVDD = 3.3V, OCL 1.2V, 0dB CPI
fOUT = 1kHz, 16Ω
Headphone THD+N vs Output Power
AVDD = 5V, OCL 1.2V, 12dB AUX
fOUT = 1kHz, 32Ω
201341I9
201341J0
Headphone THD+N vs Output Power
AVDD = 3.3V, OCL 1.2V, 0dB CPI
fOUT = 1kHz, 32Ω
Headphone THD+N vs Output Power
AVDD = 5V, OCL 1.2V, 0dB CPI
fOUT = 1kHz, 16Ω
201341J1
201341J2
Headphone THD+N vs Output Power
AVDD = 3.3V, OCL 1.5V, 0dB AUX
fOUT = 1kHz, 16Ω
Headphone THD+N vs Output Power
AVDD = 5V, OCL 1.2V, 0dB CPI
fOUT = 1kHz, 32Ω
201341J3
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(Continued)
201341J4
94
(Continued)
Headphone THD+N vs Output Power
AVDD = 5V, OCL 1.5V, 0dB AUX
fOUT = 1kHz, 16Ω
Headphone THD+N vs Output Power
AVDD = 3.3V, OCL 1.5V, 12dB AUX
fOUT = 1kHz, 16Ω
201341J5
201341J6
Headphone THD+N vs Output Power
AVDD = 3.3V, OCL 1.5V, 0dB AUX
fOUT = 1kHz, 32Ω
Headphone THD+N vs Output Power
AVDD = 5V, OCL 1.5V, 12dB AUX
fOUT = 1kHz, 16Ω
201341J7
201341J8
Headphone THD+N vs Output Power
AVDD = 5V, OCL 1.5V, 0dB AUX
fOUT = 1kHz, 32Ω
Headphone THD+N vs Output Power
AVDD = 3.3V, OCL 1.5V, 12dB AUX
fOUT = 1kHz, 32Ω
201341J9
201341K0
95
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LM4935
13.0 Typical Performance Characteristics
LM4935
13.0 Typical Performance Characteristics
Headphone THD+N vs Output Power
AVDD = 3.3V, OCL 1.5V, 0dB CPI
fOUT = 1kHz, 16Ω
Headphone THD+N vs Output Power
AVDD = 5V, OCL 1.5V, 12dB AUX
fOUT = 1kHz, 32Ω
201341K1
201341K2
Headphone THD+N vs Output Power
AVDD = 3.3V, OCL 1.5V, 0dB CPI
fOUT = 1kHz, 32Ω
Headphone THD+N vs Output Power
AVDD = 5V, OCL 1.5V, 0dB CPI
fOUT = 1kHz, 16Ω
201341K3
201341N2
Headphone THD+N vs Output Power
AVDD = 3.3V, SE, 0dB AUX
fOUT = 1kHz, 16Ω
Headphone THD+N vs Output Power
AVDD = 5V, OCL 1.5V, 0dB CPI
fOUT = 1kHz, 32Ω
201341N3
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201341N4
96
(Continued)
Headphone THD+N vs Output Power
AVDD = 3.3V, SE, 0dB AUX
fOUT = 1kHz, 32Ω
Headphone THD+N vs Output Power
AVDD = 5V, SE, 0dB AUX
fOUT = 1kHz, 16Ω
201341K4
201341N5
Headphone THD+N vs Output Power
AVDD = 3.3V, SE, 0dB CPI
fOUT = 1kHz, 16Ω
Headphone THD+N vs Output Power
AVDD = 5V, SE, 0dB AUX
fOUT = 1kHz, 32Ω
201341K5
201341K6
Headphone THD+N vs Output Power
AVDD = 3.3V, SE, 0dB CPI
fOUT = 1kHz, 32Ω
Headphone THD+N vs Output Power
AVDD = 5V, SE, 0dB CPI
fOUT = 1kHz, 16Ω
201341K7
201341K8
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LM4935
13.0 Typical Performance Characteristics
LM4935
13.0 Typical Performance Characteristics
Loudspeaker THD+N vs Output Power
AVDD = 3.3V, 0dB AUX
fOUT = 1kHz, 15µH+8Ω+15µH
Headphone THD+N vs Output Power
AVDD = 5V, SE, 0dB CPI
fOUT = 1kHz, 32Ω
201341K9
201341O4
Loudspeaker THD+N vs Output Power
AVDD = 5V, 0dB AUX
fOUT = 1kHz, 15µH+8Ω+15µH
Loudspeaker THD+N vs Output Power
AVDD = 4.2V, 0dB AUX
fOUT = 1kHz, 15µH+8Ω+15µH
201341O5
201341O6
Loudspeaker THD+N vs Output Power
AVDD = 4.2V, 0dB CPI
fOUT = 1kHz, 15µH+8Ω+15µH
Loudspeaker THD+N vs Output Power
AVDD = 3.3V, 0dB CPI
fOUT = 1kHz, 15µH+8Ω+15µH
201341O7
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201341O8
98
(Continued)
Loudspeaker THD+N vs Output Power
AVDD = 3.3V, 0dB DAC
fOUT = 1kHz, 15µH+8Ω+15µH
Loudspeaker THD+N vs Output Power
AVDD = 5V, 0dB CPI
fOUT = 1kHz, 15µH+8Ω+15µH
201341O9
201341P0
Loudspeaker THD+N vs Output Power
AVDD = 5V, 0dB DAC
fOUT = 1kHz, 15µH+8Ω+15µH
Loudspeaker THD+N vs Output Power
AVDD = 4.2V, 0dB DAC
fOUT = 1kHz, 15µH+8Ω+15µH
201341P1
201341P2
AUXOUT THD+N vs Output Voltage
AVDD = 5V, 0dB AUX
fOUT = 1kHz, 5kΩ
AUXOUT THD+N vs Output Voltage
AVDD = 3.3V, 0dB AUX
fOUT = 1kHz, 5kΩ
201341L0
201341L1
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LM4935
13.0 Typical Performance Characteristics
LM4935
13.0 Typical Performance Characteristics
AUXOUT THD+N vs Output Voltage
AVDD = 5V, 0dB CPI
fOUT = 1kHz, 5kΩ
AUXOUT THD+N vs Output Voltage
AVDD = 3.3V, 0dB CPI
fOUT = 1kHz, 5kΩ
201341L2
201341L3
AUXOUT THD+N vs Output Voltage
AVDD = 5V, 0dB DAC
fOUT = 1kHz, 5kΩ
AUXOUT THD+N vs Output Voltage
AVDD = 3.3V, 0dB DAC
fOUT = 1kHz, 5kΩ
201341L4
201341L5
AUXOUT THD+N vs Output Voltage
AVDD = 5V, 12dB DAC
fOUT = 1kHz, 5kΩ
AUXOUT THD+N vs Output Voltage
AVDD = 3.3V, 12dB DAC
fOUT = 1kHz, 5kΩ
201341L6
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201341L7
100
LM4935
13.0 Typical Performance Characteristics
(Continued)
CPOUT THD+N vs Output Voltage
AVDD = 5V, 0dB AUX
fOUT = 1kHz, 5kΩ
CPOUT THD+N vs Output Voltage
AVDD = 3.3V, 0dB AUX
fOUT = 1kHz, 5kΩ
201341L8
201341L9
CPOUT THD+N vs Output Voltage
AVDD = 5V, 0dB DAC
fOUT = 1kHz, 5kΩ
CPOUT THD+N vs Output Voltage
AVDD = 3.3V, 0dB DAC
fOUT = 1kHz, 5kΩ
201341M1
201341M0
CPOUT THD+N vs Output Voltage
AVDD = 5V, 6dB MIC
fOUT = 1kHz, 5kΩ
CPOUT THD+N vs Output Voltage
AVDD = 3.3V, 6dB MIC
fOUT = 1kHz, 5kΩ
201341M2
201341M3
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LM4935
13.0 Typical Performance Characteristics
CPOUT THD+N vs Output Voltage
AVDD = 5V, 12dB DAC
fOUT = 1kHz, 5kΩ
CPOUT THD+N vs Output Voltage
AVDD = 3.3V, 12dB DAC
fOUT = 1kHz, 5kΩ
201341M4
201341M5
CPOUT THD+N vs Output Voltage
AVDD = 5V, 36dB MIC
fOUT = 1kHz, 5kΩ
CPOUT THD+N vs Output Voltage
AVDD = 3.3V, 36dB MIC
fOUT = 1kHz, 5kΩ
201341M6
201341M7
Headphone Crosstalk vs Frequency
OCL 1.2V, 0dB AUX, 32Ω
Headphone Crosstalk vs Frequency
OCL 1.5V, 0dB AUX, 32Ω
201341M8
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201341M9
102
LM4935
13.0 Typical Performance Characteristics
(Continued)
Headphone Crosstalk vs Frequency
SE, 0dB AUX, 32Ω
201341N0
103
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104
14.0 LM4935 Demonstration Board Schematic Diagram
20134135
LM4935
LM4935
15.0 Demoboard PCB Layout
20134132
Top Silkscreen
105
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LM4935
15.0 Demoboard PCB Layout
(Continued)
20134131
Top Layer
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106
LM4935
15.0 Demoboard PCB Layout
(Continued)
20134129
Mid Layer 1
107
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LM4935
15.0 Demoboard PCB Layout
(Continued)
20134130
Mid Layer 2
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108
LM4935
15.0 Demoboard PCB Layout
(Continued)
20134128
Bottom Layer
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LM4935
16.0 Product Status Definitions
Datasheet Status
Product Status
Definition
Advance
Information
Formative or in
Design
This data sheet contains the design specifications for product development.
Specifications may change in any manner without notice.
Preliminary
First Production
This data sheet contains preliminary data. Supplementary data will be published
at a later date. National Semiconductor Corporation reserves the right to make
changes at any time without notice in order to improve design and supply the
best possible product.
No Identification
Noted
Full Production
This data sheet contains final specifications. National Semiconductor Corporation
reserves the right to make changes at any time without notice in order to improve
design and supply the best possible product.
Obsolete
Not in Production
This data sheet contains specifications on a product that has been discontinued
by National Semiconductor Corporation. The datasheet is printed for reference
information only.
National Semiconductor B.V reserves the right to make changes without notice to any products herein to improve reliability, function or design. National does not
assume any liability arising out of the application or use of any product or circuit described herein; neither does it convey any license under its patent rights, nor the
right of others.
www.national.com
110
LM4935
17.0 Revision History
Rev
Date
Description
1.0
5/11/05
Filled in the actual limits (for TBDs) under
Limit and edited few Typical values, all
under the EC table. Edits from Alvin F.
1.1
7/29/05
Input more edits. Replaced the correct
boards. Replaced the Schematic Diagram
(pg 60).
1.2
9/8/05
Added the 1st set of Typ Perf curves.
1.3
9/21/05
Added a couple of tables.
1.4
9/30/05
Input text edits.
1.5
10/5/05
Input more edits.
1.6
10/11/05
More edits.
1.7
10/12/05
First D/S WEB release.
1.8
10/14/5
Input more text edits after the 1st
released.
1.9
10/17/05
Input some text edits, then re-released
D/S to the WEB.
2.0
10/18/05
More text edits. Also used graphic
20134107 back.
111
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LM4935 Audio Sub-System with Dual-Mode Stereo Headphone & Mono High Efficiency
Loudspeaker Amplifiers and Multi-Purpose ADC
18.0 Physical Dimensions
inches (millimeters) unless otherwise noted
49 Bump Microfil Package
Order Number LM4935
Dimensions: X1 = 3.925 mm, X2 = 3.925 mm, X3 = 0.6 mm
NS Package Number WLA49VVA
National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves
the right at any time without notice to change said circuitry and specifications.
For the most current product information visit us at www.national.com.
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WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF NATIONAL SEMICONDUCTOR
CORPORATION. As used herein:
1. Life support devices or systems are devices or systems
which, (a) are intended for surgical implant into the body, or
(b) support or sustain life, and whose failure to perform when
properly used in accordance with instructions for use
provided in the labeling, can be reasonably expected to result
in a significant injury to the user.
2. A critical component is any component of a life support
device or system whose failure to perform can be reasonably
expected to cause the failure of the life support device or
system, or to affect its safety or effectiveness.
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National Semiconductor manufactures products and uses packing materials that meet the provisions of the Customer Products
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