TI LM48903TL

April 12, 2012
Stereo Class D Spatial Array
General Description
Features
The LM48903 is a stereo Class D amplifier that utilizes TI’s
proprietary spatial sound processor to create an enhanced
sound stage for portable multimedia devices. The Class D
output stages feature National’s edge rate control (ERC)
PWM architecture that significantly reduces RF emissions
while preserving audio quality and efficiency.
The LM48903’s flexible I2S interface is compatible with standard serial audio interfaces. A stereo differential-input ADC
gives the device the ability to process analog stereo audio
signals.
The LM48903 is configured through an I2C compatible interface and is capable of delivering 1.7W/channel of continuous
output power into an 8Ω load with less than 10% THD+N.
Output short circuit and thermal overload protection prevent
the device from being damaged during fault conditions. Click
and pop suppression eliminates audible transients on powerup/down and during shutdown. The LM48903 is available in
space saving micro SMD package.
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■
■
■
■
Spatial Sound Processing
I2S Input
Stereo, Analog, Differential-Input ADC
Edge Rate Control
Short Circuit and Thermal Overload Protection
Minimum external components
Click and Pop suppression
Micro-power shutdown
Available in space-saving micro SMD package
Applications
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■
■
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Smart Phones
Portable Gaming
Tablets
Multimedia Devices
MP3 Player Accessories
Key Specifications
■ SNR (A-Weighted)
90dBA (typ)
■ Output Power/channel, PVDD = 5V
RL = 8Ω, THD+N ≤ 1%
■ THD+N
1.3W (typ)
0.08% (typ)
■ Efficiency/Channel
91% (typ)
■ PSRR at 217Hz
69dB (typ)
Boomer® is a registered trademark of National Semiconductor Corporation.
© 2012 Texas Instruments Incorporated
301858 SNAS587
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LM48903 Stereo Class D Spatial Array
LM48903
LM48903
Typical Application
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FIGURE 1. Typical Audio Amplifier Application Circuit
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LM48903
Connection Diagrams
micro SMD Package
30–Bump micro SMD Marking
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Top View
XY = Date code
TT = Die traceability
G = Boomer Family
K6 = LM48903TL
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Top View
Order NumberLM48903TL
See NS Package Number TLA30HHA
Ordering Information
Ordering Information Table
Order Number
Package
Package
Drawing
Number
Transport Media
MSL
Level
Green Status
LM48903TL
micro SMD
TLA30HHA
250 and 2500 units
on tape and reel
1
RoHS & no Sb/Br
3
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LM48903
TABLE 1. Bump Description
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BUMP
NAME
DESCRIPTION
A1
DGND
Digital Ground
A2
MCLK
Master Clock
A3
IOVDD
Digital Interface Power Supply
A4
SDA
I2C Serial Data Input
A5
SCL
I2C Clock Input
B1
DVDD
Digital Power Supply
B2
SHDN
Active Low Shutdown. Connect to VDD for normal operation.
B3
SDIO
I2S Serial Data Input/Output
B4
WS
B5
SCLK
Serial Clock Input
C1
PLLVDD
PLL Power Supply
C2
GAIN0
Gain Setting Input 0
C3
GAIN1
Gain Setting Input 1
C4
MODE0
Spatial Mode Control Input 0
C5
MODE1
Spatial Mode Control Input 1
D1
AVDD2
D2
AGND2
ADC Analog Ground
D3
AGND1
Modulator Analog Ground
D4
OUT1-
Channel 1 Inverting Output. Connect to OUT2- in Parallel Mode
D5
OUT1+
Channel 1 Non-Inverting Output. Connect to OUT2+ in Parallel Mode
E1
INL-
Left Channel Inverting Analog Input
E2
INL+
Left Channel Non-Inverting Analog Input
I2S Word Select Input
ADC Analog Power Supply
E3
AVDD1
Modulator Analog Power Supply
E4
PGND
Power Ground
E5
PVDD
Class D Power Supply
F1
INR-
Right Channel Inverting Analog Input
F2
INR+
Right Channel Non-Inverting Analog Input
F3
REF
ADC Reference Bypass
F4
OUT2-
Channel 2 Inverting Output. Connect to OUT1- in Parallel Mode.
F5
OUT2+
Channel 2 Non-Inverting Output. Connect to OUT1+ in Parallel Mode.
4
θJA (TLA30)
2)
54°C/W
Operating Ratings
If Military/Aerospace specified devices are required,
please contact the Texas Instruments Sales Office/
Distributors for availability and specifications.
Temperature Range
TMIN ≤ TA ≤ TMAX
Supply Voltage
Supply Voltage
AVDD, PVDD, PLVDD, IOVDD (Note 1)
6V
Supply Voltage, DVDD (Note 1)
2.2V
Storage Temperature
−65°C to + 150°C
−0.3V to VDD + 0.3V
Input Voltage
Power Dissipation (Note 3)
Internally limited
ESD Susceptibility (Note 4)
2000V
ESD Susceptibility (Note 5)
150V
Junction Temperature
150°C
−40°C ≤ TA ≤ +85°C
2.7V ≤ AVDD ≤ 5.5V
AVDD
2.7V ≤ PVDD ≤ 5.5V
PVDD
2.7V ≤ PLLVDD ≤ 5.5V
PLLVDD
1.62V ≤ IOVDD ≤ 5.5V
IOVDD
1.62V ≤ DVDD ≤ 1.98V
DVDD
Electrical Characteristics PVDD = AVDD , IOVDD = PLLVDD = 3.6V, DVDD = 1.8
(Note 2, Note 8)
The following specifications apply for AV = 0dB, CREF = 4.7µF, RL = 8Ω, f = 1kHz, unless otherwise specified. Limits apply for TA
= 25°C.
LM48903
Symbol
Parameter
Conditions
Min
(Note 8)
Typ
(Note 7)
Max
(Note 8)
Units
(Limits)
AVDD
Analog Supply Voltage Range
2.7
5.5
V
PVDD
Amplifier Supply Voltage Range
2.7
5.5
V
PLLVDD
PLL Supply Voltage Range
2.7
5.5
V
IOVDD
Interface Supply Voltage Range
1.62
5.5
V
DVDD
Digital Supply Voltage Range
1.62
AIDD
Analog Quiescent Supply Current
PIDD
Amplifier Quiescent Supply
Current
PLLIDD
15.2
RL = 8Ω
1.98
V
19
mA
2.6
mA
PLL Quiescent Supply Current
1.3
mA
DIDD
Quiescent Digital Power Supply
Current
5.4
5.8
mA
ISD
Shutdown Current (Analog,
Amplifier and PLL Supplies)
0.4
3.5
μA
DISTBY
Digital Standby Current
DISD
Digital Shutdown Current
VOS
Differential Output Offset Voltage VIN = 0
TWU
Wake-up Time
fSW
Switching Frequency
Shutdown Enabled
μA
30
Shutdown Enabled
–7.5
6.6
10
μA
0.8
7.5
mV
Power Up (Device Initialization)
150
From Shutdown
28.5
ms
fS = 48kHz
384
kHz
5
ms
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LM48903
Thermal Resistance
Absolute Maximum Ratings (Note 1, Note
LM48903
LM48903
Symbol
Parameter
Conditions
Min
(Note 8)
Typ
(Note 7)
Max
(Note 8)
Units
(Limits)
RL = 4Ω, THD+N = 10%
f = 1kHz, 22kHz BW
VDD = 5V
2.8
W
VDD = 3.6V
1.4
W
VDD = 5V
2.2
W
VDD = 3.6V
1.2
W
RL = 4Ω, THD+N = 1%
f = 1kHz, 22kHz BW
PO
Output Power/Channel
RL = 8Ω, THD+N = 10%
f = 1kHz, 22kHz BW
VDD = 5V
1.7
W
VDD = 3.6V
860
mW
1.3
W
650
mW
VDD = 5V
3.3
W
VDD = 3.6V
1.7
W
VDD = 5V
2.5
W
VDD = 3.6V
1.2
W
0.08
%
RL = 8Ω, THD+N = 1%
f = 1kHz, 22kHz BW
VDD = 5V
VDD = 3.6V
500
RL = 4Ω, THD+N = 10%, f = 1kHz, 22kHz BW
PO
THD+N
Output Power (Parallel Mode)
Total Harmonic Distortion +
Noise
RL = 4Ω, THD+N = 1%, f = 1kHz, 22kHz BW
PO = 350mW, f = 1kHz, RL = 8Ω
VRIPPLE = 200mVP-P sine, Inputs AC GND, CIN = 1μF
PSRR
Power Supply Rejection Ratio
(ADC Path)
fRIPPLE = 217Hz, Applied to PVDD
69
dB
fRIPPLE = 217Hz, Applied to DVDD
64
dB
fRIPPLE = 1kHz, Applied to PVDD
60
68
dB
fRIPPLE = 1kHz, Applied to DVDD
56
62
dB
fRIPPLE = 10kHz, Applied to PVDD
62
dB
fRIPPLE = 10kHz, Applied to DVDD
52
dB
68
dB
VRIPPLE = 200mVP-P sine, Inputs –∞dBFS
fRIPPLE = 217Hz, Applied to PVDD
PSRR
Power Supply Rejection Ratio
(I2S Path)
CMRR
Common Mode Rejection Ratio
η
Efficiency/Channel
η
Efficiency
SNR
Signal-to-NoiseRatio
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fRIPPLE = 217Hz, Applied to DVDD
72
dB
fRIPPLE = 1kHz, Applied to PVDD
60
67
dB
fRIPPLE = 1kHz, Applied to DVDD
55
69
dB
fRIPPLE = 10kHz, Applied to PVDD
58
dB
fRIPPLE = 10kHz, Applied to DVDD
56
dB
VRIPPLE = 1VP-P, fRIPPLE = 217Hz,
AV = 0dB
78
dB
VDD = 5V, PO = 1.1W
91
%
VDD = 3.6V, PO = 400mW
90
%
VDD = 5V, PO = 1.1W
86
%
VDD = 3.6V, PO = 400mW
83
%
ADC Input, PO = 1W
89
dB
I2S Input, PO = 1W
90
dB
6
εOS
Parameter
Conditions
Output Noise
XTALK
Min
(Note 8)
Max
(Note 8)
Units
(Limits)
Inputs AC GND, A-weighted,
AV = 0dB
130
μV
I2S Input
72
μV
72
dB
Crosstalk
I2C Interface Characteristics
Typ
(Note 7)
(Note 1, Note 2)
The following specifications apply for RPU = 1kΩ to IOVDD, unless otherwise specified. Limits apply for TA = 25°C.
LM48903
Symbol
Parameter
Conditions
VIH
Logic Input High Threshold
SDA, SCL
Min
(Note 7)
Typ
(Note 6)
Max
(Note 7)
0.7*IOVDD
Units
V
VIL
Logic Input Low Threshold
SDA, SCL
0.3
mV
VOL
Logic Output Low Threshold
SDA, ISDA = 3.6mA
0.35
V
IOH
Logic Output High Current
SDA, SCL
SCL Frequency
1
Hold Time
(repeated START Condition)
2
3
2
μA
400
kHz
0.6
µs
Clock Low Time
1.3
µs
Clock High Time
600
ns
4
Setup Time for Repeated
START condition
600
ns
5
Data Hold Time
6
Data Setup Time
7
SDA Rise Time
300
ns
8
SDA Fall Time
300
ns
9
Setup Time for STOP Condition
600
ns
10
Bus Free Time Between STOP
and START Condition
1.3
µs
Output
300
900
100
ns
ns
I2S Timing Characteristics
(Note 2, Note 8)
The following specifications apply for DVDD = 1.8V, unless otherwise specified. Limits apply for TA = 25°C.
LM48903
Symbol
Parameter
Conditions
Min
(Note 7)
Typ
(Note 6)
Max
(Note 7)
Units
(Limits)
tMCLKL
MCLK Pulse Width Low
16
ns
tMCLKH
MCLK Pulse Width High
16
ns
tMCLKY
MCLK Period
27
tBCLKR
SCLK rise time
tBCLKCF
SCLK fall time
tBCLKDS
SCLK Duty Cycle
ns
3
ns
3
ns
50
%
TDL
LRC Propagation Delay from
SCLK falling edge
TDST
DATA Setup Time to SCLK
Rising Edge
10
ns
TDHT
DATA Hold Time from SCLK
Rising Edge
10
ns
10
7
ns
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LM48903
LM48903
Symbol
LM48903
Note 1: “Absolute Maximum Ratings” indicate limits beyond which damage to the device may occur, including inoperability and degradation of device reliability
and/or performance. Functional operation of the device and/or non-degradation at the Absolute Maximum Ratings or other conditions beyond those indicated in
the Recommended Operating Conditions is not implied. The Recommended Operating Conditions indicate conditions at which the device is functional and the
device should not be operated beyond such conditions. All voltages are measured with respect to the ground pin, unless otherwise specified.
Note 2: The Electrical Characteristics tables list guaranteed specifications under the listed Recommended Operating Conditions except as otherwise modified
or specified by the Electrical Characteristics Conditions and/or Notes. Typical specifications are estimations only and are not guaranteed.
Note 3: The maximum power dissipation must be derated 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 given in Absolute Maximum Ratings, whichever is lower.
Note 4: Human body model, applicable std. JESD22-A114C.
Note 5: Machine model, applicable std. JESD22-A115-A.
Note 6: Typical values represent most likely parametric norms at TA = +25ºC, and at the Recommended Operation Conditions at the time of product
characterization and are not guaranteed.
Note 7: Datasheet min/max specification limits are guaranteed by design, test, or statistical analysis.
Note 8: RL is a resistive load in series with two inductors to simulate an actual speaker load. For RL = 8Ω, the load is 15μH+8Ω+15μH. For RL = 4Ω, the load is
15μH+4Ω+15μH.
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LM48903
Typical Performance Characteristics
THD+N vs FREQUENCY
VDD = 3.6V, POUT = 400mW, RL = 8Ω
Stereo Mode, I2S Input
THD+N vs FREQUENCY
VDD = 3.6V, POUT = 500mW, RL = 4Ω
Stereo Mode, I2S Input
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THD+N vs FREQUENCY
VDD = 3.6V, POUT = 250mW, RL = 4Ω
Stereo Mode, ADC Input
THD+N vs FREQUENCY
VDD = 3.6V, POUT = 200mW, RL = 8Ω
Stereo Mode, ADC Input
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THD+N vs FREQUENCY
VDD = 5V, POUT = 1.2W, RL = 4Ω
Stereo Mode, I2S Input
THD+N vs FREQUENCY
VDD = 5V, POUT = 800mW, RL = 8Ω
Stereo Mode, I2S Input
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LM48903
THD+N vs FREQUENCY
VDD = 5V, POUT = 550mW, RL = 4 Ω
Stereo Mode, ADC Input
THD+N vs FREQUENCY
VDD = 5V, POUT = 350mW, RL = 8Ω
Stereo Mode, ADC Input
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THD+N vs FREQUENCY
VDD = 3.6V, POUT = 800mW, RL = 4Ω
Parallel Mode, I2S Input
THD+N vs FREQUENCY
VDD = 3.6V, POUT = 350mW, RL = 4Ω
Parallel Mode, ADC Input
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THD+N vs FREQUENCY
VDD = 5V, POUT = 800mW, RL = 4Ω
Parallel Mode, I2S Input
THD+N vs FREQUENCY
VDD = 5V, POUT = 1.7W, RL = 4Ω
Parallel Mode, I2S Input
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THD+N vs OUTPUT POWER
RL = 8Ω, f = 1kHz, Stereo Mode, I2S Input
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LM48903
THD+N vs OUTPUT POWER
RL = 4Ω, f = 1kHz, Stereo Mode, I2S Input
THD+N vs OUTPUT POWER
RL = 4Ω, f = 1kHz, Stereo Mode, ADC Input
THD+N vs OUTPUT POWER
RL = 4Ω, f = 1kHz, Parallel Mode, I2S Input
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THD+N vs OUTPUT POWER
RL = 8Ω, f = 1kHz, Stereo Mode, ADC Input
THD+N vs OUTPUT POWER
RL = 4Ω, f = 1kHz, Parallel Mode, ADC Input
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LM48903
EFFICIENCY vs OUTPUT POWER
RL = 4Ω, f = 1kHz, Stereo Mode, ADC Input
EFFICIENCY vs OUTPUT POWER
RL = 8Ω, f = 1kHz, Stereo Mode, ADC Input
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POWER DISSIPATION vs OUTPUT POWER
RL = 4Ω, Per Channel, Stereo Mode, ADC Input
POWER DISSIPATION vs OUTPUT POWER
RL = 8Ω, Per Channel, Stereo Mode, ADC Input
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OUTPUT POWER vs SUPPLY VOLTAGE
RL = 4Ω, Stereo Mode, ADC Input
OUTPUT POWER vs SUPPLY VOLTAGE
RL = 4Ω, Stereo Mode, ADC Input
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LM48903
OUTPUT POWER vs SUPPLY VOLTAGE
RL = 8Ω, Stereo Mode, ADC Input
PSRR vs FREQUENCY
PVDD = 5V, VRIPPLE = 200mVP-P, RL = 8Ω,
ADC Input = AC GND
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PSRR vs FREQUENCY
DVDD = 1.8V, VRIPPLE = 200mVP-P, RL = 8Ω,
ADC Input = AC GND
PSRR vs FREQUENCY
PVDD = 5V, VRIPPLE = 200mVP-P, RL = 8Ω,
I2S input = –120dBFS
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PSRR vs FREQUENCY
DVDD = 1.8V, VRIPPLE = 200mVP-P, RL = 8Ω,
I2S input = –120dBFS
CMRR vs FREQUENCY
VRIPPLE = 200mVP-P, RL = 8Ω,
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LM48903
SUPPLY CURRENT vs SUPPLY VOLTAGE
ADC Mode
ANALOG SUPPLY CURRENT vs SUPPLY VOLTAGE
ADC Mode
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PLL SUPPLY CURRENT vs SUPPLY VOLTAGE
DIGITAL SUPPLY CURRENT vs SUPPLY VOLTAGE
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SHUTDOWN CURRENT vs SUPPLY VOLTAGE
DIGITAL SHUTDOWN CURRENT vs SUPPLY VOLTAGE
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I2C COMPATIBLE INTERFACE
The LM48903 is controlled through an I2C compatible serial
interface that consists of a serial data line (SDA) and a serial
clock (SCL). The clock and data lines are bi-directional (open
drain). The LM48903 communicates at clock rates up to
400kHz. Figure 2 shows the I2C interface timing diagram. Data on the SDA line must be stable during the HIGH period of
SCL. The LM48903 is a transmit/receive device, and can act
30185840
FIGURE 2. I2C Timing Diagram
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FIGURE 3. Start and Stop Diagram
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LM48903
as the I2C master, generating the SCL signal. Each transmission sequence is framed by a START condition and a STOP
condition Figure 3.
Due to the number of data registers, the LM48903 employs a
page mode scheme. Each data write consists of 7, 8 bit data
bytes, device address (1 byte), 16 bit register address (2
bytes), and 32 bit register data (4 bytes). Each byte is followed
by an acknowledge pulse Figure 4. Single byte read and write
commands are ignored. The LM48903 device address is
0110000X.
Application Information
LM48903
Once the master device registers the ACK bit, the first 8-bit
register address word is sent, MSB first [15:8]. Each data bit
should be stable while SCL is HIGH. After the first 8-bit register address is sent, the LM48903 sends another ACK bit.
Upon receipt of acknowledge, the second 8-bit register address word is sent [7:0], followed by another ACK bit. The
register data is sent, 8-bits at a time, MSB first in the following
order [7:0], [15:8], [23:16], [31.24]. Each 8-bit word is followed
by an ACK, upon receipt of which the successive 8-bit word
is sent. Following the acknowledgement of the last register
data word [31:24], the master issues a STOP bit, allowing
SDA to go high while SDA is high.
WRITE SEQUENCE
The example write sequence is shown in Figure 4. The
START signal, the transition of SDA from HIGH to LOW while
SDA is HIGH, is generated, altering all devices on the bus that
a device address is being written to the bus.
The 7-bit device address is written to the bus, most significant
bit (MSB) first, followed by the R/W bit (R/W = 0 indicating the
master is writing to the LM48903). The data is latched in on
the rising edge of the clock. Each address bit must be stable
while SDA is HIGH. After the R/W\ bit is transmitted, the master device releases SDA, during which time, an acknowledge
clock pulse is generated by the slave device. If the LM48903
receives the correct address, the device pulls the SDA line
low, generating and acknowledge bit (ACK).
301858g0
FIGURE 4. Example I2C Write Sequence
LM48903. Upon receipt of the acknowledge, the second 8-bit
register address word is sent [7:0], followed by another ACK
bit. Following the acknowledgment of the last register address, the master initiates a REPEATED START, followed by
the 7-bit device address, followed by R/W = 1 (R/W = 1 indicating the master wants to read data from the LM48903). The
LM48903 sends an ACK, followed by the selected register
data. The register data is sent, 8-bits at a time, MSB first in
the following order [7:0], [15:8], [23:16], [31:24]. Each 8-bit
word is followed by an ACK, upon receipt of which the successive 8-bit word is sent. Following the acknowledgement of
the last register data word [7:0], the master issues a STOP
bit, allowing SDA to go high while SDA is high.
READ SEQUENCE
The example read sequence is shown in Figure 5. The
START signal, the transition of SDA from HIGH to LOW while
SDA is HIGH, is generated, altering all devices on the bus that
a device address is being written to the bus.
The 7-bit device address is written to the bus, followed by the
R/W = 0. After the R/W bit is transmitted, the master device
releases SDA, during which time, an acknowledge clock
pulse is generated by the slave device. If the LM48903 receives the correct address, the device pulls the SDA line low,
generating and acknowledge bit (ACK). Once the master device registers the ACK bit, the first 8-bit register address word
is sent, MSB first [15:8], followed by and ACK from the
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FIGURE 5. Example I2C Read Sequence
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FIGURE 6. I2S Normal Input Format
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FIGURE 7. I2S Left Justified Input Format
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FIGURE 8. I2S Right Justified Input Format
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LM48903
Mode, the audio data format is similar to the Normal Mode,
without the delay between the LSB and the change in
I2S_WS. In Right Justified Mode, the audio data MSB is transmitted after a delay of a preset number of bits.
I2S DATA FORMAT
The LM48903 supports three I2S formats: Normal Mode Figure 6, Left Justified Mode Figure 7, and Right Justified Mode
Figure 8. In Normal Mode, the audio data is transmitted MSB
first, with the unused bits following the LSB. In Left Justified
LM48903
configuration settings, and a 48-bit wide Audio Sample Space
that holds the current audio data sampled from either the ADCs or the I2S interface, organized as shown in Figure 9.
MEMORY ORGANIZATION
The LM48903 memory is organized into three main regions:
a 32-bit wide Coefficient Space that holds the spatial coefficients, a 32-bit wide Register Space that holds the device
301858g4
FIGURE 9. LM48903 Memory Organization
Register 1 (0x504h) = 1 to enable Debug mode. The Coefficient Memory Space is organized as follows.
COEFFICIENT MEMORY
The device must be in Debug mode in order to write to the
Coefficient memory. Set Bit 7 (DBG_ENABLE) in Filter Debug
TABLE 2. Coefficient Memory Space
REGISTER ADDRESS
REGISTER CONTENTS
(31:16)
(15:0)
0x000h - 0x0FFh
256x16 bit Array Taps
(Right Input to OUT2)
256x16 bit Array Taps
(Left Input to OUT2)
0x100h - 0x1FFh
256x16 bit Array Taps
(Right Input to OUT1)
256x16 bit Array Taps
(Left Input to OUT1)
0x400h - 0x47Eh (EVEN)
C2 128x16 bit Prefilter Taps
(Right to Right)
C0 128x16 bit Prefilter FIR Taps
(Left to Left)
0x441h - 0x47Fh (ODD)
C3 128x16 bit Prefilter Taps
(Right to Left)
C1 128x16 bit Prefilter FIR Taps
(Left to Right)
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LM48903
CONTROL REGISTERS
TABLE 3. Register Map
Register
Name
FILTER
CONTRO
L
FILTER
COMP1
FILTER
COMP2
FILTER
DEBUG0
FILTER
DEBUG1
FILTER
STATS
Register
Address
Default
Value
0x500h
[7:0]
0xFFh
0x500h
[15:8]
0x7Fh
0x500h
[23:16]
0xE4h
0x500h
[31:24]
0xC1h
0x501h
[7:0]
0x98h
0x501h
[15:8]
0x11h
0x501h
[23:16]
0x00h
ARRAY_COMP_SELECT
0x501h
[31:24]
0x00h
UNUSED
0x502h
[7:0]
0XB8h
0x502h
[15:8]
0x11h
0x502h
[23:16]
0XB8h
0x502h
[31:24]
0x11h
0x503h
[7:0]
0x00h
DBG_DATA [7:0]
0x503h
[15:8]
0x00h
DBG_DATA [15:8]
0x503h
[23:16]
0x00h
DBG_DATA [23:16]
0x503h
[31:24]
0x00h
UNUSED
0x504h
[7:0]
0x00h
0x504h
[15:8]
0x00h
UNUSED
0x504h
[23:16]
0x00h
UNUSED
0x504h
[31:24]
0x00h
UNUSED
0x505h
[7:0]
0x00h
0x505h
[15:8]
0x80h
0x505h
[23:16]
0x00h
0x505h
[31:24]
0x80h
7
6
5
4
3
2
1
0
ARRAY_TAP
UNUSED
PRE_TAP
UNUSED
ARRAY_
ENABLE
PRE_
ENABLE
CH2_SEL
ARRAY_
BYPASS
PRE_
BYPASS
UNUSED
G1_GAIN
UNUSED
COMP_TH
POST_GAIN
UNUSED
G1_GAIN
UNUSED
UNUSED
G1_GAIN
DBG_
ENABLE
UNUSED
PCOUNT1_MODE
PCLEAR
UNUSED
ACOUNT1_MODE
ACLEAR
COMP_RATIO
COMP_TH
POST_GAIN
STEP_
ENABLE
COMP_RATIO
COMP_TH
POST_GAIN
UNUSED
CH1_SEL
UNUSED
19
UNUSED
FILTER_
SELECT
COMP_RATIO
ACC_ADDR
PCH_SEL
PCOUNT2_MODE
ACH_SEL
ACOUNT2_MODE
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LM48903
Register
Name
FILTER
DEBUG1
ACCUML
DEBUG
(READONLY)
ACCUMH
DEBUG
(READONLY)
DBG
SAT
(READONLY)
STAT
PCNT1
(READONLY)
STAT
PCNT2
(READONLY)
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Register
Address
Default
Value
0x506h
[7:0]
0x00h
DBG_DATA [7:0]
0x506h
[15:8]
0x00h
DBG_DATA [15:8]
0x506h
[23:16]
0x00h
DBG_DATA [23:16]
0x506h
[31:24]
0x00h
DBG_DATA [31:24]
0x509h
[7:0]
0xXXh
DBG_ACCL [7:0]
0x509h
[15:8]
0xXXh
DBG_ACCL [15:8]
0x509h
[23:16]
0xXXh
DBG_ACCL [23:16]
0x509h
[31:24]
0xXXh
DBG_ACCL [31:24]
0x50Ah
[7:0]
0xXXh
DBG_ACC [39:32]
0x50Ah
[15:8]
0xXXh
DBG_ACC [47:40]
0x50Ah
[23:16]
0xXXh
UNUSED
0x50Ah
[31:24]
0xXXh
UNUSED
0x50Bh
[7:0]
0xXXh
DBG_SAT [7:0]
0x50Bh
[15:8]
0xXXh
DBG_SAT [15:8]
0x50Bh
[23:16]
0xXXh
DBG_SAT [23:16]
0x50Bh
[31:24]
0xXXh
UNUSED
0x50Ch
[7:0]
0xXXh
COUNT [7:0]
0x50Ch
[15:8]
0xXXh
COUNT [15:8]
0x50Ch
[23:16]
0xXXh
COUNT [23:16]
0x50Ch
[31:24]
0xXXh
COUNT [31:24]
0x50Dh
[7:0]
0xXXh
COUNT [7:0]
0x50Dh
[15:8]
0xXXh
COUNT [15:8]
0x50Dh
[23:16]
0xXXh
COUNT [23:16]
0x50Dh
[31:24]
0xXXh
COUNT [31:24]
7
6
5
20
4
3
2
1
0
STAT
ACNT1
(READONLY)
STAT
ACNT2
(READONLY)
ADC
OFFSET
CLASS D
OFFSET
DELAY
ENABLE
&
CLOCKS
Register
Address
Default
Value
0x50Eh
[7:0]
0xXXh
COUNT [7:0]
0x50Eh
[15:8]
0xXXh
COUNT [15:8]
0x50Eh
[23:16]
0xXXh
COUNT [23:16]
0x50Eh
[31:24]
0xXXh
COUNT [31:24]
0x50Fh
[7:0]
0xXXh
COUNT [7:0]
0x50Fh
[15:8]
0xXXh
COUNT [15:8]
0x50Fh
[23:16]
0xXXh
COUNT [23:16]
0x50Fh
[31:24]
0xXXh
COUNT [31:24]
0x510h
[7:0]
0X00h
ADCR_VOS [7:0]
0x510h
[15:8]
0X00h
ADCR_VOS [15:8]
0x510h
[23:16]
0X00h
ADCL_VOS [7:0]
0x510h
[31:24]
0X00h
ADCL_VOS [15:8]
0x511h
[7:0]
0X00h
OUT1_VOS [7:0]
0x511h
[15:8]
0X00h
OUT1_VOS [15:8]
0x511h
[23:16]
0X00h
OUT2_VOS [7:0]
0x511h
[31:24]
7
6
5
4
3
0X00h
OUT2_VOS [15:8]
0x520h
[7:0]
0x06h
POWER_UP_DELAY [7:0]
0x520h
[15:8]
0x00h
POWER_UP_DELAY [15:8]
0x520h
[23:16]
0x20h
DEGLITCH_DELAY
0x520h
[31:24]
0x09h
STATE_DELAY
0x521h
[7:0]
0x00h
PWM_DC
ADC_SYN ADC_DC_ ADC_DC_
_CORREC
C_SEL CORRECT
CAL
T
0x521h
[15:8]
0x20h
QSA_
QSA_MBI
CLK_STO
ST
P
0x521h
[23:16]
0x00h
UNUSED
0x521h
[31:24]
0x00h
2
1
0
PULSE
FORCE
ENABLE
VREF_
DELAY
PCM_
HIFI
CLK_SEL
I2S_CLK
ADC_HPF ADC_HPF
_TO_1_4 _ENABLE
UNUSED
21
MCLK_RATE
ADC_HPF_MODE
OFFSET_READBACK_SELECT
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LM48903
Register
Name
LM48903
Register
Name
DIGITAL
MIXER
ANALOG
I2S PORT
ADC
TRIM
CO-EF
FICIENT
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Register
Address
Default
Value
7
6
0x522h
[7:0]
0x33h
ZERO_
CROSS
MUTE
0x522h
[15:8]
0x33h
0x522h
[23:16]
0x02h
UNUSED
I2SA_TX_SEL
0x522h
[31:24]
0x05h
UNUSED
OUT2_SEL
0x523h
[7:0]
0x00h
0x523h
[15:8]
0x10h
0x523h
[23:16]
0x00h
0x523h
[31:24]
0x00h
0x524h
[7:0]
0x01h
0x524h
[15:8]
0x00h
0x524h
[23:14]
0x00h
0x524h
[31:24]
0x00h
UNUSED
MONO_SYNC_WIDTH
SYNC_RATE
0x525h
[7:0]
0x00h
TX_BIT
TX_WIDTH
RX_WIDTH
0x525h
[15:8]
0x02h
0x525h
[23:16]
0x02h
0x525h
[31:24]
0x00h
UNUSED
0x526h
[7:0]
0x00h
ADC_COMP_COEFF_C0 [7:0]
0x526h
[15:8]
0x00h
ADC_COMP_COEFF_C0 [15:8]
0x526h
[23:14]
0x00h
ADC_COMP_COEFF_C1 [7:0]
0x526h
[31:24]
0x00h
ADC_COMP_COEFF_C1 [15:8]
0x527h
[7:0]
0x00h
ADC_COMP_COEFF_C2 [7:0]
0x527h
[15:8]
0x00h
ADC_COMP_COEFF_C2 [15:8]
0x527h
[23:16]
0x00h
UNUSED
0x527h
[31:24]
0x00h
UNUSED
5
4
3
2
1
0
ADC_DS
P
I2S_DSP
ADC_LVL
UNUSED
I2S_LVL
BYPASS_
AUTO_SD ADCTRIM
MOD
ZERO_DI
G
SCAN_TRI
SE_MOD
G
UNUSED
OUT1_SEL
ZERO_AN
A
PARALL
EL
ANA_LVL
PMC_
TEST
TSD_DIS
SCKT_DI
TST_SHT
S
UNUSED
I2C_ANA
_LEVEL
UNUSED
SYNC_
MODE
STEREO_
SYNC_
PHASE
CLOCK_
SYNC_MS
PHASE
UNUSED
A/µLAW
TX_
A/µLAW
RX_
ENABLE
ENABLE
STEREO
HALF_CYCLE_DIVIDER
SYNTH_
DENOM
UNUSED
RX_
TX_
CLK_MS
SYNTH_NUM
RX_
COMPAN
D
RX_MSB_POSITION
RX_MOD
E
TX_
COMPAN
D
TX_MSB_POSITION
TX_MOD
E
22
READ
BACK0
(READONLY)
READ
BACK1
(READONLY)
SYS
CONFIG
Register
Address
Default
Value
0x528h
[7:0]
0x00h
0x528h
[15:8]
0x00h
0x528h
[23:14]
0x00h
SPARE
0x528h
[31:24]
0x00h
UNUSED
0x529h
[7:0]
0x00h
0x529h
[15:8]
0x00h
OFF_RD_BACK [11:4]
0x529h
[23:14]
0x00h
OFF_RD_BACK [19:12]
0x529h
[31:24]
0x00h
SPARE_RD_BACK
0x530h
[7:0]
0x30h
0x530h
[15:8]
0x00h
0x530h
[23:16]
0x8Ch
0x530h
[31:24]
SPEAKE
R
OVER
DRIVE
CONTRO
L
SODP
THRES
HOLD
LOW
POWER
CONTRO
L
7
6
5
4
I2SL_LVL
UNUSED
CLIP
UNUSED
3
I2SR_LVL ADCL_LVL
CLIP
CLIP
2
0
ADCL_
ADCR_
CLIP
CLIP
SHORT2
SHORT1
ADCR_L
VL
CLIP
THERMAL
OFF_RD_BACK [3:0]
1
CE_STATE
I2C_MCL
K_REQ
DEVICE_ID
UNUSED
I2C_SP_MOD
W_CLE
_EN
USE_22C
USE_RA
_ROM_S
M
EL
UNUSED
MBIST1_ MBIST0_
ENABLE ENABLE
UNUSED
0x00h
0x531h
[7:0]
0x65h
0x531h
[15:8]
0x43h
0x531h
[23:16]
0x83h
0x531h
[31:24]
0x27h
0x532h
[7:0]
0x70h
LEVEL1
0x532h
[15:8]
0x20h
LEVEL2
0x532h
[23:16]
0x64h
INT_TH1
0x532h
[31:24]
0x64h
INT_TH2
0x533h
[7:0]
0x00h
0x533h
[15:8]
0x09h
0x533h
[23:16]
0x00h
ADC_TH [11:4]
0x533h
[31:24]
0x00h
OVR_AD OVR_ADC
OVR_VRE
OVR_OU
OVR_PLL
OVR_OUT
OVR_OU OVR_OU
CL_ENAB R_ENABL
F_ENABL
T2_ENAB
_ENABLE
1_ENABLE
T1_RST T2_RST
LE
E
E
LE
W2
UNUSED
W1
RL_RES
UNUSED
MAX_GAIN
SODP_E
NABLE
FS
UNUSED
AT_GAIN
SINP_MODE
UNUSED
LOW_PWR_MODE
UNUSED
ADC_TH [3:0]
23
AT_RES
INT_GAIN
AUDET_LEVEL
AUDET
_ENABLE
TIMEOUT_DELAY
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LM48903
Register
Name
LM48903
Register
Name
SYSTEM
STATUS
DEVICE
ID
SPEAKE
R
OVER
DRIVE
DEBUG
Register
Address
Default
Value
0x538h
[7:0]
0x00h
0x538h
[15:8]
0x00h
0x538h
[23:16]
0x00h
MEM_ADDR [7:0]
0x538h
[31:24]
0x00h
MEM_ADDR [15:8]
0x539h
[7:0]
0XA0h
CHIP_ID [7:0]
0x539h
[15:8]
0x3Ah
CHIP_ID [15:8]
0x539h
[23:16]
0x90h
CHIP_ID [23:16]
0x539h
[31:24]
0x48h
CHIP_ID [31:24]
7
6
2b0
5
4
3
MBIST_ENABLE
2
1
MBIST_GO
CL_ACTI
VE
UNUSED
0x53Ah
[7:0]
SODP_INT [7:0]
0x53Ah
[15:8]
SODP_INT [15:8]
0x53Ah
[23:16]
SODP_INT[23:16]
0x53Ah
[31:24]
GAIN_INT_MAG
0
MBIST_DONE
BUS_ER
ROR
DEV_EXI
STS
FILTER CONTROL REGISTER (0x500h)
Configures the LM48903 Array and Pre-Array filters (Spatial Engine). The Filter Control Register sets the length of the Array and
Pre-Array filter taps, and selects the filter channel source for each audio output. Set PRE_BYPASS and ARRAY_BYPASS to 1 to
bypass the Spatial Engine, disabling the spatial effect without modifying the coefficients. Set PRE_ENABLE and ARRAY_ENABLE
to 1 to enable the Spatial Engine. Set PRE_ENABLE and ARRAY_ENABLE to 0 to disable the spatial engine. Disabling the Spatial
Engine does not affect the register contents. Disable the Spatial Engine during coefficient programming.
TABLE 4. Filter Control Register
BIT
NAME
7:0
ARRAY_TAP
14:8
PRE_TAP
15
UNUSED
17:16
CH1_SEL
VALUE
DESCRIPTION
Array Filter Tap Length
Pre-filter Tap Length. Pre-filter tap length should be
less than or equal to the Array filter tap length
Channel 1 Output Routing Selection
0
Array Filter Channel 0 Output Select
1
Array Filter Channel 1 Output Select
Channel 2 Output Routing Selection
19:18
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CH2_SEL
27:20
UNUSED
28
PRE_BYPASS
29
ARRAY_BYPASS
0
Array Filter Channel 0 Output Select
1
Array Filter Channel 1 Output Select
0
Pre-Array filter not bypassed
1
Pre-Array filter bypassed
0
Array filter not bypassed
1
Array filter bypassed
24
30
31
NAME
PRE_ENABLE
ARRAY_ENABLE
VALUE
DESCRIPTION
0
Pre-Array filter disabled. Disable the Pre-Array Filter
during filter and coefficient programming. Disabling
the Pre-Array Filter does not affect the device
memory contents.
1
Pre-Array filter enabled
0
Array filter disabled. Disable the Array Filter during
filter and coefficient programming. Disabling the Array
Filter does not affect the device memory contents.
1
Array filter enabled
COMPRESSOR CONTROL REGISTER 1 (FILTER COMP1) (0x501h)
TABLE 5. Compressor Control Register
BIT
NAME
4:0
COMP_TH
VALUE
DESCRIPTION
Pre-Filter Compressor Threshold
Pre-Compression Gain
7:5
G1_GAIN
000
2
001
4
010
8
011
16
100
32
101
64
110
128
111
256
Compression Ratio
10:8
11
COMP_RATIO
000
1:1
001
2:1
010
2.66:1
011
4:1
100
5.33:1
101
8:1
110
10.66:1
111
16:1
UNUSED
Post Compression Gain (V/V)
14:12
POST_GAIN
15
UNUSED
23:16
ARRAY_COMP_SELECT
31:24
UNUSED
000
1
001
1.25
010
1.5
011
2
100
2.5
101
3
110
4
111
8
Array Filter Compression Control Register Select
25
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LM48903
BIT
LM48903
COMPRESSOR CONTROL REGISTER 2 (FILTER COMP2) (0x502h)
TABLE 6. Compressor Control Register 2
BIT
NAME
4:0
COMP_TH
VALUE
DESCRIPTION
Pre-Filter Compressor Threshold
Pre-Compression Gain
7:5
G1_GAIN
000
2
001
4
010
8
011
16
100
32
101
64
110
128
111
256
Compression Ratio
000
10:8
11
COMP_RATIO
1:1
001
2:1
010
2.66:1
011
4:1
100
5.33:1
101
8:1
110
10.66:1
111
16:1
UNUSED
Post Compression Gain (V/V)
14:12
POST_GAIN
15
UNUSED
20:16
COMP_TH
0
1
1
1.25
10
1.5
11
2
100
2.5
101
3
110
4
111
8
Pre-Filter Compressor Threshold
Pre-Compression Gain
23:21
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G1_GAIN
0
2
1
4
10
8
11
16
100
32
101
64
110
128
111
256
26
NAME
VALUE
LM48903
BIT
DESCRIPTION
Compression Ratio
24:26
COMP_RATIO
27
000
1:001
001
2:001
010
2.66:1
011
4:001
100
5.33:1
101
8:001
110
10.66:1
111
16:1
UNUSED
Post Compression Gain (V/V)
30:28
POST_GAIN
31
000
1
001
1.25
010
1.5
011
2
100
2.5
101
3
110
4
111
8
UNUSED
FILTER DEBUG REGISTER 0 (FILT_DBG0) (0x503h)
TABLE 7. Filter Debug Register 0
BIT
NAME
23:0
DBG_DATA
31:24
UNUSED
VALUE
DESCRIPTION
Audio Data. Common data for both left and right audio
channels
FILTER DEBUG REGISTER 1 (FILT_DBG1) (0x504h)
TABLE 8. Filter Debug Register 1
BIT
NAME
3:0
ACC_ADDR
4
FILTER_SELECT
5
UNUSED
6
STEP_ENABLE
7
DBG_ENABLE
31:8
UNUSED
VALUE
DESCRIPTION
Accumulator Address. Selects which accumulator is
read during debug mode
0
Selects Pre-Filter Accumulators
1
Selects Array Filter Accumulators
0
Single Step Disabled
1
Single Step Enabled
0
Debug Mode Disabled
1
Debug Mode Enabled
27
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LM48903
FILTER STATISTICS CONTROL REGISTER (FILT_STC) (0x505h)
TABLE 9. Filter Statistics Control Register
BIT
NAME
VALUE
DESCRIPTION
PRE-FILTER Counter
Channel Select
3:0
PCH_SEL
000
Channel 0
001
Channel 1
010
Channel 2
011
Channel 3
100
Channel 4
101
Channel 5
110
Channel 6
111
Channel 7
Counter 1 Mode Select. Specifies input of Counter 1
7:4
PCOUNT1_MODE
0000
Sample Count Mode. Every audio sample is counted
0001
Overflow. Overflow events counted
0010
Frequency Error. Indicates input frequency not
sufficient for given filter length
1000
MAGN[7}
1001
MAGN[7:6]
1010
MAGN[7:5}
1011
MAGN[7:4}
1100
MAGN[7:3}
1101
MAGN[7:2]
1110
MAGN[7:1}
1111
MAGN[7:0]
Counter 2 Mode Select. Specifies input of Counter 2
11:8
PCOUNT2_MODE
14:12
UNUSED
15
PCLEAR
0000
Sample Count Mode. Every audio sample is counted
0001
Overflow. Overflow events counted
0010
Frequency Error. Indicates input frequency not
sufficient for given filter length
1000
MAGN[7}
1001
MAGN[7:6]
1010
MAGN[7:5}
1011
MAGN[7:4}
1100
MAGN[7:3}
1101
MAGN[7:2]
1110
MAGN[7:1}
1111
MAGN[7:0]
0
Counter Enabled
1
Counter Cleared
ARRAY-FILTER Counter
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28
NAME
VALUE
LM48903
BIT
DESCRIPTION
Channel Select
19:16
ACH_SEL
000
Channel 0
001
Channel 1
010
Channel 2
011
Channel 3
100
Channel 4
101
Channel 5
110
Channel 6
111
Channel 7
Counter 1 Mode Select. Specifies input of Counter 1
23:20
ACOUNT1_MODE
0000
Sample Count Mode. Every audio sample is counted
0001
Overflow. Overflow events counted
0010
Frequency Error. Indicates input frequency not
sufficient for given filter length
1000
MAGN[7}
1001
MAGN[7:6]
1010
MAGN[7:5}
1011
MAGN[7:4}
1100
MAGN[7:3}
1101
MAGN[7:2]
1110
MAGN[7:1}
1111
MAGN[7:0]
Counter 2 Mode Select. Specifies input of Counter 2
27:24
ACOUNT2_MODE
30:28
UNUSED
31
ACLEAR
0000
Sample Count Mode. Every audio sample is counted
0001
Overflow. Overflow events counted
0010
Frequency Error. Indicates input frequency not
sufficient for given filter length
1000
MAGN[7}
1001
MAGN[7:6]
1010
MAGN[7:5}
1011
MAGN[7:4}
1100
MAGN[7:3}
1101
MAGN[7:2]
1110
MAGN[7:1}
1111
MAGN[7:0]
0
Counter Enabled
1
Counter Cleared
FILTER DEBUG REGISTER 2 (FILTER DEBUG 2) (0x506h)
TABLE 10. Filter Debug Register 2
BIT
NAME
31:0
DGB_DATA
VALUE
DESCRIPTION
Debug Data. Read Only
ACCUMULATOR DEBUG LOWER REGISTER (ACCUML DEBUG) (0x509h)
TABLE 11. Accumulator Debug Lower Register
BIT
NAME
31:0
DBG_ACCL
VALUE
DESCRIPTION
Accumulator Debug Data. Read Only
29
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LM48903
ACCUMULATOR DEBUG UPPER REGISTER (ACCUML DEBUG) (0x50Ah)
TABLE 12. Accumulator Debug Upper Register
BIT
NAME
VALUE
31:0
DBG_ACCL
DESCRIPTION
Accumulator Debug Data. Read Only
COMPRESSOR OUTPUT DATA REGISTER (DBG_SAT) (0x50Bh)
TABLE 13. Compressor Output Data Register
BIT
NAME
23:0
DBG_SAT
VALUE
31:24
UNUSED
DESCRIPTION
24-Bit Compressor Output Data. Read Only
FILTER STATISTICS COUNTER (STAT_ACNT) (0x50Ch)
TABLE 14. Filter Statistics Counter Register
BIT
31:0
NAME
VALUE
DESCRIPTION
Statistics of Post-Processed Array and Pre-Filter Data.
Read Only
COUNT
FILTER STATISTICS COUNTER (STAT_ACNT) (0x50Dh)
TABLE 15. Filter Statistics Counter Register
BIT
31:0
NAME
VALUE
DESCRIPTION
Statistics of Post-Processed Array and Pre-Filter Data.
Read Only
COUNT
FILTER STATISTICS COUNTER (STAT_ACNT) (0x50Eh)
TABLE 16. Filter Statistics Counter Register
BIT
NAME
31:0
COUNT
VALUE
DESCRIPTION
Statistics of Post-Processed Array and Pre-Filter Data.
Read Only
FILTER STATISTICS COUNTER (STAT_ACNT) (0x50Fh)
TABLE 17. Filter Statistics Counter Register
BIT
31:0
NAME
VALUE
DESCRIPTION
Statistics of Post-Processed Array and Pre-Filter Data.
Read Only
COUNT
ADC DC OFFSET REGISTER (ADC OFFSET) (0x510h)
TABLE 18. ADC DC Offset Register
BIT
NAME
VALUE
DESCRIPTION
15:0
ADCR_VOS
ADC Right Channel Output DC Offset
31:16
ADCL_VOS
ADC Left Channel Output DC Offset
CLASS D DC OFFSET REGISTER (CLASS D OFFSET) (0x511h)
TABLE 19. Class D DC Offset Register
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BIT
NAME
15:0
OUT1_VOS
VALUE
OUT1 Output DC Offset
31:16
OUT2_VOS
OUT2 Output DC Offset
30
DESCRIPTION
LM48903
DELAY REGISTER (DELAY) (0x520h)
TABLE 20. Delay Register
BIT
NAME
15:0
POWER_UP_DELAY
23:16
DEGLITCH_DELAY
31:24
STATE_DELAY
VALUE
DESCRIPTION
Sets
I2C
Delay Time. Default 10ms delay.
Sets ENABLE Bit Polling Timeout. Default 32ms delay
Sets Delay Between Power Up/Down States
ENABLE AND CLOCK CONFIGURATION REGISTER (ENABLE & CLOCKS) (0x521h)
TABLE 21. Enable and Clock Configuration Register
BIT
NAME
0
ENABLE
1
FORCE
2
PULSE
3
RELY_ON_VREF
4
PWM_DC_CORRECT
5
ADC_DC_CAL
6
ADC_DC_CORRECT
7
ADC_SYNC_SEL
VALUE
DESCRIPTION
0
Device Disabled in Manual Mode
1
Device Enabled in Manual Mode
0
Device Enabled Via SHDN Pin
1
Device Enabled Via I2C
0
SHDN Requires a Stable Logic Level
1
SHDN Accepts a Pulse Input
0
Device waits for delay time determined by
STATE_DELAY to enable.
1
Device waits for stable VREF
0
Disable Class D Offset Correction
1
Enable Class D Offset Correction
0
Disable ADC Offset Calibration
1
Enable ADC Offset Calibration
0
Disable ADC Offset Correction
1
Enable ADC Offset Correction
0
Normal Operation
1
Invert SYNC Signal. Increases timing margin at low
supplies
Selects PLL Input Divider
10:8
11
MCLK_RATE
I2S_CLK
12
PMC_CLK_SEL
13
HIFI
14
SAP_CLK_STOP
15
SAP_MBIST
000
32fs (1.536MHz)
001
64fs (3.072MHz)
010
128fs (6.114MHz)
011
256fs (12.288MHz)
100
512fs (24.576MHz)
101
UNUSED
110
UNUSED
111
UNUSED
0
MCLK Input to PLL
1
I2S_CLK Input to PLL
0
Oscillator Clock Input to Power Management Circuitry
1
MCLK or I2S_CLK Input to Power Management
Circuitry. Clock source depends on the state of
I2S_CLK
0
HiFi Mode Disabled
1
HiFi Mode Enabled. PLL always produces a 4096fs
clock.
0
SAP Clock Enabled
1
SAP Clock Disabled Following Device Configuration
0
Disable MBIST
1
Enable MBIST
31
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LM48903
BIT
NAME
VALUE
DESCRIPTION
ADC High Pass Filter Mode
000
001
010
18:16
ADC_HPF_MODE
011
100
101
110
111
19
ADC_HPF_ENABLE
31:20
UNUSED
0
ADC High Pass Filter Disabled
1
ADC High Pass Filter Enabled
DIGITAL MIXER CONTROL REGISTER (DIGITAL MIXER) (0x522h)
TABLE 22. Digital Mixer Control Register
BIT
NAME
VALUE
DESCRIPTION
Sets the Gain of the ADC Path (dB)
5:0
6
7
ADC_LVL
MUTE
ZXD_DISABLE
000000
-76.5
000001
-75
-
1.5dB steps
110010
-1.5
110011
0
110100
1.5
-
1.5dB Steps
111111
18
0
Normal Operation
1
Mute
0
Zero Crossing Detection Enabled
1
Zero Crossing Detection Disabled
Sets the Gain of the I2S Path (dB)
000000
13:8
I2S_LVL
15:14
UNUSED
16
I2S_DSP
17
ADC_DSP
-76.5
000001
-75
-
1.5dB steps
110010
-1.5
110011
0
110100
1.5
-
1.5dB Steps
111111
18
0
I2S Data Not Passed to DSP
1
I2S Data Passed to DSP
0
ADC Output Not Passed to DSP
1
ADC Output Passed to DSP
Selects Input of Primary I2S Transmitter
19:18
23:20
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ISA_TX_SEL
00
None
01
ADC
10
DSP
11
UNUSED
UNUSED
32
NAME
VALUE
LM48903
BIT
DESCRIPTION
Selects OUT1 Amplifier Input Source
25:24
OUT1_SEL
00
OUT1 Disabled
01
DSP
10
I2S
11
ADC
Selects OUT2 Amplifier Input Source
27:26
31:28
OUT2_SEL
00
OUT2 Disabled
01
DSP
10
I2S
11
ADC
UNUSED
ANALOG CONFIGURATION REGISTER (ANALOG) (0x523h)
TABLE 23. Analog Configuration Register
BIT
NAME
VALUE
DESCRIPTION
Sets ADC Preamplifier Gain (dB)
1:00
2
ANA_LVL
0
11
2.4
10
3.5
11
6
0
Normal Operation. OUT1 and OUT2 operate as separate
amplifiers.
1
Parallel Operation. OUT1 and OUT2 operate in parallel
as a single amplifier.
0
Normal Operation
1
Auto-Shutdown Mode. Automatically disables the
amplifiers when no analog input is detected.
0
Normal Operation
1
Auto-Shutdown Mode. Automatically disables the
amplifiers when there is no I2S input.
0
ADC Trim Disabled
1
ADC Trim Enabled. Use ADC_COMP_COEFF_C0-C2
to trim ADC.
0
Normal Operation
1
Fault Conditions Disable the Amplifiers
0
Normal Operation
1
Pulse Correction Bypass. Amplifier output stages act as
a buffer, passing PWM signal without correction to
output.
0
Normal Operation
1
Short Amplifier Inputs. Sets amplifier outputs to 50% duty
cycle, minimizing click and pop during power up/down.
0
Normal Operation
1
Output Short Circuit Protection Disabled
0
Normal Operation
1
Thermal Shutdown Disabled
0
Normal Operation
1
PMC uses PLL Source Clock
0
Normal Operation
1
Single Edge Modulation Mode
PARALLEL
3
ZERO_ANA
4
ZERO_DIG
5
ADCTRIM
6
AUTO_SD
7
BYPASS_MOD
8
TST_SHT
9
SCKT_DIS
10
00
TSD_DIS
11
PMC_TEST
12
SE_MOD
33
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LM48903
BIT
NAME
23:13
UNUSED
24
I2C_ANA_LVL
31:25
UNUSED
VALUE
DESCRIPTION
0
External ADC Gain Control. ADC gain set by G0 and G1
1
Internal ADC Gain Control. ADC gain set by ANA_LVL.
I2S PORT CONFIGURATION REGISTER (I2S PORT) (0x524h/0x525h)
TABLE 24. I2S Port Configuration Register
BIT
NAME
VALUE
DESCRIPTION
0x524h
0
1
2
3
4
5
6
STEREO
RX_ENABLE
TX_ENABLE
0
Mono Mode
1
Stereo Mode
0
Receive Mode Disabled
1
Receive Mode Enabled
0
Transmit Mode Disabled
1
Transmit Mode Enabled
0
I2S Clock Slave. Device requires an external SCLK for
proper operation.
1
I2S Clock Master. Device generates SCLK and transmits
when either RX or TX mode are enabled.
0
I2S WS Slave. Device requires an external WS for proper
operation.
1
I2S WS Master. Device generates WS and transmits
when either RX or TX mode are enabled.
0
I2S Clock Phase. Transmit on falling edge, receive on
rising edge.
1
PCM Clock Phase. Transmit on rising edge, receive on
falling edge.
0
I2S Data Format: Left, Right
1
I2S Data Format: Right, Left
CLK_MS
SYNC_MS
CLOCK_PHASE
STEREO_SYNC
_PHASE
Mono
7
SYNC_MODE
Rising edge indicates start of data word.
0
SYNC low = Left, SYNC high = Right
1
SYNC low = Right, SYNC high = left
Configures the I2S port master clock half-cycle divider.
Program the half-cycle divider by: (ReqDiv*2) 1
000000
13:8
15:14
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HALF_CYCLE
_DIVIDER
BYPASS
000001
1
000010
1.5
000011
2
-
-
111101
31
111110
31.5
111111
32
UNUSED
34
NAME
VALUE
LM48903
BIT
DESCRIPTION
Sets the Clock Generator Numerator
18:16
SYNTH_NUM
000
SYNTH_DENOM (1/)
001
100/SYNTH_DENOM
010
96/SYNTH_DENOM
011
80/SYNTH_DENOM
100
72/SYNTH_DENOM
101
64/SYNTH_DENOM
110
48/SYNTH_DENOM
111
19
SYNTH_DENOM
23:20
UNUSED
0/SYNTH_DENOM
0
Clock Generator Denominator = 128
1
Clock Generator Denominator = 125
Sets number of clock cycles before SYNC pattern
repeats.
MONO MODE
26:24
SYNC_RATE
000
8
001
12
010
16
011
18
100
20
101
24
110
25
111
32
STEREO MODE
000
16
001
24
010
32
011
36
100
40
101
48
110
50
111
64
Sets SYNC symbol width in Mono Mode
29:27
31:30
MONO_SYNC_WIDTH
000
1
001
2
010
4
011
7
100
8
101
11
110
15
111
16
UNUSED
0x525h
35
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LM48903
BIT
NAME
VALUE
DESCRIPTION
Sets number of valid RECEIVE bits.
2:0
RX_WIDTH
000
24
001
20
010
18
011
16
100
14
101
13
110
12
111
8
Sets number of TRANSMIT bits.
5:3
TX_WIDTH
000
24
001
20
010
18
011
16
100
14
101
13
110
12
111
8
Sets number of pad bits after the valid Transmit bits.
00
7:6
8
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TX_BIT
RX_MODE
0
01
1
10
High-Z
11
High-Z
0
MSB Justified Receive Mode
1
LSB Justified Receive Mode
36
NAME
VALUE
DESCRIPTION
MSB location from the frame start (MSB Justified) or LSB
location from the frame end (LSB Justified)
13:9
RX_MSB_POSITION
00000
0 (DSP/PCM LONG)
00001
1 (I2S/PCM SHORT)
00010
2
00011
3
00100
4
00101
5
00110
6
00111
7
01000
8
01001
9
01010
10
01011
11
01100
12
01101
13
01110
14
01111
15
10000
16
10001
17
10010
18
10011
19
10100
20
10101
21
10110
22
10111
23
11000
24
11001
25
11010
26
11011
27
11100
28
11101
29
11110
30
11111
14
15
16
RX_COMPAND
RX_A/µLAW
TX_MODE
31
0
Normal Operation
1
Audio Data Companded
0
µLaw Compand Mode
1
A-Law Compand Mode
0
MSB Justified Transmit Mode
1
LSB Justified Transmit Mode
37
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LM48903
BIT
LM48903
BIT
NAME
VALUE
DESCRIPTION
MSB location from the frame start (MSB Justified) or LSB
location from the frame end (LSB Justified)
21:17
TX_MSB_POSITION
00000
0 (DSP/PCM LONG)
00001
1 (I2S/PCM SHORT)
00010
2
00011
3
00100
4
00101
5
00110
6
00111
7
01000
8
01001
9
01010
10
01011
11
01100
12
01101
13
01110
14
01111
15
10000
16
10001
17
10010
18
10011
19
10100
20
10101
21
10110
22
10111
23
11000
24
11001
25
11010
26
11011
27
11100
28
11101
29
11110
30
11111
22
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TX_COMPAND
23
TX_A/µLAW
31:24
UNUSED
31
0
Normal Operation
1
Audio Data Companded
0
µLaw Compand Mode
1
A-Law Compand Mode
38
LM48903
ADC TRIM COEFFICIENT REGISTER (ADC_TRIM) (0x526h/0x527)
TABLE 25. ADC Trim Coefficient Register
BIT
NAME
VALUE
15:0
ADC_COMP_COEFF_C0
31:16
ADC_COMP_COEFF_C1
DESCRIPTION
0x526h
Sets ADC Trim Coefficient C0
Sets ADC Trim Coefficient C1
0x527h
15:0
ADC_COMP_COEFF_C2
31:16
UNUSED
Sets ADC Trim Coefficient C2
READBACK REGISTER 0(READBACK0) (0x528h) READ-ONLY
TABLE 26. Readback Register 0
BIT
NAME
VALUE
DESCRIPTION
0
ADCR_CLIP
1
Right Channel ADC Input Clipped
1
ADCL_CLIP
1
Left Channel ADC Input Clipped
2
ADCR_LVLCLIP
1
Right Channel ADC Output Clipped
3
ADCL_LVLCLIP
1
Left Channel ADC Output Clipped
4
I2SR_LVLCLIP
1
Right Channel I2S Output Clipped
5
I2SL_LVLCLIP
1
Left Channel I2S Output Clipped
8
SHORT1
1
9
SHORT2
1
7:6
UNUSED
OUT1 Output Short Circuit
OUT2 Output Short Circuit
11:10
12
UNUSED
THERMAL
23:13
SPARE
31:24
UNUSED
1
Thermal Shutdown Threshold Exceeded
READBACK REGISTER 1(READBACK1) (0x528h) READ-ONLY
TABLE 27. Readback Register 1
BIT
3.0
31:4
NAME
CE_STATE
VALUE
DESCRIPTION
0000
Wait for supply
0001
Wait For I2C CLK REQ
0010
Enable I2C CLOCK
0011
Power up delay
0100
Standby
0101
Enable REF
0110
Enable Inputs
0111
Enable Outputs
1000
Unmute
1001
Enabled
1010
Off Deglitch
1011
Mute
1100
Disable Outputs
1101
Disable Inputs
1111
UNUSED
UNUSED
39
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LM48903
SYSTEM CONFIGURATION REGISTER (SYS_CONFIG) (0x530h)
TABLE 28. System Configuration Register
BIT
NAME
6:0
DEVICE_ID
7
I2C_MCLK_REQ
8
USE_RAM
9
USE_I2C_ROM_SEL
VALUE
DESCRIPTION
Sets LM48903 Device ID in slave mode. Default is
0x30h.
0
I2C does not require MCLK
1
I2C requires MCLK
0
Disable RAM Memory Usage
1
Enable RAM Memory Usage
0
MODE0, MODE1, Selects SPATIAL mode
1
I2C_SP_MD, Selects Spatial mode
ROM mode spatial effects select. Selects which ROM
page is loaded into coefficient memory.
11:10
I2C_SP_MD
22
UNUSED
23
W_CLE_EN
24
MBIST0_ENABLE
25
MBIST1_ENABLE
31:26
UNUSED
00
4.5cm speaker spacing
01
6cm speaker spacing
10
11.5cm speaker spacing
11
DSP bypassed, stereo mode
0
Write clock disabled
1
Write clock enabled
0
Memory BIST Controller 0 Disabled
1
Memory BIST Controller 0 Enabled.
0
Memory BIST Controller 1 Disabled
1
Memory BIST Controller 1 Enabled.
SPEAKER OVERDRIVE CONTROL REGISTER (SPEAKER OVERDRIVE) (0x531h)
TABLE 29. Speaker Overdrive Protection Register
BIT
NAME
VALUE
DESCRIPTION
Window 1. Sets the sample window time the device uses
to estimate audio energy for samples between LEVEL1
and LEVEL2 (0x532h)
3:0
W1
0000
5ms
0001
10ms
0010
20ms
0011
50ms
0100
100ms
0101
200ms
0110
500ms
0111
800ms
1000
1s
1001
2s
1010
5s
1011
10s
1100-1111
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UNUSED
40
NAME
VALUE
DESCRIPTION
Window 2. Sets the sample window time the device uses
to estimate audio energy for samples above INT_TH1
(0x532h)
7:4
W2
0000
5ms
0001
10ms
0010
20ms
0011
50ms
0100
100ms
0101
200ms
0110
500ms
0111
800ms
1000
1s
1001
2s
1010
5s
1011
10s
1100-1111
UNUSED
Attack Time Resolution
10:8
11
AT_RES
000
1ms
001
2ms
010
5ms
011
10ms
100
20ms
101
50ms
110
100ms
111
200ms
UNUSED
Release Time Resolution
14:12
15
RL_RES
000
1ms
001
2ms
010
5ms
011
10ms
100
20ms
101
50ms
110
100ms
111
200ms
UNUSED
Attack Mode Gain Reduction
19:16
AT_GAIN
000
0dB. No gain reduction
001
3dB
—
3dB steps
110
18dB
111
21dB
Maximum Gain
23:17
MAX_GAIN
000
0dB
001
3dB
—
3dB steps
110
18dB
111
21dB
41
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LM48903
BIT
LM48903
BIT
NAME
VALUE
DESCRIPTION
Integrator Gain
26:24
27
INT_GAIN
000
0dB
001
6dB
—
6dB steps
110
36dB
111
42dB
UNUSED
SODP Input Mode
29:28
30
31
SINP_MODE
FS
SODP_EN
00
No Signal Applied
01
OUT1 Input to SODP
10
OUT2 Input to SODP
11
Average (OUT1+OUT2/2)
0
48ksps
1
44.1ksps
0
Speaker Overdrive protection Disabled
1
Speaker Overdrive protection Enabled
SPEAKER OVERDRIVE PROTECTION THRESHOLD REGISTER (SODP_THRESHOLD) (0x532h)
TABLE 30. Filter Debug Register 1
BIT
NAME
VALUE
DESCRIPTION
LEVEL1
Output Level Threshold. Set LEVEL1 such that signals
above LEVEL1 increase die temperature. Signal levels
above LEVEL1 are added to the estimated audio energy
in a given time window.
15:8
LEVEL2
Output Level Threshold. Set LEVEL2 such that signals
below LEVEL2 reduce die temperature. Signal levels
below LEVEL2 are subtracted from the estimated audio
energy in a given time window.
23:16
INT_TH1
Attack Threshold. Integrator level above INT_TH1
enables the SOPD, reducing device gain.
31:24
INT_TH2
Release Threshold. Integrator level below INT_TH2
disables the SOPD, increasing device gain.
7:0
LOW POWER CONTROL REGISTER (0x533h)
TABLE 31. Low Power Configuration Register
BIT
0
NAME
AUDET_EN
VALUE
DESCRIPTION
0
Disable Wake up On Audio Signal
1
Enable Wake up On Audio Signal
Wake Up Detection Threshold
2:1
3
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AUDET_LEVEL
00
25mV
01
50mV
10
75mV
11
100mV
UNUSED
42
NAME
VALUE
LM48903
BIT
DESCRIPTION
Low Power Mode
5:4
7:6
LPWR_MODE
00
Normal Mode. No power saving modes enabled
01
Analog Audio Detect Mode. Input signal compared to
AUDET_LEVEL.
10
ADC Audio Detect Mode
11
Digital Audio Detect Mod. Rising edge on I2S WS
enables the device.
UNUSED
Time Out Delay. Delay time between no audio detected
and the device entering low power mode.
11:8
TIMEOUT_DLY
0000
10ms
0001
20ms
0010
50ms
0011
100ms
0100
200ms
0101
500ms
0110
1s
0111
2s
1000
5s
1001
10s
1010
20s
1011
50s
1100
60s
1101
80s
1110
100s
1111
200s
23:12
ADC_TH
ADC Audio Detection Threshold
24
OVR_OUT2_RST
1
Override OUT2 Reset
25
OVR_OUT1_RST
1
Override OUT1 Reset
26
OVR_OUT1_EN
1
Override OUT1 Enable
27
OVR_OUT2_EN
1
Override OUT2 Enable
28
OVR_VREF_EN
1
Override Reference Enable
29
OVR_PLL_EN
1
Override PLL Enable
30
OVR_ADCR_EN
1
Override Right Channel ADC Enable
31
OVR_ADCL_EN
1
Override Left Channel ADC Enable
43
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LM48903
SYSTEM STATUS REGISTER (SYS_STAT) (0x538h) READ ONLY
TABLE 32. MBIST Status Register
BIT
NAME
VALUE
1:0
MBIST_DONE
3:2
MBIST_GO
5:4
MBIST_EN
8:6
UNUSED
9
DEV_EXISTS
10
BUS_ERR
11
CL_ACTIVE
16:12
UNUSED
31:16
MEM_ADDR
DESCRIPTION
Logic HIGH indicates memory test complete
Logic Low indicates memory fault when MBIST_DONE
is HIGH
0
MBIST Read-back Disabled
1
MBIST Read-back Enabled
Logic HIGH indicates the presence of an EEPROM
Logic HIGH indicates an I2C bus error during EEPROM
read
Logic HIGH indicates the I2C master is active and
loading from the EEPROM
Memory Address
DEVICE ID REGISTER (0x539h) READ ONLY
TABLE 33. Device ID Register
BIT
NAME
VALUE
31:0
CHIP_ID
4890_3AA0h
DESCRIPTION
32-bit Device ID
SPEAKER OVERDRIVE PROTECTION DEBUG REGISTER (0x53Ah) READ ONLY
TABLE 34. Speaker Overdrive Debug Register
BIT
NAME
23:0
SODP_INT
31:24
GAINED_INT_MAG
VALUE
DESCRIPTION
Current Integrator Value
Integrator Magnitude. 8 most significant bits of the
integrator magnitude
DEVICE ADDRESS
The 0110000X is the defaultLM48903 I2C address hard coded into the device. An alternate device address can be programmed,
via the SYS CONFIG (0x530h) Register. Use the default address during initial device configuration.
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44
LM48903
GENERAL AMPLIFIER FUNCTION
Class D Amplifier
The LM48903 features stereo efficiency Class D audio power amplifiers that utilizes Texas Instruments’ filterless modulation
scheme external component count, conserving board space and reducing system cost. The Class D outputs transition from VDD
to GND with a 384kHz switching frequency. With no signal applied, the outputs switch with a 50% duty cycle, in phase, causing
the two outputs to cancel. This cancellation results in no net voltage across the speaker, thus there is no current to the load in the
idle state.
With the input signal applied, the duty cycle (pulse width) of the LM48903 outputs changes. For increasing output voltage, the duty
cycle of OUT_+ increases while the duty cycle of OUT_- decreases. For decreasing output voltages, the converse occurs. The
difference between the two pulse widths yield the differential output voltage.
Edge Rate Control (ERC)
The LM48903 features Texas Instruments’ advanced edge rate control (ERC) that reduces EMI, while maintaining high quality
audio reproduction and efficiency. The LM48903 ERC greatly reduces the high frequency components of the output square waves
by controlling the output rise and fall times, slowing the transitions to reduce RF emissions, while maximizing THD+N and efficiency
performance. The overall result of the E2S system is a filterless Class D amplifier that passes FCC Class B radiated emissions
standards with 24in of twisted pair cable, with excellent 0.08% THD+N and high 91% efficiency.
POWER DISSIPATION AND EFFICIENCY
The major benefit of a Class D amplifier is increased efficiency versus a Class AB. The efficiency of the LM48903 is attributed to
the region of operation of the transistors in the output stage. The Class D output stage acts as current steering switches, consuming
negligible amounts of power compared to their Class AB counterparts. Most of the power loss associated with the output stage is
due to the IR loss of the MOSFET on-resistance, along with switching losses due to gate charge.
ANALOG INPUT
The LM48903 features a stereo, 18-bit, differential ADC for systems without a digital audio source. The ADC front end includes a
variable gain preamplifier with 4 gain settings, 0dB, 2.4dB, 3.5dB, and 6dB. The preamplifier gain is controlled by bits 0 and 1
(ANA_LVL) of the Analog Configuration Register (0x523h). The analog inputs can be configured as either differential or single
ended inputs. The differential configuration SNR is 6dB higher than single-ended configuration. The differential input configuration
also offers improved common mode rejection (CMRR). The increased CMRR reduces sensitivity to ground offset related noise
injection. Configure the LM48903 for single-ended inputs as shown in Figure 10.
The ADC input range is dependent on AVDD. The maximum input swing of each single ADC input, ie INL+, referenced to GND is
0.7*AVDD . This gives a maximum differential input of 7VP-P when AVDD = 5V.
301858g5
FIGURE 10. ADC Input Configurations
45
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LM48903
POWER SUPPLY REQUIREMENTS
At power up, sequence the LM48903 power supplies in the following order:
1) PVDD
2) AVDD/PLLVDD
3) DVDD/IOVDD
Ensure PVDDis higher or equal to AVDD/PLLVDD, and PVDD is always higher than DVDD.
MODULATOR POWER SUPPLY
The AVDD1 powers the class D modulators. For maximum output swing, set AVDD1 and PVDD to the same voltage. Table 35 shows
the output voltage for different AVDD1 levels.
TABLE 35. Amplifier Output Voltage with variable AVDD1 Voltage
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AVDD1 (V)
VOUT (VRMS) @PVDD = 5V, THD+N = 1%
VOUT (VRMS) @PVDD = 3.6V, THD+N = 1%
5
3.3
—
4.5
3.1
—
4.2
2.9
—
4
2.7
—
3.6
2.5
2.4
3.3
2.3
2.2
3
2.1
2.1
2.8
1
1.9
46
In Parallel mode, channels OUT1 and OUT2 are driven from the same audio source, allowing the two channels to be connected
in parallel, increasing output power to 3.3W into 4Ω at 10% THD+N. Set bit 2 (PARALLEL) of the Analog Configuration Register
(0x532h) = 1 to configured the device in Parallel mode. After the device is set to Parallel mode, make an external connection
between OUT1+ and OUT2+, and a connection between OUT1- and OUT2- Figure 11. In Parallel mode, the combined channels
are driven from the OUT1 source. Signal routing, mixing, filtering, and equalization are done through the Spatial Engine.
Make sure the device is configured in Parallel mode, before connecting OUT1 and OUT2 and enabling the outputs. Do not make
a connection between OUT1 and OUT2 together while the outputs are enabled. Disable the outputs first, then make the connections
between OUT1 and OUT2.
301858g2
FIGURE 11. Parallel Mode
47
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LM48903
PARALLEL MODE
LM48903
GAIN SETTING
I2C Gain Setting
The LM48903 has three gain stages, the ADC preamplifier, and two independent volume controls in the Digital Mixer, one for the
ADC path and one for the I2S path. The ADC preamplifier has four gain settings (0dB, 2.4dB, 3.5dB, and 6dB). The preamplifier
gain is set by bits 0 and 1 (ANA_LVL) of the Analog Configuration Register (0x523h). The Digital Mixer has two 64 step volume
controls. The ADC path volume control is set by bits 5:0 (ADC_LVL) in the Digital Mixer Control Register (0x522h). The I2S path
volume control is set by bits 13:8 (I2S_LVL) in the Digital Mixer Control Register (0x522h). Both volume controls have a range of
-76.5dB to 18dB in 1.5dB increments.
GAIN1 and GAIN0 Gain Setting
For systems without I2C control, the ADC preamplifier gain is set by GAIN1 and GAIN0. The gain settings are shown in Table
36. The I2C preamplifier gain settings override GAIN1 and GAIN0.
TABLE 36. Hardware Gain Setting
GAIN1
GAIN0
GAIN (dB)
0
0
0
0
1
2.4
1
0
3.5
1
1
6
ROM MODE
The LM48903 features a ROM with four preset operating modes; three spatial modes, and a stereo mode. The spatial modes are
designed for three different speaker distances, 4.5cm, 6cm and 11.5cm. Due to the spatial processing, there may be a perceived
Left/Right channel swap when switching between Stereo and the three preset spatial configurations in ROM mode.
The ROM modes are selected through both the I2C interface and by MODE1/MODE0. For systems without I2C, MODE1 and
MODE0 select the ROM mode as shown in Table 37. For systems with I2C, bits 11:10 (I2C_SP_MD1 and I2C_SP_MD0) of the
SYS_CONFIG register (0x530h) select the ROM mode as shown in Table 38. Set bit 9 (USE_I2C_SP_MD) of the SYS_CONFIG
register = 1 to select the ROM mode through I2C. Set bit 8 (USE_RAM) of the SYS_CONFIG register = 0 (default) to use the preset
ROM modes. Set USE_RAM = 1 to use custom spatial coefficients. The LM48903 only accepts analog inputs in ROM mode, I2S
inputs are ignored.
TABLE 37. ROM Settings, Hardware Mode (USE_I2C_SP_MD = 0)
MODE1
MODE0
DESCRIPTION
0
0
4.5cm Speaker Spacing
0
1
6cm Speaker Spacing
1
0
11.5 Speaker Spacing
1
1
DSP Bypassed, Stereo Mode
TABLE 38. ROM Settings, I2C Mode (USE_I2C_SP_MD = 1)
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USE_RAM
I2C_SP_MD1
I2C_SP_MD0
DESCRIPTION
0
0
0
4.5cm Speaker Spacing
0
0
1
6cm Speaker Spacing
0
1
0
11.5 Speaker Spacing
0
1
1
DSP Bypassed, Stereo Mode
1
X
X
Custom Spatial Mode. The device
bypasses the ROM and loads coefficients
from an external source.
48
Speaker overdrive protection (SODP) monitors the DSP outputs and adjusts the signal path gain to prevent speaker overheating.
SODP monitors two levels, LEVEL1, the output amplitude above which the voice coil temperature rises, and LEVEL2 the output
amplitude below which the voice coil temperature falls. Speaker Overdrive Protection Threshold Register (0x532h) bits 7:0 set
LEVEL1. Bits 15:8 set LEVEL2.
The difference between LEVEL1 and LEVEL2 is the amplitude where the voice coil temperature remains stable. The device integrates the difference between the output signal and LEVEL1 for signals above LEVEL1, and the difference between the output
signal and LEVEL2 for signals below LEVEL2. There are two integration time windows. Bits 3:0, (W1), of the Speaker Overdrive
Control Register (0x531h), set the duration of Window 1. Window 1 is integration time when during normal operation. Bits 7:4 (W2)
set the duration of Window 2. Window 2 is the integration time when the SODP is active, and the device gain is reduced.
At the end of Window 1, the device compares the integrator output the INT_TH1 (0x532h, bits 23:16), or the attack threshold. Bits
19:16, (AT_GAIN), of register 0x531h, set the gain reduction step. Bits 10:8 (AT_RES) set the attack time. For example, if AT_GAIN
= 6dB and AT_RES = 5ms, once the integrator output exceeds INT_TH1, the signal path gain is reduced by 6dB in 1.5dB steps
over 5ms. Following the gain reduction, the device switches to integrator Window 2. If the integrator output exceeds INT_TH1
again, the gain reduction is repeated until the integrator output no longer exceeds INT_TH1.
The device remains in the reduced gain state until the integrator output falls below INT_TH2 (0x532h, bits 31:24), or the release
threshold. Once the integrator output falls below INT_TH2, the device gain is increased to the original gain setting in 1.5dB steps.
The release time set by bits 14:12 (RL_RES). Following the gain release, the device switches back to integrator Window 1.
Set register 0x531h bit 21 (SODP_EN) = 1 to enable the speaker overdrive protection.
DSP Output Selection
The DSP outputs to the Digital Mixer can be selected from either of the two Array Filter signal paths. This allows the left and right
inputs to be swapped or mixed before being output to the Class Ds. Filter Control Register (0x500h) bits 17:16 (CH1_SEL) the
select the Array filter source for DSP1. Bits 19:18 (CH2_SEL) select the Array filter source for DSP2. Use channel routing to correct
the perceived left/right channel swap that can occur with certain spatial configurations.
Low Power Mode
The LM48903 features three low power modes that enable and disable the device based on the presence of an input signal. Mode
1 monitors the ADC input signal. Mode 2 monitors the ADC output, and offers a faster wake up time (<10ms) compared to Mode
1. Mode 3 monitors the I2S interface and enables the device on the rising edge of WS.
The low power mode is configured through the Low Power Control Register (0x533h) (Table 29). Bit 0 (AUDET_EN) enables the
automatic signal detection. Bits 2:1 (AUDET_LEVEL) set the ADC input threshold. Bits 5:4 (LPWR_MODE) select the operating
mode. Bits 11:8 (TIMEOUT_DLY) sets the delay time between loss of audio signal/WS clock to device disable. Bits 23:12 (ADC_TH)
sets the ADC output threshold.
49
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LM48903
SPEAKER OVERDRIVE PROTECTION
LM48903
DIGITAL MIXER
The digital mixer Figure 12 is responsible for routing the digital audio signals within the LM48903. The digital mixer is configured
through the Digital Mixer register (0x522h). There are six inputs to the digital mixer, left and right ADC data, left and right I2S RX
data, and two DSP output channels. ADC and I2S RX data can be routed to the DSP inputs (DSP_L and DSP_R), the class D
amplifiers (OUT1-OUT2), and the I2S TX buses. The DSP output data can be routed to the class D amplifiers, and the I2S TX bus.
The digital mixer includes independent digital gain blocks for the ADC and I2S RX data. The gain range is -76.5dB to 18dB in 1.5dB
steps. The ADC gain is set by bits 5:0 (ADC_LVL) of the Digital Mixer Control Register (0x522h). The I2S gain is set by bits 13:8
(I2S_LVL) of the Digital Mixer Control Register. With a 0dBFS input and I2S_LVL = 110011 (0dB), the output voltage is
3.36VRMS.
For additional output routing flexibility, use the digital mixer in conjunction with the Array filter channel routing. The Array filter
channel routing control selects which filter channel is output on each DSP output. The DSP must be active to use the Array filter
channel routing, however, no coefficients are required. With no spatial effect, Array filter channel contains left channel audio data,
channel contains right channel audio data. The Array filter channel routing is controlled by bits 19:16 in the Filter Control Register
(0X500h). See DSP Output Selection section.
301858g3
FIGURE 12. Digital Mixer
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50
The LM48903 Spatial Engine is a specialized DSP that is optimized for TI’s proprietary spatial audio algorithm. The Spatial Engine
consists of two processing stages, the Pre Filter and Array Filter (Figure 14). The filters perform different portions of the spatial
processing, and are configured and controlled independent of each other. The Pre Filter uses virtual speaker positioning to set the
width of the sound stage. The Array Filter is responsible for equalization and positioning the audio content within the virtual sound
stage created by the Pre Filter.
301858f9
FIGURE 13. DSP Routing
51
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LM48903
SPATIAL ENGINE (DSP)
LM48903
Filter Enable and Filter Bypass
The Pre Filter and Array Filter are enabled independently. Filter Control Register (0x500h) bit 30 (PRE_ENABLE) enables the Pre
Filter, bit 31 (ARRAY_ENABLE) enables the Array Filter. The independent filter enables maximize power savings when only a
portion of the LM48903’s DSP processing is required.
The filter bypass allows audio data to pass through the DSP without any processing. The Pre Filter and Array Filter can be independently bypassed. Filter Control Register (0x500h) bit 28 (PRE_BYPASS) bypasses the Pre Filter, bit 29 (ARRAY_BYPASS)
bypasses the Array Filter. When using a portion of the DSP path, bypass the filter that is not in use. Audio data will not pass through
the disabled filter. For example, if the Pre Filter is disabled while the Array Filter is enabled, bypass the Pre Filter.
Compressor
The Pre filter and Array filter each have a compressor that monitors the filter output and maintains the amplitude below the set
threshold (Figure 15). The compressors have four user configurable settings, compressor threshold (COMP_TH), pre-compression
gain (G1_GAIN), compression ratio (COMP_RATIO), and post compression gain (POST_GAIN). COMP_TH sets the threshold
above which the compression is applied to the filter output signal. G1_GAIN sets the gain applied before compression. COMP_RATIO sets the linear compression ratio applied to the filter output signal. POST_GAIN sets the post compression gain, increasing
the compressor output signal when either COMP_TH is low or COMP_RATIO is high.
Compressor Control Register 1 (0x501h) configures the Pre Filter compressor. Bits 4:0 (COMP_TH) set the Pre Filter compressor
threshold. Bits 7:5 (G1_GAIN set the Pre Filter pre-compression gain. Bits 10:8 (COMP_RATIO) set the Pre Filter compression
ratio. Bits 14:12 (POST_GAIN) set the post compression gain.
The Array Filter outputs can be routed through one of two compressors, allowing different signal paths to have different compression
profiles. This feature is useful if the LM48903 outputs are driving different speakers, for example, two tweeters and two subwoofers.
One compression profile is applied to the tweeter channels, while the second compression profile is applied to the subwoofer
channels. Bits 19:16 of Compressor Control Register 1 and Compressor Control Register 2 (0x502h) configure the Array Filter.
Bits 14:0 of the Compressor Control Register 2 configure the Array Filter compressor 0. Bits 30:16 configure the Array Filter
compressor 1. The Compressor Control Register 1 bits 17:16 (ARRAY_COMP_SELECT) selects the compressor setting used by
each Array Filter channel. Bit 16 controls DSP channel 1, bit 17 controls DSP channel 2. Set the desired channel
ARRAY_COMP_SELECT bit = 0 to select compressor 0, set the desired channel ARRAY_COMP_SELECT bit = 1 to select compressor 1.
301858g7
FIGURE 14. DSP Core Diagram
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52
LM48903
DSP Output Selection
CLOCK REQUIREMENTS
The LM48903 requires an external clock source for proper operation, regardless of input source or device configuration. The device
derives the ADC, digital mixer, DSP, I2S port, and PWM clocks from the external clock. The clock can be derived from either MCLK
or SCLK inputs. Set bit 11 (I2S_CLK) of the Enable and Clock configuration register (0x521h) to 0 to select MCLK, set I2S_CLK to
1 to select SCLK. The LM48903 accepts five different clock frequencies, 1.536, 3.072, 6.114, 12.288, and 24.576MHz. Set bits
10:8 (MCLK_RATE) of the Enable and Clock Configuration Register to the appropriate clock frequency. In systems where both
MCLK and SCLK are available, choose the lower frequency clock for improved power consumption.
SHUTDOWN FUNCTION
There are two ways to shutdown the LM48903, hardware mode, and software mode. The default is hardware mode.
Set bit 1 (FORCE) of the Enable and Clock Configuration Register (0x521h) to 0 to enable hardware shutdown mode. In hardware
mode, the device is enabled and disabled through SHDN. Connect SHDN to VDD for normal operation. Connect SHDN to GND to
disable the device. Hardware shutdown mode supports a one shot, or momentary switch SHDN input. When bit 2 (PULSE) of the
Enable and Clock Configuration Register (0x521h) is set to 1, the LM48903 responds to a rising edge on SHDN to change the
device state. When PULSE = 0, the device requires a stable logic level on SHDN.
Set FORCE = 1 to enable software shutdown mode. In software shutdown mode, the device is enabled and disabled through bit
0 (ENABLE) of the Enable and Clock Configuration Register (0x512h). Set ENABLE = 0 to disable the LM48903. Set ENABLE =
1 to enable the LM48903.
In either hardware or software mode, the content of the LM48903 memory registers is retained after the device is disabled, as long
as power is still applied to the device. Minimize power consumption by disabling the PMC clock oscillator when the LM48903 is
shutdown. Set bit 12 (PMC_CLK_SEL) and bit 14 (QSA_CLK_STOP) of the Enable and Clock configuration Register (0x521h) =
1 to disable the PMC clock oscillator.
EXTERNAL CAPACITOR SELECTION
Power Supply Bypassing and Filtering
Proper power supply bypassing is critical for low noise performance and high PSRR. Place the supply bypass capacitors as close
to the device as possible. Typical applications employ a voltage regulator with 10μF and 0.1μF bypass capacitors that increase
supply stability. These capacitors do not eliminate the need for bypassing of the LM48903 supply pins. A 1μF capacitor is recommended for IOVDD, PLLVDD, DVDD, and AVDD. A 2.2μF capacitor is recommended for PVDD.
REF and BYPASS Capacitor Selection
For best performance, bypass REF with a 4.7μF ceramic capacitor.
53
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LM48903
INPUT CAPACITOR SELECTION
The LM48903 analog inputs require input coupling capacitors. Input capacitors block the DC component of the audio signal, eliminating any conflict between the DC component of the audio source and the bias voltage of the LM48903. The input capacitors
create a high-pass filter with the input resistors RIN. The -3dB point of the high pass filter is found using Equation (1) below.
f = 1 / 2πRINCIN
Where the value of RIN is 20kΩ.
The input capacitors can also be used to remove low frequency content from the audio signal. Small speakers cannot reproduce,
and may even be damaged by low frequencies. High pass filtering the audio signal helps protect the speakers. When the LM48903
is using a single-ended source, power supply noise on the ground is seen as an input signal. Setting the high-pass filter point above
the power supply noise frequencies, 217Hz in a GSM phone, for example, filters out the noise such that it is not amplified and
heard on the output. Capacitors with a tolerance of 10% or better are recommended for impedance matching and improved CMRR
and PSRR.
PCB LAYOUT GUIDELINES
As output power increases, interconnect resistance (PCB traces and wires) between the amplifier, load, and power supply create
a voltage drop. The voltage loss due to the traces between the LM48903 and the load results in lower output power and decreased
efficiency. Higher trace resistance between the supply and the LM48903 has the same effect as a poorly regulated supply, increasing ripple on the supply line, and reducing peak output power. The effects of residual trace resistance increases as output
current increases due to higher output power, decreased load impedance or both. To maintain the highest output voltage swing
and corresponding peak output power, the PCB traces that connect the output pins to the load and the supply pins to the power
supply should be as wide as possible to minimize trace resistance.
The use of power and ground planes will give the best THD+N performance. In addition to reducing trace resistance, the use of
power planes creates parasitic capacitors that help to filter the power supply line.
The inductive nature of the transducer load can also result in overshoot on one of both edges, clamped by the parasitic diodes to
GND and VDD in each case. From an EMI standpoint, this is an aggressive waveform that can radiate or conduct to other components in the system and cause interference. In is essential to keep the power and output traces short and well shielded if possible.
Use of ground planes beads and micros-strip layout techniques are all useful in preventing unwanted interference.
As the distance from the LM48903 and the speaker increases, the amount of EMI radiation increases due to the output wires or
traces acting as antennas become more efficient with length. Ferrite chip inductors places close to the LM48903 outputs may be
needed to reduce EMI radiation.
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54
LM48903
Revision History
Rev
Date
1.0
04/12/12
Description
Initial WEB released.
55
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LM48903
Physical Dimensions inches (millimeters) unless otherwise noted
30–pin micro SMD
Order NumberLM48903TL
NS Package Number TLA30HHA
X1 = 2670±0.03mm X2 = 3179±0.03mm X3 = 0.6±0.075mm
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56
LM48903
Notes
57
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LM48903 Stereo Class D Spatial Array
Notes
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