LM48410
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LM48410 Low EMI, Filterless, 2.3W Stereo Class D Audio
Power Amplifier with 3D Enhancement
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1FEATURES DESCRIPTION
The LM48410 is a single supply, high efficiency,
2• Selectable Spread Spectrum Mode Reduces 2.3W/channel, filterless switching audio amplifier. A
EMI low noise PWM architecture eliminates the output
• Output Short Circuit Protection filter, reducing external component count, board area
• Stereo Class D Operation consumption, system cost, and simplifying design. A
selectable spread spectrum modulation scheme
• No Output Filter Required suppresses RF emissions, further reducing the need
• 3D Enhancement for output filters.
• Logic Selectable Gain The LM48410 is designed to meet the demands of
• Independent Channel Shutdown Controls mobile phones and other portable communication
• Minimum External Components devices. Operating from a single 5V supply, the
device is capable of delivering 2.3W/channel of
• Click and Pop Suppression continuous output power to a 4Ωload with less than
• Micro-Power Shutdown 10% THD+N. Flexible power supply requirements
• Available in Space-Saving 4mm x 4mm WQFN allow operation from 2.4V to 5.5V. The LM48410
Package offers two logic selectable modulation schemes, fixed
frequency mode, and an EMI reducing spread
spectrum mode.
APPLICATIONS The LM48410 features high efficiency compared with
• Mobile Phones conventional Class AB amplifiers. When driving an
• PDAs 8Ωspeaker from a 3.6V supply, the device operates
• Laptops with 85% efficiency at PO= 500mW/Ch. Four gain
options are pin selectable through the G0 and G1
KEY SPECIFICATIONS pins. The LM48410 also includes 3D audio
enhancement that improves stereo sound quality. In
• Quiescent Power Supply Current at 3.6V devices where the left and right speakers are in close
supply 4mA proximity, 3D enhancement affects channel
• Power Output at VDD = 5V, RL= 4Ω, THD ≤10% specialization, widening the perceived soundstage.
2.3W (typ) Output short circuit protection prevents the device
• Power Output at VDD = 5V, RL= 8Ω, THD ≤10% from being damaged during fault conditions. Superior
1.5W (typ) click and pop suppression eliminates audible
transients on power-up/down and during shutdown.
• Shutdown current 0.03μA (typ) Independent left/right shutdown controls maximizes
• Efficiency at 3.6V, 100mW into 8Ω80% (typ) power savings in mixed mono/stereo applications.
• Efficiency at 3.6V, 500mW into 8Ω85% (typ)
• Efficiency at 5V, 1W into 8Ω86% (typ)
1Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
2All trademarks are the property of their respective owners.
PRODUCTION DATA information is current as of publication date. Copyright © 2007–2013, Texas Instruments Incorporated
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
GAIN
3D
MODULATOR H-
BRIDGE
GAIN MODULATOR H-
BRIDGE
OSCILLATOR
VDD PVDD PVDD
INR+
INR-
SDR
G0
G1
SDL
INL+
INL-
3DEN
3DL- 3DR-
3DL+
GND PGND
OUTLA
OUTLB
OUTRA
OUTRB
+2.5V to +5.5V
CSCS
C3D+
C3D-
CIN
CIN
CIN
CIN
R3D+
R3D-
SS/FF
3DR+
LM48410
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EMI Plot
Typical Application
Figure 1. Typical Audio Amplifier Application Circuit
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121110987
18
17
16
15
14
13
1
2
3
4
5
6
24 23 22 21 20 19
3DR+
INR+
INR-
3DEN
INL-
INL+
3DL+
3DL-
G1
PVDD
OUTLA
OUTLB
PGND
SDL
SS/FF
SDR
GND
PGND
OUTRB
OUTRA
PVDD
VDD
G0
3DR-
LM48410
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Connection Diagram
Figure 2. 24-Lead WQFN
4mm x 4mm x 0.8mm - Top View
See RTW0024A Package
PIN DESCRIPTIONS
Pin Name Description
Right Channel non-inverting 3D connection. Connect to 3DL+ through
1 3DR+ C3D+ and R3D+
2 INR+ Right Channel Non-Inverting Input
3 INR- Right Channel Inverting Input
4 3DEN 3D Enable Input
5 INL- Left Channel Inverting Input
6 INL+ Left Channel Non-Inverting Input
Left Channel non-inverting 3D connection. Connect to 3DR+ through C3D+
7 3DL+ and R3D+
Left Channel inverting 3D connection. Connect to 3DR- through C3D-and
8 3DL- R3D-
9 G1 Gain Select Input 1
10, 21 PVDD Speaker Power Supply
11 OUTLA Left Channel Non-Inverting Output
12 OUTLB Left Channel Inverting Output
13, 18 PGND Power Ground
Left Channel Active Low Shutdown. Connect to VDD for normal operation.
14 SDL Connect to GND to disable the left channel.
Modulation Mode Select. Connect to VDD for spread spectrum mode.
15 SS/FF Connect to GND for fixed frequency mode
Right Channel Active Low Shutdown. Connect to VDD for normal
16 SDR operation. Connect to GND to disable the right channel.
17 GND Ground
19 OUTRB Right Channel Inverting Output
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PIN DESCRIPTIONS (continued)
Pin Name Description
20 OUTRA Right Channel Non-Inverting Output
22 VDD Power Supply
23 G0 Gain Select Input 0
Right Channel inverting 3D connection. Connect to 3DL- through C3D-and
24 3DR- R3D-
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam
during storage or handling to prevent electrostatic damage to the MOS gates.
Absolute Maximum Ratings(1)(2)(3)
Supply Voltage(1) 6.0V
Storage Temperature −65°C to +150°C
Input Voltage –0.3V to VDD +0.3V
Power Dissipation(4) Internally Limited
ESD Susceptibility(5) 2000V
ESD Susceptibility(6) 200V
Junction Temperature 150°C
Thermal Resistance θJC 5.3°C/W
θJA 36.5°C/W
(1) All voltages are measured with respect to the ground pin, unless otherwise specified.
(2) 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 ensure specific performance limits. Electrical Characteristics state DC and AC electrical
specifications under particular test conditions which ensure specific performance limits. This assumes that the device is within the
Operating Ratings. Specifications are not ensured for parameters where no limit is given, however, the typical value is a good indication
of device performance.
(3) å
(4) 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 number given in Absolute Maximum Ratings,
whichever is lower.
(5) Human body model, 100pF discharged through a 1.5kΩresistor.
(6) Machine Model, 220pF–240pF discharged through all pins.
Operating Ratings(1)(2)
Temperature Range TMIN ≤TA≤TMAX −40°C ≤TA≤85°C
Supply Voltage (VDD, PVDD) 2.4V ≤VDD ≤5.5V
(1) All voltages are measured with respect to the ground pin, unless otherwise specified.
(2) 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 ensure specific performance limits. Electrical Characteristics state DC and AC electrical
specifications under particular test conditions which ensure specific performance limits. This assumes that the device is within the
Operating Ratings. Specifications are not ensured for parameters where no limit is given, however, the typical value is a good indication
of device performance.
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Electrical Characteristics VDD = PVDD = 3.6V(1)(2)
The following specifications apply for AV= 6dB, RL= 15μH + 8Ω+ 15μH, SS/FF = VDD = (Spread Spectrum mode), f = 1kHz,
unless otherwise specified. Limits apply for TA= 25°C. LM48410 Units
Symbol Parameter Conditions (Limits)
Typical(3) Limit(4)(5)
VOS Differential Output Offset Voltage VIN = 0, VDD = 2.4V to 5.0V 5 mV
VIN = 0, No Load
IDD Quiescent Power Supply Current Both channels active, VDD = 3.6V 4 6.5 mA (max)
VDD = 5V 5 8.5 mA (max)
ISD Shutdown Current VSDL = VSDR = GND 0.03 1 μA (max)
VIH Logic Input High Voltage 1.4 V (min)
VIL Logic Input Low Voltage 0.4 V (max)
TWU Wake Up Time 4 ms
SS/FF = VDD (Spread Spectrum) 300 390 kHz (max)
fSW Switching Frequency SS/FF = GND (Fixed Frequency) 300 kHz
G0, G1 = GND, RL=∞5.5 dB (min)
66.5 dB (max)
11.5 dB (min)
G0 = VDD, G1 = GND 12 12.5 dB (max)
AVGain 17.5 dB (min)
G0 = GND, G1 = VDD 18 18.5 dB (max)
23.5 dB (min)
G0, G1 = VDD 24 24.5 dB (max)
AV= 6dB 160 kΩ
AV= 12dB 80 kΩ
RIN Input Resistance AV= 18dB 40 kΩ
AV= 24dB 20 kΩ
(1) All voltages are measured with respect to the ground pin, unless otherwise specified.
(2) 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 ensure specific performance limits. Electrical Characteristics state DC and AC electrical
specifications under particular test conditions which ensure specific performance limits. This assumes that the device is within the
Operating Ratings. Specifications are not ensured for parameters where no limit is given, however, the typical value is a good indication
of device performance.
(3) Typicals are measured at 25°C and represent the parametric norm.
(4) Limits are specified to TI's AOQL (Average Outgoing Quality Level).
(5) Datasheet min/max specification limits are specified by design, test, or statistical analysis.
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Electrical Characteristics VDD = PVDD = 3.6V(1)(2) (continued)
The following specifications apply for AV= 6dB, RL= 15μH + 8Ω+ 15μH, SS/FF = VDD = (Spread Spectrum mode), f = 1kHz,
unless otherwise specified. Limits apply for TA= 25°C. LM48410 Units
Symbol Parameter Conditions (Limits)
Typical(3) Limit(4)(5)
RL= 15μH + 4Ω+ 15μH, THD ≤10%
f = 1kHz, 22kHz BW
VDD = 5V 2.3 W
VDD = 3.6V 1.14 W
VDD = 2.5V 490 mW
RL= 15μH + 8Ω+ 15μH, THD ≤10%
f = 1kHz, 22kHz BW
VDD = 5V 1.5 W
VDD = 3.6V 740 600 mW (min)
VDD = 2.5V 330 mW
POOutput Power (Per Channel) RL= 15μH + 4Ω+ 15μH, THD ≤1%
f = 1kHz, 22kHz BW
VDD = 5V 1.85 W
VDD = 3.6V 940 mW
VDD = 2.5V 400 mW
RL= 15μH + 8Ω+ 15μH, THD = 1%
f = 1kHz, 22kHz BW
VDD = 5V 1.18 W
VDD = 3.6V 580 mW
VDD = 2.5V 270 mW
PO= 500mW/Ch, f = 1kHz, RL= 8Ω0.025 %
THD+N Total Harmonic Distortion PO= 300mW/Ch, f = 1kHz, RL= 8Ω0.07 %
VRIPPLE = 200mVP-P Sine,
Inputs AC GND,
PSRR Power Supply Rejection Ratio CIN = 1μF, input referred
fRipple = 217Hz 70 dB
fRipple = 1kHz, 68 dB
VRIPPLE = 1VP-P
CMRR Common Mode Rejection Ratio 65 dB
fRIPPLE = 217Hz
PO= 1W/Ch, f = 1kHz,
ηEfficiency 86 %
RL= 8Ω, VDD = 5V
Xtalk Crosstalk PO= 500mW/Ch, f = 1kHz 82 dB
VDD = 5V, PO= 1W
SNR Signal to Noise Ratio 88 dB
Fixed Frequency Mode
Input referred, Fixed Frequency
εOS Output Noise Mode 28 μV
A-Weighted Filter
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0.001
0.01
0.1
1
10
100
20 100 1k 10k 20k
FREQUENCY (Hz)
THD+N (%)
0.001
0.01
0.1
1
10
100
20 100 1k 10k 20k
FREQUENCY (Hz)
THD+N (%)
0.001
0.01
0.1
1
10
100
20 100 1k 10k 20k
FREQUENCY (Hz)
THD+N (%)
0.001
0.01
0.1
1
10
100
20 100 1k 10k 20k
FREQUENCY (Hz)
THD+N (%)
0.01
0.1
1
10
100
0.001 0.01 0.1 1 10
OUTPUT POWER (W)
THD+N (%)
VDD = 2.5V
VDD = 3.6V
VDD = 5V
0.01
0.1
1
10
100
0.001 0.01 0.1 1 10
OUTPUT POWER (W)
THD+N (%)
VDD = 5V
VDD = 2.5V
= 3.6VVDD
LM48410
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Typical Performance Characteristics
THD+N vs Output Power THD+N vs Output Power
f = 1kHz, AV= 6dB, RL= 8Ωf = 1kHz, AV= 6dB, RL= 4Ω
Figure 3. Figure 4.
THD+N vs Frequency THD+N vs Frequency
VDD = 2.5V, POUT = 100mW, RL= 8ΩVDD = 3.6V, POUT = 250mW, RL= 8Ω
Figure 5. Figure 6.
THD+N vs Frequency THD+N vs Frequency
VDD = 5V, POUT = 375mW, RL= 8ΩVDD = 2.5V, POUT = 100mW, RL= 4Ω
Figure 7. Figure 8.
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0
50
100
150
200
250
300
350
400
450
500
0 500 1000 1500 2000 2500 3000
OUTPUT POWER (mW)
POWER DISSIPATION (mW)
VDD = 5V
VDD = 3.6V
VDD = 2.5V
POUT = POUTL + POUTR
0
300
600
900
1200
1500
0 1000 2000 3000 4000
OUTPUT POWER (mW)
POWER DISSIPATION (mW)
VDD = 5V
VDD = 3.6V
VDD = 2.5V
POUT = POUTL + POUTR
0 500 1000 1500 2000
OUTPUT POWER (mW)
EFFICIENCY (%)
VDD = 5V
VDD = 2.5V
VDD = 3.6V
0
10
20
30
40
50
60
70
80
90
100
0 300 600 900 1200 1500
OUTPUT POWER (mW)
EFFICIENCY (%)
VDD = 5V
VDD = 2.5V
VDD = 3.6V
0
10
20
30
40
50
60
70
80
90
100
0.001
0.01
0.1
1
10
100
20 100 1k 10k 20k
FREQUENCY (Hz)
THD+N (%)
0.001
0.01
0.1
1
10
100
20 100 1k 10k 20k
FREQUENCY (Hz)
THD+N (%)
LM48410
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Typical Performance Characteristics (continued)
THD+N vs Frequency THD+N vs Frequency
VDD = 3.6V, POUT = 250mW, RL= 4ΩVDD = 5V, POUT = 375mW, RL= 4Ω
Figure 9. Figure 10.
Efficiency vs Output Power Efficiency vs Output Power
RL= 4Ω, f = 1kHz RL= 8Ω, f = 1kHz
Figure 11. Figure 12.
Power Dissipation vs Output Power Power Dissipation vs Output Power
RL= 4Ω, f = 1kHz RL= 8Ω, f = 1kHz
Figure 13. Figure 14.
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-80
-70
-60
-50
-40
-30
-20
-10
0
20 100 1k 10k 20k
FREQUENCY (Hz)
CMRR (dB)
2.5 33.5 4 4.5 5 5.5
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (mA)
0
1
2
3
4
5
6
7
8
-80
-70
-60
-50
-40
-30
-20
-10
0
20 100 1k 10k 20k
FREQUENCY (Hz)
PSRR(dB)
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
20 100 1k 10k 20k
FREQUENCY (Hz)
CROSSTALK (dB)
0
500
1000
1500
2000
2500
3000
2.5 3 3.5 4 4.5 5 5.5
SUPPLY VOLTAGE (V)
OUTPUT POWER (mW)
THD+N = 10%
THD+N = 1%
0
500
1000
1500
2000
2.5 3 3.5 4 4.5 5 5.5
SUPPLY VOLTAGE (V)
OUTPUT POWER (mW)
THD+N = 10%
THD+N = 1%
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Typical Performance Characteristics (continued)
Output Power vs Supply Voltage Output Power vs Supply Voltage
RL= 4Ω, f = 1kHz RL= 8Ω, f = 1kHz
Figure 15. Figure 16.
PSRR vs Frequency Crosstalk vs Frequency
VDD = 3.6V, VRIPPLE= 200mVP-P, RL= 8ΩVDD = 3.6V, VRIPPLE = 1VP-P, RL= 8Ω
Figure 17. Figure 18.
CMRR vs Frequency Supply Current vs Supply Voltage
VDD = 3.6V, VCM = 1VP-P, RL= 8ΩNo Load
Figure 19. Figure 20.
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20 Hz 10 MHz
-100
0 dB 0
-40
-50
-70
-80
-30
-90
-60
-20
-10
20 Hz 10 MHz
-100
0 dB
0
-10
-20
-30
-40
-50
-60
-70
-80
-90
LM48410
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Typical Performance Characteristics (continued)
Fixed Frequency FFT Spread Spectrum FFT
VDD = 3.6V VDD = 3.6V
Figure 21. Figure 22.
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APPLICATION INFORMATION
GENERAL AMPLIFIER FUNCTION
The LM48410 stereo Class D audio power amplifier features a filterless modulation scheme that reduces external
component count, conserving board space and reducing system cost. The outputs of the device transition from
VDD to GND with a 300kHz 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.
When an input signal is applied, the duty cycle (pulse width) of the LM48410 output's change. For increasing
output voltage, the duty cycle of one side of each output increases, while the duty cycle of the other side of each
output decreases. For decreasing output voltages, the converse occurs. The difference between the two pulse
widths yields the differential output voltage.
FIXED FREQUENCY MODE
The LM48410 features two modulations schemes, a fixed frequency mode and a spread spectrum mode. Select
the fixed frequency mode by setting SS/FF = GND. In fixed frequency mode, the amplifier outputs switch at a
constant 300kHz. In fixed frequency mode, the output spectrum consists of the fundamental and its associated
harmonics (see Typical Performance Characteristics).
SPREAD SPECTRUM
The logic selectable spread spectrum mode eliminates the need for output filters, ferrite beads or chokes. In
spread spectrum mode, the switching frequency varies randomly by 30% about a 300kHz center frequency,
reducing the wideband spectral content and improving EMI emissions radiated by the speaker and associated
cables and traces. A fixed frequency class D exhibits large amounts of spectral energy at multiples of the
switching frequency. The spread spectrum architecture of the LM48410 spreads the same energy over a larger
bandwidth (See Typical Performance Characteristics). The cycle-to-cycle variation of the switching period does
not affect the audio reproduction, efficiency, or PSRR. Set SS/FF = VDD for spread spectrum mode.
DIFFERENTIAL AMPLIFIER EXPLANATION
As logic supplies continue to shrink, system designers are increasingly turning to differential analog signal
handling to preserve signal to noise ratios with restricted voltage swings. The LM48410 features two fully
differential speaker amplifiers. A differential amplifier amplifies the difference between the two input signals.
Traditional audio power amplifiers have typically offered only single-ended inputs resulting in a 6dB reduction of
SNR relative to differential inputs. The LM48410 also offers the possibility of DC input coupling which eliminates
the input coupling capacitors. A major benefit of the fully differential amplifier is the improved common mode
rejection ratio (CMRR) over single-ended input amplifiers. The increased CMRR of the differential amplifier
reduces sensitivity to ground offset related noise injection, especially important in noisy systems.
POWER DISSIPATION AND EFFICIENCY
The major benefit of a Class D amplifier is increased efficiency versus a Class AB. The efficiency of the
LM48410 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 a Class AB amplifier.
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.
SHUTDOWN FUNCTION
The LM48410 features independent left and right channel shutdown controls, allowing each channel to be
disabled independently. SDR controls the right channel, while SDL controls the left channel. Driving either low
disables the corresponding channel, reducing supply current to 0.1µA.
It is best to switch between ground and VDD for minimum current consumption while in shutdown. The LM48410
may be disabled with shutdown voltages in between GND and VDD, the idle current will be greater than the
typical 0.1μA value.
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The LM48410 shutdown inputs have internal pulldown resistors. The purpose of these resistors is to eliminate
any unwanted state changes when SD is floating. To minimize shutdown current, SD should be driven to GND or
left floating. If SD is not driven to GND or floating, an increase in shutdown supply current will be noticed.
PROPER SELECTION OF EXTERNAL COMPONENTS
Power Supply Bypassing/Filtering
Proper power supply bypassing is important for low noise performance and high PSRR. Place the supply bypass
capacitor 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
LM48410 supply pins. A 1µF capacitor is recommended.
Input Capacitor Slection
Input capacitors may be required for some applications, or when the audio source is single-ended. 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 LM48410. The input capacitors create a high-pass filter with the
input resistance RIN. The -3dB point of the high-pass filter is found using Equation 1 below.
f = 1 / 2πRINCIN (1)
The values for RIN can be found in the Electrical Characteristics table for each gain setting.
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 LM48410 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, 217 Hz 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.
3D Enhancement
The LM48410 features TI’s 3D enhancement effect that widens the perceived soundstage of a stereo audio
signal. The 3D enhancement increases the apparent stereo channel separation, improving audio reproduction
whenever the left and right speakers are too close to one another.
An external RC network shown in Figure 1 is required to enable the 3D effect. Because the LM48410 is a fully
differential amplifier, there are two separate RC networks, one for each stereo input pair (INL+ and INR+, and
INL- and INR-). Set 3DEN high to enable the 3D effect. Set 3DEN low to disable the 3D effect.
The 3D RC network acts as a high pass filter. The amount of the 3D effect is set by the R3D resistor. Decreasing
the value of R3D increases the 3D effect. The C3D capacitor sets the frequency at which the 3D effect occurs.
Increasing the value of C3D decreases the low frequency cutoff point, extending the 3D effect over a wider
bandwidth. The low frequency cutoff point is given by:
f3D(–3dB) = 1 / 2π(R3D)(C3D) (2)
Enabling the 3D effect increase the gain by a factor of (1+20kΩ/R3D). Setting R3D to 20kΩresults in a gain
increase of 6dB whenever the 3D effect is enabled. In fully differential configuration, the component values of the
two RC networks must be identical. Any component variations can affect the sound quality of the 3D effect. In
single-ended configuration, only the RC network of the input pairs being driven by the audio source needs to be
connected. For instance, if audio is applied to INR+ and INL+, then a 3D network must be connected between
3DL+ and 3DR+. 3DL- and 3DR- can be left unconnected.
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GAIN
CONTROL
INL+
INL-
INR+
INR-
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AUDIO AMPLIFIER GAIN SETTING
The LM48410 features four internally configured gain settings. The device gain is selected through the two logic
inputs, G0 and G1. The gain settings are as shown in the following table.
LOGIC INPUT GAIN
G1 G0 V/V dB
0026
0 1 4 12
1 0 8 18
1 1 16 24
SINGLE-ENDED AUDIO AMPLIFIER CONFIGURATION
The LM48410 is compatible with single-ended sources. When configured for single-ended inputs, input
capacitors must be used to block and DC component at the input of the device. Figure 23 shows the typical
single-ended applications circuit.
Figure 23. Single-Ended Circuit Diagram
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 LM48410 and the load
results in lower output power and decreased efficiency. Higher trace resistance between the supply and the
LM48410 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.
Copyright © 2007–2013, Texas Instruments Incorporated Submit Documentation Feedback 13
Product Folder Links: LM48410
LM48410
SNAS403E –FEBRUARY 2007–REVISED MAY 2013
www.ti.com
The inductive nature of the transducer load can also result in overshoot on one or 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 LM48410 and the speaker increases, the amount of EMI radiation increases due to the
output wires or traces acting as antennas. An antenna becomes a more efficient radiator with lenth. Ferrite chip
inductors places close to the LM48410 outputs may be needed to reduce EMI radiation.
EXPOSED-DAP MOUNTING CONSIDERATIONS
The LM48410 WQFN package features an exposed thermal pad on its underside (DAP, or die attach paddle).
The exposed DAP lowers the package’s thermal resistance by providing a direct heat conduction path from the
die to the printed circuit board. Connect the exposed thermal pad to GND though a large pad and multiple vias to
a GND plane on the bottom of the PCB.
Bill of Materials
Table 1. LM48410SQ Demo Board Bill of Materials
Recommended
Designation Qty Description Part Number
Manufacturer
1μF±10%, 16V X7R ceramic
C1–C4 4 Panasonic ECJ-3YB1C105K
capacitors (1206)
1μF±10%, 16V X7R ceramic
C5–C9 5 Panasonic ECJ-1VB1C105K
capacitors (603)
1μF±10%, 16V X7R tantalum
C10 1 AVX TPSB106K016R0800
capacitors (B-case))
R1, R2 2 82kΩ±5% resistor (603)
R3, R4 2 100kΩpotentiometer ST4B104CT
Common mode choke, A1, 800Ω
T1, T2 2 TDK ACM4532–801
at 100HHz
JU1–JU6 6 3–pin header
LM48410SQ (24–pin SQA, 4mm
U1 Texas Instruments
x 4mm x 0.8mm)
14 Submit Documentation Feedback Copyright © 2007–2013, Texas Instruments Incorporated
Product Folder Links: LM48410
LM48410
SNAS403E –FEBRUARY 2007–REVISED MAY 2013
www.ti.com
REVISION HISTORY
Rev Date Description
1.0 02/21/07 Initial release.
1.1 03/19/07 Text edits.
1.2 07/11/07 Added the demo boards and schematic diagram.
1.3 02/22/08 Fixed the PID (product folder).
1.4 04/29/08 Text edits.
1.5 07/03/08 Text edits (under SHUTDOWN FUNCTION).
Changes from Revision D (May 2013) to Revision E Page
• Changed layout of National Data Sheet to TI format .......................................................................................................... 17
18 Submit Documentation Feedback Copyright © 2007–2013, Texas Instruments Incorporated
Product Folder Links: LM48410
PACKAGE OPTION ADDENDUM
www.ti.com 24-Aug-2014
Addendum-Page 1
PACKAGING INFORMATION
Orderable Device Status
(1)
Package Type Package
Drawing Pins Package
Qty Eco Plan
(2)
Lead/Ball Finish
(6)
MSL Peak Temp
(3)
Op Temp (°C) Device Marking
(4/5)
Samples
LM48410SQ/NOPB ACTIVE WQFN RTW 24 1000 Green (RoHS
& no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 85 L48410
LM48410SQX/NOPB ACTIVE WQFN RTW 24 4500 Green (RoHS
& no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 85 L48410
(1) The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability
information and additional product content details.
TBD: The Pb-Free/Green conversion plan has not been defined.
Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that
lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.
Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between
the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above.
Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight
in homogeneous material)
(3) MSL, Peak Temp. - The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature.
(4) There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device.
(5) Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation
of the previous line and the two combined represent the entire Device Marking for that device.
(6) Lead/Ball Finish - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead/Ball Finish values may wrap to two lines if the finish
value exceeds the maximum column width.
Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information
provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and
continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals.
TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release.
PACKAGE OPTION ADDENDUM
www.ti.com 24-Aug-2014
Addendum-Page 2
In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis.
TAPE AND REEL INFORMATION
*All dimensions are nominal
Device Package
Type Package
Drawing Pins SPQ Reel
Diameter
(mm)
Reel
Width
W1 (mm)
A0
(mm) B0
(mm) K0
(mm) P1
(mm) W
(mm) Pin1
Quadrant
LM48410SQ/NOPB WQFN RTW 24 1000 178.0 12.4 4.3 4.3 1.3 8.0 12.0 Q1
LM48410SQX/NOPB WQFN RTW 24 4500 330.0 12.4 4.3 4.3 1.3 8.0 12.0 Q1
PACKAGE MATERIALS INFORMATION
www.ti.com 18-Aug-2014
Pack Materials-Page 1
*All dimensions are nominal
Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm)
LM48410SQ/NOPB WQFN RTW 24 1000 210.0 185.0 35.0
LM48410SQX/NOPB WQFN RTW 24 4500 367.0 367.0 35.0
PACKAGE MATERIALS INFORMATION
www.ti.com 18-Aug-2014
Pack Materials-Page 2
www.ti.com
PACKAGE OUTLINE
C
24X 0.3
0.2
24X 0.5
0.3
0.8 MAX
(0.1) TYP
0.05
0.00
20X 0.5
2X
2.5
2X 2.5
2.6 0.1
A4.1
3.9 B
4.1
3.9
WQFN - 0.8 mm max heightRTW0024A
PLASTIC QUAD FLATPACK - NO LEAD
4222815/A 03/2016
PIN 1 INDEX AREA
0.08 C
SEATING PLANE
1
613
18
7 12
24 19
(OPTIONAL)
PIN 1 ID 0.1 C A B
0.05 C
EXPOSED
THERMAL PAD
25
NOTES:
1. All linear dimensions are in millimeters. Any dimensions in parenthesis are for reference only. Dimensioning and tolerancing
per ASME Y14.5M.
2. This drawing is subject to change without notice.
3. The package thermal pad must be soldered to the printed circuit board for thermal and mechanical performance.
SCALE 3.000
www.ti.com
EXAMPLE BOARD LAYOUT
0.07 MIN
ALL AROUND
0.07 MAX
ALL AROUND
24X (0.25)
24X (0.6)
( ) TYP
VIA
0.2
20X (0.5)
(3.8)
(3.8)
(1.05)
( 2.6)
(R )
TYP
0.05
(1.05)
WQFN - 0.8 mm max heightRTW0024A
PLASTIC QUAD FLATPACK - NO LEAD
4222815/A 03/2016
SYMM
1
6
712
13
18
19
24
SYMM
LAND PATTERN EXAMPLE
SCALE:15X
25
NOTES: (continued)
4. This package is designed to be soldered to a thermal pad on the board. For more information, see Texas Instruments literature
number SLUA271 (www.ti.com/lit/slua271).
SOLDER MASK
OPENING
METAL UNDER
SOLDER MASK
SOLDER MASK
DEFINED
METAL
SOLDER MASK
OPENING
SOLDER MASK DETAILS
NON SOLDER MASK
DEFINED
(PREFERRED)
www.ti.com
EXAMPLE STENCIL DESIGN
24X (0.6)
24X (0.25)
20X (0.5)
(3.8)
(3.8)
4X ( 1.15)
(0.675)
TYP
(0.675) TYP
(R ) TYP0.05
WQFN - 0.8 mm max heightRTW0024A
PLASTIC QUAD FLATPACK - NO LEAD
4222815/A 03/2016
NOTES: (continued)
5. Laser cutting apertures with trapezoidal walls and rounded corners may offer better paste release. IPC-7525 may have alternate
design recommendations.
SYMM
METAL
TYP
SOLDER PASTE EXAMPLE
BASED ON 0.125 mm THICK STENCIL
EXPOSED PAD 25:
78% PRINTED SOLDER COVERAGE BY AREA UNDER PACKAGE
SCALE:20X
SYMM
1
6
712
13
18
19
24
25
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