LM4952
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SNAS230A –AUGUST 2004–REVISED MAY 2013
LM4952 Boomer™ Audio Power Amplifier Series 3.1W Stereo-SE Audio Power Amplifier
with DC Volume Control
Check for Samples: LM4952
1FEATURES DESCRIPTION
The LM4952 is a dual audio power amplifier primarily
23• Pop & Click Circuitry Eliminates Noise During designed for demanding applications in flat panel
Turn-on and Turn-off Transitions monitors and TV's. It is capable of delivering 3.1
• Low Current, Active-low Shutdown Mode watts per channel to a 4Ωsingle-ended load with less
• Low Quiescent Current than 1% THD+N when powered by a 12VDC power
supply.
• Stereo 3.8W Output, RL= 4ΩEliminating external feedback resistors, an internal,
• DC-controlled Volume Control DC-controlled, volume control allows easy and
• Short Circuit Protection variable gain adjustment.
APPLICATIONS Boomer audio power amplifiers were designed
specifically to provide high quality output power with a
• Flat Panel Monitors minimal amount of external components. The
• Flat Panel TV's LM4952 does not require bootstrap capacitors or
snubber circuits. Therefore, it is ideally suited for
• Computer Sound Cards display applications requiring high power and minimal
size.
KEY SPECIFICATIONS The LM4952 features a low-power consumption
• Quiscent Power Supply Current 18mA (typ) active-low shutdown mode. Additionally, the LM4952
• POUT @features an internal thermal shutdown protection
VDD = 12V, RL = 4Ω, 10% THD+N 3.8W (typ) mechanism along with short circuit protection.
• Shutdown current 55μA (typ) The LM4952 contains advanced pop & click circuitry
that eliminates noises which would otherwise occur
during turn-on and turn-off transitions.
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.
2Boomer is a trademark of Texas Instruments Incorporated.
3All other trademarks are the property of their respective owners.
PRODUCTION DATA information is current as of publication date. Copyright © 2004–2013, 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.
SHUTDOWN
CONTROL
AUDIO
INPUT A
AUDIO
INPUT B
4.7 PF
0.39 PF
0.39 PF
BIAS
VOLUME
VOLUME
BYPASS
SHUTDOWN
2
3
9
8
VDD
6
5
4:
7
10V - 3.3V
470 PF
DC-VOL
+
-
DC-
CONTROLLED
VOLUME
CONTROL
+
-470 PF
4:
4
COUTA
COUTB
CINA
CBYPAS
S
CINB
-VINA
-VINBRL
RL
AMPB
AMPA
CS
VOUTB
VOUTA
10 PF
-VINA
SHUTDOWN
VOUTA
DC VOL
GND
VDD
VOUTB
BYPASS
-VINB
L4952TS
UZXYTT
LM4952
SNAS230A –AUGUST 2004–REVISED MAY 2013
www.ti.com
Connection Diagram
Figure 1. DDPAK – Top View
See Package Number KTW
L4952TS = LM4952TS
Typical Application
Figure 2. Typical LM4952 SE Audio Amplifier Application Circuit
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.
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SNAS230A –AUGUST 2004–REVISED MAY 2013
Absolute Maximum Ratings(1)(2)(3)
Supply Voltage (pin 6, referenced to GND, pins 4 and 5) 18.0V
Storage Temperature −65°C to +150°C
pins 4, 6, and 7 −0.3V to VDD + 0.3V
Input Voltage pins 1, 2, 3, 8, and 9 −0.3V to 9.5V
Power Dissipation(4) Internally limited
ESD Susceptibility(5) 2000V
ESD Susceptibility(6) 200V
Junction Temperature 150°C
θJC (TS) 4°C/W
Thermal Resistance θJA (TS)(4) 20°C/W
(1) All voltages are measured with respect to the GND 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 specify specific performance limits. Electrical Characteristics state DC and AC electrical
specifications under particular test conditions which specify specific performance limits. This assumes that the device is within the
Operating Ratings. Specifications are not specified for parameters where no limit is given, however, the typical value is a good indication
of device performance.
(3) If Military/Aerospace specified devices are required, please contact the Texas Instruments Sales Office/ Distributors for availability and
specifications.
(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 given in Absolute Maximum Ratings, whichever is
lower. For the LM4952 typical application (shown in Figure 2) with VDD = 12V, RL= 4Ωstereo operation the total power dissipation is
3.65W. θJA = 20°C/W for the DDPAK package mounted to 16in2heatsink surface area.
(5) Human body model, 100pF discharged through a 1.5kΩresistor.
(6) Machine Model, 220pF–240pF discharged through all pins.
Operating Ratings
Temperature Range TMIN ≤TA≤TMAX −40°C ≤TA≤85°C
Supply Voltage 9.6V ≤VDD ≤16V
Electrical Characteristics VDD = 12V(1)(2)
The following specifications apply for VDD = 12V, AV= 20dB (nominal), RL= 4Ω, and TA= 25°C unless otherwise noted.
Symbol Parameter Conditions LM4952 Units
(Limits)
Typical(3) Limit(4)(5)
IDD Quiescent Power Supply Current VIN = 0V, IO= 0A, No Load 18 35 mA (max)
ISD Shutdown Current VSHUTDOWN = GND(6) 55 85 µA (max)
RIN Amplifier Input Resistance VDC VOL = VDD/2 44 kΩ
VDC VOL = GND 200 kΩ
VIN Amplifier Input Signal VDD/2 Vp-p (max)
VSDIH Shutdown Voltage Input High 2.0 V (min)
VDD/2 V (max)
VSDIL Shutdown Voltage Input Low 0.4 V (max)
TWU Wake-up Time CB= 4.7µF 440 ms
TSD Thermal Shutdown Temperature 170 °C
POOutput Power f = 1kHz,
THD+N = 1% 3.1 2.8 W (min)
THD+N = 10% 3.8
(1) All voltages are measured with respect to the GND 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 specify specific performance limits. Electrical Characteristics state DC and AC electrical
specifications under particular test conditions which specify specific performance limits. This assumes that the device is within the
Operating Ratings. Specifications are not specified 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 ensured to AOQL (Average Outgoing Quality Level).
(5) Datasheet min/max specification limits are ensured by design, test, or statistical analysis.
(6) Shutdown current is measured in a normal room environment. The Shutdown pin should be driven as close as possible to GND for
minimum shutdown current.
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Electrical Characteristics VDD = 12V(1)(2) (continued)
The following specifications apply for VDD = 12V, AV= 20dB (nominal), RL= 4Ω, and TA= 25°C unless otherwise noted.
Symbol Parameter Conditions LM4952 Units
(Limits)
Typical(3) Limit(4)(5)
THD+N Total Harmomic Distortion + Noise PO= 2.0Wrms, f = 1kHz 0.08 %
εOS Output Noise A-Weighted Filter, VIN = 0V, 8 µV
Input Referred
XTALK Channel Separation fIN = 1kHz, PO= 1W,
Input Referred
RL= 8Ω78
RL= 4Ω72 dB
PSRR Power Supply Rejection Ratio VRIPPLE = 200mVp-p, f = 1kHz, 89 80 dB (min)
Input Referred
IOL Output Current Limit VIN = 0V, RL= 500mΩ5 A
Electrical Characteristics for Volume Control(1)(2)
The following specifications apply for VDD = 12V, AV= 20dB (nominal), and TA= 25°C unless otherwise noted.
LM4952 Units
Symbol Parameter Conditions (Limits)
Typical(3) Limit(4)
VOLmax Gain VDC-VOL = Full scale, No Load 20 dB
VOLmin Gain VDC-VOL = +1LSB, No Load -46 dB
AMMute Attenuation VDC-VOL = 0V, No Load 75 63 dB (min)
(1) All voltages are measured with respect to the GND 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 specify specific performance limits. Electrical Characteristics state DC and AC electrical
specifications under particular test conditions which specify specific performance limits. This assumes that the device is within the
Operating Ratings. Specifications are not specified 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 ensured to AOQL (Average Outgoing Quality Level).
External Components Description
Refer to Figure 2.
Components Functional Description
This is the input coupling capacitor. It blocks DC voltage at the amplifier's inverting input. CIN and RIN create a
1. CIN highpass filter. The filter's cutoff frequency is fC= 1/(2πRINCIN). Refer to SELECTING EXTERNAL COMPONENTS,
for an explanation of determining CIN's value.
The supply bypass capacitor. Refer to POWER SUPPLY BYPASSING for information about properly placing, and
2. CSselecting the value of, this capacitor.
This capacitor filters the half-supply voltage present on the BYPASS pin. Refer to SELECTING EXTERNAL
3. CBYPASS COMPONENTS for information about properly placing, and selecting the value of, this capacitor.
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6
OUTPUT POWER (W)
0.01
0.1
1
10
THD+N (%)
0.02
0.2
2
0.05
0.5
5
10m 100m 120m 200m50m 500m 2 5
6
OUTPUT POWER (W)
0.01
0.1
1
10
THD+N (%)
0.02
0.2
2
0.05
0.5
5
10m 100m 120m 200m50m 500m 2 5
20 100 1k 20k
FREQUENCY (Hz)
0.01
0.02
0.05
0.1
0.2
0.5
1
2
5
10
THD+N (%)
10k
200 2k500 5k
50
20 100 1k 20k
FREQUENCY (Hz)
0.01
0.02
0.05
0.1
0.2
0.5
1
2
5
10
THD+N (%)
10k
200 2k500 5k
50
LM4952
www.ti.com
SNAS230A –AUGUST 2004–REVISED MAY 2013
Typical Performance Characteristics
AV= 20dB and TA= 25°C, unless otherwise noted.
THD+N vs Frequency THD+N vs Frequency
VDD = 12V, RL= 4Ω, VDD = 12V, RL= 8Ω,
POUT = 2W, CIN = 1.0µF POUT = 1W, CIN = 1.0µF
Figure 3. Figure 4.
THD+N vs Output Power THD+N vs Output Power
VDD = 12V, RL= 4Ω, VDD = 12V, RL= 8Ω,
fIN = 1kHz fIN = 1kHz
Figure 5. Figure 6.
Output Power vs Power Supply Voltage Output Power vs Power Supply Voltage
RL= 4Ω, fIN = 1kHz RL= 8Ω, fIN = 1kHz
both channels driven and loaded (average shown), both channels driven and loaded (average shown),
at (from top to bottom at 12V): at (from top to bottom at 12V):
THD+N = 10%, THD+N = 1% THD+N = 10%, THD+N = 1%
Figure 7. Figure 8.
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-0 +1 +2 +4 +5
-80
-70
-60
-50
-40
-30
-20
-10
0
10
20
AMPLIFIER GAIN (dB)
DC VOLUME VOLTAGE (V)
+3+0.5 +1.5 +2.5 +4.5+3.5
20 20k
FREQUENCY (Hz)
50 100 200 500 10k1k 2k 5k
-120
-110
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
+0
AMPLITUDE (dB)
20 20k
FREQUENCY (Hz)
50 100 200 500 10k1k 2k 5k
-120
-110
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
+0
AMPLITUDE (dB)
20 20k
FREQUENCY (Hz)
-100
+0
MAGNITUDE (dB)
10k1k 2k 5k50 100 200 500
-90
-80
-70
-60
-50
-40
-30
-20
-10
-95
-85
-75
-65
-55
-45
-35
-25
-15
-5
LM4952
SNAS230A –AUGUST 2004–REVISED MAY 2013
www.ti.com
Typical Performance Characteristics (continued)
AV= 20dB and TA= 25°C, unless otherwise noted.
Power Supply Rejection vs Frequency Total Power Dissipation vs Load Dissipation
VDD = 12V, RL= 4Ω,VDD = 12V, fIN = 1kHz,
VRIPPLE = 200mVp-p at (from top to bottom at 1W):
RL= 4Ω, RL= 8Ω
Figure 9. Figure 10.
Output Power vs Load Resistance Channel-to-Channel Crosstalk vs Frequency
VDD = 12V, RL= 4Ω, POUT = 1W, Input Referred
VDD = 12V, fIN = 1kHz, at (from top to bottom at 1kHz): VINB driven,
at (from top to bottom at 15Ω): VOUTA measured, VINA driven, VOUTB measured
THD+N = 10%, THD+N = 1% Figure 11. Figure 12.
Channel-to-Channel Crosstalk vs Frequency Amplifier Gain vs DC Volume Voltage
VDD = 12V, RL= 8Ω, POUT = 1W, Input Referred VDD = 12V, RL= 8Ω, at (from top to bottom at 1.5V):
at (from top to bottom at 1kHz): VINB driven, Decreasing DC Volume Voltage, Increasing DC Volume Voltage
VOUTA measured, VINA driven, VOUTB measured
Figure 13. Figure 14.
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6
OUTPUT POWER (W)
0.01
0.1
1
10
THD+N (%)
0.02
0.2
2
0.05
0.5
5
10m 100m 120m 200m50m 500m 2 5
6
OUTPUT POWER (W)
0.01
0.1
1
10
THD+N (%)
0.02
0.2
2
0.05
0.5
5
10m 100m 120m 200m50m 500m 2 5
20 100 1k 20k
FREQUENCY (Hz)
0.01
0.02
0.05
0.1
0.2
0.5
1
2
5
10
THD+N (%)
10k
200 2k500 5k
50
-0 +1 +2 +4 +5
-80
-70
-60
-50
-40
-30
-20
-10
0
10
20
AMPLIFIER GAIN (dB)
DC VOLUME VOLTAGE (V)
+3+0.5 +1.5 +2.5 +4.5+3.5
20 100 1k 20k
FREQUENCY (Hz)
0.01
0.02
0.05
0.1
0.2
0.5
1
2
5
10
THD+N (%)
10k
200 2k500 5k
50
LM4952
www.ti.com
SNAS230A –AUGUST 2004–REVISED MAY 2013
Typical Performance Characteristics (continued)
AV= 20dB and TA= 25°C, unless otherwise noted.
Amplifier Gain vs Part-to-Part DC Volume Voltage
Variation (Five parts) THD+N vs Frequency
VDD = 9.6V, RL= 4Ω,
POUT = 1.1W, CIN = 1.0µF
VDD = 12V, RL= 8Ω,Figure 15. Figure 16.
THD+N vs Frequency THD+N vs Output Power
VDD = 9.6V, RL= 8Ω,VDD = 9.6V, RL= 4Ω,
POUT = 850mW, CIN = 1.0µF fIN = 1kHz
Figure 17. Figure 18.
THD+N vs Output Power Total Power Dissipation vs Load Dissipation
VDD = 9.6V, RL= 8Ω,VDD = 9.6V, fIN = 1kHz
fIN = 1kHz at (from top to bottom at 1W):
RL= 4Ω, RL= 8Ω
Figure 19. Figure 20.
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20 100 1k 20k
FREQUENCY (Hz)
0.01
0.02
0.05
0.1
0.2
0.5
1
2
5
10
THD+N (%)
10k
200 2k500 5k
50
20 100 1k 20k
FREQUENCY (Hz)
0.01
0.02
0.05
0.1
0.2
0.5
1
2
5
10
THD+N (%)
10k
200 2k500 5k
50
20 20k
FREQUENCY (Hz)
50 100 200 500 10k1k 2k 5k
-120
-110
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
+0
AMPLITUDE (dB)
20 20k
FREQUENCY (Hz)
50 100 200 500 10k1k 2k 5k
-120
-110
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
+0
AMPLITUDE (dB)
20 20k
FREQUENCY (Hz)
-100
+0
MAGNITUDE (dB)
10k1k 2k 5k50 100 200 500
-90
-80
-70
-60
-50
-40
-30
-20
-10
-95
-85
-75
-65
-55
-45
-35
-25
-15
-5
LM4952
SNAS230A –AUGUST 2004–REVISED MAY 2013
www.ti.com
Typical Performance Characteristics (continued)
AV= 20dB and TA= 25°C, unless otherwise noted.
Output Power vs Load Resistance Power Supply Rejection vs Frequency
VDD = 9.6V, RL= 4Ω,
VDD = 9.6V, fIN = 1kHz, VRIPPLE = 200mVP-P
at (from top to bottom at 15Ω):
THD+N = 10%, THD+N = 1% Figure 21. Figure 22.
Channel-to Channel Crosstalk vs Frequency Channel-to Channel Crosstalk vs Frequency
VDD = 9.6V, RL= 4Ω, POUT = 1W, Input Referred VDD = 9.6V, RL= 8Ω, POUT = 1W, Input Referred
at (from top to bottom at 1kHz): VINB driven, VOUTA measured; VINA at (from top to bottom at 1kHz): VINB driven, VOUTA measured; VINA
driven, VOUTB measured driven, VOUTB measured
Figure 23. Figure 24.
THD+N vs Frequency THD+N vs Frequency
VDD = 14V, RL= 4Ω, VDD = 14V, RL= 8Ω,
POUT = 2W, CIN = 1.0µF POUT = 1W, CIN = 1.0µF
Figure 25. Figure 26.
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20 20k
FREQUENCY (Hz)
-100
+0
POWER SUPPLY REJECTION (dB)
10k1k 2k 5k50 100 200 500
-90
-80
-70
-60
-50
-40
-30
-20
-10
-95
-85
-75
-65
-55
-45
-35
-25
-15
-5
6
OUTPUT POWER (W)
0.01
0.1
1
10
THD+N (%)
0.02
0.2
2
0.05
0.5
5
10m 100m 120m 200m50m 500m 2 5
6
OUTPUT POWER (W)
0.01
0.1
1
10
THD+N (%)
0.02
0.2
2
0.05
0.5
5
10m 100m 120m 200m50m 500m 2 5
LM4952
www.ti.com
SNAS230A –AUGUST 2004–REVISED MAY 2013
Typical Performance Characteristics (continued)
AV= 20dB and TA= 25°C, unless otherwise noted.
THD+N vs Output Power THD+N vs Output Power
VDD = 14V, RL= 4Ω, VDD = 14V, RL= 8Ω
fIN = 1kHz fIN = 1kHz
Figure 27. Figure 28.
Power Supply Rejection vs Frequency Output Power vs Load Resistance
VDD = 14V, RL= 4ΩVDD = 15V, fIN = 1kHz,
VRIPPLE = 200mVP-P at (from top to bottom at 2W):
RL= 4Ω, RL= 8Ω
Figure 29. Figure 30.
THD+N vs Output Power THD+N vs Output Power
VDD = 15V, at (from top to bottom at 15Ω): VDD = 16V, RL= 4Ω,
THD+N = 10%, THD+N = 1%, fIN = 1kHz fIN = 1kHz
Figure 31. Figure 32.
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9.5 10.5 11.5 12.5 13.5 14.5 15.5
POWER SUPPLY VOLTAGE (V)
0
1.25
CLIPPING VOLTAGE (V)
1
0.75
0.5
0.25
9 10 11 12 13 14 15 16 17
POWER SUPPLY VOLTAGE (V)
POWER SUPPLY CURRENT (mA)
5
10
15
20
25
30
9.5 10.5 11.5 12.5 13.5 14.5 15.5
POWER SUPPLY VOLTAGE (V)
0
0.25
0.5
0.75
1
1.25
1.5
1.75
CLIPPING VOLTAGE (V)
20 20k
FREQUENCY (Hz)
50 100 200 500 10k1k 2k 5k
-120
-110
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
+0
AMPLITUDE (dB)
20 20k
FREQUENCY (Hz)
50 100 200 500 10k1k 2k 5k
-120
-110
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
+0
AMPLITUDE (dB)
LM4952
SNAS230A –AUGUST 2004–REVISED MAY 2013
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Typical Performance Characteristics (continued)
AV= 20dB and TA= 25°C, unless otherwise noted.
Channel-to-Channel Crosstalk vs Frequency Channel-to-Channel Crosstalk vs Frequency
VDD = 16V, RL= 4Ω, POUT = 1W, Input Referred VDD = 16V, RL= 8Ω, POUT = 1W, Input Referred
at (from top to bottom at 1kHz): VINB driven, VOUTA measured; VINA at (from top to bottom at 1kHz): VINB driven, VOUTA measured; VINA
driven, VOUTB measured driven, VOUTB measured
Figure 33. Figure 34.
Power Supply Current vs Power Supply Voltage Clipping Voltage vs Power Supply Voltage
RL= 4Ω, fIN = 1kHz
RL= 4Ω,at (from top to bottom at 12.5V):
VIN = 0V, RSOURCE = 50Ωpositive signal swing, negative signal swing
Figure 35. Figure 36.
Clipping Voltage vs Power Supply Voltage Power Dissipation vs Ambient Temperature
RL= 8Ω, fIN = 1kHz VDD = 12V, RL= 4Ω(SE), fIN = 1kHz,
at (from to bottom at 12.5V): (from to bottom at 80°C): 16in2copper plane heatsink area, 8in2
positive signal swing, negative signal swing copper plane heatsink area
Figure 37. Figure 38.
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Typical Performance Characteristics (continued)
AV= 20dB and TA= 25°C, unless otherwise noted.
Power Dissipation vs Ambient Temperature
VDD = 12V, RL= 8Ω, fIN = 1kHz,
(from to bottom at 120°C): 16in2copper plane heatsink area, 8in2copper plane heatsink area
Figure 39.
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SHUTDOWN
CONTROL
AUDIO
INPUT A
AUDIO
INPUT B
4.7 PF
0.39 PF
0.39 PF
BIAS
VOLUME
VOLUME
BYPASS
SHUTDOWN
2
3
9
8
VDD
6
5
4:
7
10V - 3.3V
470 PF
DC-VOL
+
-
DC-
CONTROLLED
VOLUME
CONTROL
+
-470 PF
4:
4
COUTA
COUTB
CINA
CBYPAS
S
CINB
-VINA
-VINBRL
RL
AMPB
AMPA
CS
VOUTB
VOUTA
10 PF
LM4952
SNAS230A –AUGUST 2004–REVISED MAY 2013
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APPLICATION INFORMATION
HIGH VOLTAGE BOOMER WITH INCREASED OUTPUT POWER
Figure 40. Typical LM4952 SE Application Circuit
Unlike previous 5V Boomer amplifiers, the LM4952 is designed to operate over a power supply voltages range of
9.6V to 16V. Operating on a 12V power supply, the LM4952 will deliver 3.8W into a 4ΩSE load with no more
than 10% THD+N.
POWER DISSIPATION
Power dissipation is a major concern when designing a successful single-ended or bridged amplifier. Equation 1
states the maximum power dissipation point for a single-ended amplifier operating at a given supply voltage and
driving a specified output load.
PDMAX-SE = (VDD)2/(2π2RL): Single Ended (1)
The LM4952's dissipation is twice the value given by Equation 1 when driving two SE loads. For a 12V supply
and two 4ΩSE loads, the LM4952's dissipation is 1.82W.
The maximum power dissipation point given by Equation 1 must not exceed the power dissipation given by
Equation 2:
PDMAX' = (TJMAX - TA)/θJA (2)
The LM4952's TJMAX = 150°C. In the TS package, the LM4952's θJA is 20°C/W when the metal tab is soldered to
a copper plane of at least 16in2. This plane can be split between the top and bottom layers of a two-sided PCB.
Connect the two layers together under the tab with a 5x5 array of vias. At any given ambient temperature TA, use
Equation 2 to find the maximum internal power dissipation supported by the IC packaging. Rearranging
Equation 2 and substituting PDMAX for PDMAX' results in Equation 3. This equation gives the maximum ambient
temperature that still allows maximum stereo power dissipation without violating the LM4952's maximum junction
temperature.
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Product Folder Links: LM4952
LM4952
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SNAS230A –AUGUST 2004–REVISED MAY 2013
TA= TJMAX - PDMAX-SEθJA (3)
For a typical application with a 12V power supply and an SE 4Ωload, the maximum ambient temperature that
allows maximum stereo power dissipation without exceeding the maximum junction temperature is approximately
77°C for the TS package.
TJMAX = PDMAX-MONOBTLθJA + TA(4)
Equation 4 gives the maximum junction temperature TJMAX. If the result violates the LM4952's 150°C, reduce the
maximum junction temperature by reducing the power supply voltage or increasing the load resistance. Further
allowance should be made for increased ambient temperatures.
The above examples assume that a device is operating around the maximum power dissipation point. Since
internal power dissipation is a function of output power, higher ambient temperatures are allowed as output
power or duty cycle decreases.
If the result of Equation 1 is greater than that of Equation 2, then decrease the supply voltage, increase the load
impedance, or reduce the ambient temperature. Further, ensure that speakers rated at a nominal 4Ωdo not fall
below 3Ω. If these measures are insufficient, a heat sink can be added to reduce θJA. The heat sink can be
created using additional copper area around the package, with connections to the ground pins, supply pin and
amplifier output pins. Refer to the Typical Performance Characteristics curves for power dissipation information at
lower output power levels.
POWER SUPPLY VOLTAGE LIMITS
Continuous proper operation is ensured by never exceeding the voltage applied to any pin, with respect to
ground, as listed in Absolute Maximum Ratings(1)(2)(3).
POWER SUPPLY BYPASSING
As with any power amplifier, proper supply bypassing is critical for low noise performance and high power supply
rejection. Applications that employ a voltage regulator typically use a 10µF in parallel with a 0.1µF filter
capacitors to stabilize the regulator's output, reduce noise on the supply line, and improve the supply's transient
response. However, their presence does not eliminate the need for a local 10µF tantalum bypass capacitance
connected between the LM4952's supply pins and ground. Do not substitute a ceramic capacitor for the
tantalum. Doing so may cause oscillation. Keep the length of leads and traces that connect capacitors between
the LM4952's power supply pin and ground as short as possible.
BYPASS PIN BYPASSING
Connecting a 4.7µF capacitor, CBYPASS, between the BYPASS pin and ground improves the internal bias
voltage's stability and improves the amplifier's PSRR. The PSRR improvements increase as the bypass pin
capacitor value increases. Too large, however, increases turn-on time. The selection of bypass capacitor values,
especially CBYPASS, depends on desired PSRR requirements, click and pop performance (as explained in
SELECTING EXTERNAL COMPONENTS), system cost, and size constraints.
MICRO-POWER SHUTDOWN
The LM4952 features an active-low micro-power shutdown mode. When active, the LM4952's micro-power
shutdown feature turns off the amplifier's bias circuitry, reducing the supply current. The low 55µA typical
shutdown current is achieved by applying a voltage to the SHUTDOWN pin that is as near to GND as possible. A
voltage that is greater than GND may increase the shutdown current.
(1) All voltages are measured with respect to the GND 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 specify specific performance limits. Electrical Characteristics state DC and AC electrical
specifications under particular test conditions which specify specific performance limits. This assumes that the device is within the
Operating Ratings. Specifications are not specified for parameters where no limit is given, however, the typical value is a good indication
of device performance.
(3) If Military/Aerospace specified devices are required, please contact the Texas Instruments Sales Office/ Distributors for availability and
specifications.
Copyright © 2004–2013, Texas Instruments Incorporated Submit Documentation Feedback 13
Product Folder Links: LM4952
-0 +1 +2 +4 +5
-80
-70
-60
-50
-40
-30
-20
-10
0
10
20
AMPLIFIER GAIN (dB)
DC VOLUME VOLTAGE (V)
+3+0.5 +1.5 +2.5 +4.5+3.5
47 k:
47 k:
To SHUTDOWN Pin
VDD
SPST
LM4952
SNAS230A –AUGUST 2004–REVISED MAY 2013
www.ti.com
There are a few methods to control the micro-power shutdown. These include using a single-pole, single-throw
switch (SPST), a microprocessor, or a microcontroller. Figure 41 shows a simple switch-based circuit that can be
used to control the LM4952's shutdown fucntion. Select normal amplifier operation by closing the switch.
Opening the switch applies GND to the SHUTDOWN pin, activating micro-power shutdown. The switch and
resistor ensure that the SHUTDOWN pin will not float. This prevents unwanted state changes. In a system with a
microprocessor or a microcontroller, use a digital output to apply the active-state voltage to the SHUTDOWN pin.
Figure 41. Simple switch and voltage divider generates shutdown control signal
DC VOLUME CONTROL
The LM4952 has an internal stereo volume control whose setting is a function of the DC voltage applied to the
DC VOL input pin.
The LM4952 volume control consists of 31 steps that are individually selected by a variable DC voltage level on
the volume control pin. As shown in Figure 42, the range of the steps, controlled by the DC voltage, is 20dB to -
46dB.
The gain levels are 1dB/step from 20dB to 14dB, 2dB/step from 14dB to -16dB, 3dB/step from -16dB to -27dB,
4dB/step from -27db to -31dB, 5dB/step from -31dB to -46dB.
Figure 42. Volume Control Response
Like all volume controls, the LM4952's internal volume control is set while listening to an amplified signal that is
applied to an external speaker. The actual voltage applied to the DC VOL input pin is a result of the volume a
listener desires. As such, the volume control is designed for use in a feedback system that includes human ears
and preferences. This feedback system operates quite well without the need for accurate gain. The user simply
sets the volume to the desired level as determined by their ear, without regard to the actual DC voltage that
14 Submit Documentation Feedback Copyright © 2004–2013, Texas Instruments Incorporated
Product Folder Links: LM4952
VDD
DC VOL
4
LM4952
91 k:
50 k:
RVOL
* optional
RS
10 PF*
-0 +1 +2 +4 +5
-80
-70
-60
-50
-40
-30
-20
-10
0
10
20
AMPLIFIER GAIN (dB)
DC VOLUME VOLTAGE (V)
+3+0.5 +1.5 +2.5 +4.5+3.5
LM4952
www.ti.com
SNAS230A –AUGUST 2004–REVISED MAY 2013
produces the volume. Therefore, the accuracy of the volume control is not critical, as long as volume changes
monotonically and step size is small enough to reach a desired volume that is not too loud or too soft. Since the
gain is not critical, there may be a volume variation from part-to-part even with the same applied DC volume
control voltage. The gain of a given LM4952 can be set with fixed external voltage, but another LM4952 may
require a different control voltage to achieve the same gain. Figure 43 is a curve showing the volume variation of
five typical LM4952s as the voltage applied to the DC VOL input pin is varied. For gains between –20dB and
+16dB, the typical part-to-part variation is typically ±1dB for a given control voltage.
Figure 43. Typical Part-to-Part Gain Variation as a Function of DC Vol Control Voltage
VOLUME CONTROL VOLTAGE GENERATION
Figure 44 shows a simple circuit that can be used to create an adjustable DC control voltage that is applied to
the DC Vol input. The 91kΩseries resistor and the 50kΩpotentiometer create a voltage divider between the
supply voltage, VDD, and GND. The series resistor’s value assumes a 12V power supply voltage. The voltage
present at the node between the series resistor and the top of the potentiometer need only be a nominal value of
3.5V and must not exceed 9.5V, as stated in the LM4952’s Absolute Maximum Ratings.
Capacitor connected to DC VOL pin minimizes voltage fluctuation when using unregulated supplies that could cause
changes in perceived volume setting.
Figure 44. Typical Circuit Used for DC Voltage Volume Control
UNREGULATED POWER SUPPLIES AND THE DC VOL CONTROL
As an amplifier’s output power increases, the current that flows from the power supply also increases. If an
unregulated power supply is used, its output voltage can decrease (“droop” or “sag”) as this current increases. It
is not uncommon for an unloaded unregulated 15V power supply connected to the LM4952 to sag by as much as
2V when the amplifier is drawing 1A to 2A while driving 4Ωstereo loads to full power dissipation. Figure 45 is an
oscilloscope photo showing an unregulated power supply’s voltage sag while powering an LM4952 that is driving
4Ωstereo loads. The amplifier’s input is a typical music signal supplied by a CD player. As shown, the sag can
be quite significant.
Copyright © 2004–2013, Texas Instruments Incorporated Submit Documentation Feedback 15
Product Folder Links: LM4952
LM4952
SNAS230A –AUGUST 2004–REVISED MAY 2013
www.ti.com
Wave forms shown include VDD (Trace A), VOUT A (Trace B), VOUT B (Trace C), and the DC voltage applied to the DC
VOL pin (Trace D).
Figure 45. LM4952 Operating on an Unregulated 12V (Nominal) Power Supply
This sagging supply voltage presents a potential problem when the voltage that drives the DC Vol pin is derived
from the voltage supplied by an unregulated power supply. This is the case for the typical volume control circuit
(a 50kΩpotentiometer in series with a 91kΩresistor) shown in Figure 44. The potentiometer’s wiper is
connected to the DC Vol pin. With this circuit, power supply voltage fluctuations will be seen by the DC Vol input.
Though attenuated by the voltage divider action of the potentiometer and the series resistor, these fluctuations
may cause perturbations in the perceived volume. An easy and simple solution that suppresses these
perturbations is a 10μF capacitor connected between the DC Vol pin and ground. See the result of this capacitor
in Figure 46. This capacitance can also be supplemented with bulk capacitance in the range of 1000μF to
10,000μF connected to the unregulated power supply’s output. Figure 48 shows how this bulk capacitance
minimizes fluctuations on VDD.
Same conditions and waveforms as shown in Figure 45, except that a 10μF capacitor has been connected between
the DC VOL pin and GND (Trace D).
Figure 46.
If space constraints preclude the use of a 10μF capacitor connected to the DC Vol pin or large amounts of bulk
supply capacitance, or if more resistance to the fluctuations is desired, using an LM4040-4.1 voltage reference
shown in Figure 47 is recommended. The value of the 91kΩresistor, already present in the typical volume
applications circuit, should be changed to 62kΩ. This sets the LM4040-4.1’s bias current at 125μA when using a
nominal 12V supply, well within the range of current needed by this reference.
16 Submit Documentation Feedback Copyright © 2004–2013, Texas Instruments Incorporated
Product Folder Links: LM4952
VDD
DC VOL
4
LM4952
62 k:
50 k:
RVOL
LM4040-4.1
LM4952
www.ti.com
SNAS230A –AUGUST 2004–REVISED MAY 2013
Using an LM4040–4.1 to set the maximum DC volume control voltage and attenuate power supply variations when
using unregulated supplies that would otherwise perturb the volume setting.
Figure 47.
Same conditions and waveforms as shown in Figure 46, except that a 4700μF capacitor has been connected
between the VDD pin and GND (Trace A).
Figure 48.
SELECTING EXTERNAL COMPONENTS
Input Capacitor Value Selection
Two quantities determine the value of the input coupling capacitor: the lowest audio frequency that requires
amplification and desired output transient suppression.
The amplifier's input resistance and the input capacitor (CIN) produce a high pass filter cutoff frequency that is
found using Equation 5.
FCIN = 1/(2πRINCIN) (5)
As an example when using a speaker with a low frequency limit of 50Hz and based on the LM4952's 44kΩ
nominal minimum input resistance, CIN, using Equation 5 is 0.072μF. The 0.39μF CINA shown in Figure 40 allows
the LM4952 to drive high efficiency, full range speaker whose response extends below 30Hz.
Similarly, the output coupling capacitor and the load impedance also form a high pass filter. The cutoff frequency
formed by these two components is found using Equation 6.
fCOUT = 1/(2πRLOADCOUT) (6)
Expanding on the example above and assuming a nominal speaker impedance of 4Ω, response below 30Hz is
assured if the output coupling capacitors have a value, using Equation 6, greater than 1330μF.
Bypass Capacitor Value
Besides minimizing the input capacitor size, careful consideration should be paid to value of CBYPASS, the
capacitor connected to the BYPASS pin. Since CBYPASS determines how fast the LM4952 settles to quiescent
operation, its value is critical when minimizing turn-on pops. The slower the LM4952’s outputs ramp to their
quiescent DC voltage (nominally VDD/2), the smaller the turn-on pop. Choosing CBYPASS equal to 4.7μF along with
a small value of CIN (in the range of 0.1μF to 0.39μF) produces a click-less and pop-less shutdown function. As
discussed above, choosing CIN no larger than necessary for the desired bandwidth helps minimize clicks and
pops.
Copyright © 2004–2013, Texas Instruments Incorporated Submit Documentation Feedback 17
Product Folder Links: LM4952
LM4952
SNAS230A –AUGUST 2004–REVISED MAY 2013
www.ti.com
Routing Input and BYPASS Capacitor Grounds
Optimizing the LM4952’s low distortion performance is easily accomplished by connecting the input signal’s
ground reference directly to the DDPAK’s grounded tab connection. In like manner, the ground lead of the
capacitor connected between the BYPASS pin and GND should also be connected to the package’s grounded
tab.
OPTIMIZING CLICK AND POP REDUCTION PERFORMANCE
The LM4952 contains circuitry that eliminates turn-on and shutdown transients ("clicks and pops"). For this
discussion, turn-on refers to either applying the power supply voltage or when the micro-power shutdown mode
is deactivated.
As the VDD/4 voltage present at the BYPASS pin ramps to its final value, the LM4952's internal amplifiers are
muted. Once the voltage at the BYPASS pin reaches VDD/4, the amplifiers are unmuted.
The gain of the internal amplifiers remains unity until the voltage on the bypass pin reaches VDD/4. As soon as
the voltage on the bypass pin is stable, the device becomes fully operational and the amplifier outputs are
reconnected to their respective output pins.
In order eliminate "clicks and pops", all capacitors must be discharged before turn-on. Rapidly switching VDD may
not allow the capacitors to fully discharge, which may cause "clicks and pops".
There is a relationship between the value of CIN and CBYPASS that ensures minimum output transient when power
is applied or the shutdown mode is deactivated. Best performance is achieved by selecting a CBYPASS value that
is greater than twelve times CIN's value.
RECOMMENDED PRINTED CIRCUIT BOARD LAYOUT
Figure 47 through Figure 49 show the recommended two-layer PC board layout that is optimized for the DDPAK-
packaged, SE-configured LM4952 and associated external components. These circuits are designed for use with
an external 12V supply and 4Ω(min)(SE) speakers.
These circuit boards are easy to use. Apply 12V and ground to the board's VDD and GND pads, respectively.
Connect a speaker between the board's OUTAand OUTBoutputs and respective GND pins.
Demonstration Board Layout
Figure 49. Recommended TS SE PCB Layout:
Top Silkscreen
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Product Folder Links: LM4952
LM4952
SNAS230A –AUGUST 2004–REVISED MAY 2013
www.ti.com
REVISION HISTORY
Changes from Original (May 2013) to Revision A Page
• Changed layout of National Data Sheet to TI format .......................................................................................................... 19
20 Submit Documentation Feedback Copyright © 2004–2013, Texas Instruments Incorporated
Product Folder Links: LM4952
PACKAGE OPTION ADDENDUM
www.ti.com 9-Jun-2020
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
LM4952TS/NOPB ACTIVE DDPAK/
TO-263 KTW 9 45 Green (RoHS
& no Sb/Br) SN Level-3-245C-168 HR -40 to 85 LM4952TS
LM4952TSX/NOPB ACTIVE DDPAK/
TO-263 KTW 9 500 Green (RoHS
& no Sb/Br) SN Level-3-245C-168 HR -40 to 85 LM4952TS
(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) RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance
do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may
reference these types of products as "Pb-Free".
RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption.
Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of <=1000ppm threshold. Antimony trioxide based
flame retardants must also meet the <=1000ppm threshold requirement.
(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.
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.
PACKAGE OPTION ADDENDUM
www.ti.com 9-Jun-2020
Addendum-Page 2
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
LM4952TSX/NOPB DDPAK/
TO-263 KTW 9 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2
PACKAGE MATERIALS INFORMATION
www.ti.com 10-Dec-2013
Pack Materials-Page 1
*All dimensions are nominal
Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm)
LM4952TSX/NOPB DDPAK/TO-263 KTW 9 500 367.0 367.0 45.0
PACKAGE MATERIALS INFORMATION
www.ti.com 10-Dec-2013
Pack Materials-Page 2
MECHANICAL DATA
KTW0009A
www.ti.com
BOTTOM SIDE OF PACKAGE
TS9A (Rev B)
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