lm48311tlx

Manufacturer Part Numberlm48311tlx
DescriptionUltra-low Emi, Filterless, 2.6w, Mono, Class D Audio Power Amplifier With E2s
ManufacturerNational Semiconductor Corporation
lm48311tlx datasheet
 


1
Page 1
2
Page 2
3
Page 3
4
Page 4
5
Page 5
6
Page 6
7
Page 7
8
Page 8
9
Page 9
10
Page 10
11
12
13
14
15
16
Page 1/16

Download datasheet (476Kb)Embed
Next
Ultra-Low EMI, Filterless, 2.6W, Mono, Class D Audio
Power Amplifier with E
General Description
The LM48311 is a single supply, high efficiency, mono, 2.6W,
filterless switching audio amplifier. The LM48311 features
National’s Enhanced Emissions Suppression (E
that features a unique patent-pending ultra low EMI, spread
spectrum, PWM architecture, that significantly reduces RF
emissions while preserving audio quality and efficiency. The
E
2
S system improves battery life, reduces external compo-
nent count, board area consumption, system cost, and sim-
plifying design.
The LM48311 is designed to meet the demands of portable
multimedia devices. Operating from a single 5V supply, the
device is capable of delivering 2.6W of continuous output
power to a 4Ω load with less than 10% THD+N. Flexible power
supply requirements allow operation from 2.4V to 5.5V. The
LM48311 features both a spread spectrum modulation
scheme, and an advanced, patented edge rate control (ERC)
architecture that significantly reduces emissions, while main-
taining high quality audio reproduction (THD+N = 0.03%) and
high efficiency (η = 88%).
The LM48311 features high efficiency compared to conven-
tional Class AB amplifiers, and other low EMI Class D ampli-
fiers. When driving and 8Ω speaker from a 5V supply, the
device operates with 88% efficiency at P
the LM48311 is internally set to 6dB, further reducing external
component count. A low power shutdown mode reduces sup-
ply current consumption to 0.01µA.
Advanced output short circuit protection with auto-recovery
prevents the device from being damaged during fault condi-
tions. Superior click and pop suppression eliminates audible
transients on power-up/down and during shutdown.
Boomer® is a registered trademark of National Semiconductor Corporation.
© 2009 National Semiconductor Corporation
LM48311
2
S
Key Specifications
■ 
Efficiency at 3.6V, 400mW into 8Ω
■ 
2
S) system,
Efficiency at 5V, 1W into 8Ω
■ 
Quiescent Power Supply Current at 5V
■ 
Power Output at V
THD+N
THD+N
■ 
Power Output at V
THD+N
THD+N
■ 
Shutdown current
Features
Passes FCC Class B Radiated Emissions with 20 inches
of cable
E
2
S System Reduces EMI while Preserving Audio Quality
and Efficiency
Output Short Circuit Protection with Auto-Recovery
No output filter required
= 1W. The gain of
O
Internally Configured Gain (6dB)
Low power shutdown mode
Minimum external components
"Click and pop" suppression
Micro-power shutdown
Available in space-saving microSMD package
Applications
Mobile phones
PDAs
Laptops
300975
June 25, 2009
= 4Ω
= 5V, R
DD
L
10%
1%
= 8Ω
= 5V, R
DD
L
10%
1%
0.01μA (typ)
www.national.com
85% (typ)
88% (typ)
3.1mA
2.6W (typ)
2.1W (typ)
1.6W (typ)
1.3W (typ)

lm48311tlx Summary of contents

  • Page 1

    ... Advanced output short circuit protection with auto-recovery prevents the device from being damaged during fault condi- tions. Superior click and pop suppression eliminates audible transients on power-up/down and during shutdown. Boomer® registered trademark of National Semiconductor Corporation. © 2009 National Semiconductor Corporation LM48311   ...

  • Page 2

    Typical Application www.national.com FIGURE 1. Typical Audio Amplifier Application Circuit 2 300975a8 ...

  • Page 3

    ... Connection Diagrams TL Package 1.539mm x 1.565mm x 0.6mm Top View Order Number LM48311TL See NS Package Number TLA09BCA Ordering Information Order Number Package LM48311TL 9 Bump micro SMD LM48311TLX 9 Bump micro SMD Pin Descriptions Pin Name A1 IN+ Non-Inverting Input A2 SD Active Low Shutdown Input. Connect to V ...

  • Page 4

    Absolute Maximum Ratings If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Supply Voltage Storage Temperature Input Voltage Power Dissipation (Note 3) ESD Rating (Note 4) ESD Rating (Note 5) Electrical ...

  • Page 5

    Symbol Parameter Power Supply Rejection Ratio PSRR (Input Referred) Common Mode Rejection Ratio CMRR (Input Referred) η Efficiency SNR Signal to Noise Ratio Output Noise ε OS (Input Referred) Note 1: “Absolute Maximum Ratings” indicate limits beyond which damage to ...

  • Page 6

    Typical Performance Characteristics For all performance graphs, the Output Gains are set to 0dB, unless otherwise noted. THD+N vs Frequency V = 2.5V 250mW THD+N vs Frequency .0V 1.2W, R ...

  • Page 7

    THD+N vs Frequency = 3Ω 3.6V 1.25W 30097510 THD+N vs Output Power = 8Ω 1kHz 30097502 Efficiency vs Output Power = 4Ω 1kHz 30097511 ...

  • Page 8

    Power Dissipation vs Output Power f = 1kHz Output Power vs Supply Voltage f = 1kHz CMRR vs Frequency V = 5.0V RIPPLE www.national.com = 4Ω 30097513 = 4Ω 30097515 = 8Ω ...

  • Page 9

    Spread Spectrum Output Spectrum vs Frequency = 8Ω 5.0V RMS L Supply Current vs Supply Voltage No Load Wideband Spread Spectrum Output Spectrum vs Frequency V 30097519 Shutdown Supply Current vs ...

  • Page 10

    Application Information GENERAL AMPLIFIER FUNCTION The LM48311 mono Class D audio power amplifier features a filterless modulation scheme that reduces external compo- nent count, conserving board space and reducing system cost. The outputs of the device transition from V with ...

  • Page 11

    INEXT Where R is 40kΩ 20kΩ, and INEXT additional external resistor. FIGURE 4. Reduced Gain Configuration SINGLE-ENDED AUDIO AMPLIFIER CONFIGURATION The LM48311 is compatible ...

  • Page 12

    LM48311 Demo Board Schematic www.national.com FIGURE 6. LM48311 DEMO BOARD SCHEMATIC 12 30097530 ...

  • Page 13

    Demo Boards FIGURE 7. Top Silkscreen FIGURE 9. Bottom Silkscreen 30097526 30097524 FIGURE 10. Bottom Layer 13 30097525 FIGURE 8. Top Layer 30097523 www.national.com ...

  • Page 14

    Revision History Rev 1.0 www.national.com Date 06/25/09 Initial released. 14 Description ...

  • Page 15

    Physical Dimensions inches (millimeters) unless otherwise noted 9 Bump micro SMD Order Number LM48311TL NS Package Number TLA09BCA X1 = 1.539mm X2 = 1.565mm X3 = 0.6mm 15 www.national.com ...

  • Page 16

    ... National Semiconductor and the National Semiconductor logo are registered trademarks of National Semiconductor Corporation. All other brand or product names may be trademarks or registered trademarks of their respective holders. ...