lm48310sd

Manufacturer Part Numberlm48310sd
DescriptionUltra-low Emi, Filterless, 2.6w, Mono, Class D Audio Power Amplifier With E2s
ManufacturerNational Semiconductor Corporation
lm48310sd 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
17
18
19
20
Page 1/20

Download datasheet (483Kb)Embed
Next
LM48310
Ultra-Low EMI, Filterless, 2.6W, Mono, Class D Audio
Power Amplifier with E
General Description
The LM48310 is a single supply, high efficiency, mono, 2.6W,
filterless switching audio amplifier. The LM48310 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 LM48310 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
LM48310 offers two logic selectable modulation schemes,
fixed frequency mode, and an EMI suppressing spread spec-
trum mode. The E
2
S system includes an advanced, patent-
pending edge rate control (ERC) architecture that further
reduce emissions by minimizing the high frequency compo-
nent of the device output, while maintaining high quality audio
reproduction (THD+N = 0.03%) and high efficiency (η = 88%).
The LM48310 also features a SYNC_IN input and
SYNC_OUT, which allows multiple devices to operate with
the same switching frequency, eliminating beat frequencies
and any other interference caused by clock intermodulation.
The LM48310 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 LM48310 is internally set to 12dB, further reducing exter-
nal component count. A low power shutdown mode reduces
supply 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.
EMI Graph 20in of Speaker Cable
Boomer® is a registered trademark of National Semiconductor Corporation.
© 2008 National Semiconductor Corporation
2
S
Key Specifications
■ 
Efficiency at 3.6V, 400mW into 8Ω
■ 
Efficiency at 5V, 1W into 8Ω
2
S) system,
■ 
Quiescent Power Supply Current at 5V
■ 
Power Output at V
= 4Ω, THD+N
R
L
■ 
Power Output at V
= 8Ω, THD+N
R
L
■ 
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
Stereo Class D operation
No output filter required
Internally Configured Gain (12dB)
Synchronizable Oscillator for Multi-Channel operation
Low power shutdown mode
Minimum external components
"Click and pop" suppression
Micro-power shutdown
= 1W. The gain of
O
Available in space-saving LLP package
Applications
Mobile phones
PDAs
Laptops
300374
March 4, 2008
85% (typ)
88% (typ)
3.2mA
= 5V,
DD
2.6W (typ)
10%
= 5V,
DD
1.6W (typ)
10%
0.01μA (typ)
300374a0
www.national.com

lm48310sd Summary of contents

  • Page 1

    ... Superior click and pop suppression eliminates audible transients on power-up/down and during shutdown. EMI Graph 20in of Speaker Cable Boomer® registered trademark of National Semiconductor Corporation. © 2008 National Semiconductor Corporation 2 S Key Specifications ■ ...

  • Page 2

    Typical Application www.national.com FIGURE 1. Typical Audio Amplifier Application Circuit 2 30037459 ...

  • Page 3

    ... Inverting Output 8 GND Ground 9 PV H-Bridge Power Supply DD 10 OUTA Non-Inverting Output LLP Package 3mm x 3mm x 0.8mm Top View Order Number LM48310SD See NS Package Number SDA010 TABLE 1. Description for normal operation Spread spectrum mode with f = 300kHz ± 30 300kHz S = external clock frequency S ...

  • 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 P Output Power O THD+N Total Harmonic Distortion + Noise Power Supply Rejection Ratio PSRR (Input Referred) CMRR Common Mode Rejection Ratio η Efficiency SNR Signal to Noise Ratio ε Output Noise OS Conditions = 4Ω, THD = ...

  • Page 6

    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 ...

  • Page 7

    Typical Performance Characteristics THD+N vs Frequency V = 2.5V 300mW OUT THD+N vs Frequency V = 5.0V 1.2W OUT THD+N vs Frequency V = 3.6V 400mW OUT = ...

  • Page 8

    THD+N vs Output Power f = 1kHz Efficiency vs Output Power f = 1kHz Power Dissipation vs Output Power f = 1kHz www.national.com = 4Ω 30037464 = 4Ω 30037472 = 4Ω 30037474 8 THD+N ...

  • Page 9

    Output Power vs Supply Voltage = 4Ω 1kHz 30037476 PSRR vs Frequency = 8Ω 3.6V 200mV , R DD RIPPLE P-P L 30037497 CMRR vs Frequency = 8Ω 3.6V, V ...

  • Page 10

    Fixed Frequency Output Spectrum vs Frequency V = 5.0V Wideband Fixed Frequency Output Spectrum vs Frequency V = 5.0V Supply Current vs Supply Voltage No Load www.national.com Spread Spectrum Output Spectrum vs Frequency ...

  • Page 11

    Application Information GENERAL AMPLIFIER FUNCTION The LM48310 mono Class D audio power amplifier features a filterless modulation scheme that reduces external compo- nent count, conserving board space and reducing system cost. With no signal applied, the outputs (V switch between ...

  • Page 12

    FIGURE 2. Cascaded LM48310 12 30037460 ...

  • Page 13

    FIGURE 3. THD+N vs Output Power 30037496 FIGURE 5. Crosstalk vs Frequency FIGURE 4. THD+N vs Frequency 13 30037438 www.national.com ...

  • Page 14

    DIFFERENTIAL AMPLIFIER EXPLANATION As logic supplies continue to shrink, system designers are in- creasingly turning to differential analog signal handling to preserve signal to noise ratios with restricted voltage signs. The LM48310 features a fully differential speaker amplifier. A differential ...

  • Page 15

    ... X7R Ceramic C2 Capacitor (603) Panasonic ECJ-1VB1C105K 1μF ±10% 16V X7R Ceramic C4 Capacitor (1206) Panasonic ECJ-3YB1C105K C6 1 Not Installed Ceramic Capacitor (603) 0Ω ±1% resistor (603 JP1 — JP2 2 3 Pin Headers LM48310SDL 1 LM48310SD (10-pin LLP) 15 Description www.national.com ...

  • Page 16

    LM48310 Demo Board Schematic www.national.com FIGURE 8. LM48310 DEMO BOARD SCHEMATIC 16 30037489 ...

  • Page 17

    Demo Boards FIGURE 9. Top Silkscreen FIGURE 11. Layer 2 (GND) FIGURE 13. Bottom Layer 30037490 FIGURE 10. Top Layer 30037492 FIGURE 12. Layer 3 (V 30037494 FIGURE 14. Bottom Silkscreen 17 30037491 30037493 ) DD 30037495 www.national.com ...

  • Page 18

    Revision History Rev 1.0 1.01 1.02 www.national.com Date 11/13/07 Initial release. 02/26/08 Fixed few typos (Pin Description table). 03/04/08 Text edits under SHUTDOWN FUNCTION (Application Information section). 18 Description ...

  • Page 19

    ... Physical Dimensions inches (millimeters) unless otherwise noted LLP Order Number LM48310SD NS Package Number SDA08A 19 www.national.com ...

  • Page 20

    ... 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. ...