LM4905LDX National Semiconductor, LM4905LDX Datasheet

IC AMP AUDIO PWR 1.07W MONO 8LLP

LM4905LDX

Manufacturer Part Number
LM4905LDX
Description
IC AMP AUDIO PWR 1.07W MONO 8LLP
Manufacturer
National Semiconductor
Series
Boomer®r
Type
Class ABr
Datasheet

Specifications of LM4905LDX

Output Type
1-Channel (Mono)
Max Output Power X Channels @ Load
1.07W x 1 @ 8 Ohm
Voltage - Supply
2.2 V ~ 5.5 V
Features
Depop, Shutdown, Thermal Protection
Mounting Type
Surface Mount
Package / Case
8-LLP
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
© 2003 National Semiconductor Corporation
LM4905
1 Watt Audio Power Amplifier
General Description
The LM4905 is an audio power amplifier primarily designed
for demanding applications in mobile phones and other por-
table communication device applications. It is capable of
delivering 1 watt of continuous average power to an 8Ω BTL
load with less than 1% distortion (THD+N) from a 5V
power supply.
Boomer audio power amplifiers were designed specifically to
provide high quality output power with a minimal amount of
external components. The LM4905 does not require output
coupling capacitors or bootstrap capacitors, and therefore is
ideally suited for mobile phone and other low voltage appli-
cations where minimal power consumption is a primary re-
quirement.
The LM4905 features a low-power consumption shutdown
mode, which is achieved by driving the shutdown pin with
logic low. Additionally, the LM4905 features an internal ther-
mal shutdown protection mechanism.
The LM4905 contains advanced pop & click circuitry which
eliminates noise which would otherwise occur during turn-on
and turn-off transitions.
The LM4905 is unity-gain stable and can be configured by
external gain-setting resistors.
Typical Application
Boomer
®
is a registered trademark of National Semiconductor Corporation.
FIGURE 1. Typical Audio Amplifier Application Circuit
DS200508
DC
Key Specifications
Features
n Available in space-saving LLP package
n Ultra low current shutdown mode
n BTL output can drive capacitive loads
n Improved pop & click circuitry eliminates noise during
n 2.2 - 5.5V operation
n No output coupling capacitors, snubber networks or
n Unity-gain stable
n External gain configuration capability
Applications
n Mobile Phones
n PDAs
n Portable electronic devices
j
j
j
j
turn-on and turn-off transitions
bootstrap capacitors required
Improved PSRR at 217Hz & 1KHz
Power Output at 5.0V, 1% THD, 8Ω
Power Output at 3.0V, 1% THD, 8Ω
Shutdown Current
200508D3
390mW (typ)
www.national.com
1.07W (typ)
0.1µA (typ)
July 2003
62dB

Related parts for LM4905LDX

LM4905LDX Summary of contents

Page 1

... The LM4905 is unity-gain stable and can be configured by external gain-setting resistors. Typical Application FIGURE 1. Typical Audio Amplifier Application Circuit Boomer ® registered trademark of National Semiconductor Corporation. © 2003 National Semiconductor Corporation Key Specifications j Improved PSRR at 217Hz & 1KHz j Power Output at 5.0V, 1% THD, 8Ω ...

Page 2

Connection Diagrams www.national.com LD Package Top View Order Number LM4905LD See NS Package Number LDA08A LQ Package 20050802 Top View Order Number LM4905LQ See NS Package Number LQB08A Mini Small Outline (MSOP) Package 20050801 Top View Order Number LM4905MM See ...

Page 3

... Absolute Maximum Ratings If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Supply Voltage (Note 10) Storage Temperature Input Voltage Power Dissipation (Notes 3, 11) ESD Susceptibility (Note 4) ESD Susceptibility (Note 5) Junction Temperature Electrical Characteristics V The following specifications apply for the circuit shown in Figure 1, unless otherwise specified ...

Page 4

Electrical Characteristics V The following specifications apply for the circuit shown in Figure 1, unless otherwise specified. Limits apply for T Symbol Parameter I Quiescent Power Supply Current DD I Shutdown Current SD V Shutdown Voltage Input High SDIH V ...

Page 5

External Components Description (Figure 1) Components 1. R Inverting input resistance which sets the closed-loop gain in conjunction with R i high pass filter with Input coupling capacitor which blocks the DC voltage at the amplifiers input ...

Page 6

Typical Performance Characteristics THD+N vs Power Out 3V, 8Ω Power Supply Rejection Ratio (PSRR) vs Frequency 5V, 8Ω Input terminated with 10Ω Power Supply Rejection Ratio (PSRR) vs Frequency at ...

Page 7

Typical Performance Characteristics Power Supply Rejection Ratio (PSRR) vs Frequency 2.6V, 8Ω Input terminated with 10Ω Open Loop Frequency Response, 5V Open Loop Frequency Response, 2.6V (Continued) Power Supply Rejection Ratio (PSRR) vs Frequency L ...

Page 8

Typical Performance Characteristics Power Derating Curves Power Dissipation vs Output Power, V Shutdown Hysteresis Voltage 5V www.national.com (Continued) 20050869 =3V DD 200508C8 200508A1 8 Power Dissipation vs Output Power, 5V, 8Ω 20050897 Power Dissipation vs Output Power, V =2.6V DD ...

Page 9

Typical Performance Characteristics Shutdown Hysteresis Voltage 2.6V Output Power vs Supply Voltage, 16Ω Frequency Response vs Input Capacitor Size (Continued) 200508A5 200508A7 20050854 9 Output Power vs Supply Voltage, 8Ω 200508A6 Output Power vs Supply Voltage, 32Ω 200508A8 www.national.com ...

Page 10

Application Information BRIDGE CONFIGURATION EXPLANATION As shown in Figure 1, the LM4905 has two internal opera- tional amplifiers. The first amplifier’s gain is externally con- figurable, while the second amplifier is internally fixed in a unity-gain, inverting configuration. The closed-loop ...

Page 11

Application Information typical value of 0.1µA. In either case, the shutdown pin should be tied to a definite voltage to avoid unwanted state changes. In many applications, a microcontroller or microprocessor output is used to control the shutdown circuitry, which ...

Page 12

Application Information nates possible high frequency oscillations. Care should be taken when calculating the -3dB frequency in that an incor- rect combination of R and C will cause rolloff before 3 4 www.national.com 20kHz. A typical combination of feedback resistor ...

Page 13

Application Information DIFFERENTIAL AMPLIFIER CONFIGURATION FOR LM4905 (Continued) FIGURE 3. REFERENCE DESIGN BOARD SCHEMATIC FIGURE 4. 13 200508D5 200508D6 www.national.com ...

Page 14

Application Information LM4905 MSOP BOARD ARTWORK Composite View Top Layer Part Description LM4905 Audio AMP Tantalum Capcitor, 1µF Ceramic Capacitor, 0.39µF Resistor, 20kΩ, 1/10W Resistor, 100kΩ, 1/10W Jumper Header Vertical Mount 2X1 0.100“ spacing www.national.com (Continued) 200508E3 200508E5 MONO LM4905 ...

Page 15

Application Information PCB LAYOUT GUIDELINES This section provides practical guidelines for mixed signal PCB layout that involves various digital/analog power and ground traces. Designers should note that these are only "rule-of-thumb" recommendations and the actual results will depend heavily on ...

Page 16

Physical Dimensions www.national.com inches (millimeters) unless otherwise noted LLP Package Order Number LM4905LD NS Package Number LDA08A LLP Package Order Number LM4905LQ NS Package Number LQB08A 16 ...

Page 17

... NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant ...

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