LM4920TLBD National Semiconductor, LM4920TLBD Datasheet

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LM4920TLBD

Manufacturer Part Number
LM4920TLBD
Description
BOARD EVALUATION LM4920TL
Manufacturer
National Semiconductor
Series
Boomer®r
Datasheet

Specifications of LM4920TLBD

Amplifier Type
Class AB
Output Type
Headphones, 2-Channel (Stereo)
Max Output Power X Channels @ Load
80mW x 2 @ 16 Ohm
Voltage - Supply
1.6 V ~ 4.2 V
Operating Temperature
-40°C ~ 85°C
Board Type
Fully Populated
Utilized Ic / Part
LM4920
Lead Free Status / RoHS Status
Contains lead / RoHS non-compliant
LM4920
Ground-Referenced, Ultra Low Noise, Fixed Gain, 80mW
Stereo Headphone Amplifier
General Description
The LM4920 is a ground referenced, fixed-gain audio power
amplifier capable of delivering 80mW of continuous average
power into a 16Ω single-ended load with less than 1%
THD+N from a 3V power supply.
The LM4920 features a new circuit technology that utilizes a
charge pump to generate a negative reference voltage. This
allows the outputs to be biased about ground, thereby elimi-
nating output-coupling capacitors typically used with normal
single-ended loads.
Boomer audio power amplifiers were designed specifically to
provide high quality output power with a minimal amount of
external components. The LM4920 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 LM4920 features a low-power consumption shutdown
mode selectable for either channel separately. This is ac-
complished by driving either the SD_RC (Shutdown Right
Channel) or SD_LC (Shutdown Left Channel) (or both) pins
with logic low, depending on which channel is desired shut-
down. Additionally, the LM4920 features an internal thermal
shutdown protection mechanism.
The LM4920 contains advanced pop & click circuitry that
eliminates noises which would otherwise occur during
turn-on and turn-off transitions.
The LM4920 has an internal fixed gain of 1.5V/V.
Boomer
®
is a registered trademark of National Semiconductor Corporation.
© 2006 National Semiconductor Corporation
Key Specifications
j
Improved PSRR at 217Hz
j
Power Output at V
R
= 16Ω, THD % 1%
L
j
Shutdown Current
j
Internal Fixed Gain
j
Operating Voltage
Features
n Fixed Logic Levels
n Ground referenced outputs
n High PSRR
n Available in space-saving micro SMD package
n Ultra low current shutdown mode
n Improved pop & click circuitry eliminates noises during
turn-on and turn-off transitions
n No output coupling capacitors, snubber networks,
bootstrap capacitors, or gain-setting resistors required
n Shutdown either channel independently
Applications
n Mobile Phones
n MP3 Players
n PDAs
n Portable electronic devices
n Notebook PCs
DS201793
October 2006
70dB (typ)
= 3V,
DD
80mW (typ)
0.01µA (typ)
1.5V/V (typ)
1.6V to 4.2V
www.national.com

Related parts for LM4920TLBD

LM4920TLBD Summary of contents

Page 1

... The LM4920 contains advanced pop & click circuitry that eliminates noises which would otherwise occur during turn-on and turn-off transitions. The LM4920 has an internal fixed gain of 1.5V/V. Boomer ® registered trademark of National Semiconductor Corporation. © 2006 National Semiconductor Corporation Key Specifications j Improved PSRR at 217Hz j ...

Page 2

Typical Application FIGURE 1. Typical Audio Amplifier Application Circuit www.national.com 2 201793B8 ...

Page 3

Connection Diagrams microSMD Package Top View Order Number LM4920TL See NS Package Number TLE1411A Pin Descriptions Pin Name A1 R_IN A2 SGND A3 CPV A4 C CP+ B1 SD_RC B2 SD_LC B4 PGND C1 L_IN C2 R_OUT C4 C CP- ...

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 Susceptibility (Note 4) ESD Susceptibility (Note 5) Electrical Characteristics V The following specifications apply for V ...

Page 5

Electrical Characteristics V The following specifications apply for V Symbol Parameter Z Output Impedance OUT I Input Leakage L Note 1: All voltages are measured with respect to the GND pin unless otherwise specified. Note 2: Absolute Maximum Ratings indicate ...

Page 6

Typical Performance Characteristics THD+N vs Frequency V = 1.6V 16Ω THD+N vs Frequency V = 1.8V 16Ω THD+N vs Frequency 16Ω www.national.com ...

Page 7

Typical Performance Characteristics THD+N vs Frequency V = 3.6V 16Ω THD+N vs Frequency V = 4.2V 16Ω THD+N vs Output Power V = 1.6V 16Ω, f ...

Page 8

Typical Performance Characteristics THD+N vs Output Power V = 1.6V 16Ω 1kHz DD L Two channels in phase THD+N vs Output Power V = 1.8V 16Ω 1kHz DD L One channel enabled ...

Page 9

Typical Performance Characteristics THD+N vs Output Power V = 3.0V 16Ω 1kHz DD L One channel enabled THD+N vs Output Power V = 3.0V 16Ω 1kHz DD L Two channels in phase ...

Page 10

Typical Performance Characteristics THD+N vs Output Power V = 3.6V 16Ω 1kHz DD L Two channels in phase THD+N vs Output Power V = 4.2V 16Ω 1kHz DD L One channel enabled ...

Page 11

Typical Performance Characteristics PSRR vs Frequency V = 1.6V 16Ω PSRR vs Frequency 16Ω PSRR vs Frequency V = 4.2V 16Ω (Continued) PSRR vs Frequency ...

Page 12

Typical Performance Characteristics Output Power vs Supply Voltage R = 16Ω, one channel L Output Power vs Supply Voltage R = 16Ω, 2 channels in phase L Supply Current vs Supply Voltage R = 16Ω L www.national.com (Continued) Output Power ...

Page 13

Application Information SUPPLY VOLTAGE SEQUENCING good general practice to first apply the supply voltage to a CMOS device before any other signal or supply on other pins. This is also true for the LM4920 audio amplifier which ...

Page 14

Application Information SD_LC/SD_RC pins and V . Connect the switch between DD the SD_LC/SD_RC pins and ground. Select normal amplifier operation by opening the switch. Closing the switch con- nects the SD_LC/SD_RC pins to ground, activating micro- power shutdown. The ...

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Application Information LM4920 micro SMD DEMO BOARD ARTWORK Top Layer Mid Layer 2 (Continued) 20179305 20179307 15 Mid Layer 1 20179306 Bottom Layer 20179308 www.national.com ...

Page 16

Revision History Rev 1.0 1.1 www.national.com Date 03/27/06 10/18/06 16 Description Initial release. Text edits. ...

Page 17

... BANNED SUBSTANCE COMPLIANCE National Semiconductor follows the provisions of the Product Stewardship Guide for Customers (CSP-9-111C2) and Banned Substances and Materials of Interest Specification (CSP-9-111S2) for regulatory environmental compliance. Details may be found at: www.national.com/quality/green. ...

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