LM4804 Datasheet, PDF (1/22 Pages) National Semiconductor (TI) – Low Voltage High Power Audio Power Amplifier

LM4804
www.ti.com
SNAS268C – MARCH 2005 – REVISED APRIL 2013
LM4804 Boomer™ Audio Power Amplifier SerieLow Voltage High Power Audio Power
Amplifier
Check for Samples: LM4804
FEATURES
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•23 Pop & Click Circuitry Eliminates Noise During
Turn-On and Turn-Off Transitions
• Low, 2μA (Max) Shutdown Current
• Low, 11mA (Typ) Quiescent Current (V_DD =
4.2V, R_L = 8Ω)
• 1.8W Mono BTL Output, R_L = 8Ω, V_DD = 3V
• Short Circuit Protection
• Unity-Gain Stable
• External Gain Configuration Capability
APPLICATIONS
• Cellphone
• PDA
KEY SPECIFICATIONS
• Quiescent Power Supply Current (V_DD = 4.2V,
R_L = 8Ω), 11mA (Typ)
• BTL Output Power (R_L = 8Ω, 2% THD+N, V_DD =
3V), 1.8W (Typ)
• Shutdown Current, 2µA (Max)
DESCRIPTION
The LM4804 integrates a Boost Converter with an
Audio Power Amplifier to drive voice coil speakers in
portable applications. When powered by a 3V supply,
it is capable of creating 1.8W power dissipation in an
8Ω bridge-tied-load (BTL) with less than 1% THD+N.
Boomer audio power amplifiers were designed
specifically to provide high quality output power with a
minimal amount of external components. The
LM4804 does not require bootstrap capacitors, or
snubber circuits. Therefore it is ideally suited for
portable applications requiring high output voltage
and minimal size.
The LM4804 features a micro-power shutdown mode.
Additionally, the LM4804 features an internal thermal
shutdown protection mechanism.
The LM4804 contains advanced pop & click circuitry
that eliminates output transients which would
otherwise occur during power or shutdown cycles.
The LM4804 is unity-gain stable. Its closed-loop gain
is determined by the value of external, user selected
resistors.
Connection Diagram
NC
NC
GND1
NC
VDD
BOOT
SW
28 27 26 25 24 23 22
1
21
2
20
3
19
4
18
5
17
6
16
7
15
8 9 10 11 12 13 14
NC
NC
BYPASS
SD2
NC
NC
NC
Figure 1. LM4804LQ (5x5)
Top View
See Package Number NJB0028A
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Please 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.
Boomer is a trademark of Texas Instruments.
2
All other trademarks are the property of their respective owners.
3
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2005–2013, Texas Instruments Incorporated