LM48555TLBD

Manufacturer Part NumberLM48555TLBD
DescriptionBOARD EVALUATION LM48555TL
ManufacturerNational Semiconductor
SeriesBoomer®
LM48555TLBD datasheets
 


Specifications of LM48555TLBD

Amplifier TypeClass ABOutput Type1-Channel (Mono)
Voltage - Supply2.7 V ~ 9 VOperating Temperature-40°C ~ 85°C
Board TypeFully PopulatedUtilized Ic / PartLM48555
Lead Free Status / RoHS StatusContains lead / RoHS non-compliantMax Output Power X Channels @ Load-
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LM48555
Ceramic Speaker Driver
General Description
The LM48555 is an audio power amplifier designed to drive
ceramic speakers in applications such as cell phones, smart
phones, PDAs and other portable devices. The LM48555 pro-
duces 15.7V
with less than 1% THD+N while operating
P-P
from a 3.2V power supply. The LM48555 features a low power
shutdown mode, and differential inputs for improved noise
rejection.
The LM48555 includes advanced click and pop suppression
that eliminates audible turn-on and turn-off transients. Addi-
tionally, the integrated boost regulator features a soft start
function that minimizes transient current during power-up
Boomer audio power amplifiers were designed specifically to
provide high quality output power with a minimal number of
external components. The LM48555 does not require boot-
strap capacitors, or snubber circuits.
The LM48555 is unity-gain stable and uses external gain-set-
ting resistors.
Typical Application
* CF+ and CF- are optional. Refer to “Selecting Input and Feedback Capacitor and Resistor for Audio Amplifier” section.
FIGURE 1. Typical Audio Amplifier Application Circuit
Boomer
®
is a registered trademark of National Semiconductor Corporation.
© 2007 National Semiconductor Corporation
Key Specifications
■ 
I
(Boost Converter + Amplifier)
DDQ
at V
= 5V
DD
■ 
Output Voltage Swing
V
= 3.2V, THD
DD
■ 
Power Supply Rejection Ratio
f = 217Hz
Features
Fully differential amplifier
Externally configurable gain
Soft start function
Low power shutdown mode
Under voltage lockout
Applications
Mobile phones
PDA's
Digital cameras
300099
March 2007
7.5mA (typ)
1%
15.7V
(typ)
P-P
80dB (typ)
300099c9
www.national.com

LM48555TLBD Summary of contents

  • Page 1

    ... Typical Application * CF+ and CF- are optional. Refer to “Selecting Input and Feedback Capacitor and Resistor for Audio Amplifier” section. FIGURE 1. Typical Audio Amplifier Application Circuit Boomer ® registered trademark of National Semiconductor Corporation. © 2007 National Semiconductor Corporation Key Specifications ■  I (Boost Converter + Amplifier) ...

  • Page 2

    Connection Diagrams LM48555TL Bumps Down View Top View Order Number LM48555TL See NS Package Number TLA12Z1A www.national.com LM48555TL Marking Drawing X = One digit date code 300099c8 TLA12 Package View (Bumps Up) 2 30009956 Top View V = Die traceability ...

  • 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 ( Storage Temperature Input Voltage Power Dissipation (Note 3) ESD Susceptibility (Note 4) ESD Susceptibility (Note 5) Electrical Characteristics The following specifications apply for V Figure 1), unless otherwise specified ...

  • Page 4

    Note 1: All voltages are measured with respect to the GND pin, unless otherwise specified. Note 2: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is functional, ...

  • Page 5

    Typical Performance Characteristics THD+N vs Frequency V = 4.95V , V = 3.2V, O RMS DD = 1μF + 20Ω THD+N vs Frequency V = 4.95V , V O RMS DD = 1μF + 20Ω THD+N ...

  • Page 6

    CMRR vs Frequency = 1μF + 20Ω 3.2V 100mV IN CMRR vs Frequency = 1μF + 20Ω 5V 100mV IN PSRR vs Frequency = 1μF + ...

  • Page 7

    Inductor Current vs Output Voltage Swing = 1μF + 20Ω 1kHz 3V, 4.2V Supply Current vs Supply Voltage 30009960 7 30009967 www.national.com ...

  • Page 8

    Application Information CHARACTERISTICS OF CERAMIC SPEAKERS Because of their ultra-thin profile piezoelectric ceramic speak- ers are ideal for portable applications. Piezoelectric materials have high dielectric constants and their component electrical property is like a capacitor. Therefore, piezoelectric ceramic speakers essentially ...

  • Page 9

    Another solution is to use a single-pole, single-throw switch connected between V and Shutdown pins. DD BOOTSTRAP PIN The bootstrap pin provides a voltage supply for the internal switch driver. Connecting the bootstrap pin to ...

  • Page 10

    OUTPUT VOLTAGE OF BOOST CONVERTER The output voltage is set using two internal resistors. The output voltage of the boost converter is set to 8V (typ). DUTY CYCLE The maximum duty cycle of the boost converter determines the maximum boost ...

  • Page 11

    Revision History Rev Date 0.1 03/15/07 Description Initial Web Release 11 www.national.com ...

  • Page 12

    Physical Dimensions X1 = 1.463±0.03mm www.national.com inches (millimeters) unless otherwise noted Thin micro SMD Order Number LM48555TL NS Package Number TLA12Z1A     1.970±0.03mm X3 = 0.600±0.075mm 12 ...

  • Page 13

    Notes 13 www.national.com ...

  • Page 14

    ... 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. ...