lm48557tlx

Manufacturer Part Numberlm48557tlx
DescriptionMono, Bridge-tied Load, Ceramic Speaker Driver With I2c Volume Control And Reset
ManufacturerNational Semiconductor Corporation
lm48557tlx datasheet
 
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Mono, Bridge-Tied Load, Ceramic Speaker Driver with I
Volume Control and Reset
General Description
The LM48557 is a single supply, mono, ceramic speaker driv-
er with an integrated charge-pump, designed for portable
devices, such as cell phones and portable media players,
where board space is at a premium. The LM48557 charge
pump allows the device to deliver 5.8V
supply.
The LM48557 features high power supply rejection ratio
(PSRR), 80dB at 217Hz, allowing the device to operate in
noisy environments without additional power supply condi-
tioning. Flexible power supply requirements allow operation
from 2.7V to 4.5V. The LM48557 features an active low reset
input that reverts the device to its default state. Additionally,
the LM48557 features a 36-step I
2
C volume control and mute
function. The low power Shutdown mode reduces supply cur-
rent consumption to 0.01µA.
The LM48557’s superior click and pop suppression elimi-
nates audible transients on power-up/down and during shut-
down. The LM48557 is available in an ultra-small 16-bump
micro SMD package (1.965mmx1.965mm).
Boomer® is a registered trademark of National Semiconductor Corporation.
© 2009 National Semiconductor Corporation
LM48557
Key Specifications
■ 
Output Voltage at V
R
= 1µF +22Ω, THD+N
L
■ 
Quiescent Power Supply Current
from a single 4.2V
RMS
at 4.2V
■ 
PSRR at 217Hz
■ 
Shutdown current
Features
Integrated Charge Pump
Bridge-tied Load Output
Differential Input
High PSRR
I
2
C Volume and Mode Control
Reset Input
Advanced Click-and-Pop Suppression
Low Supply Current
Minimum external components
Micro-power shutdown
Available in space-saving 16-bump micro SMD package
Applications
Mobile phones
PDAs
Notebook Electronic Devices
MP3 Players
300981
August 6, 2009
2
C
= 4.2V
DD
1%
5.8V
(typ)
RMS
5mA (typ)
80dB (typ)
0.01μA (typ)
www.national.com

lm48557tlx Summary of contents

  • Page 1

    ... The LM48557’s superior click and pop suppression elimi- nates audible transients on power-up/down and during shut- down. The LM48557 is available in an ultra-small 16-bump micro SMD package (1.965mmx1.965mm). Boomer® registered trademark of National Semiconductor Corporation. © 2009 National Semiconductor Corporation LM48557 Key Specifications ■ ...

  • Page 2

    Typical Application www.national.com FIGURE 1. Typical Audio Amplifier Application Circuit 2 30098103 ...

  • Page 3

    ... Top View Order Number LM48557TL See NS Package Number TLA1611A Ordering Information Order Number Package LM48557TL 16–Bump micro SMD LM48557TLX 16–Bump micro SMD 16–Bump micro SMD Marking 30098112 Package DWG # Transport Media TLA1611A 250 units on tape and reel TLA1611A ...

  • Page 4

    Bump Descriptions Bump www.national.com Name SV Signal Power Supply DD SGND Signal Ground VCM Common Mode Sense Input IN- Amplifier Inverting input OUT- Amplifier ...

  • Page 5

    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 1) Storage Temperature Input Voltage Power Dissipation (Note 3) ESD Rating-Human Body Model (Note 4) ESD ...

  • Page 6

    Symbol Parameter Power Supply Rejection Ratio PSRR (Figure 2) Common Mode Rejection Ratio CMRR (Figure 3) Charge Pump Switching f SW Frequency SNR Signal To Noise Ratio ∈ Output Noise OS T Wake Up Time Interface ...

  • Page 7

    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 8

    Typical Performance Characteristics THD+N vs Frequency V = 3.6V 1µF + 22Ω 48dB THD+N vs Output Voltage Z = 1µF + 22Ω Power Consumption vs Output Voltage V = ...

  • Page 9

    CMRR vs Frequency V = 4.2V 200mV , A DD RIPPLE P-P V Output Voltage vs Supply Voltage Z = 1µF + 22Ω, THD Charge Pump Output Voltage vs Load Current V = 4.2V DD ...

  • Page 10

    Application Information COMPATIBLE INTERFACE The LM48557 is controlled through an I interface that consists of a serial data line (SDA) and a serial clock (SCL). The clock line is uni-directional. The data line is bi-directional (open drain). ...

  • Page 11

    B7 B6 Device 1 1 Address Register B7 B6 Name Mode 0 0 Control Volume 1 0 Control BIT NAME VALUE B0 SHDN B1 MUTE B2 RESERVED* B3 RESERVED* B4 TESTMODE B5 RESERVED* B6 RESERVED* REGISTER B7 ADDRESS *RESERVED bits ...

  • Page 12

    SINGLE AND MULTI-BYTE WRITE OPERATION The LM48557 supports both single-byte and multi-byte write operations. A single-byte write operation begins with the mas- ter device transmitting a START condition followed by the device address (Figure 7). After receiving the correct device ...

  • Page 13

    VOLUME VOL5 VOL4 STEP (MUTE ...

  • Page 14

    VOLUME VOL5 STEP ...

  • Page 15

    VOLUME CONTROL The LM48557 has a 64 step volume control, but only 36 steps are recommended for use. Use steps 1 through 32 and steps 61 through 64 to set the gain of the device. Accessing steps 33 through 60 ...

  • Page 16

    SINGLE-ENDED INPUT CONFIGURATION Ground-Referenced Audio Source The LM48557 input stage is compatible with ground-refer- enced input sources, such as CODECs with an integrated headphone amplifier. Connect either input, IN+ or IN- to the FIGURE 9. Single-Ended Input Configuration with a ...

  • Page 17

    PCB Layout Guidelines Minimize trace impedance of the power, ground and all output traces for optimum performance. Voltage loss due to trace resistance between the LM48557 and the load results in de- creased output power and efficiency. Trace resistance be- ...

  • Page 18

    PC Board Layout Silk Screen Layer 2 www.national.com 30098125 Top Layer 30098122 18 30098124 30098123 Layer 3 ...

  • Page 19

    Bottom Layer 19 30098121 Bottom Silkscreen www.national.com ...

  • Page 20

    Demo Board Schematic www.national.com FIGURE 11. LM48557 Demo Board Schematic 20 30098119 ...

  • Page 21

    Revision History Rev Date 1.0 07/08/09 1.01 07/15/09 1.02 08/05/09 1.03 08/06/09 Description Initial released. Deleted the “Tru-GND...” trademark on the cover page. Text edits. Fixed a typo error. 21 www.national.com ...

  • Page 22

    Physical Dimensions www.national.com inches (millimeters) unless otherwise noted 16-Bump micro SMD Order Number LM48557TL NS Package Number TLA1611A X = 1.965± 0. 1.965 ± 0. 0.6 ± 0.075 ...

  • Page 23

    Notes 23 www.national.com ...

  • Page 24

    ... 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. ...