LM4802BLQBD/NOPB National Semiconductor, LM4802BLQBD/NOPB Datasheet

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LM4802BLQBD/NOPB

Manufacturer Part Number
LM4802BLQBD/NOPB
Description
Manufacturer
National Semiconductor
Datasheet
1.LM4802BLQBDNOPB.pdf (17 pages)

Specifications of LM4802BLQBD/NOPB

Lead Free Status / Rohs Status
Compliant
© 2005 National Semiconductor Corporation
LM4802B
Audio Power Amplifier with Boost Converter to Drive
Ceramic Speakers
General Description
The LM4802B integrates a Boost Converter with an Audio
Power Amplifier to drive Ceramic Speakers in portable ap-
plications. When powered by a 3V supply, it is capable of
forcing 12Vp-p across a 2µF + 30Ω 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 LM4802B does not require boot-
strap capacitors, or snubber circuits. Therefore it is ideally
suited for portable applications requiring high output voltage
and minimal size.
The LM4802B features a low-power consumption shutdown
mode. Additionally, the LM4802B features an internal ther-
mal shutdown protection mechanism.
The LM4802B contains advanced pop & click circuitry that
eliminates noises which would otherwise occur during
turn-on and turn-off transitions.
The LM4802B is unity-gain stable. Its gain is set by external
resistors.
Connection Diagram
Boomer
®
is a registered trademark of National Semiconductor Corporation.
DS200941
See NS Package Number 2LQAQ028
Order Number LM4802BLQ
LM4802BLQ (5x5)
Top View
Key Specifications
Features
n Pop & click circuitry eliminates noise during turn-on and
n Low, 2µA (max) shutdown current
n Low, 12mA (typ) quiescent current
n 12Vp-p mono BTL output, load = 2µF + 30Ω, V
n Short circuit protection
n Unity-gain stable
n External gain configuration capability
Applications
n Cellphone
n PDA
j
j
j
turn-off transitions
(2µF + 30Ω load, 1% THD+N,
V
Quiescent Power Supply Current
BTL Voltage Swing
Shutdown Current
DD
= 3V)
20094184
www.national.com
12Vp-p (typ)
March 2005
12mA (typ)
2µA (max)
DD
= 3V

LM4802BLQBD/NOPB Summary of contents

Page 1

... The LM4802B is unity-gain stable. Its gain is set by external resistors. Connection Diagram Boomer ® registered trademark of National Semiconductor Corporation. © 2005 National Semiconductor Corporation Key Specifications j Quiescent Power Supply Current j BTL Voltage Swing (2µ ...

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Typical Application FIGURE 1. Typical Audio Amplifier Application Circuit www.national.com 20094110 2 ...

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... Absolute Maximum Ratings If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Supply Voltage ( 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 otherwise specified ...

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Electrical Characteristics V The following specifications apply for V otherwise specified. Limits apply for T Symbol Parameter THD+N Total Harmomic Distortion + Noise e Output Noise OS PSRR Power Supply Rejection Ratio V Feedback Pin Reference Voltage FB Note 1: ...

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Typical Performance Characteristics THD+N vs Frequency 2µF + 30Ω THD+N vs Output Voltage 2µF + 30Ω THD+N vs Output Voltage V = 3V, Z ...

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Typical Performance Characteristics THD+N vs Output Voltage 2µF + 30Ω Load Current vs V PSRR vs Frequency V = 5.0V 2µF + 30Ω 200mV , A ...

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Typical Performance Characteristics PSRR vs Frequency V = 6.1V 2µF + 30Ω 200mV , A ripple pp V-BTL Power Derating Curve - LLP P = 136mW DMAX V = 4.2V 2µF + ...

Page 8

Typical Performance Characteristics Amplifier Frequency Response vs Input Capacitor Size Oscillator Frequency vs Temperature - “X” Feedback Bias Current vs Temperature www.national.com (Continued) 20094102 20094104 20094109 8 Switch Current Limit vs Duty Cycle - “X” 20094103 Feedback Voltage vs Temperature ...

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Typical Performance Characteristics Temperature (Continued) 20094107 20094108 www.national.com ...

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... This plane forms a thermal mass, heat sink, and radiation area. Further detailed and specific information con- cerning PCB layout, fabrication, and mounting an LD (LLP) package is found in National Semiconductor’s Package En- gineering Group under application note AN1187 ...

Page 11

Application Information SHUTDOWN FUNCTION In many applications, a microcontroller or microprocessor output is used to control the shutdown circuitry to provide a quick, smooth transition into shutdown. Another solution is to use a single-pole, single-throw switch, and a pull-up resistor. ...

Page 12

Application Information SETTING THE OUTPUT VOLTAGE (V CONVERTER The output voltage is set using the external resistors R1 and R2 (see Figure 1). A value of approximately 13.3kΩ is rec- ommended for R2 to establish a divider current of approxi- ...

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Application Information CALCULATING OUTPUT CURRENT OF BOOST CONVERTER (I ) AMP As shown in Figure 2 which depicts inductor current, the load current is related to the average inductor current by the relation (AVG ...

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Application Information www.national.com (Continued) FIGURE 3. Demo Board Reference Schematic 14 20094183 ...

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Demonstration Board Layout Composite Layer Top Layer 15 200941A0 200941A1 www.national.com ...

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Demonstration Board Layout www.national.com (Continued) Top Overlay Bottom Layer 16 200941A2 20094199 ...

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... BANNED SUBSTANCE COMPLIANCE National Semiconductor manufactures products and uses packing materials that meet the provisions of the Customer Products Stewardship Specification (CSP-9-111C2) and the Banned Substances and Materials of Interest Specification (CSP-9-111S2) and contain no ‘‘Banned Substances’’ as defined in CSP-9-111S2. ...