LM4802B Datasheet, PDF (1/17 Pages) National Semiconductor (TI) – Audio Power Amplifier with Boost Converter to Drive Ceramic Speakers

November 2004
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.
Key Specifications
j Quiescent Power Supply Current
j BTL Voltage Swing
(2µF + 30Ω load, 1% THD+N,
V_DD = 3V)
j Shutdown Current
12mA (typ)
12Vp-p (typ)
2µA (max)
Features
n Pop & click circuitry eliminates noise during turn-on and
turn-off transitions
n Low, 2µA (max) shutdown current
n Low, 12mA (typ) quiescent current
n 12Vp-p mono BTL output, load = 2µF + 30Ω, V_DD = 3V
n Short circuit protection
n Unity-gain stable
n External gain configuration capability
Applications
n Cellphone
n PDA
Connection Diagram
LM4802BLQ (5x5)
Top View
Order Number LM4802BLQ
See NS Package Number 2LQAQ028
20094184
Boomer^® is a registered trademark of National Semiconductor Corporation.
© 2004 National Semiconductor Corporation DS200941
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