LM4961 Datasheet, PDF (1/16 Pages) National Semiconductor (TI) – Ceramic Speaker Driver

October 2004
LM4961
Ceramic Speaker Driver
General Description
The LM4961 is an audio power amplifier primarily designed
for driving Ceramic Speaker for applications in Cell Phone
and PDAs. It integrates a boost converter, with variable
output voltage, with an audio power amplifier. It is capable of
driving 15V_p-p in BTL mode to 2uF+ 30 ohms load, continu-
ous average power, with less than 1% distortion (THD+N)
from a 3.2V_DC power supply.
Boomer audio power amplifiers were designed specifically to
provide high quality output power with a minimal number of
external components. The LM4961 does not require boot-
strap capacitors, or snubber circuits therefore it is ideally
suited for portable applications requiring high voltage output
to drive capacitive loads like Ceramic Speakers. The
LM4961 features a low-power consumption shutdown mode.
Additionally, the LM4961 features an internal thermal shut-
down protection mechanism.
The LM4961 contains advanced pop & click circuitry that
eliminates noises which would otherwise occur during
turn-on and turn-off transitions.
The LM4961 is unity-gain stable and can be configured by
external gain-setting resistors.
Key Specifications
n Quiescent Power Supply Current
n Voltage Swing in BTL at 1% THD
n Shutdown current
7mA (typ)
15Vp-p (typ)
0.1µA (typ)
Features
n Pop & click circuitry eliminates noise during turn-on and
turn-off transitions
n Low current shutdown mode
n Low quiescent current
n Mono 15Vp-p BTL output, R_L = 2µF+30Ω, f = 1kHz
n Thermal shutdown protection
n Unity-gain stable
n External gain configuration capability
n Including Band exchange SW
n Including Leakage cut SW
Applications
n Cellphone
n PDA
Connection Diagram
LM4961LQ (5x5)
Top View
Order Number LM4XXX
See NS Package Number
20094084
Boomer^® is a registered trademark of National Semiconductor Corporation.
© 2004 National Semiconductor Corporation DS200940
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