LM4869 Datasheet, PDF (1/20 Pages) National Semiconductor (TI) – 1.9W Differential Input, BTL Output Stereo Audio Amplifier with Selectable Gain and Shutdown

August 2002
LM4869
1.9W Differential Input, BTL Output Stereo Audio
Amplifier with Selectable Gain and Shutdown
General Description
The LM4869 features differential stereo inputs, BTL (bridge-
tied load) outputs, and four externally selectable fixed gains.
Operating on a single 5V supply, the LM4869 delivers 1.2W
and 1.9W (typ) of output power to an 8Ω and 4Ω BTL load
(Note 1), respectively, with less than 1% THD+N. The
LM4869’s gain is selected using two digital inputs. The nomi-
nal gain values are 6dB, 10dB, 15.6dB, and 21.6dB.
The LM4869 is designed for notebook and other handheld
portable applications. It delivers high quality output power
from a surface-mount package and requires few external
components.
Other features include an active-low micropower shutdown
mode input and thermal shutdown protection.
Key Specifications
j BTL output Power
R_L = 4Ω, V_DD = 5.0V, and THD+N = 1%
j BTL output Power
R_L = 8Ω, V_DD = 5.0V, and THD+N = 1%
1.9W (typ)
1.2W (typ)
j Micropower shutdown current
j PSRR (@ 1kHz, V_DD = 5V, (Fig.1))
0.1µA (typ)
62dB (typ)
Features
n Fully differential input and output
n Internal gain set: 6dB, 10dB, 15.6dB, and 21.6dB
n Improved ’click and pop’ suppression
n Thermal shutdown protection circuit
n Ultra low current micropower shutdown mode
n 2.0V to 5.5V operation
n Available in space-saving exposed-DAP TSSOP
package
Applications
n Notebook computers
n PDAs
n Portable electronic devices
Connection Diagram
Top View
20042802
Order Number LM4869MH
See NS Package Number MXA20A for Exposed-DAP TSSOP
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