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PRELIMINARY INFORMATION
describes products that are not in full production at the time of printing. Specifications are based on design goals
and limited characterization. They may change without notice. Contact Fairchild Semiconductor for current information.
P
www.fairchildsemi.com
Features
Low VOS, typically 2mV
THD 0.3% typically at 0.5W output power
Drives 8
W
and 4
W
non-powered speakers
User programmable gain
Internal thermal limiting circuitry
8 pin SOIC package
Applications
Multimedia PC motherboards and add-in sound cards
Companion chip to sigma-delta sound codecs
Low power portable systems
Toys and games
Cellular phones
Description
The RC4861 sound driver is an audio device that can be
used on PC motherboards and add-in sound cards. It consists
of H-bridge connected output drivers for headphones or
speakers.
The output drivers can deliver up to 0.5 Watt of continuous
average output power into 8
W
speaker from a 5V source.
The drivers use class AB amplifiers and maintain a low bias
current. A shut down function disables the device for power
savings when not in use.
The thermal limiting circuitry becomes active if the chip
temperature exceeds 150
°
C.
RC4861
1/2W Audio Power Amplifier with S hutdown
Block Diagram
65-4861-01
40 k
Av=-1
+
40 k
50 k
50 k
V
DD
V
DD
/2
Bypass
Shutdown
Bias
Vo1
Vo2
4
6
5
8
7
GND
–
–
+
3
–IN
+IN
2
1
Rev. 0.9.3