lm4905 National Semiconductor Corporation, lm4905 Datasheet - Page 5

• Manufacturer Part Number: lm4905
• Description: 1 Watt Audio Power Amplifier
• Manufacturer: National Semiconductor Corporation

External Components Description
Typical Performance Characteristics
Components
(Figure 1)
1.
2.
3.
4.
5.
at V
at V
C
C
R
C
R
S
B
i
i
f
DD
DD
= 2.6V, 8Ω R
= 5V, 8Ω R
Inverting input resistance which sets the closed-loop gain in conjunction with R
high pass filter with C
Input coupling capacitor which blocks the DC voltage at the amplifiers input terminals. Also creates a
highpass filter with R
for an explanation of how to determine the value of C
Feedback resistance which sets the closed-loop gain in conjunction with R
Supply bypass capacitor which provides power supply filtering. Refer to the Power Supply Bypassing
section for information concerning proper placement and selection of the supply bypass capacitor.
Bypass pin capacitor which provides half-supply filtering. Refer to the section, Proper Selection of External
Components, for information concerning proper placement and selection of C
THD+N vs Frequency
THD+N vs Frequency
L
L
, and PWR = 500mW
, and PWR = 150mW
i
i
at f
at f
c
C
= 1/(2π R
= 1/(2π R
20050830
20050832
i
i
C
C
i
i
). Refer to the section, Proper Selection of External Components,
).
Functional Description
5
i
.
at V
DD
= 3V, 8Ω R
at V
THD+N vs Frequency
THD+N vs Power Out
DD
= 5V, 8Ω R
i
.
L
, and PWR = 250mW
B
f
. This resistor also forms a
.
L
, 1kHz
20050834
20050831
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