LM4991LDX National Semiconductor, LM4991LDX Datasheet - Page 5

• Manufacturer Part Number: LM4991LDX
• Manufacturer: National Semiconductor

Specifications of LM4991LDX

• Operational Class: Class-AB
• Audio Amplifier Output Configuration: 1-Channel Mono
• Output Power (typ): 3x1@3OhmW
• Audio Amplifier Function: Speaker
• Total Harmonic Distortion: 0.2@8Ohm@0.5W%
• Single Supply Voltage (typ): 3/5V
• Dual Supply Voltage (typ): Not RequiredV
• Power Supply Requirement: Single
• Rail/rail I/o Type: No
• Power Supply Rejection Ratio: 64dB
• Single Supply Voltage (min): 2.2V
• Single Supply Voltage (max): 5.5V
• Dual Supply Voltage (min): Not RequiredV
• Dual Supply Voltage (max): Not RequiredV
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 8
• Package Type: LLP EP
• Lead Free Status / Rohs Status: Not Compliant

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