LM3875TF National Semiconductor, LM3875TF Datasheet - Page 18

• Manufacturer Part Number: LM3875TF
• Description: Audio Power Amplifier IC
• Manufacturer: National Semiconductor

Specifications of LM3875TF

• Amplifier Case Style: TO-220
• No. Of Pins: 11
• Peak Reflow Compatible (260 C): No
• Termination Type: Through Hole
• Supply Voltage Max: 84V
• Leaded Process Compatible: No
• Mounting Type: Through Hole
• Operational Class: Class-AB
• Audio Amplifier Output Configuration: 1-Channel Mono
• Output Power (typ): 56x1@8OhmW
• Audio Amplifier Function: Speaker
• Input Offset Voltage: 10@±35VmV
• Input Bias Current: 1uA
• Total Harmonic Distortion: 0.06@8Ohm@40W%
• Single Supply Voltage (typ): 24/28V
• Dual Supply Voltage (typ): ±12/±15/±18/±24/±28V
• Power Supply Requirement: Single/Dual
• Power Dissipation: 125W
• Unity Gain Bandwidth Product (typ): 8MHz
• Rail/rail I/o Type: No
• Power Supply Rejection Ratio: 120dB
• Single Supply Voltage (min): 20V
• Single Supply Voltage (max): 84V
• Dual Supply Voltage (min): ±10V
• Dual Supply Voltage (max): ±42V
• Operating Temp Range: -20C to 85C
• Operating Temperature Classification: Commercial
• Mounting: Through Hole
• Pin Count: 11 +Tab
• Package Type: TO-220
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

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Definition of Terms
is also an excellent equation to determine the 3 dB point of a
closed-loop gain, assuming that you know the GBWP of the
device. Refer to the diagram below.
Bi-amplification: The technique of splitting the audio fre-
quency spectrum into two sections and using individual
power amplifiers to drive a separate woofer and tweeter.
Crossover frequencies for the amplifiers usually vary be-
tween 500 Hz and 1600 Hz. “Biamping” has the advantages
of allowing smaller power amps to produce a given sound
pressure level and reducing distortion effects produced by
overdrive in one part of the frequency spectrum affecting the
other part.
C.C.I.R./A.R.M.:
Literally: International
Average Responding Meter
Radio
Consultative
(Continued)
Committee
FIGURE 3.
18
This refers to a weighted noise measurement for a Dolby B
type noise reduction system. A filter characteristic is used
that gives a closer correlation of the measurement with the
subjective annoyance of noise to the ear. Measurements
made with this filter cannot necessarily be related to un-
weighted noise measurements by some fixed conversion
factor since the answers obtained will depend on the spec-
trum of the noise source.
S.P.L.: Sound Pressure Level — usually measured with a
microphone/meter combination calibrated to a pressure level
of 0.0002 µBars (approximately the threshold hearing level).
Where P is the R.M.S sound pressure in microbars. (1 Bar =
1 atmosphere = 14.5 lb./in
S.P.L. = 20 Log 10P/0.0002 dB
01144914
2
= 194 dB S.P.L.).