LM4892MMX National Semiconductor, LM4892MMX Datasheet - Page 13

• Manufacturer Part Number: LM4892MMX
• Manufacturer: National Semiconductor

Specifications of LM4892MMX

• Operational Class: Class-AB
• Audio Amplifier Output Configuration: 1-Channel Mono
• Audio Amplifier Function: Headphone/Speaker
• Total Harmonic Distortion: 0.1@8Ohm@0.4W%
• 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: 66dB
• 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: MSOP
• Lead Free Status / Rohs Status: Not Compliant

Application Information
The LM4892 is unity-gain stable and requires no external
components besides gain-setting resistors, an input coupling
capacitor, and proper supply bypassing in the typical appli-
cation. However, if a closed-loop differential gain of greater
than 10 is required, a feedback capacitor (C
needed as shown in Figure 3 to bandwidth limit the amplifier.
This feedback capacitor creates a low pass filter that elimi-
(Continued)
FIGURE 3. Higher Gain Audio Amplifier
f
) may be
13
nates possible high frequency oscillations. Care should be
taken when calculating the -3dB frequency in that an incor-
rect combination of R
A typical combination of feedback resistor and capacitor that
will not produce audio band high frequency rolloff is R
20kΩ and C
point of approximately 320 kHz.
f
= 25pF. These components result in a -3dB
f
and C
f
will cause rolloff before 20kHz.
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f
=