LM4879SDBD National Semiconductor, LM4879SDBD Datasheet - Page 14

• Manufacturer Part Number: LM4879SDBD
• Description: BOARD EVALUATION LM4879SD
• Manufacturer: National Semiconductor
• Series: Boomer®r

Specifications of LM4879SDBD

• Amplifier Type: Class AB
• Output Type: 1-Channel (Mono)
• Max Output Power X Channels @ Load: 1.1W x 1 @ 8 Ohm
• Voltage - Supply: 2.2 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Board Type: Fully Populated
• Utilized Ic / Part: LM4879
• Lead Free Status / RoHS Status: Not applicable / Not applicable

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Application Information
The LM4879 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 (C4) may be
needed as shown in Figure 2 to bandwidth limit the amplifier.
This feedback capacitor creates a low pass filter that elimi-
FIGURE 2. HIGHER GAIN AUDIO AMPLIFIER
(Continued)
14
nates possible high frequency oscillations. Care should be
taken when calculating the -3dB frequency in that an incor-
rect combination of R
20kHz. A typical combination of feedback resistor and ca-
pacitor that will not produce audio band high frequency rolloff
is R
-3dB point of approximately 320 kHz.
3
= 20kΩ and C
4
= 25pf. These components result in a
3
and C
20024388
4
will cause rolloff before