LM4889MA/NOPB National Semiconductor, LM4889MA/NOPB Datasheet - Page 11

• Manufacturer Part Number: LM4889MA/NOPB
• Description: IC AMP AUDIO PWR 1W MONO 8SOIC
• Manufacturer: National Semiconductor
• Series: Boomer®r
• Type: Class ABr

Specifications of LM4889MA/NOPB

• Output Type: 1-Channel (Mono)
• Max Output Power X Channels @ Load: 1W x 1 @ 8 Ohm
• Voltage - Supply: 2.2 V ~ 5.5 V
• Features: Depop, Shutdown, Thermal Protection
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Amplifier Class: AB
• No. Of Channels: 1
• Output Power: 1W
• Supply Voltage Range: 2.2V To 5.5V
• Load Impedance: 8ohm
• Operating Temperature Range: -40°C To +85°C
• Amplifier Case Style: SOIC
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: *LM4889MA; *LM4889MA/NOPB; LM4889MA; LM4889MANOPB; LM4889MANOPB

The LM4889 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 eliminates
FIGURE 2. Higher Gain Audio Amplifier
11
possible high frequency oscillations. Care should be taken
when calculating the -3dB frequency in that an incorrect com-
bination of R
combination of feedback resistor and capacitor that will not
produce audio band high frequency rolloff is R
C
proximately 320kHz.
4
= 25pf. These components result in a -3dB point of ap-
3
and C
4
will cause rolloff before 20kHz. A typical
20035824
3
= 20kΩ and
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