LM4892M/NOPB National Semiconductor, LM4892M/NOPB Datasheet - Page 13

• Manufacturer Part Number: LM4892M/NOPB
• Description: IC AMP AUDIO PWR 1W MONO 8SOIC
• Manufacturer: National Semiconductor
• Series: Boomer®r
• Type: Class ABr

Specifications of LM4892M/NOPB

• Output Type: 1-Channel (Mono) with Mono Headphones
• Max Output Power X Channels @ Load: 1W x 1 @ 8 Ohm; 90mW x 1 @ 32 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)
• For Use With: LM4892MBD - BOARD EVALUATION LM4892M
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: *LM4892M; *LM4892M/NOPB; LM4892M

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.
20012724
www.national.com
f
=