LM4982 datasheet(17/21 Pages) NSC

Part #	LM4982

Description	Ground-Referenced, Ultra Low Noise, 80mW Stereo Headphone Amplifier with IntelliSense and I2C Volume

PDF	21 Pages

Scroll/Zoom	100%

Manufacturer	NSC [National Semiconductor (TI)]

Direct Link	http://www.national.com

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17 / 21 page

Application Information (Continued)

Thus, pops can be minimized by selecting an input capacitor

value that is no higher than necessary to meet the desired

−3dB frequency.

As shown in Figure 1, the internal input resistor, R

i and the

input capacitor, C

i, produce a -3dB high pass filter cutoff

frequency that is found using Equation (3). Conventional

headphone amplifiers require output capacitors; Equation (3)

can be used, along with the value of R

L, to determine to-

wards the value of output capacitor needed to produce a

–3dB high pass filter cutoff frequency.

i-3dB =1/2

πR

iCi

(3)

Also, careful consideration must be taken in selecting a

certain type of capacitor to be used in the system. Different

types of capacitors (tantalum, electrolytic, ceramic) have

unique performance characteristics and may affect overall

system performance. (See the section entitled Charge Pump

Capacitor Selection.)

LM4982 Datasheet(PDF) 17 Page - National Semiconductor (TI)