LM4861 datasheet(4/8 Pages) NSC

4 / 8 page

External Components Description (Figures 1, 2)

Components

Functional Description

1. R

Inverting input resistance which sets the closed-loop gain in conjunction with R

f. This resistor also forms a

high pass filter with C

i at fC = 1/(2π Ri Ci).

2. C

Input coupling capacitor which blocks DC voltage at the amplifier’s input terminals. Also creates a highpass

filter with R

i at fC = 1/(2π Ri Ci).

3. R

Feedback resistance which sets closed-loop gain in conjunction with R

4. C

Supply bypass capacitor which provides power supply filtering. Refer to the Application Information

section for proper placement and selection of supply bypass capacitor.

5. C

Bypass pin capacitor which provides half supply filtering. Refer to the Application Information section for

proper placement and selection of bypass capacitor.

6. C

f (Note 9)

f in conjunction with Rf creates a low-pass filter which bandwidth limits the amplifier and prevents possible

high frequency oscillation bursts.

C = 1/(2π Rf Cf)

Note 9: Optional component dependent upon specific design requirements. Refer to the Application Information section for more information.

Typical Performance Characteristics

THD+N vs Frequency

DS011986-5

THD+N vs Frequency

DS011986-6

THD+N vs Frequency

DS011986-7

THD+N vs Output Power

DS011986-8

THD+N vs Output Power

DS011986-9

THD+N vs Output Power

DS011986-10

LM4861 Datasheet(PDF) 4 Page - National Semiconductor (TI)