LM8261 datasheet(18/19 Pages) NSC

18 / 19 page

Application Notes: (Continued)

Other Application Hints:

The use of supply decoupling is mandatory in most applica-

tions. As with most relatively high speed/high output current

Op Amps, best results are achieved when each supply line is

decoupled with two capacitors; a small value ceramic ca-

pacitor (

∼0.01µF) placed very close to the supply lead in ad-

dition to a large value Tantalum or Aluminum (> 4.7µF). The

large capacitor can be shared by more than one device if

necessary. The small ceramic capacitor maintains low sup-

ply impedance at high frequencies while the large capacitor

will act as the charge

″bucket″ for fast load current spikes at

the Op Amp output. The combination of these capacitors will

provide supply decoupling and will help keep the Op Amp os-

cillation free under any load.

LM8261 Advantages:

Compared to other Rail-to-Rail Input/Output devices, the

LM8261 offers several advantages such as:

•

Improved cross over distortion.

•

Nearly constant supply current throughout the output

voltage swing range and close to either rail.

•

Consistent stability performance for all input/output volt-

age and current conditions.

•

Nearly constant Unity gain frequency (f

u) and Phase Mar-

gin (Phi

m) for all operating supplies and load conditions.

•

No output phase reversal under input overload condition.

LM8261 Datasheet(PDF) 18 Page - National Semiconductor (TI)