TLV2760, TLV2761, TLV2762, TLV2763, TLV2764, TLV2765

FAMILY OF 1.8 V MICROPOWER RAIL-TO-RAIL INPUT/OUTPUT

OPERATIONAL AMPLIFIERS WITH SHUT DOWN

SLOS326D – JUNE 2000 – REVISED FEBRUARY 2001

15

POST OFFICE BOX 655303

APPLICATION INFORMATION

general configurations (continued)

VI

VO

C1

+

–

RG

RF

R1

f

–3dB +

1

2

pR1C1

V

O

V

I

+ 1 )

R

F

R

G

1

1

) sR1C1

VDD/2

Figure 33. Single-Pole Low-Pass Filter

If even more attenuation is needed, a multiple pole filter is required. The Sallen-Key filter can be used for this

task. For best results, the amplifier should have a bandwidth that is 8 to 10 times the filter frequency bandwidth.

Failure to do this can result in phase shift of the amplifier.

VI

C2

R2

R1

C1

RF

RG

R1 = R2 = R

C1 = C2 = C

Q = Peaking Factor

(Butterworth Q = 0.707)

(

=

1

Q

2 –

)

RG

RF

_

+

f

–3dB +

1

2

pRC

VDD/2

Figure 34. 2-Pole Low-Pass Sallen-Key Filter

circuit layout considerations

To achieve the levels of high performance of the TLV276x, follow proper printed-circuit board design techniques.

A general set of guidelines is given in the following.

components with a low inductive ground connection. However, in the areas of the amplifier inputs and

output, the ground plane can be removed to minimize the stray capacitance.

capacitor on each supply terminal. It may be possible to share the tantalum among several amplifiers

depending on the application, but a 0.1-

µF ceramic capacitor should always be used on the supply terminal

of every amplifier. In addition, the 0.1-

µF capacitor should be placed as close as possible to the supply

terminal. As this distance increases, the inductance in the connecting trace makes the capacitor less

effective. The designer should strive for distances of less than 0.1 inches between the device power

terminals and the ceramic capacitors.