TLV2711, TLV2711Y

Advanced LinCMOS

™ RAIL-TO-RAIL

MICROPOWER SINGLE OPERATIONAL AMPLIFIERS

SLOS196 – AUGUST 1997

24

POST OFFICE BOX 655303

TYPICAL CHARACTERISTICS

UNITY-GAIN BANDWIDTH

vs

LOAD CAPACITANCE

CL – Load Capacitance – pF

60

10

40

0

80

50

70

20

30

101

10 2

10 3

10 4

10 5

TA = 25°C

10 6

Figure 52

APPLICATION INFORMATION

driving large capacitive loads

The TLV2711 is designed to drive larger capacitive loads than most CMOS operational amplifiers. Figure 50

and Figure 51 illustrate its ability to drive loads up to 600 pF while maintaining good gain and phase margins

when driving large capacitive loads. Figure 50 and Figure 51 show the effects of adding series resistances of

500

Ω and 1000 Ω. The addition of this series resistor has two effects: the first is that it adds a zero to the transfer

function and the second is that it reduces the frequency of the pole associated with the output load in the transfer

function.

The zero introduced to the transfer function is equal to the series resistance times the load capacitance. To

calculate the improvement in phase margin, equation 1 can be used.

∆φ

–1

2

null ×

C

L

∆φ

UGBW

+ unity-gain bandwidth frequency

R

C

(1)

where :