TLC27M4, TLC27M4A, TLC27M4B, TLC27M4Y, TLC27M9

LinCMOS

™ PRECISION QUAD OPERATIONAL AMPLIFIERS

SLOS093C – OCTOBER 1987 – REVISED MAY 1999

32

POST OFFICE BOX 655303

APPLICATION INFORMATION

noise performance (continued)

VI

(a) NONINVERTING AMPLIFIER

(c) UNITY-GAIN AMPLIFIER

(b) INVERTING AMPLIFIER

VI

VI

VO

VO

VO

Figure 40. Guard-Ring Schemes

output characteristics

The output stage of the TLC27M4 and TLC27M9 is designed to sink and source relatively high amounts of

current (see

typical characteristics). If the output is subjected to a short-circuit condition, this high current

capability can cause device damage under certain conditions. Output current capability increases with supply

voltage.

All operating characteristics of the TLC27M4 and TLC27M9 were measured using a 20-pF load. The devices

drive higher capacitive loads; however, as output load capacitance increases, the resulting response pole

occurs at lower frequencies, thereby causing ringing, peaking, or even oscillation (see Figure 41). In many

cases, adding a small amount of resistance in series with the load capacitance alleviates the problem.

2.5 V

VO

CL

– 2.5 V

VI

(d) TEST CIRCUIT

TA = 25°C

f = 1 kHz

VIPP = 1 V

(a) CL = 20 pF, RL = NO LOAD

(b) CL = 170 pF, RL = NO LOAD

(c) CL = 190 pF, RL = NO LOAD

Figure 41. Effect of Capacitive Loads and Test Circuit