TLC27L2, TLC27L2A, TLC27L2B, TLC27L7

LinCMOS

™ PRECISION DUAL OPERATIONAL AMPLIFIERS

SLOS052B – OCTOBER 1987 – REVISED AUGUST 1994

28

POST OFFICE BOX 655303

APPLICATION INFORMATION

output characteristics (continued)

(b) CL = 260 pF, RL = NO LOAD

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

VI

– 2.5 V

CL

VO

2.5 V

TA = 25°C

f = 1 kHz

VI(PP) = 1 V

(d) TEST CIRCUIT

(c) CL = 310 pF, RL = NO LOAD

Figure 41. Effect of Capacitive Loads and Test Circuit

Although the TLC27L2 and TLC27L7 possess excellent high-level output voltage and current capability,

methods for boosting this capability are available, if needed. The simplest method involves the use of a pullup

to the use of this circuit. First, the NMOS pulldown transistor N4 (see equivalent schematic) must sink a

comparatively large amount of current. In this circuit, N4 behaves like a linear resistor with an on-resistance

between approximately 60

Ω and 180 Ω, depending on how hard the operational amplifier input is driven. With

drain load to N4 and the gain of the operational amplifier is reduced at output voltage levels where N5 is not

supplying the output current.