LT1014, LT1014A, LT1014D

QUAD PRECISION OPERATIONAL AMPLIFIERS

SLOS039D − JULY 1989 − REVISED AUGUST 2009

19

POST OFFICE BOX 655303

APPLICATION INFORMATION

comparator applications

The single-supply operation of the LT1014 can be used as a precision comparator with TTL-compatible output.

In systems using both operational amplifiers and comparators, the LT1014 can perform multiple duties (see

Figures 25 and 26).

Figure 25. Low-to-High-Level Output Response

for Various Input Overdrives

100 mV

10 mV

5 mV

2 mV

t − Time −

µs

Overdrive

5

4

3

2

1

0

0

50

100 150 200 250 300 350 400 450

Figure 26. High-to-Low-Level Output Response

for Various Input Overdrives

2 mV

5 mV

100 mV

Overdrive

10 mV

t − Time −

µs

5

4

3

2

1

0

0

50

100 150 200 250 300 350 400 450

low-supply operation

The minimum supply voltage for proper operation of the LT1014 is 3.4 V (three Ni-Cad batteries). Typical supply

current at this voltage is 290

µA; therefore, power dissipation is only 1 mW per amplifier.

offset voltage and noise testing

Figure 30 shows the test circuit for measuring input offset voltage and its temperature coefficient. This circuit

with supply voltages increased to

±20 V is also used as the burn-in configuration.

The peak-to-peak equivalent input noise voltage of the LT1014 is measured using the test circuit shown in

Figure 27. The frequency response of the noise tester indicates that the 0.1-Hz corner is defined by only one

zero. The test time to measure 0.1-Hz to 10-Hz noise should not exceed 10 seconds, as this time limit acts as

an additional zero to eliminate noise contribution from the frequency band below 0.1 Hz.

An input noise-voltage test is recommended when measuring the noise of a large number of units. A 10-Hz input

noise-voltage measurement correlates well with a 0.1-Hz peak-to-peak noise reading because both results are

determined by the white noise and the location of the 1/f corner frequency.

Noise current is measured by the circuit and formula shown in Figure 28. The noise of the source resistors is

subtracted.