Datasheet

  
   
SLOS018H − MAY 1988 − REVISED NOVEMBER 2004
19
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
APPLICATION INFORMATION
comparator applications
The single-supply operation of the LT1013 is well suited for use as a precision comparator with TTL-compatible
output. In systems using both operational amplifiers and comparators, the LT1013 can perform multiple duties
(see Figures 25 and 26).
VO − Output Voltage − V
V
O
100 mV
V
CC+
= 5 V
V
CC−
= 0
T
A
= 25°C
Overdrive
10 mV
5 mV
2 mV
0 50 100 150 200 250 300 350 400 450
5
4
3
2
1
0
Differential
Input Voltage
t − Time − µs
Figure 25. Low-to-High-Level Output
Response for Various Input Overdrives
VO − Output Voltage − V
V
O
2 mV
5 mV
Overdrive
10 mV
0 50 100 150 200 250 300 350 400 450
5
4
3
2
1
0
Differential
Input Voltage
t − Time − µs
V
CC+
= 5 V
V
CC−
= 0
T
A
= 25°C
100 mV
Figure 26. High-to-Low-Level Output
Response for Various Input Overdrives
low-supply operation
The minimum supply voltage for proper operation of the LT1013 is 3.4 V (three NiCad batteries). Typical supply
current at this voltage is 290 µA; therefore, power dissipation is only 1 mW per amplifier.
offset voltage and noise testing
The test circuit for measuring input offset voltage and its temperature coefficient is shown in Figure 30. This
circuit, with supply voltages increased to ±20 V, also is used as the burn-in configuration.
The peak-to-peak equivalent input noise voltage of the LT1013 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.
Current noise is measured by the circuit and formula shown in Figure 28. The noise of the source resistors is
subtracted.