LT6703-2/LT6703-3

LT6703HV-2/LT6703HV-3

10

670323fd

The LT6703-2/LT6703-3/LT6703HV-2/LT6703HV-3 devices

are micropower comparators with a built-in 400mV refer-

ence. Features include wide supply voltage range (1.4V to

18V), Over-The-Top input and output range, 2% accurate

rising input threshold voltage and 6.5mV typical built-in

hysteresis.

TYPICAL PERFORMANCE CHARACTERISTICS

Internal Reference

Each comparator has one input available externally. The two

versions of the part differ by the polarity of the available

input (i.e., inverting or noninverting). The other comparator

input is connected internally to the 400mV reference. The

rising input threshold voltage of the comparator is designed

to be equal to that of the reference (i.e., ≈400mV). The

reference voltage is established with respect to the device

GND connection.

Hysteresis

Each comparator has built-in 6.5mV (typical) of hysteresis

to simplify designs, to insure stable operation in the pres-

ence of noise at the inputs, and to reject supply rail noise

that might be induced by state change load transients. The

hysteresis is designed such that the falling input threshold

voltage is nominally 393.5mV. External positive feedback

circuitry can be employed to increase effective hysteresis

if desired, but such circuitry will provide an apparent effect

on both the rising and falling input thresholds (the actual

internal thresholds remain unaffected).

Figure 1. Additional Hysteresis Circuit

APPLICATIONS INFORMATION

Propagation Delay

vs Input Overdrive

Rise and Fall Times

vs Output Pull-Up Resistor

Noninverting and Inverting

Comparator Propagation Delay

INPUT OVERDRIVE (mV)

0

30

40

50

60

80

670323 G25

20

10

0

20

40

60

100

LH NONINV

HL NONINV

LH INV

HL INV

OUTPUT PULL-UP RESISTOR (kΩ)

0.1

0.01

1

100

1

10

100

1000

670323 G26

0.1

10

RISE

FALL

670323 G27

VOLTAGE THRESHOLDS

5V/DIV

DC

5V/DIV

DC

10mV/DIV

AC

20μs/DIV

THRESHOLD EQUATIONS:

670323 F01

R4

OUT

+IN

GND

LT6703-3

R3

R2

R1

+

+

1

R1

1

R2

1

R3

+

+

–

1

R1

1

R2

1

R3 + R4

R3 + R4