High-Speed, Low-Power Voltage Comparators

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11

OUTPUT

1V/div

INPUT

10mV/div

5ns/div

Figure 6. Response to 50MHz Sine Wave

MX7228

IN1

UNDER

LIMIT

IN2

IN3

IN4

IN5

IN6

IN8

IN7

OVER

LIMIT

UNDER

LIMIT

UNDER

LIMIT

UNDER

LIMIT

UNDER

LIMIT

OVER

LIMIT

OVER

LIMIT

VDAC8

VDAC1

OCTAL

8-BIT

DAC

8 x 8

DATA

LATCH

CONTROL

LOGIC

A0

A1

A2

MSB

D7

8-BIT

DATA

INPUT

LSB

D1

VREF

+1.25V

MAX901

MAX901

Figure 8. Alarm Circuit Level Monitors Eight Separate Inputs

OUTPUT

1V/div

INPUT

10mV/div

5ns/div

Figure 7. Response to 100MHz Sine Wave Photo

Typical Application

Programmed, Variable-Alarm Limits

By combining two quad analog comparators with an

octal 8-bit D/A converter (the MX7228), several alarm

and limit-defect functions can be performed simultane-

ously without external adjustments

The MX7228’s internal latches allow the system

processor to set the limit points for each comparator

independently and update them at any time. Set the

upper and lower thresholds for a single transducer by

pairing the D/A converter and comparator sections.