MAX900–MAX903
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
VOUT8
MAX901
VOUT1
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.