Rainbow Electronics MAX984 - Manual (Page 8)

MAX971–MAX974/MAX981–MAX984
Ultra-Low-Power, Open-Drain,
Single/Dual-Supply Comparators
8 _______________________________________________________________________________________
_______________Detailed Description
The MAX971–MAX974 and MAX981–MAX984 comprise
various combinations of a micropower 1.182V reference
and micropower comparators. The
Typical Operating
Circuit shows the MAX971/MAX981 configuration, and
Figures 1a–1d show the MAX9_2–MAX9_4 configurations.
Internal hysteresis in the MAX9_1, MAX982, and
MAX9_3 provides the easiest method for implementing
hysteresis. It also produces faster hysteresis action and
consumes much less current than circuits using external
positive feedback.
Power-Supply and Input Signal Ranges
This family of devices operates from a single +2.5V to
+11V power supply. The MAX9_1 and MAX9_4 have a
separate ground for the output driver, allowing operation
with dual supplies ranging from ±1.25V to ±5.5V.
Connect V- to GND when operating the MAX9_1 or
MAX9_4 from a single supply. The maximum total
supply voltage in this case is still 11V.
For proper comparator operation, the input signal can
range from the negative supply (V-) to within one volt of
the positive supply (V+ - 1V). The guaranteed
common-mode input voltage range extends from V- to
(V+ - 1.3V). The inputs can be taken above and below
the supply rails by up to 300mV without damage.
OUTA
V-
INA+
INA-
OUTB
V+
INB+
INB-
MAX972
1
2
3
4
8
7
6
5
Figure 1a. MAX972 Functional Diagram
OUTA
V-
INA+
INB-
OUTB
V+
REF
HYST
MAX9_3
1
2
3
4
8
7
6
5
V-
Figure 1c. MAX973/MAX983 Functional Diagram (Window
Comparator)
OUTA
V-
INA+
INB+
OUTB
V+
REF
HYST
MAX982
1
2
3
4
8
7
6
5
V-
Figure 1b. MAX982 Functional Diagram
OUTA
V+
INA-
INA+
OUTD
GND
IND+
IND-
MAX9_4
2
3
4
5
15
14
13
12
16
11
10
9
1
6
7
8
OUTB
INB-
INB+
REF
OUTC
INC+
INC-
V-
Figure 1d. MAX974/MAX984 Functional Diagram