The differential voltage at the input of the op amp should not
exceed the specified absolute maximum ratings. For real
comparators that are much faster, we recommend you to use
National’s LMV331/393/339, which are single, dual and quad
general purpose comparators for low voltage operation.
Application Notes (Continued)
4.9 COMPARATOR WITH HYSTERESIS
The LMV321/358/324 can be used as a low power compara-
tor. Figure 24 shows a comparator with hysteresis. The
hysteresis is determined by the ratio of the two resistors.
VTH+ = VREF/(1+R 1/R2)+VOH/(1+R2/R1)
VTH− = VREF/(1+R 1/R2)+VOL/(1+R2/R1)
VH = (VOH−VOL)/(1+R 2/R1)
where
VTH+: Positive Threshold Voltage
VTH−: Negative Threshold Voltage
VOH: Output Voltage at High
V
OL: Output Voltage at Low
10006078
VH: Hysteresis Voltage
FIGURE 24. Comparator with Hysteresis
Since LMV321/358/324 have rail-to-rail output, the
(VOH−VOL) equals to VS, which is the supply voltage.
VH = VS/(1+R2/R 1)
Connection Diagrams
5-Pin SC70-5/SOT23-5
8-Pin SO/MSOP
14-Pin SO/TSSOP
10006001
Top View
10006002
Top View
10006003
Top View
Ordering Information
Temperature Range
Package
5-Pin SC70-5
Industrial
−40˚C to +85˚C
LMV321M7
LMV321M7X
LMV321M5
LMV321M5X
LMV358M
Packaging Marking
Transport Media
NSC Drawing
MAA05
A12
A12
1k Units Tape and Reel
3k Units Tape and Reel
1k Units Tape and Reel
3k Units Tape and Reel
Rails
5-Pin SOT23-5
8-Pin Small Outline
8-Pin MSOP
A13
MA05B
A13
LMV358M
LMV358M
LMV358
LMV358
LMV324M
LMV324M
LMV324MT
LMV324MT
M08A
MUA08A
M14A
LMV358MX
LMV358MM
LMV358MMX
LMV324M
2.5k Units Tape and Reel
1k Units Tape and Reel
3.5k Units Tape and Reel
Rails
14-Pin Small Outline
14-Pin TSSOP
LMV324MX
LMV324MT
LMV324MTX
2.5k Units Tape and Reel
Rails
MTC14
2.5k Units Tape and Reel
21
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