MC14578P Freescale Semiconductor, MC14578P Datasheet - Page 4

• Manufacturer Part Number: MC14578P
• Description: IC SMOKE COMPARATOR MPWR 16-DIP
• Manufacturer: Freescale Semiconductor

Specifications of MC14578P

• Applications: *
• Mounting Type: Through Hole
• Package / Case: 16-DIP (0.300", 7.62mm)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

4
of
on the signal labelled OUTPUT. In some cases, the oscillation
in the transition region will not cause problems. For example,
an MPU reading OUTPUT could sample the signal two or
three times to ensure a solid level is attained. But, in a low
battery detector, this probably is not necessary.
as shown in
more operating current than the
MC14578
Low-battery
Indicator
Figure 3.
Near the switchpoint, the comparator output in the circuit
To eliminate comparator chatter, hysteresis can be added
may chatter or oscillate. This oscillation appears
Figure
NOTE: IN + and IN – have very high input impedance. Interconnect to these pins should be as short as possible.
4.. The circuit of
EXAMPLE VALUES
6.8 k
D2
R5
Archived by Freescale Semiconductor, Inc., 2009
V +
Figure 3.
Figure 4.
1
2
3
4
5
6
7
8
arrangement.
V
COMP OUT
IN A
IN B
OUT A
OUT B
IN C
OUT C1
requires slightly
DD
APPLICATIONS INFORMATION
Figure 3. Low-Battery Detector
MC14578
BUFF OUT
OUT C2
R
IN +
IN –
BIAS
V
NC
NC
SS
16
10
12
15
13
11
14
9
1.2 MΩ
470 kΩ
820 kΩ
R1
3.9 M
V +
R4
R1
R2
Figure 4. Adding Hysteresis
1.3 MΩ
1.2 MΩ
1.2 MΩ
12
V +
R2
R6
OUTPUT
15
20 kΩ
39 kΩ
62 kΩ
R3
R3
D1
R7
Freescale Semiconductor
High = Battery Low
Low = Battery Ok
Nominal Tip Point
2
4.08 V
5.05 V
6.00 V
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