mb3771ps Fujitsu Microelectronics, Inc., mb3771ps Datasheet - Page 9

• Manufacturer Part Number: mb3771ps
• Description: Power Supply Monitor
• Manufacturer: Fujitsu Microelectronics, Inc.

4. 5 V and 12 V Power Supply Monitor (2 types of power supply monitor V
5. 5 V and 12 V Power Supply Monitor (RESET signal is generated by 5 V, V
Detection voltage =
Hysterisis width =
• 5 V is monitored by V
• 12 V is monitored by V
• 5 V is monitored by V
• 12 V is monitored by V
• The detection voltage of 12 V monitoring and its hysterisis is determined by the following equations.
detection voltage is determined by the following equation.
Detection Voltage = (R
V
V
CC2
CC1
(R
R
R
R
R
1
2
V
: 390 k
2
3
V
1
R
+ R
: 33 k
: 30 k
CC2
R
CC1
SA
C
SA
+ R
1
2
T
SC
SB
1
. Detection voltage is about 4.2 V
, and generates RESET signal when VSA detects voltage sagging.
(R
+ R
3
, and generates its detection signal at OUT
. When R
+ R
) (R
2
3
+ R
3
2
)
R
2
3
R
+ R
3
4
V
// R
: 510 k
SB
3
1
1
2
3
4
// R
= 390 k
/R
MB3771
4
V
)
SC
2
4
)
R
8
7
6
5
5
: 100 k
V
and R
SC
C
T
2
= 62 k , Detection voltage is about 9.0 V.Generally the
R
L
R
R
: 10 k
(8.95 V in the circuit above)
1
2
1
2
3
4
: 390 k
: 62 k
(200 mV in the circuit above)
MB3771
8
7
6
5
C
.
RESET
circuit
Logic
IRQ
RESET
Port Logic Circuit
CC1
CC1
= 5 V, V
or
= 5 V, V
MB3771
CC2
CC2
=12 V)
= 12 V)
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