MAX6751KA29+T Maxim Integrated Products, MAX6751KA29+T Datasheet - Page 7
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MAX6751KA29+T
Manufacturer Part Number
MAX6751KA29+T
Description
IC MPU/RESET CIRC SOT23-8
Manufacturer
Maxim Integrated Products
Type
Multi-Voltage Supervisorr
Datasheet
1.MAX6749KAT.pdf
(14 pages)
Specifications of MAX6751KA29+T
Number Of Voltages Monitored
2
Output
Open Drain or Open Collector
Reset
Active Low
Reset Timeout
Adjustable/Selectable
Voltage - Threshold
2.925V, Adj
Operating Temperature
-40°C ~ 125°C
Mounting Type
Surface Mount
Package / Case
SOT-23-8
Monitored Voltage
1.575 V to 5 V
Undervoltage Threshold
2.867 V, Adjustable
Overvoltage Threshold
2.984 V, Adjustable
Output Type
Active Low, Open Drain
Manual Reset
Not Resettable
Watchdog
Watchdog
Battery Backup Switching
No Backup
Supply Voltage (max)
5.5 V
Supply Voltage (min)
1 V
Supply Current (typ)
5 uA
Maximum Power Dissipation
714 mW
Maximum Operating Temperature
+ 125 C
Mounting Style
SMD/SMT
Minimum Operating Temperature
- 40 C
Power Fail Detection
No
Power-up Reset Delay (typ)
9.487 ms
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Other names
MAX6751KA29+TTR
The MAX6746–MAX6753 assert a reset signal whenever
the V
threshold. The reset output remains asserted for the
reset timeout period after V
its respective reset threshold. A watchdog timer triggers
a reset pulse whenever a watchdog fault occurs.
The reset and watchdog delays are adjustable with
external capacitors. The MAX6746–MAX6751 contain a
watchdog select input that extends the watchdog time-
out period to 128x.
The MAX6752 and MAX6753 have a sophisticated
watchdog timer that detects when the processor is run-
ning outside an expected window of operation. The
watchdog signals a fault when the input pulses arrive too
early (faster that the selected t
late (slower than the selected t
Figure 1).
The reset output is typically connected to the reset input
of a µP. A µP’s reset input starts or restarts the µP in a
known state. The MAX6746–MAX6753 µP supervisory
circuits provide the reset logic to prevent code-execu-
tion errors during power-up, power-down, and
brownout conditions (see the Typical Operating Circuit ).
RESET changes from high to low whenever the moni-
tored voltage, RESET IN and/or V
reset threshold voltages. Once V
exceeds its respective reset threshold voltage(s),
RESET remains low for the reset timeout period, then
goes high.
Figure 1. MAX6752/MAX6753 Detailed Watchdog Input Timing Relationship
CC
supply voltage or RESET IN falls below its reset
µP Reset Circuits with Capacitor-Adjustable
_______________________________________________________________________________________
Detailed Description
WDI CONDITION 1
WDI CONDITION 2
WDI CONDITION 3
GUARANTEED
TO ASSERT
CC
RESET
WD1
and RESET IN rise above
WD2
*UNDETERMINED STATES MAY OR MAY NOT GENERATE A FAULT CONDITION
RESET IN
timeout period) or too
timeout period) (see
CC
Reset Output
drop below the
Reset/Watchdog Timeout Delay
t
WD1
*UNDETERMINED
and/or V
(MIN) t
WD1
CC
GUARANTEED TO
(MAX)
NOT ASSERT
RESET
RESET is guaranteed to be in the correct logic state for
V
reset logic when V
Ensuring a Valid RESET Output Down to V
The MAX6748–MAX6751 monitor the voltage on RESET IN
using an adjustable reset threshold (V
an external resistor voltage-divider (Figure 2). Use the
following formula to calculate the externally monitored
voltage (V
t
Figure 2. Calculating the Monitored Threshold Voltage
(V
WD2
CC
*UNDETERMINED
MON_TH
(MIN) t
greater than 1V. For applications requiring valid
R1
R2
V
MON_TH
V
WD2
)
MON_TH
MON_TH
(MAX)
GUARANTEED TO
RESET IN
GND
ASSERT
RESET
):
FAST FAULT
NORMAL OPERATION
SLOW FAULT
MAX6748
MAX6749
MAX6750
MAX6751
= V
CC
RESET IN
is less than 1V, see the section
V
CC
RESET IN Threshold
x (R1 + R2) / R2
V
MON_TH
V
CC
= 1.235 x (R1 + R2) / R2
RESET IN
CC
= 0V.
) set with
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