MAX6344LUT+T Maxim Integrated Products, MAX6344LUT+T Datasheet - Page 7

• Manufacturer Part Number: MAX6344LUT+T
• Description: IC RESET MPU W/COMP SOT23-6
• Manufacturer: Maxim Integrated Products
• Type: Simple Reset/Power-On Resetr

Specifications of MAX6344LUT+T

• Number Of Voltages Monitored: 1
• Output: Push-Pull, Totem Pole
• Reset: Active High
• Reset Timeout: 100 ms Minimum
• Voltage - Threshold: 4.63V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: SOT-23-6
• Undervoltage Threshold: 4.56 V
• Overvoltage Threshold: 4.7 V
• Output Type: Active High, Push-Pull
• Manual Reset: Resettable
• Watchdog: No Watchdog
• Battery Backup Switching: No Backup
• Power-up Reset Delay (typ): 360 ms
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 1 V
• Supply Current (typ): 30 uA
• Maximum Power Dissipation: 320 mW
• Maximum Operating Temperature: + 125 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Power Fail Detection: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Figure 7. Monitoring Two Supplies
Figure 8. Monitoring a Negative Voltage
Note that this method does not work with the open-drain
output of the MAX6343. The resistor value used is not
critical, but it must be large enough not to load the reset
output when V
applications, 100kΩ is adequate.
Monitor another voltage by connecting a resistor-divider
to PFI as shown in Figure 7. The threshold voltage will
then be given by:
where V
voltage will trip PFO.
A good rule of thumb for selecting the resistors is to
choose R2 between 250kΩ and 500kΩ and solve for R1.
Connect PFO to MR in applications that require reset to
assert when the second voltage falls below its threshold.
( ) ARE FOR MAX6344 ONLY.
( ) ARE FOR MAX6344 ONLY.
TH(PFI)
V
V-
TH(PFI)
V+
R1
R2
CC
R1
V
R2
CC
is the threshold at which the monitored
V
CC
is above the reset threshold. For most
_______________________________________________________________________________________
= 1.25[(R1 + R2) / R2]
PFI
V
PFI
CC
GND
MAX6342
MAX6343
MAX6344
Monitoring Two Supplies
MAX6342
MAX6343
MAX6344
V
CC
GND
(RESET)
(RESET)
RESET
RESET
V
PFO
CC
MR
PFO
MR
- 1.25V = 1.25V - V
R1
100kΩ
V
TRIP
100kΩ
< 0
TO µP
R2
TRIP
6-Pin µP Reset Circuit with
Power-Fail Comparator
Connect the circuit as shown in Figure 8 to use the
power-fail comparator to monitor a negative supply rail.
PFO stays low when V- is good. When V- rises to cause
PFI to be above +1.25V, PFO goes high. By adding the
resistors and transistor as shown, a high PFO triggers
reset. As long as PFO remains high, the MAX6342/
MAX6343/MAX6344 will keep reset asserted. Note that
the accuracy of this circuit depends on the PFI thresh-
old tolerance, the V
Also, ensure that the voltage at PFI remains above
GND.
Figure 9. Interfacing to µPs with Bidirectional Reset I/O
MAX6342LUT-T
MAX6342MUT-T
MAX6342TUT-T
MAX6342SUT-T
MAX6342RUT-T
MAX6342ZUT-T
MAX6343LUT-T
MAX6343MUT-T
MAX6343TUT-T
MAX6343SUT-T
MAX6343RUT-T
MAX6343ZUT-T
PART
MAX6342
MAX6345
GND
V
CC
RESET
Monitoring a Negative Voltage
SOT TOP
MARK
AACW
AACQ
CC
AACP
AACR
AACS
AACU
AACV
AACX
AACY
AACZ
AADA
AACT
4.7kΩ
line voltage, and the resistors.
Bidirectional Reset Pins
Interfacing to µPs with
MAX6344LUT-T
MAX6344MUT-T
MAX6344TUT-T
MAX6344SUT-T
MAX6344RUT-T
MAX6344ZUT-T
MAX6345LUT-T
MAX6345MUT-T
MAX6345TUT-T
MAX6345SUT-T
MAX6345RUT-T
MAX6345ZUT-T
SOT Top Marks
RESET
PART
BUFFERED RESET TO
OTHER SYSTEM
COMPONENTS
GND
V
µP
CC
SOT TOP
MARK
AADW
AADQ
AADU
AADR
AADS
AADT
AADV
AADX
AADY
AADZ
AAEA
AAEB
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