MAX6712MEXS-T10 Maxim Integrated, MAX6712MEXS-T10 Datasheet - Page 6

• Manufacturer Part Number: MAX6712MEXS-T10
• Description: Supervisory Circuits
• Manufacturer: Maxim Integrated
• Series: MAX6711, MAX6711L, MAX6711M, MAX6711R, MAX6711S, MAX6711T, MAX6711Z, MAX6712, MAX6712L, MAX6712M, MAX6712R, MAX6712S, MAX6712T, MAX6712Z, MAX6713, MAX6713L, MAX6713M, MAX6713R, MAX6713S, MAX6713T, MAX6713Zr

Specifications of MAX6712MEXS-T10

• Number Of Voltages Monitored: 1
• Monitored Voltage: 2.5 V, 3 V, 3.3 V, 5 V
• Undervoltage Threshold: 4.31 V
• Overvoltage Threshold: 4.45 V
• Output Type: Active High, Push-Pull
• Manual Reset: Resettable
• Watchdog: No Watchdog
• Battery Backup Switching: No Backup
• Power-up Reset Delay (typ): 640 ms
• Supply Voltage - Max: 5.5 V
• Maximum Operating Temperature: + 125 C
• Mounting Style: SMD/SMT
• Package / Case: SC-70
• Chip Enable Signals: No
• Maximum Power Dissipation: 245 mW
• Minimum Operating Temperature: - 40 C
• Power Fail Detection: No
• Supply Current (typ): 16 uA
• Supply Voltage - Min: 1.2 V

maximum allowable pulse width decreases. Typically, for
the MAX671_L and MAX671_M, a V
goes 100mV below the reset threshold and lasts 20µs or
less will not cause a reset pulse. A 0.1µF bypass capaci-
tor mounted as close as possible to the V
additional transient immunity.
When V
no longer sinks current—it becomes an open circuit.
Therefore, high-impedance CMOS-logic inputs con-
nected to RESET can drift to undetermined voltages.
This presents no problem in most applications since
most µP and other circuitry is inoperative with V
below 1V. However, in applications where RESET must
be valid down to 0, adding a pull-down resistor to
RESET causes any stray leakage currents to flow to
ground, holding RESET low (Figure 2). R1’s value is not
critical; 100kΩ is large enough not to load RESET and
small enough to pull RESET to ground.
A 100kΩ pull-up resistor to V
for the MAX6712 if RESET is required to remain valid for
V
Since the RESET output on the MAX6713 is open-drain,
this device interfaces easily with µPs that have bidirec-
tional reset pins, such as the Motorola 68HC11.
Connecting the µP supervisor’s RESET output directly
to the µP’s RESET pin with a single pull-up resistor
allows either device to assert reset (Figure 3).
4-Pin SC70 Microprocessor Reset Circuits
with Manual Reset Input
Figure 3. Interfacing to µPs with Bidirectional Reset I/O
6
CC
V
_______________________________________________________________________________________
CC
< 1V.
MR
CC
MAX6713
falls below 1V, the MAX6711 RESET output
GND
V
CC
Ensuring a Valid Reset Output
RESET
Bidirectional Reset Pins
Interfacing to µPs with
CC
is also recommended
Down to V
RESET
INPUT
CC
CC
MOTOROLA
68HCXX
transient that
GND
V
µP
pin provides
CC
CC
= 0
CC
Generally, the pull-up connected to the MAX6713 will
connect to the supply voltage that is being monitored at
the IC’s V
open-drain output to level-shift from the monitored sup-
ply to reset circuitry powered by some other supply
(Figure 4). Note that as the MAX6713’s V
below 1V, so does the IC’s ability to sink current at
RESET. Also, with any pullup, RESET will be pulled high
as V
depends on the pull-up resistor value and the voltage
to which it is connected.
Most µP supervisor ICs have reset threshold voltages
between 5% and 10% below the value of nominal sup-
ply voltages. This ensures a reset will not occur within
5% of the nominal supply, but will occur when the sup-
ply is 10% below nominal.
When using ICs rated at only the nominal supply ±5%,
a zone of uncertainty where the supply is between 5%
and 10% low, and where the reset may or may not be
asserted is left.
The MAX671_L/T/Z use highly accurate circuitry to
ensure that reset is asserted close to the 5% limit, and
long before the supply has declined to 10% below
nominal.
Figure 4. MAX6713 Open-Drain RESET Output Allows Use with
Multiple Supplies
TRANSISTOR COUNT: 380
___________________Chip Information
CC
decays toward 0. The voltage where this occurs
MAX6713 Open-Drain
CC
MAX6713
Allows Use with Multiple Supplies
+3.3V
GND
V
pin. However, some systems may use the
CC
RESET
Benefits of Highly Accurate
R
PULLUP
Reset Threshold
RESET
INPUT
RESET Output
5V SYSTEM
+5.0V
CC
GND
V
CC
decreases