MAX6420UK50-T Maxim Integrated, MAX6420UK50-T Datasheet - Page 5

• Manufacturer Part Number: MAX6420UK50-T
• Description: Supervisory Circuits
• Manufacturer: Maxim Integrated
• Series: MAX6412, MAX6413, MAX6414, MAX6415, MAX6416, MAX6417, MAX6418, MAX6419, MAX6420r

Specifications of MAX6420UK50-T

• Number Of Voltages Monitored: 2
• Monitored Voltage: 1.6 V to 5 V
• Undervoltage Threshold: 4.875 V, Adjustable
• Overvoltage Threshold: 5.125 V, Adjustable
• Output Type: Active Low, Open Drain
• Manual Reset: Not Resettable
• Watchdog: No Watchdog
• Battery Backup Switching: No Backup
• Power-up Reset Delay (typ): 5.4 ms
• Supply Voltage - Max: 5.5 V
• Maximum Operating Temperature: + 125 C
• Mounting Style: SMD/SMT
• Package / Case: SOT-23
• Chip Enable Signals: No
• Maximum Power Dissipation: 571 mW
• Minimum Operating Temperature: - 40 C
• Power Fail Detection: No
• Supply Current (typ): 2.7 uA
• Supply Voltage - Min: 1 V

The MAX6412–MAX6420 low-power microprocessor
(µP) supervisory circuits provide maximum adjustability
for supply-voltage monitoring and reset functionality. In
addition, the MAX6412–MAX6420 reset timeout period
is adjustable using an external capacitor.
The MAX6412/MAX6413/MAX6414 have factory-
trimmed reset threshold voltages in approximately
100mV increments from 1.575V to 5.0V with a manual
reset input. The MAX6415/MAX6416/MAX6417 contain
a reset threshold that can be adjusted to any voltage
above 1.26V using external resistors. The MAX6418/
MAX6419/MAX6420 offer both a factory-trimmed reset
threshold and an adjustable reset threshold input for
dual-voltage monitoring.
A reset signal is asserted when V
falls below the preset values or when MR is asserted.
The reset remains asserted for an externally pro-
grammed interval after V
above the reset threshold or MR is deasserted.
The reset output is typically connected to the reset
input of a µP. A µP’s reset input starts or restarts the µP
Maxim Integrated
MAX6412/
MAX6413/
MAX6414
Low-Power, Single/Dual-Voltage µP Reset Circuits
—
2
3
4
5
1
with Capacitor-Adjustable Reset Timeout Delay
MAX6415/
MAX6416/
MAX6417
PIN
—
1
2
3
4
5
Detailed Description
CC
MAX6418/
MAX6419/
MAX6420
and/or RESET IN has risen
—
1
2
3
4
5
CC
and/or RESET IN
Reset Output
RESET
RESET
RESET
NAME
GND
SRT
V
MR
IN
CC
RESET changes from high to low whenever V
the selected reset threshold voltage (V
manual reset is pulled low. RESET remains low for the reset timeout period
after all reset conditions are deasserted and then goes high.
RESET changes from low to high whenever the V
below the selected reset threshold voltage (V
reset is pulled low. RESET remains high for the reset timeout period after all
reset conditions are deasserted and then goes low.
Ground
Reset Input. High-impedance input to the adjustable reset comparator.
Connect RESET IN to the center point of an external resistor-divider
network to set the threshold of the externally monitored voltage. See Reset
Threshold section.
Manual Reset Input. Pull this pin low to manually reset the device. Reset
remains asserted for the reset timeout period after MR is released.
Set Reset Timeout Input. Connect a capacitor between SRT and ground to
set the timeout period. Determine the period as follows:
t
Supply Voltage and Input for Fixed-Threshold V
RP
= (2.71 x 10
in a known state. The MAX6412–MAX6420 µP supervi-
sory circuits provide the reset logic to prevent code-
execution errors during power-up, power-down, and
brownout conditions (see Typical Operating Circuit ).
For the MAX6413, MAX6416, and MAX6419, RESET
changes from low to high whenever V
drops below the reset threshold voltages. Once RESET
IN and V
age(s), RESET remains high for the reset timeout period,
then goes low.
On power-up, once V
teed to be a logic high. For applications requiring valid
reset logic when V
Ensuring a Valid RESET/RESET Output Down to V
The active-low RESET output of the remaining supervi-
sors is the inverse of the MAX6413, MAX6416, and
MAX6419 active-high RESET output and is guaranteed
valid for V
The MAX6415–MAX6420 monitor the voltage on RESET
IN with an external resistor voltage-divider (Figure 1).
6
)
✕
C
SRT
MAX6412–MAX6420
CC
CC
+ 275µs with t
exceed their respective reset threshold volt-
≥ 1V.
FUNCTION
CC
CC
TH
RP
is less than 1V, see the section
or V
reaches 1V, RESET is guaran-
in seconds and C
TH
CC
RESET IN
CC
or V
CC
or RESET IN drops below
Pin Description
Monitor
or RESET IN drops
RESET IN
Reset Threshold
, respectively) or
CC
SRT
) or manual
or RESET IN
in Farads.
CC
= 0V .
5