MAX6467US36D7-T Maxim Integrated, MAX6467US36D7-T Datasheet - Page 5

• Manufacturer Part Number: MAX6467US36D7-T
• Description: Supervisory Circuits
• Manufacturer: Maxim Integrated
• Series: MAX6467, MAX6468r

Specifications of MAX6467US36D7-T

• Number Of Voltages Monitored: 1
• Monitored Voltage: 1.8 V to 5 V
• Undervoltage Threshold: 3.51 V
• Overvoltage Threshold: 3.69 V
• Output Type: Active Low, Open Drain
• Manual Reset: Resettable
• Watchdog: No Watchdog
• Battery Backup Switching: No Backup
• Power-up Reset Delay (typ): 1800 ms
• Supply Voltage - Max: 5.5 V
• Maximum Operating Temperature: + 125 C
• Mounting Style: SMD/SMT
• Package / Case: SOT-143
• Chip Enable Signals: No
• Maximum Power Dissipation: 320 mW
• Minimum Operating Temperature: - 40 C
• Power Fail Detection: No
• Supply Current (typ): 7 uA
• Supply Voltage - Min: 1 V

Figure 1. Timing Diagram
The MAX6467 provides an active-low open-drain
RESET output. The MAX6468 provides an active-low
push-pull RESET output. RESET asserts low if V
drops below the selected threshold or if a falling edge
occurs on MR. RESET remains low for the V
timeout period after V
voltage or is one-shot pulsed low for the MR timeout
period after a falling edge on MR.
Many µP-based products require manual reset capability,
allowing the operator, a test technician, or external logic
circuitry to initiate a reset. A falling edge on MR asserts
PIN
1
2
3
4
with Edge-Triggered, One-Shot Manual Reset
RESET
GND
GND
GND
V
MR
CC
RESET
NAME
GND
Microprocessor Supervisory Reset Circuits
V
MR
CC
_______________________________________________________________________________________
V
Ground
Reset Output. RESET is an active-low open-drain (MAX6467) or push-pull (MAX6468) output. RESET asserts
low when V
V
falling edge of the manual reset input. The open-drain output requires an external pullup resistor.
Manual Reset Input. Drive MR low to initiate a reset output. MR controls an edge-triggered one-shot that
asserts RESET low for a fixed MR timeout period when MR is driven low. Internal timing circuitry ignores
switch close and open bounce to ensure proper one-shot reset timing.
Power-Supply Input. V
below the selected threshold, RESET asserts low and remains low for the reset timeout period after V
above the threshold. For better noise immunity, bypass V
TH
CC
CC
Detailed Description
t
RP
rises above the threshold. The RESET one-shot asserts low for a fixed MR reset timeout period on the
increases above the threshold
Manual Reset Input
CC
drops below the selected threshold and remains low for the V
Reset Output
BOUNCE
SWITCH
CC
t
MRP
provides power to the device and is also a monitored voltage. When V
CC
reset
CC
RESET low. RESET is one-shot pulsed low for the MR
timeout period after a falling edge on MR. An internal
1.5kΩ pullup resistor to V
nected if not used. MR can be driven with TTL or CMOS-
logic levels, or with open-drain/collector outputs. Connect
a normally open momentary pushbutton switch from MR
to GND to realize a manual reset function. External
debounce circuitry is not required, as the MAX6467/
MAX6468 respond to the first falling edge on MR and
ignore subsequent falling edges within the reset timeout
period and during the MR debounce period (see Figure
1). After MR goes high for 150ms (t
one-shot is ready to trigger a reset on the next MR falling
edge. Connect a 0.1µF capacitor from MR to GND when
using long cables to provide additional noise immunity
(Figure 2).
FUNCTION
BOUNCE
SWITCH
CC
t
DEB
to GND with a 0.1µF capacitor.
BOUNCE
SWITCH
CC
CC
t
MRP
allows MR to be left uncon-
reset timeout period after
Pin Description
DEB
), the manual reset
CC
drops
CC
rises
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