Obsolete Device
Recommended Replacements:
TC1270A, TC1270AN, TC1271A
TC1270/TC1271
4-Pin Reset Monitors
Features:
General Description
• Precision VCC Monitor for 1.8V, 2.7V, 3.0V, 3.3V
and 5.0V Nominal Supplies
• Manual Reset Input
• 140 ms Minimum RESET, Reset Output Duration
• RESET Output Valid to VCC = 1.0V (TC1270)
• Low 7 µA Supply Current
• VCC Transient Immunity
• Small 4-Pin SOT-143 Package
• No External Components
• Replacement for MAX811/812 and Offers a Lower
Threshold Voltage Option
The TC1270 and TC1271 are cost-effective system
supervisor circuits designed to monitor VCC in digital
systems and provide a reset signal to the host
processor when necessary. A manual reset input is
provided to override the reset monitor, and is suitable
for use as a push button reset. No external components
are required.
Applications:
•
•
•
•
Computers
Embedded Systems
Battery Powered Equipment
Critical µP Power Supply Monitoring
The reset output is driven active within 20 µs (4 µs for
F version) of VCC falling through the reset voltage
threshold. Reset is maintained active for a minimum of
140 ms after VCC rises above the reset threshold. The
TC1271 has an active-high RESET output while the
TC1270 has an active-low RESET output. The output
of the TC1270 is valid down to VCC = 1V. Both devices
are available in a 4-Pin SOT-143 package.
The TC1270/TC1271 devices are optimized to reject
fast transient glitches on the VCC line. Low supply
current of 7 µA (VCC = 3.3V) makes these devices
suitable for battery powered applications.
Package Type
Typical Operating Circuit
VCC
VCC
VCC
Processor
Push
Button
MR
RESET
TC1270
GND
© 2007 Microchip Technology Inc.
Reset
Input
(Active Low)
GND
4
VCC
3
GND 1
MR
TC1270
TC1271
TC1270 RESET
TC1271 (RESET)
2
DS21381D-page 1
