TC1270 Datasheet, PDF (1/12 Pages) Microchip Technology – 4-Pin μP Reset Monitors

TC1270/TC1271
4-Pin µP Reset Monitors
Features
• Precision V_CC Monitor for 1.8V, 2.7V, 3.0V, 3.3V
and 5.0V Nominal Supplies
• Manual Reset Input
• 140msec Minimum RESET, RESET Output
Duration
• RESET Output Valid to V_CC = 1.0V (TC1270)
• Low 7µA Supply Current
• V_CC Transient Immunity
• Small 4-Pin SOT-143 Package
• No External Components
• Replacement for MAX811/812 and Offers a Lower
Threshold Voltage Option
Applications
• Computers
• Embedded Systems
• Battery Powered Equipment
• Critical µP Power Supply Monitoring
Device Selection Table
Part Number
TC1270xERC
TC1271xERC
Package
4-Pin SOT-143
4-Pin SOT-143
Temp. Range
-40°C to +85°C
-40°C to +85°C
NOTE: “x” denotes a suffix for VCC threshold (see table
below)
Suffix*
Reset V_CC Threshold (V)
L
4.63
M
4.38
T
3.08
S
2.93
R
2.63
F
1.75
*Custom thresholds available, contact factory.
Package Type
4-Pin SOT-143
GND 1
TC1270
TC1271
4 ^VCC
TC1270 RESET 2
TC1271 (RESET)
3 MR
General Description
The TC1270 and TC1271 are cost-effective system
supervisor circuits designed to monitor V_CC 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.
The reset output is driven active within 20µsec (4µsec
for F version) of V_CC falling through the reset voltage
threshold. RESET is maintained active for a minimum
of 140msec after V_CC 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 V_CC = 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 V_CC line. Low supply
current of 7µA (V_CC = 3.3V) makes these devices
suitable for battery powered applications.
Typical Operating Circuit
V_CC
V_CC
Push-
Button
MR RESET
TC1270
GND
V_CC
Processor
RESET
Input
(Active Low)
GND
© 2002 Microchip Technology Inc.
DS21381B-page 1