TC1278 Datasheet, PDF (1/12 Pages) Microchip Technology – 3-Pin Reset Monitors for 5V Systems

TC1278/TC1279
3-Pin Reset Monitors for 5V Systems
Features
• Precision V_CC Monitor for 5.0V System Supplies
• 250msec Minimum RESET Output Duration
• Output Valid to V_CC = 1.2V
• V_CC Transient Immunity
• Small 3-Pin SOT-23B Package
• No External Components
Applications
• Computers
• Embedded Systems
• Battery Powered Equipment
• Critical µP Power Supply Monitoring
Device Selection Table
Part
Number
Order
Package
Temp.
Range
TC1278-xENB Open Drain 3-Pin SOT-23B -40°C to +85°C
TC1279-xENB Open Drain 3-Pin SOT-23B -40°C to +85°C
NOTE: “x” denotes a suffix for V_CC threshold (see table below).
Suffix
5
10
15
Package Type
Reset V_CC Threshold (V)
4.625
4.375
4.125
3-Pin SOT-23B
General Description
The TC1278/TC1279 are cost-effective system super-
visor circuits designed to monitor V_CC in digital systems
and provide a reset signal to the host processor when
necessary. No external components are required.
The reset output is driven active within 5µsec of V_CC
falling through the reset voltage threshold. RESET is
maintained active for a minimum of 250msec after V_CC
rises above the reset threshold. The TC1278 has an
active-high RESET output while the TC1279 has an
active-low RESET output, and both devices have an
open drain output stage. The output is valid down to
V_CC = 1.2V. Both devices are available in a 3-Pin SOT-
23B package.
Typical Operating Circuit
V_CC
2
V_CC
V_CC
1
RESET
Processor
RESET
Input
TC1279
GND
3
GND
RESET 1
TC1278-xENB
TC1279-xENB 3 ^GND
V_{CC 2}
NOTE: 3-Pin SOT-23B is equivalent to JEDEC TO-236
© 2002 Microchip Technology Inc.
DS21384B-page 1