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Features
TCM811/TCM812
General Description
The TCM811 and TCM812 are cost effective system supervisory circuits designed to monitor VDD in digital systems and provide a reset signal to the host controller 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 20 µsec (5 µsec for F version) of VDD falling through the reset voltage threshold. RESET is maintained active for a minimum of 140 msec after VDD rises above the reset threshold. The TCM812 has an active high RESET output while the TCM811 has an active low RESET output. The output of the TCM811 is valid down to VDD = 1V. Both devices are available in a 4-Pin SOT-143 package, specified with a temperature range of -40°C to +85°C. The TCM811/TCM812 are optimized to reject fast transient glitches on the VDD line. A low supply current of 6 µA (VDD = 3.3V) makes these devices ideal for battery powered applications.
4-Pin Microcontroller Reset Monitors
• Precision VDD Monitor for 2.0V, 2.8V, 3.0V, 3.3V, 5.0V Nominal Supplies • Manual Reset Input • 140 msec Minimum RESET Output Duration • RESET Output Valid to V DD = 1.0V (TCM811) • Low 6 µA (typ.) Supply Current • VDD Transient Immunity • Small 4-Pin SOT-143 Package • No External Components • Replacement for MAX811/812 and Offers a Lower Threshold Voltage Option • Push-Pull RESET Output • Temperature Range: - Commercial (C) -40°C to +85°C
Applications
• • • • Computers Embedded Systems Battery Powered Equipment Critical Microcontroller Power Supply Monitoring
Package Types:
SOT-143 GND 1 TCM811 or TCM812 4 VDD
Typical Application Circuit
VDD 0.1µF 4
VDD
PIC Microcontroller 2 RESET INPUT (Active Low) GND
VDD
TCM811 3 MR
PUSH BUTTON
RESET GND
TCM811 RESET TCM812 (RESET)
2
3
MR
2002 Microchip Technology Inc.
DS21615B-page 1
TCM811/TCM812
1.0 ELECTRICAL CHARACTERISTICS PIN FUNCTION TABLE
NAME GND RESET (TCM811) Ground RESET push-pull output remains low while VDD is below the reset voltage threshold, and for at least 140 msec (min.) after VDD rises above reset threshold. RESET push-pull output remains high while VDD is below the reset voltage threshold, and for at least 140 msec (min.) after VDD rises above reset threshold. Manual Reset input generates a reset when MR is below VIL. Supply Voltage FUNCTION
ABSOLUTE MAXIMUM RATINGS*
Supply Voltage (VDD to GND).........................................+6.0V RESET, RESET.................................... - 0.3V to (VDD + 0.3V) Input Current, VDD .........................................................20 mA Output Current, RESET, RESET...................................20 mA Operating Temperature Range...................... – 40°C to +85°C Storage Temperature Range....................... – 65°C to +150°C Maximum Junction Temperature, TS .............................. 150°C
*Notice: Stresses beyond those listed under “Absolute Maximun Rati.