TC1272, TC1273 and TC1274 are cost-effective system supervisor circuits designed to monitor VCC 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 20 µsec of VCC falling through the reset voltage threshold. Reset is maintained active for a minimum of 100 msec after VCC rises above the reset threshold. The TC1274 has an active-high RESET output while the TC1272 and TC1273 have an active-low RESET output. The TC1272 and TC1274 each have a complimentary output while the TC1273 has an open drain output. The output of the TC1272 and TC1273 is rated down to VCC = 1.2V. The TC1274 is rated down to VCC = 1.8V. All three devices are available in a 3-pin SOT-23B package. The TC1272/3/4 are optimized to reject fast transient glitches on the VCC line.