The STM6717/18/19/20 and STM6777/78/79/80 supervisors are a family of low-voltage/low-supply current processor (micro or DSP) supervisors, designed to monitor two (or three) system power supply voltages. They are targeted at applications such as set-top boxes (STBs), portable, battery-powered systems, networking, and communication systems.All device options have a push-button-type manual reset input (MR). The STM6777/78/79/80 also includes an option which enables the user to delay the start of the manual reset process from 6 µs (MRC pin left open) or more with external capacitor. The delay is implemented by connecting the appropriately sized capacitor between the MRC pin and VSS(typical 4 s delay with a 3.3 µF capacitor).Two of the three supplies monitored (VCC1and VCC2) have fixed (customer-selectable, factory-trimmed) thresholds (VRST1and VRST2). The third voltage is monitored using an externally adjustable RSTIN threshold (0.626 V internal reference).If any of the three monitored voltages drop below its factory-trimmed or adjustable thresholds, or ifMRis asserted to logic low, aRSTis asserted (driven low). Once asserted,RSTis maintained at low for a minimum delay period (trec) after ALL supplies rise above their respective thresholds andMRreturns to high. These devices are guaranteed to be in the correct reset output logic state when VCC1and/or VCC2is greater than 0.8 V.These devices are available in standard 5-pin or 6-pin SOT23 packages.Primary supply (VCC1) monitor. Fixed (factory-programmed) reset thresholds: 4.63 V to 1.58 VSecondary supply (VCC2) monitor (STM6717/18/19/20/77/78)Fixed (factory-programmed) reset thresholds: 3.08 V to 0.79 VTertiary supply monitor (using externally adjustable RSTIN): 0.626 V internal referenceRSToutputs (push-pull or open drain); state guaranteed if VCC1or VCC2= 0.8 VReset delay time (trec) on power-up: 13.2 ms, 210 ms, 900 ms (typ)Manual reset input (MR)Optional delayed manual reset input (MRC) with external capacitor (STM6777/78/79/80)Low supply current - 11 µA (typ), VCC1= VCC2= 3.6 VOperating temperature: –40 °C to 85 °C (industrial grade)