概要

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 V_SS(typical 4 s delay with a 3.3 μF capacitor).
Two of the three supplies monitored (V_CC1and V_CC2) have fixed (customer-selectable, factory-trimmed) thresholds (V_RST1and V_RST2). 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 if MRis asserted to logic low, a RSTis asserted (driven low). Once asserted, RSTis maintained at low for a minimum delay period (t_rec) after ALL supplies rise above their respective thresholds and MRreturns to high. These devices are guaranteed to be in the correct reset output logic state when V_CC1and/or V_CC2is greater than 0.8 V.
These devices are available in standard 5-pin or 6-pin SOT23 packages.