The STM6904 supervisor is a low voltage/low supply current processor supervisor, designed to monitor up to four system power supply voltages. This device is targeted at applications such as "Set-Top Boxes" (STBs), portable, battery-powered systems, networking and communication systems. The device supports a push-button type manual reset input (MR). Two of the four supply monitors (VCCand V2IN) have fixed (customer-selectable, factory-trimmed) thresholds (VRST1and VRST2). The other two voltage monitor inputs (V3IN and V4IN) are monitored using externally adjustable threshold (0.600 V internal reference) to meet specific level requirements. If any of the four monitored voltages drops below its factory-trimmed or adjustable thresholds, or if theMRis asserted to logic low, the reset outputRSTis asserted (driven low). Once asserted, RST is maintained low for a minimum delay period (tREC) after ALL monitored supplies rise above their respective thresholds and MR returns to high. This device is in the correct reset output logic state when VCCgreater than 0.8 V. The STM6904 is available in a standard 8-lead MSOP (TSSOP) package.