STM6779 系列 1.575 V 140 ms 表面贴装 超低压 监控器 - SOT-23-6
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 VSStypical 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 if MRis asserted to logic low, a RSTis asserted driven low. Once asserted, RSTis maintained at low for a minimum delay period trec 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 VCC1and/or VCC2is greater than 0.8 V.
These devices are available in standard 5-pin or 6-pin SOT23 packages.
**Key Features**
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- Primary supply VCC1 monitor. Fixed factory-programmed reset thresholds: 4.63 V to 1.58 V
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- Secondary supply VCC2 monitor STM6717/18/19/20/77/78
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- Fixed factory-programmed reset thresholds: 3.08 V to 0.79 V
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- Tertiary supply monitor using externally adjustable RSTIN: 0.626 V internal reference
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- RST outputs push-pull or open drain; state guaranteed if VCC1 or VCC2 ≥ 0.8 V
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- Reset delay time trec on power-up: 13.2 ms, 210 ms, 900 ms typ
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- Manual reset input MR
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- Optional delayed manual reset input MRC with external capacitor STM6777/78/79/80
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- Low supply current - 11 μA typ, VCC1 = VCC2 = 3.6 V
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- Operating temperature: –40 °C to 85 °C industrial grade
