STM1810

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Low power reset circuit

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Product overview

Description

STM181x devices are low power reset devices used to monitor power supplies for microcontrollers. They perform a single function: asserting a reset signal whenever VCCsupply voltage drops below a preset value and keeping it asserted until VCChas risen above the preset threshold for a minimum period of time (trec). They provide excellent circuit reliability without additional external components when used with +3.0 V / +3.3 V (STM1815–STM1818), and +5 V (STM1810–STM1813) power supply systems.

A precision voltage reference and comparator monitors the VCCinput for an out-of-tolerance condition. When an invalid VCCcondition occurs, the reset output (RST) is forced low (or high in the case of RST) and remains asserted for trecafter VCCrises above the reset threshold. The STM1813/1818 also keep reset asserted for trecafter the output is momentarily pulled to ground by an external push-button switch.

The STM1812 and STM1817 have an active-high, push-pull output. The STM1810 and STM1815 (push-pull) and STM1811, STM1813, STM1816, and STM1818 (open-drain) have an active-low RSToutput. The open-drain devices (STM1811 / STM1813 / STM1816 / STM1818) also have an internal pull-up resistor to VCC. The STM1813 and STM1818 feature a debounced manual reset feature that asserts a reset if the RSTpin is pulled low for more than 1.5 μs. When used to initiate manual reset, RSTdebounces signals from devices such as mechanical switches. For devices with this feature, the release of the external switch triggers the reset period.

The STM181x devices are guaranteed to output the correct logic state for VCCdown to 1.0 V (0 °C to +105 °C). They also provide a reset comparator designed to ignore fast transients on VCC.

Reset thresholds are available between +2.55 V and +4.62 V. These small, low power devices are ideal for use in portable equipment. All are available in the space-saving 3-pin SOT23 package, and are specified from –40 °C to +105 °C.

  • All features

    • Precision monitoring of 3 V, 3.3 V, and 5 V supply voltages
    • Four output configurations:
      • Push-pull, active-high (STM1812,1817)
      • Push-pull, active-low (STM1810,1815)
      • Open-drain, active-low (STM1811,1816)
      • Open-drain, active-low with push-button detect (STM1813,1818)
    • Reset pulse width - 100 ms (min.)
    • Low supply current - 4 μA (typ.)
    • Guaranteed assertion down to VCC= 1.0 V (0 °C to 105 °C)
    • Factory-trimmed reset thresholds of 2.55 V, 2.88 V, 3.06 V, 4.37 V, and 4.62 V (typ.)
    • Power supply transient immunity
    • Push-button/manual reset detect (STM1813/1818)
    • Operating temperature: –40 °C to 105 °C
    • ± 2.5% reset threshold accuracy:(–40 °C to 105 °C)
    • Available in the SOT23-3 package
    • Fully compatible with DS181x and MXD181x products.

The current status of a product:
Active: Product is in volume production
Evaluation: Product is under characterization. Limited Engineering samples available
Preview: Product is in design stage
Target: Product is in design feasibility stage.No commitment taken to produce
Proposal: Marketing proposal for customer feedback.No commitment taken to design or produce
NRND: Not Recommended for New Design.Product is in volume production only to support customers ongoing production.
Marketing description of the package type.Compliancy of the device with industry requirement domains (IRD)The RoHS status of a product:
ECOPACK 1: Initial grade to identify European RoHS compliant products.
ECOPACK 2: New grade to identify brominated chlorinated and antimony oxide flame retardant free products.
ECOPACK 3: Halogen free RoHS exemptions free products.
(*): ECOPACK 2 version available upon request.
(**): Some versions still existing in ECOPACK 1 or not compliant.
The current status of a product:
Active: Product is in volume production
Evaluation: Product is under characterization. Limited Engineering samples available
Preview: Product is in design stage
Target: Product is in design feasibility stage.No commitment taken to produce
Proposal: Marketing proposal for customer feedback.No commitment taken to design or produce
NRND: Not Recommended for New Design.Product is in volume production only to support customers ongoing production.
Budgetary PriceMarketing description of the package type.Storage method used to contain product.Main country of assembly or fabrication of the product.ECCNs are five character alpha-numeric designations used on the Commerce Control List to identify dual-use items for export control purposes. ECCNs are five character alpha-numeric designations used on the Commerce Control List to identify dual-use items for export control purposes.The value as specified by level (minTypMax) of the ambient temperature (in Cel) in which this item was designed to operate.The value as specified by level (minTypMax) of the ambient temperature (in Cel) in which this item was designed to operate.The value as specified by level (minTypMax) of the ambient temperature (in Cel) in which this item was designed to operate.