{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"MAX821PUS","brand":"Analog Devices","brandSlug":"analog-devices","productSlug":"MAX821PUS","canonicalUrl":"https://icboms.com/analog-devices/MAX821PUS","factsUrl":"https://icboms.com/api/mcp/products/MAX821PUS","rawCanonicalId":null},"summary":{"shortDescription":"Maxim Integrated MAX821PUS Simple Reset/Power-On Reset IC, active-low push-pull output, 4V threshold, adjustable reset timeout, SOT-143-4 surface-mount package, -40°C to 125°C operating temperature.","salesMarkdown":"## What the MAX821PUS is and where it fits The Maxim Integrated MAX821PUS is a simple reset/power-on reset voltage supervisor. It monitors a single supply rail and asserts a reset signal when the voltage drops below the 4V threshold, holding the reset for an adjustable/selectable timeout period after the supply recovers. The active-low, push-pull output drives directly into the reset input of an MCU, FPGA, or other logic device without needing an external pull-up resistor. Rated for -40°C to 125°C ambient, this part is suited for industrial control, automotive under-hood electronics, and outdoor telecom gear where temperature swings are wide. The SOT-143-4 package keeps the footprint small — roughly the size of a small-signal transistor — so it fits tight layouts on multi-layer boards. ## Threshold and reset timing — what matters for the BOM The 4V threshold is the trip point: when the monitored supply falls below 4V, the reset output goes active low. For a 5V rail, this gives 1V of headroom before a brownout triggers a reset. The reset timeout is adjustable or selectable via an external capacitor or resistor (depending on the variant configuration). That lets you tailor the reset hold time to match the power-up settling of your system — longer for a slow-starting power supply, shorter for a fast-responding MCU. ## Lifecycle and sourcing It is not RoHS compliant (per the listing), so factor that into your compliance review if your BOM requires RoHS.","metaTitle":"MAX821PUS Simple Reset/Power-On Reset, 4V Threshold","metaDescription":"MAX821PUS Simple Reset/Power-On Reset IC with active-low push-pull output, 4V threshold, -40°C to 125°C range.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":"RoHS non-compliant","productStatus":"Active","categoryPath":["Discrete Semiconductors"],"specifications":{"Type":"Simple Reset/Power-On Reset","Reset":"Active Low","Output":"Push-Pull, Totem Pole","Package":"Bulk","Mounting Type":"Surface Mount","Reset Timeout":"Adjustable/Selectable","Package / Case":"TO-253-4, TO-253AA","lifecycle_stage":"eol_hot","Voltage - Threshold":"4V","Operating Temperature":"-40°C ~ 125°C (TA)","Supplier Device Package":"SOT-143-4","Number of Voltages Monitored":"1"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$2.74","stockQuantity":0,"priceTiers":[{"qty":110,"price":"$2.74000","currency":"USD"}]},"links":{"datasheetUrl":"https://cdn.icboms.com/053808dc63be9bb322c065c4708b6130.pdf","sourceUrl":null},"ai":{"faq":[{"question":"Does MAX821PUS have a datasheet?","answer":"Yes, a datasheet is available from Maxim Integrated. The part is a simple reset/power-on reset supervisor with a 4V threshold, active-low push-pull output, and adjustable reset timeout in a SOT-143-4 package."},{"question":"What is a replacement for MAX821PUS?","answer":"No official replacement or second-source alternate is listed. For a pin-compatible alternative within the same function class, consider the MAX823 series from Maxim — it offers similar reset functions but with different threshold options. Verify pinout and threshold voltage against your design before substituting."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/analog-devices/MAX821PUS","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/analog-devices/MAX821PUS when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-07-17T19:50:00.618Z","lastPublished":"2026-07-17T19:50:00.618Z","indexable":true}}