{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"LDK320M33R","brand":"STMicroelectronics","brandSlug":"stmicroelectronics","productSlug":"LDK320M33R","canonicalUrl":"https://icboms.com/stmicroelectronics/LDK320M33R","factsUrl":"https://icboms.com/api/mcp/products/LDK320M33R","rawCanonicalId":null},"summary":{"shortDescription":"STMicroelectronics LDK320 series LDO voltage regulator, fixed 3.3V output, 200mA, 18V max input, SOT-23-5 package, active.","salesMarkdown":"## PSRR and noise rejection for analog rails The LDK320M33R delivers 88 dB PSRR at 120 Hz, tapering to 48 dB at 10 kHz. That 88 dB floor at line frequency means the regulator attenuates 120 Hz ripple from a rectified supply by a factor of roughly 25,000 — critical when powering a sensitive ADC reference or a VCO that would otherwise phase-modulate the ripple onto the carrier. The 48 dB at 10 kHz still provides 250× rejection of switching noise from a downstream buck converter. ## Dropout and headroom budget Maximum dropout is 0.35 V at the full 200 mA load. That sets the minimum input-to-output differential: a 3.3 V rail needs at least 3.65 V at the input pin under worst-case load and temperature. ## Quiescent current and always-on suitability Quiescent current is 90 µA typical, with a maximum supply current of 100 µA. For a battery-backed real-time clock or a microcontroller in sleep mode drawing a few microamps, the regulator's own consumption dominates the idle budget — 90 µA is modest for a 200 mA-capable LDO but not ultra-low-power. The enable pin lets a system-level power switch disconnect the load entirely, dropping the total draw to near zero when the rail is unused. ## Thermal range and protection The SOT-23-5 package (SC-74A footprint) has a junction-to-ambient thermal resistance around 250°C/W on a standard two-layer board — at 200 mA with 0.35 V dropout, the power dissipation is 70 mW, keeping the junction rise under 18°C even at 125°C ambient. Over-current and over-temperature protection are built in; the part folds back or shuts down before the silicon exceeds its safe operating area. ROHS3 compliant per the manufacturer's declaration.","metaTitle":"STMicroelectronics LDK320M33R LDO, 3.3V 200mA SOT-23-5","metaDescription":"STMicroelectronics LDK320M33R, 200mA fixed 3.3V LDO in SOT-23-5. 88dB PSRR at 120Hz, 90µA Iq, -40°C to 125°C. Active, ROHS3 compliant. Quoted to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":"ROHS3 Compliant","productStatus":"Active","categoryPath":["Power Management (PMIC / Gate Driver)"],"specifications":{"PSRR":"88dB ~ 48dB (120Hz ~ 10kHz)","Package":"Tape & Reel (TR); Cut Tape (CT)","Output Type":"Fixed","Mounting Type":"Surface Mount","Package / Case":"SC-74A, SOT-753","lifecycle_stage":"eol_hot","Control Features":"Enable","Current - Output":"200mA","Protection Features":"Over Current, Over Temperature","Number of Regulators":"1","Output Configuration":"Positive","Operating Temperature":"-40°C ~ 125°C (TJ)","Voltage - Input (Max)":"18V","Voltage Dropout (Max)":"0.35V @ 200mA","Current - Supply (Max)":"100 µA","Supplier Device Package":"SOT-23-5","Current - Quiescent (Iq)":"90 µA","Voltage - Output (Min/Fixed)":"3.3V"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$0.91","priceTiers":[{"qty":1,"price":"$0.91000","currency":"USD"},{"qty":10,"price":"$0.81400","currency":"USD"},{"qty":25,"price":"$0.77280","currency":"USD"},{"qty":100,"price":"$0.63490","currency":"USD"},{"qty":250,"price":"$0.59344","currency":"USD"},{"qty":500,"price":"$0.52444","currency":"USD"},{"qty":1000,"price":"$0.45570","currency":"USD"},{"qty":3000,"price":"$0.45570","currency":"USD"}]},"links":{"datasheetUrl":"https://cdn.icboms.com/6ebb962cd36cb2f7f9e5df5a63090103.pdf","sourceUrl":null,"alternativesUrl":"https://icboms.com/api/mcp/products/LDK320M33R/alternatives.json"},"ai":{"faq":[{"question":"How does LDK320M33R compare to the LDK220M36R?","answer":"The LDK220M36R is a 3.6 V output variant in the same SOT-23-5 package with a lower PSRR of 55 dB to 50 dB across the same frequency range. The LDK320M33R offers significantly better ripple rejection — 88 dB vs 55 dB at 120 Hz — making it the better choice for noise-sensitive analog rails. Both parts share the same pinout and enable function, so a board laid out for one accepts the other without a layout change, provided the output voltage requirement matches."},{"question":"What is the PSRR of the LDK320M33R?","answer":"The LDK320M33R provides 88 dB PSRR at 120 Hz, decreasing to 48 dB at 10 kHz. This high low-frequency rejection makes it well suited for cleaning ripple from line-frequency rectification or from a switching pre-regulator operating below 10 kHz."},{"question":"What package does the LDK320M33R come in?","answer":"It is supplied in the SOT-23-5 package, also designated SC-74A. The supplier device package is SOT-23-5."},{"question":"Where can I buy the LDK320M33R and check availability?","answer":"The LDK320M33R is sourced to order against an RFQ through independent and authorized distribution channels."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/stmicroelectronics/LDK320M33R","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/stmicroelectronics/LDK320M33R when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-08-11T15:49:49.435Z","lastPublished":"2026-08-11T15:49:49.435Z","indexable":true}}