{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"UC2845D8","brand":"Texas Instruments","brandSlug":"texas-instruments","productSlug":"UC2845D8","canonicalUrl":"https://icboms.com/texas-instruments/UC2845D8","factsUrl":"https://icboms.com/api/mcp/products/UC2845D8","rawCanonicalId":null},"summary":{"shortDescription":"Texas Instruments UC2845D8 current-mode PWM controller, 8-SOIC package, 12V to 28V supply, up to 500kHz switching, 48% max duty cycle, -40°C to 85°C operating temperature.","salesMarkdown":"## Current-mode PWM controller for isolated and non-isolated topologies The Texas Instruments UC2845D8 is a current-mode PWM controller designed for step-up, step-down, and step-up/step-down converter topologies including boost, buck, flyback, and forward converters. It operates from a 12V to 28V supply rail and delivers a single transistor-driver output with a maximum duty cycle of 48%. The switching frequency reaches up to 500kHz, allowing the designer to shrink magnetics and reduce output capacitor size in medium-power isolated supplies. ## 48% duty cycle — what it means for flyback and forward designs The 48% max duty cycle prevents transformer saturation in single-ended topologies. In a flyback converter, this cap sets the maximum volt-second product across the primary winding. ## Switching frequency up to 500 kHz — magnetics and EMI trade-offs The oscillator can be programmed to switch at frequencies up to 500 kHz. Running at the upper end shrinks the transformer core size and reduces output filter capacitance. ## Supply voltage range and bias rail design The UC2845D8 requires a Vcc supply between 12V and 28V. In a flyback converter, this bias is typically derived from an auxiliary winding on the transformer. The 12V minimum means the controller will not start until the auxiliary rail has built up to at least 12V, which sets the startup resistor and the Vcc capacitor sizing. The 28V upper limit accommodates 24V industrial bus supplies directly, but if the auxiliary winding produces a higher voltage under light load, an external zener clamp or a linear regulator may be needed to keep Vcc within the 28V absolute maximum. ## Package and footprint: 8-SOIC Housed in an 8-pin SOIC package (body 3.90 mm wide), the UC2845D8 is a surface-mount part that fits standard SOIC-8 land patterns. The tube shipping option is typical for engineering samples and low-volume production; for higher volumes the part is also available in tape-and-reel (check the full ordering code suffix). The part is ROHS3 compliant.","metaTitle":"UC2845D8 PWM Controller, 500kHz, 48% Duty Cycle, 8-SOIC","metaDescription":"UC2845D8 current-mode PWM controller. Step-Up/Down, Flyback, Forward topologies. Up to 500kHz switching, 48% max duty, -40 to 85°C.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":"ROHS3 Compliant","productStatus":"Active","categoryPath":["Analog & Data Acquisition"],"specifications":{"Package":"Tube","Function":"Step-Up, Step-Down, Step-Up/Step-Down","Topology":"Boost, Buck, Flyback, Forward","Clock Sync":"No","Output Type":"Transistor Driver","Mounting Type":"Surface Mount","Output Phases":"1","Package / Case":"8-SOIC (0.154\\\", 3.90mm Width)","lifecycle_stage":"eol_hot","Control Features":"Frequency Control","Duty Cycle (Max)":"48%","Number of Outputs":"1","Output Configuration":"Positive, Isolation Capable","Frequency - Switching":"Up to 500kHz","Operating Temperature":"-40°C ~ 85°C (TA)","Synchronous Rectifier":"No","Supplier Device Package":"8-SOIC","Voltage - Supply (Vcc/Vdd)":"12V ~ 28V"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$1.56","priceTiers":[{"qty":1,"price":"$1.56000","currency":"USD"},{"qty":10,"price":"$1.40400","currency":"USD"},{"qty":25,"price":"$1.32480","currency":"USD"},{"qty":100,"price":"$1.12890","currency":"USD"},{"qty":250,"price":"$1.06000","currency":"USD"},{"qty":500,"price":"$0.92750","currency":"USD"},{"qty":1000,"price":"$0.76850","currency":"USD"},{"qty":2500,"price":"$0.75000","currency":"USD"}]},"links":{"datasheetUrl":"https://cdn.icboms.com/3edad1712993fb3b1751953d793dcfb6.pdf","sourceUrl":null,"alternativesUrl":"https://icboms.com/api/mcp/products/UC2845D8/alternatives.json"},"ai":{"faq":[{"question":"What is the difference between UC2845 and UC3845?","answer":"The UC2845 and UC3845 share the same functional architecture and pinout, but the UC2845 is specified for the industrial temperature range (-40°C to 85°C) while the UC3845 is a commercial-grade part (0°C to 70°C). For designs that must operate in cold environments or outdoor enclosures, the UC2845 is the correct choice."},{"question":"Can UC2845D8 be used in a flyback converter?","answer":"Yes, the UC2845D8 is specifically designed for flyback and forward topologies. Its 48% max duty cycle and current-mode control make it a standard choice for single-switch flyback converters in the 10W to 100W range. The 500 kHz switching ceiling allows the use of small ferrite cores."},{"question":"What is the closest functional second-source for UC2845D8?","answer":"The UCC2806DWTR from Texas Instruments is a related current-mode PWM controller, but it is not a direct pin-compatible replacement. The UCC2806 offers dual outputs and synchronous rectification capability, which suits designs needing higher efficiency at light load, but its switching frequency is limited to 47 kHz — much lower than the UC2845D8's 500 kHz ceiling. For a drop-in replacement, stick with the UC2845 family in the same package and temperature grade."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/texas-instruments/UC2845D8","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/texas-instruments/UC2845D8 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}}