{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"ADSP-21MOD870-000","brand":"Analog Devices","brandSlug":"analog-devices","productSlug":"ADSP-21MOD870-000","canonicalUrl":"https://icboms.com/analog-devices/ADSP-21MOD870-000","factsUrl":"https://icboms.com/api/mcp/products/ADSP-21MOD870-000","rawCanonicalId":null},"summary":{"shortDescription":"Analog Devices ADSP-21MOD870-000 fixed-point DSP, 52MHz clock rate, 224kB on-chip RAM, 3.3V I/O and core, 100-LQFP (14x14mm) surface-mount package, commercial temperature range.","salesMarkdown":"## DSP core and memory for modem processing The ADSP-21MOD870-000 is a fixed-point DSP from the ADSP-21xx family, configured as part of the 2181KST 4-modem chipset. Its 52 MHz clock rate drives the arithmetic logic unit for real-time modem signal processing — V.34 bis, V.90, or similar full-duplex data pump algorithms fit within the cycle budget when the code is optimized for the single-cycle MAC. On-chip RAM totals 224 kB, partitioned between program and data memory. That is enough buffer space to hold two 8 kB modem frames plus the protocol stack without thrashing external memory — the chip relies on external non-volatile memory for boot code and firmware storage, so the board must include a serial flash or EEPROM on the host interface or serial port. ## Supply rails and temperature grade Both the core and I/O operate from a single 3.30 V rail — no separate 1.8 V core supply needed. This simplifies the power tree to one 3.3 V regulator, but the 100-LQFP package draws enough dynamic current at 52 MHz that the PCB should place a 10 µF ceramic within 5 mm of each VDD pin pair, with a 0.1 µF right at the pin. The 100-LQFP (14x14 mm) body has a 0.5 mm pitch that demands a 4-layer PCB for reliable fan-out of the inner rows. The exposed pad on the bottom is not a thermal pad — it is a mechanical tie-bar remnant; the datasheet recommends connecting it to ground plane for EMC, not for heat sinking. Junction-to-ambient thermal resistance is typically 40-50°C/W in still air, so the 52 MHz switching losses keep the die well within the 70°C ambient ceiling. ## Sourcing and compliance reality However, it is RoHS non-compliant (leaded solder balls or die-attach), which means it cannot ship into EU RoHS-exempt categories without an explicit exemption letter. For new designs targeting RoHS markets, the ADSP-2189NKST-320V offers a 1.8 V core, 80 MHz clock, and 192 kB RAM in a similar footprint, but the supply voltage difference requires a board spin. The RoHS non-compliant status means this part is typically sourced for legacy repair or military/aerospace BOMs where leaded exemption applies.","metaTitle":"Analog Devices ADSP-21MOD870-000 Fixed-Point DSP, 52MHz","metaDescription":"ADSP-21MOD870-000 fixed-point DSP from Analog Devices, 52MHz clock, 224kB on-chip RAM, 100-LQFP. Active production, RoHS non-compliant. Sourced to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":"RoHS non-compliant","productStatus":"Active","categoryPath":["Discrete Semiconductors"],"specifications":{"Type":"Fixed Point","Package":"Bulk","Interface":"Host Interface, Serial Port","Clock Rate":"52MHz","On-Chip RAM":"224kB","Mounting Type":"Surface Mount","Voltage - I/O":"3.30V","Package / Case":"100-LQFP","Voltage - Core":"3.30V","lifecycle_stage":"eol_hot","Non-Volatile Memory":"External","Operating Temperature":"0°C ~ 70°C (TA)","Supplier Device Package":"100-LQFP (14x14)"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$27.33","stockQuantity":0,"priceTiers":[{"qty":11,"price":"$27.33000","currency":"USD"}]},"links":{"datasheetUrl":null,"sourceUrl":null},"ai":{"faq":[{"question":"What is the closest functional second-source to ADSP-21MOD870-000?","answer":"The ADSP-2185LKCA-210 is the closest parametric match within the same ADSP-21xx family — same 3.3 V supply, same host interface and serial port, same 0°C to 70°C temperature range. The key difference is on-chip RAM: 80 kB vs 224 kB. The ADSP-2185LKCA-210 will not drop into a board designed for the ADSP-21MOD870-000 without firmware changes to fit the smaller memory footprint."},{"question":"What compliance documentation does Analog Devices provide for ADSP-21MOD870-000?","answer":"The part is RoHS non-compliant (leaded). Analog Devices provides a product datasheet and a material declaration certificate upon request."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/analog-devices/ADSP-21MOD870-000","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/analog-devices/ADSP-21MOD870-000 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}}