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PSS25SA2FT Intelligent Power Module Guide

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This article walks through everything an engineer needs to know when evaluating or designing with the PSS25SA2FT power driver / IPM (DIPIPM) module. It synthesizes the manufacturer datasheet and distributor information into practical guidance: what the module is, its electrical and thermal capabilities, protection and control behavior, pinout highlights, suitable applications, close equivalents, design-in tips, sourcing/pricing notes, and lifecycle considerations. **What is PSS25SA2FT ** The PSS25SA2FT is a 6-pack intelligent power module in Mitsubishi’s Large DIPIPM (transfer-molding, insulated) family. It combines six insulated-gate power devices (LPT-CSTBT 6th-generation IGBTs) plus internal gate-drive, bootstrap diodes, protection circuits (short-circuit trip, under-voltage lockout), and logic-level inputs so it can be driven directly from a microcontroller/PWM driver in low-to-medium power three-phase inverters (for example, AC 400 V class motor control). The module is specified for 1200 V blocking and 25 A continuous per IGBT (with higher short-term peaks). **Key features** ●1200 V V_CES rating, 25 A per IGBT (50 A 1 ms peak). ●Built-in LPT-CSTBT (6th generation low-loss IGBT) and internal fast recovery diodes. ●Integrated drive and protection: P-side high-voltage level shifting and UV protection; N-side drive with under-voltage and short-circuit protection (SC) and fault signaling. ●Temperature output (analog) from LVIC, Schmitt-trigger 5 V inputs for direct MCU connection, and bootstrap diodes to generate gate supply for P-side. ●Insulated transfer-molded package for improved creepage/isolation to heat sink and compact DIP form factor (42-PowerDip style). **Pinout & interface highlights** The datasheet includes the full pin map and internal block diagram; the important control and power terminals to be aware of: ●Power/Phase terminals: U, V, W (upper outputs) and UN, VN, WN (lower outputs / emitters) — these are the inverter outputs to the motor phases. ●NU / NV / NW: N-side common points used for current sensing / shunt connection; note some protective features depend on connecting the external shunt correctly. ●VP1 / VPC, VN1 / VNC, VUFS / VUFB, VVFS / VVFB, VWFS / VWFB: control supply pins and feedback pins for P/N side supplies and bootstrap. ●UP / VP / WP / UN / VN / WN: logic input pins (5 V high-active, Schmitt trigger). Datasheet recommends adding an RC input filter depending on PWM/noise. ●FO: open-collector fault output that signals SC or N-side UV events. CFO capacitor shapes the FO pulse width. ●CIN: current sensing input. ●VOT: analog temperature output from the LVIC. (For the exact physical pin numbers and recommended PCB footprint, reference the datasheet diagrams — pin assignments are given in the manufacturer PDF.) **Electrical specifications (select, engineering-critical numbers)** Selected limits and typical figures (all values from the datasheet; Tj = 25 °C unless otherwise stated): ●Collector-emitter voltage (V_CES): 1200 V. ●Continuous collector current (per IGBT): 25 A (TC = 25 °C). Peak 50 A (≤1 ms). ●Collector dissipation (per chip): 103 W (TC = 25 °C). ●V_CE(sat) (IC = 25 A, Vd = 15 V): typ ~1.5 V (up to 2.2 V depending on temperature). ●Switching times (example, VCC=600 V, IC=25 A): ton ≈ 1.1–1.9 µs, toff ≈ 2.6–3.6 µs (see datasheet timing table). ●Short-circuit trip threshold (ISC): typ 42.5 A (measured under datasheet conditions; intended for fast SC detect on N-side through external Rsense + RC). ●Operating case temperature (Tc): −30 °C to +100 °C; junction Tj up to +150 °C. ●Isolation rating: 2500 Vrms (1 min) between pins and heatsink plate (insulated package). These are the numbers to use for thermal budgeting, avalanche/spike planning, and protection logic thresholds. Always read the full datasheet for pulse-rating, derating curves, and the limits that depend on thermal path and ambient conditions. Protection, control behavior & “what the module handles” The [PSS25SA2FT](https://www.avaq.com/chip/pss25sa2ft) is an IPM in the sense that it contains gate drivers and limited system protection. Useful details: ●Short-circuit protection (N-side): the IC senses current via the CIN input and trips quickly if the threshold is exceeded (the short-circuit detection path relies on the proper external Rsense / RC filter). After a trip, the module requires input re-sequencing to recover (see timing chart). ●Under-voltage lockout (UV) for P/N supplies: P-side and N-side gate supplies have UV thresholds and reset/release hysteresis (trip and reset levels listed in the datasheet). If VD/VDB falls below the trip level, the module asserts FO and blocks outputs until supply recovers. ●Fault signaling (FO): open-collector output; CFO capacitor sets the fault pulse width. The FO pin indicates SC and N-side UV events — your MCU should sample FO and shut down the drive if asserted. ●Thermal monitoring: LVIC provides an analog temperature output (VOT) that represents LVIC temperature; the IPM itself does not fully autonomously shut down on over-temperature — the system MCU must read VOT and take action if necessary. (Datasheet explicitly recommends MCU intervention when VOT indicates high temp.) Applications (where this part is a natural fit) ●Small/medium 3-phase inverters for pump, fan and HVAC motor control in the ≲5–10 kW range (depending on motor and cooling). ●Consumer / appliance motor drives (where DIPIPM packaging and built-in drive/protection reduce BOM). ●Low-to-medium power industrial motor control, compact servo drives and white-goods inverter boards where direct MCU PWM drive is desired. **Equivalents and close alternatives** ●Within Mitsubishi family: other DIPIPM “Version 6” large packages (e.g., PSS35SA2FT, PSS50SA2FT) provide higher current ratings at the same 1200 V voltage class — useful if you need higher continuous current but want the same footprint/drive interface. ●Other manufacturers / comparable modules: look for 1200 V, ~25–50 A 6-pack IPMs with integrated gate drive and protection in a similar DIP package from major suppliers (Infineon, ROHM, Fuji, etc.). When substituting, compare: gate-driver voltage and timing, SC detection method (some modules detect at different nodes), pinout, thermal resistance, and the availability of bootstrap diodes if you plan to use single-supply bootstrap arrangements. (Always validate on the bench; equivalent rating alone doesn’t guarantee drop-in interchange.) — datasheet comparison required per vendor. **Datasheet & performance benchmarks** The authoritative source is Mitsubishi’s datasheet (published May 2025 for this Version 6 device). It contains: ●Rated and surge voltages, thermal resistance R_th(j-c) values, switching timing tables, VCE(sat) vs. temperature, ISC trip test method and curves, application notes for thermal grease thickness and recommended PCB wiring. Benchmarks engineers will commonly extract from the datasheet for system modeling: ●VCE(sat) vs. temperature for conduction loss calculation. ●Switching time and turn-off energy (used to calculate switching losses at your chosen frequency and dV/dt) — datasheet gives ton/toff and related timings for typical inductive loads. ●Thermal resistance per sub-module (≈0.97 K/W junction-to-case for IGBT) for thermal design and heat sink selection. If you need measured dynamic switching loss or EMC behavior in your exact board layout, plan a short characterization campaign (double-pulse test, turn-on/off energy, and full inverter thermal run-in). The datasheet provides the baseline but board parasitics and gate drive timing will dominate real world loss/EMI. **Firmware & software support** ●No embedded firmware on the module — it presents logic-level inputs (5 V Schmitt trigger) and simple fault/temperature outputs. The “support” is therefore software you write on the host MCU: PWM generation, dead-time management, FO handling, temperature monitoring via VOT, and controlled recovery after UV/SC events. The datasheet documents input timing constraints, recommended input RC filtering, and suggested FO/CFO handling — follow those to avoid nuisance trips. Helpful MCU software patterns: ●Implement FO interrupt with debouncing using the CFO timing recommendation. ●Monitor VOT and implement soft-shutdown thresholds before LVIC temperatures approach unsafe levels. ●Add verification of VD/VDB supply rails (if you build the bootstrap supply from BSD) and refuse to enable PWM until supply resets above the UV reset level. **Longevity & reliability considerations** ●Thermal design is critical. The datasheet specifies R_th(j-c) and recommends thermal grease thickness (~100–200 µm; example references give R_th(c-f) ≈ 0.2 K/W with 20 µm grease). Follow the grease and mounting guidance — a poorly mated heat sink or inadequate grease will significantly reduce allowable continuous current. ●Operating envelope: junction Tj up to 150 °C, but module case Tc rated −30 to +100 °C. Design for realistic ambient, account for conduction and switching losses, and include thermal margin for aging and worst-case ambient. ●Protection reliance: some protections are on the N-side only (short-circuit), and the IPM expects the system MCU to handle over-temperature. Architect your system so the MCU remains responsive even during faults (watchdog, safe-state outputs). Practical design-in tips (dos & don’ts) Do: ●Follow the datasheet’s advice for thermal grease and flatness; use mounting hardware that ensures even pressure on the module base. ●Size your external shunt resistor and RC filter as datasheet suggests to get reliable short-circuit detection (ISC). ●Use proper decoupling and keep control wiring (UP/VP/WP, UN/VN/WN) short; add recommended input RC filters to avoid false input detection at high PWM frequencies/noisy environments. ●Implement an MCU routine that interprets FO and VOT, and a controlled restart sequence (don’t rely on manual resets). Don’t: ●Drive inputs with levels outside VIN allowable window (−0.5 V to VD+0.5 V). ●Assume the module will autonomously handle over-temperature — it will provide VOT but expects the system to act. **Market availability & pricing (what distributors show)** ●Mouser: shows current stock (example snapshot: 9 units in stock) and a list price entry (sample price tiers shown on the product page). The Mouser catalog entry includes the Mitsubishi datasheet link and ECAD models. (Price and stock fluctuate — see distributor page for live info). ●DigiKey / other sellers: some listings or cross-listings (e.g., older Powerex listings) indicate variant/discontinued status in some catalogues; availability therefore varies among distributors and regional stocks. Always confirm with the vendor before qualifying a part for production. ●Secondary markets / broker listings (eBay, independent brokers) may have inventory; prefer franchised distributors for production buys and traceability. (Note: prices and stock are dynamic — consult the distributor links for the current snapshot.) Lifecycle status & PCN/PDN notes ●The authoritative place to check lifecycle, obsolescence announcements, and Product Change Notices (PCNs) is the manufacturer’s product page and official distributor communications. Mitsubishi’s product page for the DIPIPM series and the PSS25SA2FT datasheet are the primary references; if you plan to use this part in production, register with Mitsubishi’s semiconductor notifications for PCNs and quality bulletins. Because some distributors show different stocking notes (some discontinued cross references exist in certain seller catalogs), do not assume long-term availability — qualify alternate modules or secure long-term supply agreements if the application has multi-year production needs. Quick checklist for prototyping → production 1.Download Mitsubishi’s PSS25SA2FT datasheet and footprint file; confirm pinout and mechanicals. 2.On bench, validate gate timing, FO behavior, and ISC trip using the same Rsense and RC filter values proposed in the datasheet. 3.Characterize conduction and switching losses on your PCB layout (double-pulse test) and derive heatsink and fan requirements from measured losses + R_th values. 4.Implement MCU fault handling: FO interrupt, VOT monitoring, controlled restart, and UV/SC logging for field diagnostics. 5.Lock parts with a trusted distributor; confirm lead time and PCN policy with Mitsubishi or your local sales rep. **Final thoughts** The PSS25SA2FT is a compact, well-featured DIPIPM suited to three-phase motor control where ease of drive and integrated protections reduce BOM and development time. Its strengths are the integrated gate drives, built-in bootstrap diodes, thermal performance (when properly mounted), and clear protection signals to a host MCU. The tradeoffs are the design responsibility that remains on the system side (thermal design, MCU fault handling, shunt sizing and filtering), and the usual caveat for power modules — real-world switching/EMI and thermal behavior must be validated on your specific board and layout. **References / primary sources** ●Mitsubishi Electric — PSS25SA2FT datasheet (PDF), Publication Date: May 2025. (datasheet with full electrical tables, pinouts, timing charts and thermal guidance). ●Mouser product page — PSS25SA2FT (stock/price snapshot & docs). ●Distributor / catalog listings (examples of availability, alternate sellers): DigiKey / Powerex cross-listings; [Avaq](https://www.avaq.com/) / other brokers for volume availability. (Note: some distributor pages show discontinued/rebranded cross references — verify with manufacturer). ●Farnell / Version-6 DIPIPM family documentation (series table referencing related parts PSS35 / PSS50 etc.).