MIMXRT685SFFOB - 300MHz Cortex-M33 + HiFi4 Audio DSP MCU | NXP
MPN: MIMXRT685SFFOB ✓ פעילMIMXRT685SFFOB סקירה
A crossover MCU is a microcontroller that sits between general-purpose MCUs and application processors: it retains the deterministic real-time control, rich peripheral set and low-power characteristics of an MCU while adding enough DSP horsepower to decode, mix and render audio streams without an external DSP. The Cortex-M33 core includes two hardware coprocessors for enhanced performance, and the HiFi4 core provides the vector/floating-point throughput required for multi-channel audio processing.
Key characteristics include a 300 MHz Arm Cortex-M33 application core, an Xtensa HiFi4 audio DSP core rated up to 600 MHz, dual-core operation in a single package, a 249-FOWLP (7x7 mm) footprint, and RoHS-compliant environmental compliance. The package size makes the device suitable for space-constrained consumer audio hardware such as soundbars, smart speakers, voice panels and Bluetooth or Wi-Fi audio dongles.
Architecturally the part separates control-plane and signal-plane workloads: the Cortex-M33 runs RTOS or bare-metal control code, connectivity stacks and user interface logic, while the HiFi4 core is dedicated to audio acceleration such as mixing, resampling, decoding and voice wake-up processing. This division avoids a round trip through external SPI or I2S DSP links and reduces both latency and board area.
Typical applications include smart speakers and voice assistants, soundbars, wireless and USB audio dongles, Bluetooth headset control planes, smart displays with voice interaction, and industrial voice panels or HMI units. The Cortex-M33 side handles USB, Ethernet and control peripherals, while the HiFi4 side handles the audio pipeline.
A key design consideration is thermal and power budget: at 300 MHz the Cortex-M33 core and the 600 MHz HiFi4 core draw substantial dynamic current, so the board layout must provide low-impedance supply paths to the core rails and adequate exposed-pad heat spreading under the 7x7 mm FOWLP. Verify the exact core rail decoupling and maximum junction temperature limits in the NXP RT600 product documentation before finalizing a thermal design.
This page consolidates distributor availability, same-package family alternatives and practical integration notes into a single engineering reference that goes beyond the manufacturer overview page.
חלופות תחליף ישיר עבור MIMXRT685SFFOB — אותו מארז, תואם פין-לפין. חלקים במארז שונה הדורשים עיבוד מחדש של ה-PCB אינם נכללים.
MIMXRT6856DFFOB
✅ Drop-In ⚠️ מפרטים לא מאומתים📋 חלופה להתייחסות (לא בקטלוג)
MIMXRT6857DFFOB
✅ Drop-In ⚠️ מפרטים לא מאומתים📋 חלופה להתייחסות (לא בקטלוג)
MIMXRT6855DFFOB
✅ Drop-In ⚠️ מפרטים לא מאומתים📋 חלופה להתייחסות (לא בקטלוג)
MIMXRT596SFFOB
✅ Drop-In ⚠️ מפרטים לא מאומתים📋 חלופה להתייחסות (לא בקטלוג)
MIMXRT595SFFOB
✅ Drop-In ⚠️ מפרטים לא מאומתים📋 חלופה להתייחסות (לא בקטלוג)
MIMXRT685SFFOB דירוגים מרביים ומאפיינים חשמליים
| Device Type | Crossover Microcontroller (MCU) with integrated Audio DSP |
| Product Family | i.MX RT600 |
| Application CPU | Arm Cortex-M33 |
| Cortex-M33 Max Frequency | 300 MHz |
| Cortex-M33 Coprocessors | 2 hardware coprocessors |
| Audio DSP Core | Cadence Xtensa HiFi4 |
| HiFi4 Max Frequency | 600 MHz |
| Core Count | 2 (Cortex-M33 + HiFi4) |
| מארז | 249-FOWLP (7x7 mm) |
| Ball Count | 249 |
| סוג הרכבה | Surface Mount (WLCSP / FOWLP) |
| Target Applications | Audio, voice, consumer IoT |
| Environmental Compliance | RoHS |
| סטטוס מחזור חיים | Active |
| Product Type per NXP | ARM-MSeries 300 MHz FOWLP-249 (7x7) MCU/MPU/SoC |
מדריך תצורת פינים של MIMXRT685SFFOB 249-fowlp (7x7 mm)
תצורת פינים עבור MIMXRT685SFFOB (מארזת 249-fowlp (7x7 mm)). מעגל משולב דיגיטלי זה כולל GPIO, ממשקי תקשורת (UART, SPI, I2C) ופיני מתח. יש לעיין בגיליון הנתונים של היצרן לפונקציות פינים חלופיות ולאפשרויות תצורה. חיוני לתכנון מערכות משובצות ולפריסת PCB.
אין נתוני פריסת פינים מפורטים עבור MIMXRT685SFFOB.
עיינו ב- גיליון נתונים עבור תצורת פינים מלאה.
יישומים טיפוסיים
MIMXRT685SFFOB מתאים עבור 6 יישוםs: Smart Speaker and Voice Assistant, Soundbar and Home Theater Front End, Bluetooth and USB Audio Dongle, Industrial Voice Panel and HMI, Smart Display with Voice Interaction, Voice-Controlled IoT Appliance.
Smart Speaker and Voice Assistant
The MIMXRT685SFFOB fits smart speakers because it runs two workloads on one 7x7 mm device: the 300 MHz Arm Cortex-M33 core handles Wi-Fi or Bluetooth control, microphone array capture and the application layer, while the 600 MHz Cadence Xtensa HiFi4 core executes wake-word detection, beamforming pre-processing and audio mixing. That division of labour removes the external HiFi DSP that a Cortex-M33-only design would require, shrinking the bill of materials and shortening the latency between the microphone front end and the wake-word engine. The two hardware coprocessors in the Cortex-M33 core offload cryptographic and signal pre-processing tasks, keeping the control loop responsive while audio code runs on the DSP core.
מומלץ
Soundbar and Home Theater Front End
A soundbar needs multi-channel mixing, volume control, dynamic range compression and codec management, all with predictable latency. The MIMXRT685SFFOB assigns the HiFi4 core to the audio pipeline - channel routing, resampling and surround effects - and keeps the Cortex-M33 core free for HDMI control, IR decoding, button handling and system firmware. Because both cores share one 249-FOWLP (7x7 mm) package, the board needs only a single IC footprint in the center of the main board rather than two packages separated by a short SPI or I2S link. The Cortex-M33's two coprocessors also let the design handle bus encryption or effect-parameter transforms without disturbing the real-time audio thread.
מומלץ
Bluetooth and USB Audio Dongle
In a compact dongle form factor, area is the binding constraint. The MIMXRT685SFFOB provides the full protocol and audio stack in a single 7x7 mm wafer-level package: the Cortex-M33 core terminates Bluetooth or USB audio streams and handles enumeration and control, and the HiFi4 core performs decoding, resampling and output-stage mixing at up to 600 MHz. Compared with a two-chip solution, this integration reduces board area, cuts one power rail and removes a digital inter-chip link that would otherwise add latency and EMI risk. Because the part is RoHS compliant and is offered in volume by multiple distributors, it suits both consumer dongles and professional USB audio interfaces.
מומלץ
Industrial Voice Panel and HMI
Industrial panels and machine-control HMIs increasingly require local voice control in noisy factory environments. The MIMXRT685SFFOB suits this role because the Cortex-M33 core handles deterministic machine control, safety-adjacent I/O and HMI graphics while the HiFi4 core runs far-field echo cancellation, noise suppression and keyword spotting entirely on-chip, avoiding a cloud round trip. The 300 MHz Cortex-M33 has ample headroom for a display interface and industrial fieldbus tasks, and its two coprocessors relieve the main core during simultaneous control and audio activity. System integrators benefit from the fact that the 249-FOWLP (7x7 mm) footprint is a fixed, published land pattern for the whole family, so a second-generation design can reuse the same layout.
מומלץ
Smart Display with Voice Interaction
Smart displays must render a user interface and simultaneously listen and respond. The MIMXRT685SFFOB allows the display pipeline to run on the 300 MHz Cortex-M33 core while the Xtensa HiFi4 audio core at up to 600 MHz handles microphone conditioning, far-field processing and the text-to-speech playback path, so voice response latency does not compete with graphics refresh work. Because the audio accelerator is on the same die, the design avoids an external DSP-to-MCU I2S bus that would tie up peripheral resources and add EMI. The result is a compact module that fits behind compact LCD or OLED panels, which is exactly the space-constrained environment where the 7x7 mm FOWLP package is advantageous.
מומלץ
Voice-Controlled IoT Appliance
Appliances, thermostats and kitchen devices are adding offline voice capability, and many run Linux-class or RTOS-class stacks alongside an always-listening audio front end. The MIMXRT685SFFOB fits this pattern: the 300 MHz Cortex-M33 core with two coprocessors runs the connectivity stack, device state machine and over-the-air update logic, while the HiFi4 core performs keyword detection and audio pre-processing locally so wake-up decisions never depend on network latency. Operating the two cores from one package simplifies power management, since one chip can be held in a low-power state between activations. The 249-FOWLP (7x7 mm) form factor also suits sealed appliance enclosures where a small footprint and a single exposed thermal pad matter.
מומלץ
סיכום מוצרים מומלצים
נתוני עזר הנדסיים עבור MIMXRT685SFFOB — השוואה, הנחיות תכנון ומידע על תאימות.
מדריך בחירה
השוואה עם חלופות
| פרמטר | מוצר זה | MIMXRT6856DFFOB | MIMXRT6857DFFOB | MIMXRT596SFFOB | MIMXRT595SFFOB |
|---|---|---|---|---|---|
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Package | 249-FOWLP (7x7 mm) | 249-FOWLP (7x7 mm) - same | 249-FOWLP (7x7 mm) - same | 249-FOWLP (7x7 mm) - same | 249-FOWLP (7x7 mm) - same |
מבדילים עיקריים
- Integrated HiFi4 audio DSP removes an external DSP from the design (לעומתMIMXRT595SFFOB)
- Single-package integration reduces BOM and board area for audio products (לעומתMIMXRT685SFAWBR)
- Control and signal workloads isolated across two cores (לעומתMIMXRT596SFFOB)
- Family-wide 249-FOWLP footprint enables second-generation reuse (לעומתMIMXRT6856DFFOB)
הערות תכנון
The Cortex-M33 core runs up to 300 MHz and the HiFi4 core up to 600 MHz, so dynamic current during full HiFi4 audio processing is far higher than at idle. Provide separate local decoupling close to the core and I/O rails - typically one 100 nF ceramic per supply pin group plus bulk capacitance near the part - and follow the NXP RT600 hardware design guidelines for rail sequencing. Keep the audio DSP domain on its own rail branch so switching from low-power idle to full DSP load does not pull a large step current through shared supply traces.
A 7x7 mm FOWLP package has very little exposed thermal area compared with the die it carries. Estimated: at a 600 MHz HiFi4 load with a 1.0 V core rail and roughly 30 percent average activity factor, core dissipation on the order of 100 mW to a few hundred mW is plausible, which at a 40 C/W package-to-ambient path produces only a modest junction rise; however the same estimate at a 1.2 V rail and full activity can push dissipation well above 0.5 W and raise junction temperature by tens of degrees. Spread heat through the full exposed-pad array and, if the enclosure is sealed, verify the junction margin against the NXP maximum junction temperature specification.
The 249-ball FOWLP land pattern is fine-pitch, so escape routing from the inner ball array is the dominant layout constraint. Route the HiFi4 core and high-speed memory or codec interfaces as length-matched, continuous-impedance traces, and place the 100 nF decoupling capacitors inside the escape region rather than around the package perimeter. Because there is no published two-page pinout table for this device, use the NXP ball-map and land-pattern files directly when assigning PCB tracks, and do not substitute a generic QFN footprint.
The most common mistake is treating this part as a generic Cortex-M33 MCU and assuming audio runs on the main core. The HiFi4 audio core has its own program memory, boot and DMA model, so code must be built and linked for the Cadence Xtensa toolchain and loaded through the RT600 image format; mixing build targets without the correct multicore image packaging leads to a device that appears to enumerate but produces no audio. Second, check the ball map for the exact variant before layout, because the 249-FOWLP packages in this family differ in ball assignment between parts.
Audio buses between the HiFi4 core, external codecs and memory must be kept short and referenced to a solid ground plane, since 600 MHz DSP activity can radiate harmonics into adjacent analogue and microphone front-end sections. Separate the codec analogue ground and supply return currents from the digital DSP return path, and avoid routing I2S clock lines parallel to microphone inputs. Where the design includes an external flash or SDRAM for the DSP working set, keep the memory bus short and add series damping resistors on high-speed edges if the eye pattern is marginal.
מידע על תאימות
RoHS compliance is indicated in distributor product data for the MIMXRT685SFFOB. The part is an industrial and consumer crossover MCU and is not identified as AEC-Q100 qualified. Request the current material declaration and halogen-free statement through the Request a Quote form on this page.
