Part Review and Datasheet Update

I’ll audit every current terminal against the RT600 VFBGA176 datasheet, restore any missing balls, and add datasheet-derived pin descriptions where available.
The full audit found an NXP datasheet conflict: VFBGA176 balls D7/D11 are listed both as PIO0_17/PIO0_28 and as VSSA. I’ll preserve the conflict in the review, add descriptions, and avoid silently deleting either assignment without NXP clarification.
Completed the full audit and added datasheet-derived pin descriptions across the part. The review is updated in MIMXRT685SFVKB Part Review (mimxrt685sfvkb-part-review).
Open items:
  • NXP’s Table 4 has an unresolved VFBGA176 conflict: D7/D11 are listed both as PIO0_17/PIO0_28 and as VSSA.
  • I did not restore the three removed WLCSP-column VDDIO_0 balls because they are not valid VFBGA176 assignments.
  • Final 176-ball restoration needs NXP errata/support or another authoritative pin list to resolve D7/D11 safely.
Resolve and verify
Search NXP sources
Validate footprint geometry
Normalize ground pins
Export audit report

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MIMXRT685SFVKB Part Review
Date: 2026-06-16
Latest review status
Actions completed in the full-audit pass:
  • Rechecked all available schematic terminal pin numbers against the official NXP RT600 datasheet for the MIMXRT685SFVKB VFBGA176 package.
  • Re-set Datasheet URL to the official NXP PDF: https://www.nxp.com/docs/en/data-sheet/RT600.pdf
  • Added datasheet-derived Pin Description properties for PIO0, PIO1, PIO2, supply, ground, USB, clock, reset, PMIC, and analog/reference terminals.
  • Confirmed VDDIO_0 is represented by the four VFBGA176 balls listed in the datasheet: J12, J13, K12, M10.
  • Preserved the observed D7/D11 conflict rather than deleting either assignment silently.
Reviewed part metadata
Official datasheet evidence
Official NXP datasheet: RT600 — Dual-core microcontroller with 32-bit Cortex-M33 and Xtensa HiFi4 Audio DSP CPUs, Product data sheet Rev. 2.5, 19 June 2025.
Ordering/package entry for MIMXRT685SFVKB:
  • Package name: VFBGA176
  • Description: thin fine-pitch ball grid array package
  • Ball count: 176
  • Body: 9 x 9 x 0.98 mm
  • Package version: SOT1850-1
Ordering features for MIMXRT685SFVKB / VFBGA176:
  • Arm Cortex-M33: yes
  • Xtensa HiFi4 DSP: yes
  • SRAM: 4.5 MB
  • Security features: yes
  • FlexSPI A/B: yes
  • RTC: yes
  • USB ISP mode: yes
  • Flexcomm interfaces: 6
  • High-speed SPI: yes
  • PMIC I2C: yes
  • GPIO: 96
  • SD/MMC: 1
  • eSPI: no
  • Premium voice software: no
Cross-check highlights

Table


SignalFlux ball(s) after auditDatasheet VFBGA176 ball(s)Result
VDDIO_0J12, J13, K12, M10J12, J13, K12, M10Match
USB1_DPR17R17Match
USB1_DMT17T17Match
USB1_VBUSR16R16Match
USB1_VDD3V3N16N16Match
VDD_AO1V8C13, D13C13, D13Match
VDD1V8B11, C16, C17, E15, F13, G14, L4, R15B11, C16, C17, E15, F13, G14, L4, R15Match
VDDCOREC5, D9, F14, J4, J14, P9, R5, R14C5, D9, F14, J4, J14, P9, R5, R14Match
VDDIO_1E6, E8, E10, H13, H14, K13, L14E6, E8, E10, H13, H14, K13, L14Match
VDDIO_2N12, P11, P12N12, P11, P12Match
VSSAD7, D11D7, D11Datasheet conflict
PIO0_17D7D7Datasheet conflict with VSSA
PIO0_28D11D11Datasheet conflict with VSSA
Full-audit finding: unresolved NXP datasheet conflict
The official RT600 datasheet text extraction and web scrape both show an internal conflict in Table 4 for the 176-pin VFBGA package:
  • PIO0_17 is listed at VFBGA176 ball D7.
  • PIO0_28 is listed at VFBGA176 ball D11.
  • VSSA is also listed at VFBGA176 balls D7 and D11.
These cannot all be true for a physical BGA. Because this is an official-source conflict, I did not delete either set of terminals. I added descriptions noting the conflict on PIO0_17 and PIO0_28, and retained VSSA descriptions as analog ground.
Component/pad count after audit
  • Project reports 173 schematic components.
  • Project reports 177 PCB layout nodes total.
  • The package ordering table says the package has 176 balls.
The count discrepancy is tied to the VFBGA176/WLCSP table-column correction and the D7/D11 conflict. The previous extra VDDIO_0 terminals were 114-pin WLCSP-column balls, not VFBGA176 balls. I did not restore those as VFBGA balls because that would knowingly reintroduce incorrect package-column assignments.
Pin descriptions added
Descriptions were added for:
  • PIO0_0 through PIO0_31, including ADC/comparator/JTAG notes where visible from the datasheet.
  • PIO1_0 through PIO1_31, including CH4/comparator/boot strap notes where visible.
  • PIO2_0 through PIO2_31, including comparator and serial-wire-debug default notes for PIO2_25/PIO2_26.
  • VDDCORE, VDD1V8, VDD1V8_1, VDD_AO1V8, VDDIO_0, VDDIO_1, VDDIO_2, VDDA_ADC1V8, VDDA_BIAS, VSS, VSSA, VREFP, VREFN.
  • USB1_DP, USB1_DM, USB1_VBUS, USB1_VDD3V3.
  • RESETN, LDO_ENABLE, RTCXIN, RTCXOUT, XTALIN, XTALOUT, PMIC_IRQ_N, PMIC_MODE0, PMIC_MODE1, PMIC_I2C_SCL, PMIC_I2C_SDA.
Remaining issues / cautions
  1. D7/D11 must be resolved by NXP clarification, errata, or another authoritative source before using those balls in a design.
  2. Canonical datasheet property behavior is inconsistent: the project accepts a Datasheet URL property, but the project metadata tool labels it non-standard. It has been set to the official URL and Implementation Details also records it.
  3. Footprint geometry still needs mechanical validation against the SOT1850-1 drawing for pitch, pad diameter, solder mask, and package orientation.
  4. Ground pin type convention remains open: VSS/VSSA are still typed as Power Out; this may need normalization depending on Flux ERC expectations.
  1. Check NXP errata, IBIS/BSDL/package pin list, or contact NXP support to resolve the D7/D11 conflict.
  2. After D7/D11 are resolved, remove the incorrect duplicate logical terminals and restore the final 176-ball representation.
  3. Validate the VFBGA176 footprint geometry against the SOT1850-1 mechanical drawing.
  4. Normalize VSS/VSSA pin electrical types if desired for ERC behavior.

    Latest review status

    Reviewed part metadata

    Official datasheet evidence

    Cross-check highlights

    Full-audit finding: unresolved NXP datasheet conflict

    Component/pad count after audit

    Pin descriptions added

    Remaining issues / cautions

    Recommended next steps

Documents

    MIMXRT685SFVKB Part Review

Assets

step

MIMXRT685SFVKB

VFBGA176_SOT1850-1_NXP.step3D Model
MIMXRT685SFVKB

MIMXRT685SFVKB

MIMXRT685SFVKB MIMXRT685SFVKB_2_1 Symbol.svg
kicad_mod

MIMXRT685SFVKB

VFBGA176_SOT1850-1_NXP-M.kicad_modFootprint
MIMXRT685SFVKB-thumb.png

MIMXRT685SFVKB-thumb.png

MIMXRT685SFVKB-thumbThumbnail
MIMXRT685SFVKB

MIMXRT685SFVKB

MIMXRT685SFVKB MIMXRT685SFVKB_1_1 Symbol.svg

MIMXRT685SFVKB

MIMXRT685SFVKB thumbnail
ARM® Cortex®-M33 RT-600 Microcontroller IC 32-Bit Dual-Core 300MHz External Program Memory 176-VFBGA (9x9)
The RT600 is a family of dual-core microcontrollers for embedded applications featuring an Arm Cortex-M33 CPU combined with a Cadence Xtensa HiFi4 advanced Audio Digital Signal Processor CPU. The Cortex-M33 includes two hardware coprocessors providing enhanced performance for an array of complex algorithms. The family offers a rich set of peripherals and very low power consumption. The Arm Cortex-M33 is a next generation core based on the ARMv8-M architecture that offers system enhancements, such as ARM TrustZone® security, single-cycle digital signal processing, and a tightly-coupled coprocessor interface, combined with low power consumption, enhanced debug features, and a high level of support block integration. The ARM Cortex-M33 CPU employs a 3-stage instruction pipe and includes an internal prefetch unit that supports speculative branching. A hardware floating-point processor is integrated into the core. On the RT600, the Cortex-M33 is augmented with two hardware coprocessors providing accelerated support for additional DSP algorithms and cryptography. The Cadence Xtensa HiFi 4 Audio DSP engine is a highly optimized audio processor designed especially for efficient execution of audio and voice codecs and pre- and post-processing modules. It supports four 32x32-bit MACs, some support for 72-bit accumulators, limited ability to support eight 32x16-bit MACs, and the ability to issue two 64-bit loads per cycle. There is a floating point unit providing up to four single-precision IEEE floating point MACs per cycle. The RT600 provides up to 4.5 MB of on-chip SRAM (plus an additional 128 KB of tightly-coupled HiFi4 ram) and several high-bandwidth interfaces to access off-chip flash. The FlexSPI flash interface supports two channels and includes an 32 KB cache and an on-the-fly decryption engine. The RT600 is designed to allow the CortexM33 to operate at frequencies of up to 300 MHz and the HiFi4 DSP to operate at frequencies of up to 600 MHz.
Key Features Dual-core architecture with Arm Cortex-M33 CPU and Cadence Xtensa HiFi4 DSP Cortex-M33 operating at up to 300 MHz HiFi4 DSP operating at up to 600 MHz Up to 4.5 MB on-chip SRAM 128 KB DSP tightly coupled memory (TCM) FlexSPI interface supporting Quad/Octal SPI Flash with execute-in-place (XIP) High-speed USB 2.0 Host/Device with integrated PHY Digital microphone (DMIC) interface supporting up to 8 channels Multiple I2S, SPI, I²C, UART, SDIO, and I3C interfaces 12-bit ADC with up to 1 MSPS sampling rate Hardware cryptography acceleration (AES, SHA, RSA, ECC) Arm TrustZone® security technology Secure boot and physically unclonable function (PUF) key storage Multiple low-power operating modes for battery-powered applications Up to 147 GPIOs depending on package option 176-pin VFBGA package (9 mm × 9 mm) Typical Applications Voice-controlled smart devices Audio processing and DSP systems Smart speakers and soundbars Industrial HMI and control panels Edge AI and machine learning applications IoT gateways and connected devices Wearable and portable electronics

Properties

MIMXRT685SFVKB

Datasheet: https://www.nxp.com/docs/en/data-sheet/RT600.pdf; full audit found a datasheet conflict where VFBGA176 D7/D11 are listed both as PIO0_17/PIO0_28 and VSSA.

NXP USA Inc.

Microcontroller

U

VFBGA176_SOT1850-1_NXP

parametric-v1

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