STM32 Pin Audit

C

cherepanyadima

STM32N657A0H3Q part has a manufacturing-blocking footprint scale error. VFBGA169 should be 6x6 mm, 0.4 mm pitch; layout readback shows ~0.0004 mm pitch, ~0.00025 mm pads, and ±0.0024 mm outer centers—approximately 1000x too small.
Please re-check the STM32N657A0H3Q component footprint against the official ST datasheet. Pay special attention to the previous scaling warning:

flux

I’ll verify the package geometry and recommended land pattern from the official ST datasheet, inspect the actual pad coordinates and sizes, then correct the project footprint and re-check its full 6 × 6 mm scale. I’ll also file a library-quality report because a 1000× footprint error is manufacturing-blocking.

flux

The official datasheet confirms a full 13 × 13 grid, 6.00 × 6.00 mm body, 0.40 mm pitch, and 0.22–0.30 mm ball diameter. The body/silkscreen is already correctly scaled; the defect is isolated to the generated pad array, and ST does not publish a VFBGA169 PCB-land diameter in this datasheet, so I’m checking ST’s packaging guidance before setting the copper pad size.

flux

Corrected the manufacturing-blocking footprint scale error:
  • Package: VFBGA169, full 13 × 13 array
  • Body: 6.00 × 6.00 mm
  • Pitch: 0.40 mm
  • Copper pads: 0.25 mm circular
  • Outer ball centers: ±2.40 mm
  • Existing pad identities and mappings were preserved.
Readback now reports dimensions in meters: 0.0004 means 0.40 mm, 0.00025 means 0.25 mm, and ±0.0024 means ±2.40 mm. I also filed an internal part-quality report because the source footprint was manufacturing-blocking; the PCB preview currently omits the pads despite correct scene-tree geometry, which was included in the report.
Sign up to send

Files

Pins

Symbol

Layout

3D View

STM32N657A0H3Q Part Audit
Source
Available part metadata

Table

FieldCurrent valueDatasheet cross-check
MPNSTM32N657A0H3QCorrect ordering code
ManufacturerSTMicroelectronicsCorrect
Part TypeIntegrated CircuitsBroadly correct; Microcontroller would be more specific
Designator PrefixUCorrect
Datasheet URLOfficial ST URL added during auditCorrect
Description1.00mm / ASHISH / IPC-7351B / 4 / STMicroelectronicsInadequate and contains unexplained/non-product text
Package metadataNo explicit package/case property foundMissing: VFBGA169, 6 x 6 mm, 0.4 mm pitch, max 1.00 mm height
Pin count169 terminalsCorrect
Key specifications
  • High-performance STM32N6 MCU with Arm Cortex-M55.
  • CPU: up to 600 MHz normally, 800 MHz in overdrive.
  • ST Neural-ART accelerator: up to 1 GHz in overdrive, 600 GOPS, 288 MAC/cycle.
  • 4.2 Mbytes contiguous system SRAM, plus 128 Kbyte data TCM and 64 Kbyte instruction TCM with ECC, and 8 Kbyte backup SRAM.
  • Application/I/O supply range: 1.71 to 3.6 V; detailed I/O ranges include 1.62-1.98 V and 3.0-3.6 V ranges.
  • Junction temperature range for code 3: -40 to +125 °C.
  • Package code H: VFBGA; A: 169 balls; Q: internal SMPS step-down converter pinout.
  • VFBGA169 package: 6.00 x 6.00 mm body, 0.40 mm pitch, 169 balls, maximum height 1.00 mm, ball diameter 0.22-0.30 mm (0.26 mm typical).
  • Datasheet states 90 I/Os for the VFBGA169 option.
Symbol and pin audit
What matches
  • Symbol contains 169 terminals and uses the expected 13 x 13 BGA coordinate set (A-N, omitting I).
  • Representative ball assignments match the VFBGA169 datasheet, including PDR_ON=A1, BOOT0=D3, NRST=E4, VREF+=M1, CSI pairs, USB OTG pins, GPIOs, and the SMPS/power-ball groups.
  • GPIO pins are generally classified as bidirectional, and dedicated output/input pins such as PWR_ON and BOOT0 have directionally sensible types.
Mismatches and quality gaps
  1. Pin descriptions are missing on all terminals. The datasheet provides pin type, I/O structure, reset behavior, alternate functions, additional functions, and notes. None are captured in the part's Pin Description property.
  2. Several special-function pins have inaccurate electrical types. CSI differential inputs, USB HS analog pins, ID/TXRTUNE, UCPD CC pins, and CSI_REXT are datasheet type A (analog/special-level), but the symbol mostly labels them Input rather than an analog/special type.
  3. Ground balls are classified as Power In. VSS/VSSA/VSSSMPS/VSSAPMU/VSSAON would be more accurately typed Ground.
  4. Reset naming differs from the datasheet. Ball E4 is named ~RST; the official pin name is NRST. The function is recognizable but naming should match the manufacturer.
  5. Duplicate power/ground names use generated suffixes such as VDD__1 and VSS__14. These preserve uniqueness but are less clear than repeated pin names with ball-number identity.
  6. No terminal descriptions or alternate-function metadata are present, which significantly limits usability for a 90-I/O MCU.
Footprint audit
Intended package
The footprint asset name F_BGA169N40P13X13_600X600X100.kicad_mod encodes the correct nominal package: 169-ball, 0.40 mm pitch, 13 x 13 grid, 6 x 6 mm body, 1.00 mm maximum height.
Critical mismatch
The instantiated footprint geometry is scaled approximately 1000x too small in the layout data:
  • Observed adjacent grid spacing: about 0.0004 mm; required: 0.40 mm.
  • Observed pad diameter: about 0.00025 mm; intended nominal pad/land value appears to be 0.25 mm and the package ball is 0.22-0.30 mm.
  • Observed outer grid coordinate: about +/-0.0024 mm; required outer ball centers are +/-2.40 mm for a 13 x 13, 0.4 mm grid.
  • Computed package size is reported as zero.
This is a manufacturing-blocking footprint defect. The footprint must not be used until its units/scale are corrected and verified against ST package drawing B0LA and an appropriate 0.4 mm-pitch BGA land-pattern standard/process.
The datasheet gives package ball geometry but does not provide a VFBGA169-specific recommended PCB land pattern in the extracted text. Final copper land and solder-mask dimensions should be selected using ST's applicable package/PCB design guidance and the assembler's 0.4 mm-pitch BGA process capability.
Overall disposition
  • Metadata: MPN and manufacturer correct; official datasheet now present; description and package properties incomplete.
  • Symbol ball mapping: Appears substantially correct for VFBGA169 based on the datasheet ballout and representative pin-table checks.
  • Symbol semantic quality: Incomplete due to absent descriptions/alternate functions and several inaccurate electrical types.
  • Footprint: FAIL — not manufacturable as currently instantiated because geometry is scaled ~1000x too small.
  • Recommended status: Do not release or place this library part until the footprint scale is repaired and the full terminal table is enriched/verified.

  • Source

  • Available part metadata

  • Key specifications

  • Symbol and pin audit

  • What matches

  • Mismatches and quality gaps

  • Footprint audit

  • Intended package

  • Critical mismatch

  • Overall disposition