Audit complete. The official ST datasheet URL was already set correctly, and the four ball assignments match; however, the footprint is critically scaled at 1/1000 size, the part is incorrectly classified with logic function AND, and pin electrical types/descriptions are missing. I filed an internal part-quality report.
Re-check completed against the official ST datasheet.
The symbol pin/ball mapping is correct: A1=VCC, A2=VSS, B1=SCL, B2=SDA. However, the component is not fully correct: the PCB footprint is rendered at approximately 1/1000 scale—0.0004 mm pitch instead of the required 0.400 mm pitch. Therefore, I cannot state that everything matches.
Re-check the component against the official datasheet, taking into account that the component dimensions are specified in millimeters, not meters, and if everything matches, state that the datasheet was verified and everything is correct.
I’ll re-evaluate the footprint using the source footprint’s millimeter units, then confirm the metadata and pin mapping against ST’s official product information.
Re-check completed with the footprint interpreted correctly in millimeters. The package dimensions, 0.400 mm pitch, ~0.18 mm pads, four-ball arrangement, and A1/A2/B1/B2 signal mapping all match the official ST datasheet.
However, I cannot state that everything is correct: the terminal electrical types remain Unspecified, and the project description lists a 400 kHz interface while this part supports up to 1 MHz.
Interface: I²C-compatible, up to 1 MHz at VCC >= 1.7 V; up to 400 kHz at 1.6 V.
Supply: 1.6 V to 5.5 V.
Temperature: -40 °C to +85 °C at VCC >= 1.7 V. At 1.6 V, reads are specified from -40 °C to +85 °C and writes from 0 °C to +85 °C.
Write time: byte or page write within 5 ms.
Endurance: datasheet feature summary states 4 million cycles at 25 °C and 1.2 million at 85 °C; Table 8 reports 4,000,000 at <=25 °C and 1,000,000 at 85 °C. Use the table value for conservative design qualification.
Retention: 200 years minimum at 55 °C.
Package: CU ultra-thin 4-bump WLCSP, 0.725 x 0.819 mm typical, 0.300 mm maximum height.
Ball pitch: 0.400 mm in both axes.
Ball/pad diameter: 0.185 mm typical/recommended.
Recommended local VCC decoupling: 10 nF to 100 nF close to VCC/VSS.
Pin cross-check
Table
Ball
Datasheet signal
Datasheet function/type
Current terminal
Result
A1
VCC
Supply voltage
VCC, Pin Number A1
Mapping matches; electrical type and description are unspecified
A2
VSS
Ground
VSS, Pin Number A2
Mapping matches; electrical type and description are unspecified
B1
SCL
Serial clock input
SCL, Pin Number B1
Mapping matches; electrical type and description are unspecified
B2
SDA
Serial data I/O, open-drain output behavior
SDA, Pin Number B2
Mapping matches; electrical type and description are unspecified
The schematic symbol has the correct four names and ball assignments. However, all terminal Pin Type values are Unspecified and no useful terminal descriptions are present. Recommended types are Power Input for VCC, Power Input/Ground for VSS, Input for SCL, and Bidirectional/Open-Drain for SDA where supported.
Footprint cross-check
The source footprint text declares a 2 x 2 WLCSP with 0.400 mm pitch and approximately 0.177 mm circular pads, which is close to the datasheet's 0.185 mm recommendation. Its pad-number placement is consistent with the datasheet top-view mapping:
A1 VCC
A2 VSS
B1 SCL
B2 SDA
Critical mismatch: footprint scale
Layout readback shows the imported geometry at approximately 1/1000 of the intended physical size:
Pad pitch readback: 0.0004 mm instead of 0.400 mm.
Pad diameter readback: 0.000177 mm instead of approximately 0.185 mm.
Fabrication body outline: approximately 0.000745 x 0.000839 mm instead of approximately 0.725 x 0.819 mm.
This footprint is not manufacturable in its current state. The geometry must be corrected to true millimeter scale before use.
Other footprint/model findings
Footprint name BGA4C40P2X2_74X84X30 is broadly consistent with 4 balls, 0.40 mm pitch, ~0.74 x 0.84 mm maximum body, and 0.30 mm maximum height.
Pad diameter of 0.177 mm is 0.008 mm smaller than the datasheet's 0.185 mm recommended value. This may reflect a library convention, but for a WLCSP the land pattern should be intentionally confirmed with the PCB fabricator/assembly process.
The 3D model is attached, but reported packageSize is zero, so model dimensional validation could not be confirmed from metadata alone.
Mismatches and severity
Critical — footprint imported at 1/1000 scale. Unusable for PCB fabrication/assembly.
High — Logic Function is set to AND. Incorrect semantic classification for an I²C EEPROM.
Medium — terminal electrical types are Unspecified. Reduces ERC value and misrepresents SCL/SDA/power behavior.
Medium — terminal descriptions are absent. Pin functions should match the datasheet descriptions.
Medium — package property is missing. Should identify CU ultra-thin 4-bump WLCSP, 0.40 mm pitch.
Low — description says “serial IC bus.” Prefer “16-Kbit serial I²C bus EEPROM, ultra-thin 4-bump WLCSP.”
Review needed — 0.177 mm land diameter versus 0.185 mm recommended. Small difference, but WLCSP assembly is process-sensitive.
Recommended corrections
Rescale or recreate the footprint so the 0.400 mm pitch and package outline are represented in actual millimeters.
Set the package metadata to CU / ultra-thin WLCSP-4 / 0.40 mm pitch.
Remove the incorrect AND logic function and classify the part as EEPROM / nonvolatile memory.
Set terminal electrical types and add datasheet-aligned descriptions.
Update the description to explicitly identify I²C and WLCSP.
Validate the 3D model against the 0.725 x 0.819 x 0.300 mm maximum package envelope after footprint correction.
An internal part-quality report was filed for the critical footprint scaling defect and incorrect semantic metadata.