component
M41ST85WMX6TR
Public Made by Adomby adom
STMicroelectronics Real Time Clocks, SOIC-28-300mil. Pinout cross-checked by two models against the datasheet, KiCad symbol/footprint/3D.
3D Model
Open in new tab ↗
Loads on click. Unloads only if this page sits in the background.
Symbol & Footprint
Schematic Symbol
Open full view ↗Loads on click. Unloads only if this page sits in the background.
PCB Footprint
Open full view ↗Loads on click. Unloads only if this page sits in the background.
Datasheet
Open in new tab ↗Loads on click. Unloads only if this page sits in the background.
README
markdownM41ST85WMX6TR
STMicroelectronics · Real Time Clocks · SOIC-28-300mil
M41ST85WMX6TR from STMicroelectronics, in a SOIC-28-300mil. Pinout and pin descriptions extracted from the manufacturer datasheet (extract_pins, cross-checked by a second model); symbol, footprint, and 3D from KiCad-official CAD.
Pinout
| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | NF | passive | No function pin that should be tied to VSS and is internally shorted to pins 2, 3 and 4. |
| 2 | NF | passive | No function pin that should be tied to VSS and is internally shorted to pins 1, 3 and 4. |
| 3 | NF | passive | No function pin that should be tied to VSS and is internally shorted to pins 1, 2 and 4. |
| 4 | NF | passive | No function pin that should be tied to VSS and is internally shorted to pins 1, 2 and 3. |
| 5 | NC | unconnected | No connect. |
| 6 | NC | unconnected | No connect. |
| 7 | NC | unconnected | No connect. |
| 8 | SQW | output | Programmable square wave output from 1 Hz to 32.768 kHz, enabled by the SQWE bit; CMOS output with VOH 2.4 V min at IOH = -1.0 mA. |
| 9 | WDI | input | Watchdog input that resets the watchdog timer on a high-to-low or low-to-high transition; internally pulled down to VSS through 100 kΩ and tied to VSS if unused. |
| 10 | RSTIN1 | input | Active-low reset input 1 that generates an output reset on RST; internally pulled up to VCC through 100 kΩ, pulses shorter than 50 ns are ignored. |
| 11 | RSTIN2 | input | Active-low reset input 2 that generates an output reset on RST; internally pulled up to VCC through 100 kΩ, pulses shorter than 20 ms are ignored. |
| 12 | PFO | output | Power-fail output that goes low when PFI is below the 1.25 V threshold and during battery backup; left unconnected if unused. |
| 13 | NC | unconnected | No connect. |
| 14 | VSS | power_in | Ground. |
| 15 | VBAT | power_in | Backup battery supply input, 2.5 to 3.5 V (3.0 V typ), for the embedded-crystal SOIC only. |
| 16 | ECON | output | Conditioned chip enable output that write-protects external LPSRAM by going high (within 0.2 V of VBAT) when VCC is out of tolerance. |
| 17 | SDA | bidirectional | I2C serial data input/output, requiring a pull-up resistor to a positive supply. |
| 18 | NC | unconnected | No connect. |
| 19 | RST | output | Active-low open-drain reset output driven by power-fail detect, RSTIN1/RSTIN2 and watchdog; needs a pull-up resistor, up to 3.6 V. |
| 20 | NC | unconnected | No connect. |
| 21 | NC | unconnected | No connect. |
| 22 | SCL | input | I2C serial clock input, up to 400 kHz, requiring a pull-up resistor to a positive supply. |
| 23 | PFI | input | Power-fail input compared to the 1.25 V internal reference (threshold 1.225 to 1.275 V); connected to VSS if unused. |
| 24 | NC | unconnected | No connect. |
| 25 | VOUT | power_out | Supply output to external SRAM, supplying up to 100 mA from VCC or 100 µA in battery backup. |
| 26 | IRQ/FT/OUT | output | Open-drain interrupt, frequency test (512 Hz) and output-driver pin for alarm and watchdog; needs a pull-up resistor (500 Ω to 10 kΩ recommended), VOL 0.4 V at 10 mA. |
| 27 | EX | input | External chip enable input, propagated to ECON with a 15 ns max delay. |
| 28 | VCC | power_in | Supply voltage, 2.7 to 3.6 V (absolute maximum 4.6 V). |
Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | STMicroelectronics |
| Package | SOIC-28-300mil |
| Category | Clock/Timing |
| Pins | 28 |
CAD (KiCad official)
- Symbol:
M41ST85WMX6TR - Footprint:
Package_SO:SOIC-28W_7.5x17.9mm_P1.27mm - 3D model: SOIC-28-300mil (KiCad packages3D, STEP)
- 3D model files:
m41st85wmx6tr-etched.step/m41st85wmx6tr-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);m41st85wmx6tr.step/m41st85wmx6tr.glbare the bare package body.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: STMicroelectronics datasheet (43 pp, sha256
3cc1487654fb8698, retrieved 2026-10-08, tier: lcsc) - Extractor: parts-factory
2.0.0/extract_pins 0.3, primaryclaude-sonnet-5-5(text+vision), consensusclaude-opus-5-5(agreed), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish. - CAD: KiCad official libraries (CC-BY-SA 4.0).