Key facts
- Brand
- STMicroelectronics
- Model
- M41T94
- Industry
- Industrial
- Documents
- 2
- Languages
- EN
- Last added
- 2012-08-09
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STMicroelectronics M41T94 User Manual
The M41T94 is a low‑power 512‑bit (64 × 8) Serial RTC‑SRAM with an integrated 32.768 kHz oscillator and battery‑backed time‑keeping functions. It offers 44 bytes of general‑purpose RAM, automatic power‑fail switch‑over, watchdog timer, alarm, and programmable square‑wave output, all accessed via a standard SPI interface.
This manual describes the device’s features, pin assignments, timing diagrams, register maps, and operating procedures. It includes sections on SPI bus characteristics, clock operations, power‑down behavior, alarm configuration, and package mechanical data, as well as revision history and ordering information.
STMicroelectronics M41T94 specifications
| Operating Voltage | 2.7 to 5.5 V |
|---|---|
| Oscillator Frequency | 32 KHz |
| Interface | SPI (2 MHz) |
| Battery Supply Current | 500 nA (max) |
| NVRAM Size | 44 bytes |
| Watchdog Timer Range | 62.5 ms to 128 s |
Source: STMicroelectronics M41T94 Serial Real-Time Clock with NVRAM Datasheet
All STMicroelectronics M41T94 documents by type
Day-to-day operation, settings and troubleshooting. Start here if the product is already set up.
Ratings, dimensions and ordering codes, for selection and design work.
Questions answered in these manuals
What is the maximum battery supply current?
The maximum battery supply current is 500 nA.
From: STMicroelectronics M41T94 Serial Real-Time Clock with NVRAM Datasheet
Does the M41T94 include a watchdog timer?
Yes, it has an accurate programmable watchdog timer ranging from 62.5 ms to 128 s.
From: STMicroelectronics M41T94 Serial Real-Time Clock with NVRAM Datasheet
How much current does the M41T94 draw in battery‑backup mode?
In backup mode the battery supply current is up to 500 nA.
How is the chip enabled or disabled?
The Chip Enable (E) pin must be low to select the device; when E is high the device is deselected and the SDO pin is high‑impedance.