The M41T94MH6F parts manufactured by STMicroelectronics are available for purchase at Autoecuchips.com. Here you can find various types and values of electronic parts from the world's leading manufacturers. The M41T94MH6F components of Autoecuchips.com are carefully chosen, undergo stringent quality control, and are successfully meet all required standards.
The production status marked on Autoecuchips.com is for reference only. If you didn't find what you were looking for, you can get more valuable information by emails, such as the M41T94MH6F Inventory quantity, preferential price, datasheet, and manufacturer. We are always happy to hear from you, so feel free to contact us.
Here are the detailed specifications for the M41T94MH6F chip:
Technical Specifications
Parameter Specification
Function Type Serial Real-Time Clock (RTC) + Non-Volatile SRAM
Clock Accuracy 32.768 kHz crystal oscillator; integrated 12.5 pF load capacitance
Bus Interface SPI (Serial Peripheral Interface) up to 2 MHz
User RAM 44 bytes of general-purpose NVRAM
Clock/Calendar RAM 8 bytes (BCD format)
Control/Status RAM 12 bytes (Alarm, Watchdog, Square Wave Control)
Total SRAM Capacity 64 bytes (512 bits)
Operating Voltage Range 2.7 V – 5.5 V
Crystal Operating Voltage 2.5 V – 5.5 V
Battery Supply Current 500 nA (Max)
Operating Temperature Range -40°C to +85°C
Time Format Binary / BCD; HH:MM:SS:hh (Hours:Minutes:Seconds:Hundredths of a second)
Date Format Binary / BCD; D:D:M:Y:C (Day:Day of Week:Month:Year:Century)
Clock Counter Functions
Counter Range Description
Hundredths of a Second 00 – 99 0.01-second resolution
Seconds 00 – 59 BCD encoded
Minutes 00 – 59 BCD encoded
Hours 00 – 23 24-hour format, BCD encoded
Date 01 – 31 Automatic leap year correction
Day of Week 01 – 07 Day of the week
Month 01 – 12 Automatic leap month correction
Year 00 – 99 BCD encoded
Century 0 – 1 Century bit
Diagnostic and Protection Functions
Function Description
Low Battery Detection Battery Low Flag; indicates need for battery replacement
Automatic Power Switching Automatic switch to backup battery upon main power failure Power-fail detection Built-in power monitoring circuit; detects power-down events
Power-down timestamp Records the time of power failure (Power-down Time-stamp)
Power-on reset Microprocessor power-on reset output (RESET)
External reset input Dual external reset inputs (RSTIN1, RSTIN2)
---
Pin Definitions (SOIC-28 / SOH-28)
Pin Name Function
1 VCC Main power supply input (2.7V – 5.5V)
2 VSS Ground
3 SDO SPI serial data output
4 SDI SPI serial data input
5 SCL SPI serial clock input (up to 2 MHz)
6 E Chip Enable (active low)
7 RSTIN1 External reset input 1 (active low)
8 RSTIN2 External reset input 2 (active low)
9 RESET Reset output (open-drain, active low)
10 SQW Programmable square wave output (1 Hz – 32.768 kHz)
11 THS Power-fail detection threshold selection
12 VPFD Power-fail detection voltage input
13 VBAT Backup battery input (+3V lithium battery)
14 VSS Ground
15 – 28 NC / Internal connection No connect or internal connection (some pins serve as SNAPHAT battery/crystal interface)
SNAPHAT® Interface Description
- SNAPHAT® battery/crystal module mounts directly onto the top of the 28-pin SOIC package (ordered separately)
- SNAPHAT module contains: coin-cell lithium battery + 32.768 kHz crystal
- Enables a true "plug-and-play" battery backup solution
---
Typical Application Circuit
1. Basic RTC application (with SNAPHAT battery backup)
```
+VCC (+3.3V)
│
├──┬──────────────┐
│ │ │
│ VCC (1) VBAT (13)
│ M41T94 │
│ MH6F ├──→ 3V Coin Cell (SNAPHAT)
│ │
│ VSS (2,14) ──┬──→ GND
│ │
│ SDO (3) ─────┬──→ MCU SPI MISO
│ │
│ SDI (4) ─────┬──← MCU SPI MOSI
│ │
│ SCL (5) ─────┬──← MCU SPI SCK
│ │
│ E (6) ───────┬──← MCU SPI CS
│ │
│ RESET (9) ───┬──→ MCU RESET (Optional)
│ │
│ SQW (10) ────┬──→ MCU Interrupt/Timer Input
│ │
│ THS (11) ────┬──→ VSS or VCC (Threshold Selection)
│ │
│ VPFD (12) ───┬──→ Voltage Divider Detection Point (Optional)
│ │
└───────────────┘
│
GND
```
- Features: The MCU reads/writes clock/calendar data via the SPI interface; the SNAPHAT provides power-fail backup. 2. Complete application with reset control and watchdog
```
+VCC (+5V)
│
├──┬──────────────────┐
│ │ │
│ VCC (1) VBAT (13)
│ M41T94 │
│ MH6F ├──→ 3V Lithium Battery + Crystal (SNAPHAT)
│ │
├─ VSS (2,14) ──────┬──→ GND
│ │
├─ SDO (3) ──────────┬──→ MCU SPI MISO
│ │
├─ SDI (4) ──────────┬──← MCU SPI MOSI
│ │
├─ SCL (5) ──────────┬──← MCU SPI SCK
│ │
├─ E (6) ────────────┬──← MCU GPIO (SPI CS)
│ │
├─ RSTIN1 (7) ───────┬──← External Reset Button (Optional)
│ │
├─ RSTIN2 (8) ───────┬──← Watchdog Reset Input (Optional)
│ │
├─ RESET (9) ────────┬──→ MCU Reset Pin
│ │
├─ SQW (10) ─────────┬──→ MCU Interrupt Input (1Hz Wake-up)
│ │
├─ THS (11) ─────────┬──→ VCC (4.2V Threshold) or VSS (2.55V)
│ │
└─ VPFD (12) ────────┬──→ Power Supply Voltage Divider Detection
│
R1
│
├──→ MCU ADC
│
R2
│
GND
```
- THS Setting: VPFD threshold is 4.2V – 4.5V when connected to VCC; 2.55V – 2.70V when connected to VSS
- Watchdog: MCU must periodically "feed the dog" via SPI; configurable timeout range of 62.5 ms – 128 s
- Alarm Interrupt: Configurable alarm interrupt; functional even in battery backup mode
---
Key Specifications
Parameter Condition Typical Value
Crystal Startup Time VCC = 3.3V 1 s – 3 s
Clock Accuracy 25°C, 12.5 pF load ±20 ppm (±1.7 seconds/day)
SPI Clock Frequency VCC = 5V 2 MHz
SPI Clock Frequency VCC = 2.7V 1 MHz
Battery Supply Current VBAT = 3V, backup mode 500 nA (max)
VCC Operating Current VCC = 5V, SPI active 200 µA (typ)
RESET Output Pulse Width Power-on reset 100 ms – 200 ms
RESET Delay Time VCC rising edge 30 ms (typ)
Write Cycle Time SPI write to NVRAM 10 ms (max)
Data Retention Time Battery backup 10 years (typ)
Alternative Models and Competing Products
Model Manufacturer Key Differences
M41T94MH6F STMicroelectronics Original model, SOIC-28, with SNAPHAT interface
M41T94MH6 STMicroelectronics Base model, no SNAPHAT socket
M41T94MQ6F STMicroelectronics Tape-and-reel packaging version
M41T83ZMY6F STMicroelectronics Same series, I2C interface, different package
M41T62LC6F STMicroelectronics Same series, lower power consumption version
M41T56M6F STMicroelectronics I2C interface, smaller package
M41T00M6F STMicroelectronics I2C interface, basic RTC
DS1305 Maxim / Analog Devices SPI interface RTC, no NVRAM
DS3234 Maxim / Analog Devices SPI interface, built-in TCXO, high precision
PCF2123 NXP SPI interface RTC, low power consumption
RV-2123-C2 Micro Crystal High precision, low power consumption
AB0805 Abracon Integrated MEMS oscillator, no external crystal required
---
Notes
- Compatibility: The M41T94MH6F is an industrial-grade standard product. For new projects, consider the DS3234 (higher precision, built-in TCXO) or PCF2123 (lower power consumption); verify interface protocol (SPI) and package compatibility when substituting.
- Installation Instructions:
- SOIC-28 / SOH-28 package pin pitch is 1.27 mm; suitable for standard SMT reflow soldering.
- SNAPHAT module installation: The 28-pin version features a SNAPHAT socket on top; the battery/crystal module is inserted vertically and secured via a snap-fit mechanism—soldering is strictly prohibited.
- If not using the SNAPHAT module, an external 32.768 kHz crystal (12.5 pF load) and a 3V coin cell battery connected to the VBAT pin are required. - The VBAT pin must be connected to a backup power source; otherwise, clock data will be lost upon power failure.
- The THS pin must be correctly configured (connected to VCC or VSS) to select the appropriate power-fail detection threshold.
- If the VPFD pin is not used, it should be connected to VCC (THS=VCC mode) or VSS (THS=VSS mode).
- Crystal oscillator traces should be kept as short as possible and routed away from high-frequency signals to prevent clock interference.
- Soldering temperature: Reflow peak 260°C for ≤ 10 seconds; manual soldering recommended at 350°C for ≤ 3 seconds per pin.
- Software configuration:
- Initialize clock registers and set the current time upon initial power-up.
- Configure the alarm function via the ALARM register; supports single-event or periodic interrupts.
- The watchdog timer requires periodic clearing by the MCU via SPI writes; timeout triggers a RESET or an interrupt.
- Square-wave output frequency is configurable via registers (1 Hz, 1024 Hz, 4096 Hz, 32768 Hz).
- The Century bit requires manual management for date transitions across centuries.
- Technical support: For further technical assistance, please refer to the STMicroelectronics M41T94 application note or contact an authorized distributor.
---
Summary
The M41T94MH6F is a serial real-time clock (RTC) chip manufactured by STMicroelectronics. Housed in an SOIC-28 / SOH-28 package and based on low-power CMOS technology, it offers a comprehensive feature set including 44 bytes of NVRAM, a high-speed SPI interface (2 MHz), automatic power switching, a watchdog timer, programmable square-wave output, and microprocessor reset capabilities. Its integrated 32.768 kHz crystal load capacitance (12.5 pF) ensures excellent oscillation stability, while an ultra-low battery supply current of 500 nA guarantees data retention for several years during power outages. The unique SNAPHAT® top-mounted battery/crystal module design simplifies backup power integration, making it a preferred choice for high-reliability real-time clock solutions in industrial control, automotive electronics, networking equipment, and security systems. As a representative model of the M41T9x series, the M41T94MH6F balances feature richness, low power consumption, and ease of use, making it an ideal choice for clock management in moderately complex embedded systems.
Welcome to our shop!
Dear friends, if you are very interested and want to order a large number, you can contact us through Whatsapp, Wechat, email or Skype, and we will reply to you within 24 hours.
Product Description:
1.The picture only supplies the reference It may not be the exact one as in our stock because of difr NO.
2.We will ship the items within 3 working days after the payment is reached.
3.When the parts arrive at your local customs, if the parts are charged with customs duties, we are not responsible for any customs duties or import taxes.
REFUNDS & RETURN:
We offer a warranty on all items that we sold. Item will be tested before ship, it will be in good condition, if there are some problems with the item, feel free to contact us.
You must contact us before returning any product . Return must be in new condition (Buyer should return all original and undamaged items under re-saleable condition).
Return the goods and the buyer is responsible for all expenses!!
If you are satisfied with our products, please give positive feedback. Thank you for your help. If you are not satisfied, please let us know. Your constructive suggestions will become the driving force for our modification and improvement. Thanks for your understanding.
