Overview
The M41T56M6F, produced by STMicroelectronics, is a low-power, serial real-time clock (RTC) with 56 bytes of non-volatile RAM (NVRAM). This component features a built-in 32,768 Hz oscillator controlled by an external crystal and includes the first 8 bytes of the RAM for the clock/calendar function, configured in binary coded decimal (BCD) format. The device operates as a slave on a two-line, bidirectional I2C bus and includes automatic power-fail detect and switch circuitry to ensure continuous operation even during power failures, using a small lithium coin cell for backup power.
Key Specifications
| Parameter | Description | Value |
|---|---|---|
| Oscillator Frequency | 32,768 Hz | External crystal controlled |
| NVRAM Size | 56 bytes | |
| Supply Voltage | 5 V ±10% | |
| Timekeeping Voltage | Down to 2.5 V | |
| Battery Supply Current | 450 nA (typ at 3 V) | |
| Operating Temperature | –40 °C to 85 °C | |
| Package | 8-lead plastic SOIC (SO8) | |
| RoHS Compliance | Ecopack3 – Lead-free second level interconnect | |
| Data Retention Time | In excess of 10 years with a 50 mAh, 3 V lithium cell |
Key Features
- Counters for seconds, minutes, hours, day, date, month, years, and century
- 32 KHz crystal oscillator integrating load capacitance (12.5 pF) for exceptional oscillator stability
- Serial interface supports I2C bus (100 kHz protocol)
- Ultra-low battery supply current of 450 nA (typ at 3 V)
- Automatic power-fail detect and switch circuitry
- 56 bytes of general purpose RAM
- Software clock calibration to compensate crystal deviation due to temperature
- Automatic leap year compensation
- Available in an 8-lead, 150-mil, plastic SOIC package
- RoHS compliant – Lead-free second level interconnect
Applications
The M41T56M6F is suitable for a variety of applications requiring accurate timekeeping and low power consumption, such as:
- Industrial control systems
- Medical devices
- Consumer electronics
- Automotive systems
- Smart home devices
- Any system requiring real-time clock functionality with battery backup
Q & A
- What is the primary function of the M41T56M6F?
The primary function of the M41T56M6F is to serve as a low-power, serial real-time clock (RTC) with 56 bytes of NVRAM.
- What type of oscillator does the M41T56M6F use?
The M41T56M6F uses a 32,768 Hz crystal oscillator controlled by an external crystal.
- What is the typical battery supply current of the M41T56M6F?
The typical battery supply current is 450 nA at 3 V.
- What is the operating temperature range of the M41T56M6F?
The operating temperature range is –40 °C to 85 °C.
- What type of package is the M41T56M6F available in?
The M41T56M6F is available in an 8-lead plastic SOIC (SO8) package.
- Is the M41T56M6F RoHS compliant?
Yes, the M41T56M6F is RoHS compliant with an Ecopack3 – Lead-free second level interconnect.
- How long can the data be retained with a 50 mAh, 3 V lithium cell?
The data retention time is in excess of 10 years with a 50 mAh, 3 V lithium cell.
- What communication protocol does the M41T56M6F support?
The M41T56M6F supports the I2C bus protocol at 100 kHz.
- Does the M41T56M6F have automatic leap year compensation?
Yes, the M41T56M6F includes automatic leap year compensation.
- Can the M41T56M6F be calibrated for crystal deviation due to temperature?
Yes, the M41T56M6F allows for software clock calibration to compensate for crystal deviation due to temperature.
