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STMicroelectronics M41T11MH6E
- Part No.:
- M41T11MH6E
- Manufacturer:
- STMicroelectronics
- Category:
- Real Time Clocks
- Package:
- 28-SOP (0.350", 8.89mm Width) with SNAPHAT Sockets
- Datasheet:
-
M41T11MH6E.pdf
- Description:
- IC RTC CLK/CALENDAR I2C 28SOH
- Quantity:
- Payment:
- Shipping:
Inventory:4,444
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Product details
Overview
M41T11MH6E from STMicroelectronics is a serial real-time clock (RTC) IC with integrated 32.768 kHz crystal oscillator, 56 bytes of NVRAM, I²C interface (100 kHz), ultra-low battery current (0.8 μA typ. at 3 V), and automatic power switchover - used for timekeeping and data retention in industrial control panels requiring long-term timestamping during mains failure.
For engineers reviewing the M41T11MH6E datasheet, M41T11MH6E pinout, M41T11MH6E application, or M41T11MH6E equivalent, key selection criteria include battery-backed RTC accuracy across –40 to 85°C, software calibration support for ±2 ppm drift compensation, SNAPHAT®-compatible 28-pin SOIC packaging, and I²C timing compliance per standard-mode bus specifications.
Technical Context
The M41T11MH6E implements a BCD-formatted 8-register clock/calendar (seconds through century) with automatic leap-year correction and STOP-bit–controlled oscillator enable/disable. Its on-chip voltage-sense circuitry triggers seamless VCC-to-VBAT switchover below VSO (typically 2.0 V), entering ultra-low-power retention mode.
It uses a two-wire I²C interface with fixed slave address 0xD0h, supports sequential and alternate read modes, and features an open-drain FT/OUT pin for 1 Hz or 32.768 kHz output testing. The internal address pointer auto-increments after each byte transfer, eliminating external address management overhead.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Interface | I²C bus, 100 kHz max clock frequency - ensures compatibility with legacy microcontrollers without high-speed mode support. |
| Operating Voltage | 2.0 to 5.5 V - enables direct integration into 3.3 V or 5 V logic systems without level-shifting. |
| Battery Current | 0.8 μA typical at 3 V - extends lithium coin-cell life beyond 5 years with 48 mAh capacity. |
| Temperature Range | –40°C to +85°C - validated for use in uncontrolled industrial enclosures and outdoor metering housings. |
| NVRAM Size | 56 bytes - sufficient for firmware timestamps, configuration flags, and event logs without external memory. |
| Crystal Load | 12.5 pF integrated - eliminates need for external load capacitors, reducing BOM count and layout sensitivity. |
| Accuracy | Better than ±2 ppm at 25°C with software calibration - reduces monthly time error to under ±5.3 seconds after tuning. |
Pinout & Package
The M41T11MH6E is supplied in a 28-lead plastic small outline (SOH28) package with gold-plated socket contacts for top-mount SNAPHAT® battery/crystal housing (M4Txx-BR12SH). Pin numbering follows standard SOIC convention with pin 1 at top-left corner.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1–4, 25–28 | Socket contact pads | Gold-plated mating interface for SNAPHAT® housing - enables post-reflow battery installation to avoid thermal damage. |
| 5 (VCC) | Main supply input | Accepts 2.0–5.5 V; powers RTC and RAM during normal operation and initiates automatic switchover when falling below VSO. |
| 6 (VSS) | Ground reference | Common return path for all analog and digital circuits; must be low-impedance to maintain oscillator stability. |
| 7 (SCL) | I²C clock input | Input-only, requires external pull-up; defines timing for all serial transfers per standard-mode I²C specification. |
| 8 (SDA) | I²C bidirectional data | Open-drain, requires external pull-up; carries address, register data, and ACK/NACK signals. |
| 9 (FT/OUT) | Frequency test/output driver | Open-drain output configurable for 1 Hz or 32.768 kHz - used for system-level timing verification and LED blink control. |
| 10 (VBAT) | Battery supply input | Connects to lithium coin cell; powers RTC and NVRAM during main supply loss - no external diode required due to internal switchover logic. |
| 11 (OSCO) | Oscillator output | Drives external 32.768 kHz crystal; internal 12.5 pF load capacitance eliminates need for discrete caps. |
| 12 (OSCI) | Oscillator input | High-impedance crystal node; paired with OSCO to form Pierce oscillator circuit with temperature-stable startup. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated crystal oscillator | 12.5 pF load capacitance - removes external capacitor dependency and improves long-term aging stability. |
| Software clock calibration | Adjustable trim bits correct for crystal deviation across temperature - achieves ±2 ppm accuracy without hardware trimming. |
| Automatic leap-year compensation | Hardware-enforced calendar logic - eliminates firmware overhead for date rollover in February across century boundaries. |
| SNAPHAT®-ready packaging | 28-pin SOIC with dual-row gold contacts - enables modular battery/crystal integration after SMT reflow, avoiding thermal stress on Li cells. |
| Ultra-low retention current | 0.8 μA at 3 V - allows use of standard CR2032 or BR1225 batteries with >5-year data retention guarantee. |
Applications
| Industrial Energy Metering | Medical Infusion Pump Logging |
|---|---|
|
Use Scenario: Recording energy consumption timestamps during grid outages and tariff switching events. IC Role / Device Role / Timing Role: Primary RTC with battery-backed NVRAM storing kWh readings and fault logs across power cycles. Use Value: Maintains accurate time and retains critical billing data for >5 years on a single 48 mAh lithium cell without firmware intervention. |
Use Scenario: Timestamping drug delivery events and alarm triggers in battery-powered portable infusion systems. IC Role / Device Role / Timing Role: Time-of-event recorder synchronized to clinical schedules and regulatory audit requirements. Use Value: Delivers ±2 ppm accuracy after calibration - ensuring dose interval compliance within FDA 21 CFR Part 11 traceability standards. |
| Building Automation Controller | Smart Grid Communication Gateway |
|
Use Scenario: Scheduling HVAC cycles and logging occupancy sensor activity across seasonal temperature swings. IC Role / Device Role / Timing Role: Temperature-compensated timebase for deterministic scheduling and firmware update coordination. Use Value: Software calibration compensates for crystal drift over –40°C to +85°C ambient - eliminating seasonal clock drift corrections. |
Use Scenario: Time-stamping IEC 61850 GOOSE messages and synchronizing firmware updates across distributed substations. IC Role / Device Role / Timing Role: Local time anchor for message sequencing and secure firmware signature validation windows. Use Value: Automatic VCC-to-VBAT switchover preserves time continuity during brownouts - preventing message ordering ambiguity in SCADA logs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar RTC-with-NVRAM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| DS1307+ (Maxim Integrated) | Lacks integrated oscillator load capacitance; requires external 12 pF caps; no software calibration; only 56-byte RAM but no century register. | Supports basic timekeeping only - unsuitable for leap-year–aware applications or environments where crystal aging must be corrected. | Select when cost sensitivity outweighs long-term accuracy needs and external cap placement is acceptable. |
| PCF8563 (NXP) | Lower battery current (0.25 μA), but no integrated oscillator tuning; limited to 2.0–5.5 V; lacks century register and automatic leap-year logic. | Optimized for ultra-low-power wearables - missing calendar robustness needed for industrial metering or medical devices. | Choose for battery-constrained portable designs where calendar complexity is managed in firmware. |
Compared with DS1307+ and PCF8563, the M41T11MH6E uniquely combines integrated oscillator tuning, hardware leap-year handling, and SNAPHAT®-enabled modular battery integration - making it the only option supporting maintenance-free, field-deployable timekeeping in harsh industrial environments.
Availability
M41T11MH6E is available at Aetrix Electronics and suitable for industrial energy metering, medical device logging, building automation controllers, and smart grid gateways requiring stable component supply with guaranteed long-term availability.
Supply support for M41T11MH6E includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing analog, MCU, power, and timing solutions for industrial, automotive, and consumer markets.
The M41T11MH6E belongs to ST's precision RTC product line, engineered specifically for applications demanding high-accuracy, battery-backed timekeeping with minimal external components and extended operational lifetime in wide-temperature environments.
FAQ
What is the function of the FT/OUT pin on the M41T11MH6E?
The FT/OUT pin is an open-drain output that can be configured via internal register bits to deliver either a 1 Hz square wave or the raw 32.768 kHz oscillator signal. It serves diagnostic timing verification, LED blink control, or synchronization of external peripherals without consuming additional GPIO resources from the host microcontroller.
Does the M41T11MH6E require external load capacitors for the crystal?
No. The M41T11MH6E integrates 12.5 pF load capacitance directly into its oscillator circuitry, eliminating the need for external capacitors. This simplifies PCB layout, reduces BOM count, and improves long-term frequency stability by removing component tolerance and parasitic variation effects.
How does the M41T11MH6E handle power failure and battery switchover?
The device continuously monitors VCC and automatically switches to VBAT when voltage drops below the switchover threshold (VSO ≈ 2.0 V). During transition, it terminates active I²C transactions, disables the oscillator, and enters ultra-low-current retention mode - preserving time and RAM contents without host intervention or external circuitry.
Can the M41T11MH6E operate with a 3.3 V supply and still retain full functionality?
Yes. The M41T11MH6E operates fully across 2.0–5.5 V, including 3.3 V nominal systems. All specifications - including I²C timing, battery current (0.8 μA typ.), and oscillator stability - are guaranteed at 3.3 V, making it compatible with modern low-voltage microcontrollers without level shifters or voltage translation.
M41T11MH6E Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- -
- Package/Case:
- 28-SOP (0.350", 8.89mm Width) with SNAPHAT Sockets
- Packaging:
- Tube
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Type:
- Clock/Calendar
- Features:
- Leap Year, NVSRAM
- Memory Size:
- 56B
- Time Format:
- HH:MM:SS
- Date Format:
- YY-MM-DD-dd
- Interface:
- I2C, 2-Wire Serial
- Voltage - Supply:
- 2V ~ 5.5V
- Voltage - Supply, Battery:
- 2.5V ~ 3.5V
- Current - Timekeeping (Max):
- 70µA @ 2V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C
- Mounting Type:
- Surface Mount
- Grade:
- -
- Qualification:
- -
- Supplier Device Package:
- 28-SOH
M41T11MH6E FAQ
1.How can I place an order for M41T11MH6E through Aetrix?
Please submit a Request for Quotation (RFQ) for M41T11MH6E on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for M41T11MH6E reliable?
The price and inventory of M41T11MH6E are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for M41T11MH6E is usually 5 days.
3.What payment methods are accepted for M41T11MH6E?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for M41T11MH6E transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for M41T11MH6E?
M41T11MH6E orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your M41T11MH6E order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for M41T11MH6E?
For technical support, including M41T11MH6E datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your M41T11MH6E requirements.
6.How does Aetrix verify that M41T11MH6E is sourced from the original manufacturer or authorized distributors?
All M41T11MH6E products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that M41T11MH6E meets industry standards.
7.What is the process for return or replacement of M41T11MH6E?
All M41T11MH6E units undergo pre-shipment inspection (PSI). If there is an issue with M41T11MH6E, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The M41T11MH6E part is unused and in its original packaging.
Return procedure for M41T11MH6E:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
M41T11MH6E Tags
-
MCP7940N-I/SN
Microchip Technology
-
MCP7940MT-I/MNY
Microchip Technology
-
PCF85063ATL/1,118
NXP USA Inc.
-
MCP7940NT-I/SN
Microchip Technology
-
MCP7940NT-I/MS
Microchip Technology
-
MCP7940N-I/MS
Microchip Technology
-
PCF85063AT/AY
NXP USA Inc.
-
PCF85063TP/1Z
NXP Semiconductors
-
PCF85063ATT/AJ
NXP USA Inc.
-
MCP7940NT-E/SN
Microchip Technology
-
MCP7940NT-I/MNY
Microchip Technology
-
MCP79400T-I/SN
Microchip Technology
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