My Inquiry
My Account
STMicroelectronics M41T82ZM6F
- Part No.:
- M41T82ZM6F
- Manufacturer:
- STMicroelectronics
- Category:
- Real Time Clocks
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
M41T82ZM6F.pdf
- Description:
- IC RTC CLK/CALENDAR I2C 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:4,737
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
M41T82ZM6F from STMicroelectronics is an I²C real-time clock (RTC) IC with integrated 32.768 kHz oscillator interface, battery switchover circuitry, and 7-byte SRAM. It provides BCD-formatted timekeeping (tenths/hundredths of seconds through century), programmable alarm interrupt, watchdog timer, and operates from 2.0 V to 5.5 V with ultra-low 365 nA battery current. Used in industrial control panels requiring long-term timestamping during mains loss.
For engineers reviewing the M41T82ZM6F datasheet, M41T82ZM6F pinout, M41T82ZM6F application, or M41T82ZM6F equivalent, key selection criteria include battery-backed time retention at ≤2.38 V VCC, factory-calibrated ±5 ppm accuracy after reflow, I²C 400 kHz support, and SO8 package compatibility with legacy board layouts.
Technical Context
The M41T82ZM6F implements a dedicated RTC core with automatic leap-year correction, oscillator stop detection, and dual-voltage power sense (VSO = VRST = 2.32 V for Z-grade). Its I²C slave interface uses fixed 0xD0h address and supports sequential read/write across 32 registers including clock, alarm, watchdog, and calibration control.
It features hardware-based battery switchover without external components, a dedicated FT/RST open-drain output for power-on reset assertion, and a halt bit (HT) enabling precise power-down timestamping. The device lacks square wave output and IRQ2-differentiating it from M41T83 variants.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Battery supply current | 365 nA - enables >10-year coin-cell operation in backup mode |
| Accuracy (post-reflow) | ±5 ppm typical - meets industrial timing requirements without field calibration |
| Operating voltage range | 2.0 V to 5.5 V - supports wide-input power rails and brown-out resilience |
| I²C bus speed | 400 kHz - compatible with standard fast-mode microcontroller peripherals |
| Time format | BCD - simplifies firmware parsing of calendar data without binary conversion |
| Backup supply threshold | VSO = VRST = 2.32 V - ensures seamless switchover before system brown-out |
| User SRAM | 7 bytes - retains non-volatile configuration or event logs during power loss |
Pinout & Package
Package: 8-lead SOIC (SO8), 4.90 mm × 3.90 mm body, RoHS-compliant lead-free finish.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (FT/RST) | Frequency test / Reset output | Open-drain active-low reset signal asserted on power-up; also used for crystal frequency verification |
| 2 (SDA) | Serial data I/O | Bi-directional I²C data line with internal pull-up; requires external pull-up for bus operation |
| 3 (VBAT) | Battery supply input | Connects to lithium coin cell; powers RTC when VCC < 2.32 V; tie to VSS if unused |
| 4 (SCL) | Serial clock input | Input-only I²C clock line; synchronizes register access and data transfer |
| 5 (VSS) | Ground reference | Primary return path for all analog and digital circuits; must be low-impedance |
| 6 (XO) | Oscillator output | Drives external 32.768 kHz crystal; paired with XI to form Pierce oscillator |
| 7 (XI) | Oscillator input | Crystal feedback input; internal load capacitance programmable for ±5 ppm tuning |
| 8 (VCC) | Main supply voltage | Primary power source; triggers automatic switchover to VBAT when falling below 2.32 V |
Key Features
| Feature | Design Value |
|---|---|
| Factory-calibrated accuracy | ±5 ppm typical after two reflows - eliminates need for post-solder calibration in production |
| Programmable analog calibration | Adjusts internal load capacitance to compensate crystal tolerance and PCB parasitics |
| Dual alarm capability | Two independent alarms with repeat modes (daily, monthly, weekday) - enables complex scheduling without host CPU intervention |
| Watchdog timer | Configurable timeout from 16 ms to 2.1 s - provides fail-safe recovery for embedded firmware lockups |
| Oscillator fail detection | Hardware-monitored crystal oscillation - asserts flag and interrupt on startup failure or run-time stoppage |
Applications
| Industrial Data Logger | Medical Infusion Pump |
|---|---|
Use Scenario: Records sensor timestamps during AC power interruption for audit compliance. IC Role / Device Role / Timing Role: Primary time-of-day keeper with battery-backed continuity and leap-year-corrected calendar. Use Value: Maintains accurate UTC time across multi-year deployments without manual sync or drift correction. | Use Scenario: Tracks therapy session start/end times and dosage intervals under battery-only operation. IC Role / Device Role / Timing Role: Safety-critical RTC providing tamper-resistant time stamps for drug delivery logs. Use Value: Guarantees ≥10-year coin-cell runtime and ±5 ppm accuracy to meet IEC 62304 timing traceability requirements. |
| Smart Energy Meter | Building Automation Controller |
Use Scenario: Logs kWh consumption with precise interval metering during grid outages. IC Role / Device Role / Timing Role: Timebase for billing cycles and demand-response event scheduling. Use Value: Delivers sub-second timestamp resolution and automatic month-end rollover for regulatory reporting. | Use Scenario: Coordinates HVAC setpoint changes and lighting schedules across distributed nodes. IC Role / Device Role / Timing Role: Centralized time source synchronizing wireless sensor network wake-up windows. Use Value: Enables deterministic low-power operation via programmable alarms and watchdog-triggered recovery. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar real-time clock applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| DS1337+T&R | Lacks built-in oscillator interface; requires external crystal and load caps; no analog calibration | Higher BOM cost and layout complexity; less accurate over temperature without trimming | Select when footprint compatibility is secondary and crystal sourcing is constrained |
| M41T00M6F | Single-alarm only; no watchdog timer; 512-bit EEPROM instead of SRAM; same SO8 package | Reduced feature set for cost-sensitive designs where alarm redundancy and fail-safe reset are unnecessary | Select when only basic timekeeping and one alarm are required, and EEPROM retention is preferred over SRAM speed |
Compared with DS1337+T&R and M41T00M6F, the M41T82ZM6F delivers superior accuracy stability via programmable analog/digital calibration, integrated power-fail switchover logic, and dual-alarm flexibility - making it optimal for industrial systems demanding long-term reliability and minimal external components.
Availability
M41T82ZM6F is available at Aetrix Electronics and suitable for industrial data loggers, medical infusion pumps, smart energy meters, and building automation controllers requiring stable component supply across extended product lifecycles.
Supply support for M41T82ZM6F 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 designing and manufacturing microcontrollers, analog ICs, and timing solutions for industrial, automotive, and consumer markets.
The M41T82 belongs to ST's serial RTC product line, engineered specifically for high-accuracy, low-power, battery-backed timekeeping in space-constrained industrial and medical equipment.
FAQ
What is the minimum VCC voltage that maintains RTC functionality before switchover to VBAT?
The M41T82ZM6F switches to battery backup when VCC falls below 2.32 V (VSO/VRST threshold for Z-grade). Below this level, the RTC continues running from VBAT with full register access and alarm functionality preserved. This threshold is factory-trimmed and does not require external resistors or configuration.
Does M41T82ZM6F support automatic leap-year correction?
Yes. The M41T82ZM6F automatically adjusts calendar dates for February 29 in leap years and handles variable month lengths (28–31 days) without host software intervention. This behavior is hardwired in the RTC logic and applies to all BCD calendar registers (date, month, year, century).
Can the FT/RST pin be used solely as a reset output without frequency test function?
Yes. The FT/RST pin defaults to active-low reset output on power-up and remains in that mode unless explicitly configured via the frequency test enable bit (FTEN) in the control register. When FTEN = 0, the pin functions exclusively as RST with no frequency test activity.
How is oscillator accuracy calibrated in production?
ST performs factory calibration using a precision oven-controlled crystal reference, measuring deviation at 25 °C and programming digital correction values into the device's calibration register. Each unit receives a unique trim value, achieving ±5 ppm typical accuracy after two reflow cycles - documented in ST's production test report for M41T82ZM6F.
M41T82ZM6F Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Programmable:
- Not Verified
- Type:
- Clock/Calendar
- Features:
- Alarm, Leap Year, SRAM, Watchdog Timer
- Memory Size:
- 7B
- Time Format:
- HH:MM:SS:hh (24 hr)
- Date Format:
- YY-MM-DD-dd
- Interface:
- I2C, 2-Wire Serial
- Voltage - Supply:
- 2.38V ~ 5.5V
- Voltage - Supply, Battery:
- 2V ~ 5.5V
- Current - Timekeeping (Max):
- 10µA @ 5.5V
- Operating Temperature:
- -40°C ~ 85°C
- Mounting Type:
- Surface Mount
- Grade:
- -
- Qualification:
- -
- Supplier Device Package:
- 8-SOIC
M41T82ZM6F FAQ
1.How can I place an order for M41T82ZM6F through Aetrix?
Please submit a Request for Quotation (RFQ) for M41T82ZM6F 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 M41T82ZM6F reliable?
The price and inventory of M41T82ZM6F are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for M41T82ZM6F is usually 5 days.
3.What payment methods are accepted for M41T82ZM6F?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for M41T82ZM6F transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for M41T82ZM6F?
M41T82ZM6F orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your M41T82ZM6F 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 M41T82ZM6F?
For technical support, including M41T82ZM6F datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your M41T82ZM6F requirements.
6.How does Aetrix verify that M41T82ZM6F is sourced from the original manufacturer or authorized distributors?
All M41T82ZM6F 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 M41T82ZM6F meets industry standards.
7.What is the process for return or replacement of M41T82ZM6F?
All M41T82ZM6F units undergo pre-shipment inspection (PSI). If there is an issue with M41T82ZM6F, 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 M41T82ZM6F part is unused and in its original packaging.
Return procedure for M41T82ZM6F:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
M41T82ZM6F 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
Tech Hub
A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
