M41T82RM6F - Low-Power I2C RTC with 32.768 kHz | STMicroelectronics
MPN: M41T82RM6F ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.0112 | $4.01 |
| 10 | $4.0112 | $40.11 |
| 100 | $4.0112 | $401.12 |
| 500 | $4.0112 | $2,005.60 |
| 1,000 | $4.0112 | $4,011.20 |
M41T82RM6F Overview
A real-time clock is a specialized timekeeping integrated circuit that maintains seconds, minutes, hours, date, day, month, and year information even when the main system is unpowered. The RTC category sits within clock and timing semiconductors, where crystal-based oscillators, dividers, registers, and digital interfaces work together to provide a stable time reference. Unlike a software timer, an RTC can continue counting through power loss and can be read again when the host processor restarts.
The M41T82RM6F combines an external-crystal-controlled oscillator architecture with low-power serial communication. Its programmable alarm and timer functions can wake a connected microcontroller or signal that a scheduled interval has elapsed. The I2C interface reduces wiring requirements in compact embedded systems, while the 2.0 V to 5.5 V operating range supports both low-voltage and conventional supply environments. The 365 nA battery supply current is especially relevant for battery-backed meters, industrial recorders, and portable instruments.
The STMicroelectronics M41T82 family description identifies the SO8 version as using an external 32.768 kHz crystal. Accurate timekeeping therefore depends not only on the RTC electronics but also on crystal selection, load-capacitance matching, layout quality, and temperature behavior. The M41T82RM6F is suited to data loggers, access-control terminals, metering equipment, industrial controllers, and consumer products requiring persistent timestamps. Its low standby consumption helps reduce energy use when the main supply is absent.
For a robust design, place the RTC and its crystal close together on the PCB, keep high-current switching paths away from the oscillator network, and provide the required bypass capacitance. Confirm the exact pin functions, register behavior, alarm polarity, and electrical limits against the manufacturer datasheet before layout release. The verified source data supports the component identity, package, interface, oscillator, supply range, and low-current claims; additional operating details remain subject to the full STMicroelectronics datasheet.
This page combines verified manufacturer and distributor information with application guidance, comparison fields, and design notes. It is intended to help engineers identify whether the M41T82RM6F fits a low-power battery-backed timekeeping design while distinguishing verified facts from parameters requiring confirmation from the latest datasheet.
Drop-in alternatives for M41T82RM6F — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with M41T82RM6F (same form factor and footprint) — differing in Function.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
M41T82RM6E
✅ Drop-In📋 Reference alternative (not in catalog)
M41T81M6F
✅ Drop-In📋 Reference alternative (not in catalog)
M41T82RM6F
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$4.0112 / Unit
View Datasheet →M41T82RM6E
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
M41T81M6F
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
M41T82RM6F Specifications
| Device Type | Serial I2C real-time clock and calendar |
| Interface | I2C, 2-wire serial |
| Register Address Format | 7-bit |
| Clock Operating Voltage | 2.0 V to 5.5 V |
| Oscillator Frequency | 32.768 kHz |
| Oscillator Control | External crystal-controlled for SO8 package |
| Battery Supply Current | 365 nA ultra-low |
| Package | 8-pin SOIC |
| Package Width | 3.90 mm |
| Mounting Type | Surface mount |
| Function | Timekeeping and calendar |
| Alarm Function | Available; detailed polarity and behavior require datasheet confirmation |
| Timer Function | Available; detailed configuration requires datasheet confirmation |
| Battery Backup | Supported by the M41T8x RTC family |
M41T82RM6F 3.90 mm Pin Configuration Guide
Pin configuration for M41T82RM6F (3.90 mm package). Pin numbering, functions, and connection diagrams are defined in the manufacturer datasheet. Refer to it for the exact footprint and soldering guidelines.
No detailed pinout data available for M41T82RM6F.
Refer to the datasheet for full pin configuration.
Typical Applications
M41T82RM6F is suitable for 6 applications: Battery-Backed Industrial Data Loggers, Access-Control and Security Systems, Utility and Smart Metering, Portable Measurement Instruments, Scheduled Industrial Control, Consumer Electronics with Persistent Time.
Battery-Backed Industrial Data Loggers
The M41T82RM6F is suitable for industrial recorders that must preserve timestamps while the main supply is removed or the operator changes equipment. Its 32.768 kHz crystal-controlled timebase provides a dedicated low-frequency reference, while the I2C interface lets a microcontroller read calendar registers without recreating time after every power cycle. The verified 365 nA ultra-low battery supply current is useful for reducing standby consumption, although total logger battery life also depends on sensor load, radio duty cycle, battery capacity, and regulator efficiency. The SO8 package helps keep the RTC compact, and the external-crystal arrangement permits frequency accuracy to be tailored through crystal selection and layout.
Recommended
Access-Control and Security Systems
The M41T82RM6F can maintain calendar time in access-control readers, electronic locks, and security terminals where event records must retain accurate date and time after a power interruption. A host processor can read the RTC through the 2-wire I2C interface and use scheduled alarm or timer events to reduce continuous polling. The 2.0 V to 5.5 V operating range supports embedded systems with varied logic rails, while the low battery supply current helps preserve timekeeping during backup operation. Designers should verify alarm polarity, interrupt behavior, and the exact backup-battery connection in the manufacturer datasheet before finalizing the security system architecture.
Recommended
Utility and Smart Metering
The M41T82RM6F fits metering products that need a persistent time reference for consumption records, billing intervals, tamper logs, or remote diagnostics. Its RTC can continue counting from a backup source while the meter main rail is unavailable, allowing a microcontroller to recover a coherent timestamp after power restoration. The 32.768 kHz crystal-controlled timebase is appropriate for calendar-resolution systems, and the low-power battery current supports long standby intervals. The final design must account for crystal aging, temperature compensation, supply switching, and communication scheduling. Because the verified data does not provide calibration, accuracy, or interrupt specifications, those details should be taken from the full STMicroelectronics documentation.
Recommended
Portable Measurement Instruments
The M41T82RM6F is appropriate for portable measurement instruments where samples must be associated with real calendar dates and times. A battery-backed RTC allows the instrument to retain timing information when the main display or measurement circuitry is powered down, improving data integrity and simplifying restart behavior. The I2C interface reduces the number of host pins required to read the clock, and the 2.0 V to 5.5 V range supports both low-voltage internal rails and higher-voltage mixed-signal sections. For handheld products, the designer should minimize leakage around the backup supply, protect the crystal from mechanical shock and temperature gradients, and confirm the device’s absolute maximum ratings and battery chemistry requirements before release.
Recommended
Scheduled Industrial Control
The M41T82RM6F can support scheduled control and maintenance functions in industrial equipment by providing a persistent clock and alarm reference. A microcontroller can use RTC time and programmed events to trigger logging, calibration, display updates, or communication windows without relying on the host remaining continuously powered. The 32.768 kHz oscillator and low battery current make the device appropriate for equipment that spends substantial time in standby. The SO8 footprint supports compact controller boards, but the crystal network should be isolated from relays, power inductors, and motor switching nodes. Firmware should account for oscillator startup, alarm behavior, and any backup-source transitions defined by the complete datasheet.
Recommended
Consumer Electronics with Persistent Time
The M41T82RM6F can be integrated into consumer products that need a reliable time reference for logs, timers, scheduled controls, or data export. Its I2C interface allows a host processor to initialize the RTC once and read time efficiently, while the backup-capable architecture avoids repeated synchronization with an external network. The 365 nA battery supply current claim can reduce maintenance requirements in products that operate from a primary source for long periods. The component is most useful when the product must retain timestamps through power loss; ordinary products that only need a host timer may not require a dedicated RTC. Confirm package, supply, crystal, and backup-battery requirements before layout.
Recommended
Recommended Products Summary
Engineering reference data for M41T82RM6F — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | M41T82RM6E | M41T81M6F | M41T82RM6F | M41T82RM6E | M41T81M6F |
|---|---|---|---|---|---|---|
| Device Type | I2C real-time clock and calendar | Related M41T82 RTC variant | Related STMicroelectronics RTC variant | I2C real-time clock and calendar | Related M41T82 orderable variant | Related STMicroelectronics RTC family member |
| Brand | STMicroelectronics | STMicroelectronics | STMicroelectronics | STMicroelectronics | STMicroelectronics | STMicroelectronics |
| Package | 8-SOIC | 8-SOIC - same package family; verify footprint | 8-SOIC - same package family; verify footprint | 8-SOIC | 8-SOIC - same package family; verify footprint | 8-SOIC - same package family; verify footprint |
Key Differentiators
- Dedicated low-power timekeeping function (vs M41T81M6F)
- Broad clock operating range (vs M41T82RM6E)
- External crystal integration in SO8 package (vs M41T82RM6F)
- Compact serial connectivity (vs M41T81M6F)
Design Notes
Place the M41T82RM6F and its external 32.768 kHz crystal close together, with the shortest practical ground and signal paths. Keep the crystal away from switching regulators, relays, motor outputs, and high-current edges because crystal amplitude and frequency stability are sensitive to electrical noise. The verified source confirms external-crystal control for the SO8 package, but exact load-capacitance and grounding values must be taken from the manufacturer layout guidance.
Design the backup-power path so the RTC receives a stable supply when the main rail collapses. Check whether the application uses a dedicated backup cell, a supercapacitor, or a switched supply, and account for leakage, reverse current, and battery chemistry. The verified 365 nA figure is a device-level claim and does not by itself guarantee system-level standby life.
Do not substitute an M41T82RM6E or M41T81M6F solely because the package name appears similar. Confirm the complete MPN, pin assignment, I2C address, register map, alarm behavior, oscillator requirements, supply limits, and orderable suffix against the manufacturer datasheet. A mechanically similar package can still require firmware changes or different initialization sequences.
Keep the I2C traces short and route them away from analog switching and high-current power paths. Confirm pull-up resistor values and bus capacitance against the operating voltage and I2C implementation specified by the manufacturer. Because the supplied data does not include bus timing, rise-time, or pull-up requirements, treat those values as datasheet-derived design inputs rather than assumptions.
Compliance Information
The supplied verified data does not state RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals status for M41T82RM6F. These fields remain unknown rather than inferred.
