Infineon Technologies FM31276-GTR

Overview

FM31276-GTR from Infineon Technologies (formerly Cypress) is a 64-Kbit integrated processor companion IC combining ferroelectric RAM (F-RAM), real-time clock (RTC), low-VDD reset, watchdog timer, dual event counter, and 64-bit lockable serial number in a single 14-pin SOIC package. It operates from 4.0 V to 5.5 V, delivers 1.15 µA RTC backup current at 2 V, supports 1-MHz I²C interface, and guarantees 10¹⁴ read/write cycles with 151-year data retention - deployed in industrial metering and embedded control systems requiring high-reliability nonvolatile state tracking.

For engineers reviewing the FM31276-GTR datasheet, FM31276-GTR pinout, FM31276-GTR application, or FM31276-GTR equivalent, key selection criteria include its NoDelay™ F-RAM write performance, battery-backed RTC/calendar with leap-year support through 2099, programmable reset threshold (VTP), dual edge-triggered event counters, and I²C slave address configuration via A0/A1 pins for multi-device bus topology.

Technical Context

The FM31276-GTR implements two logically independent I²C devices on one die: an 8K × 8 F-RAM array (slave address 0x50–0x53) and a companion peripheral block (slave address 0x68) housing RTC registers, supervisor logic, and event counters. All timekeeping and counter functions remain active under VBAK backup power (3 V battery/capacitor), decoupled from main VDD supply.

Its supervisor core features a programmable low-VDD reset trip point (selectable 4.63 V / 4.38 V / 4.00 V / 3.07 V), a 100 ms–3 s watchdog timer with timeout flag, and a comparator (PFI-to-1.2 V reference) generating early power-fail NMI. The CAL/PFO pin serves dual mode: 512 Hz calibration output or power-fail alert signal.

Key Specifications

Pinout & Package

FM31276-GTR is housed in a 14-pin small outline integrated circuit (SOIC) package with standard 1.27 mm pitch, RoHS-compliant, UL-recognized construction.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar integrated processor companion applications.

Compared with DS1307+AT24C64 and PCF2129AT, FM31276-GTR delivers unified reliability via single-chip F-RAM endurance, battery-backed event counting, and programmable reset - reducing PCB area by >60%, eliminating inter-chip timing dependencies, and removing EEPROM wear-out risk in long-life deployments.

Availability

FM31276-GTR is available at Aetrix Electronics and suitable for smart metering, industrial data loggers, medical device controllers, and building energy managers requiring stable component supply, long-term lifecycle support, and guaranteed RoHS/UL compliance.

Supply support for FM31276-GTR 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

Infineon Technologies is a global semiconductor leader headquartered in Munich, Germany, delivering power management, sensing, connectivity, and security solutions for automotive, industrial, and IoT applications.

The FM31276-GTR belongs to Infineon's integrated processor companion product line - designed specifically to replace discrete RTC, EEPROM, supervisor, and counter ICs in resource-constrained embedded systems where reliability, longevity, and board space are critical.

FAQ

What is the maximum I²C clock frequency supported by FM31276-GTR?

The FM31276-GTR supports I²C operation up to 1 MHz, with full backward compatibility for standard-mode (100 kHz) and fast-mode (400 kHz) timings. Its SDA/SCL inputs include Schmitt triggers and slew-rate control to ensure robust communication across noisy industrial environments without external filtering components.

How does the F-RAM endurance compare to standard EEPROM in practical use?

FM31276-GTR's F-RAM guarantees 10¹⁴ read/write cycles - 100 million times higher than typical EEPROM (1 million cycles). In a data logger writing every second, this extends usable life from ~11 days (EEPROM) to over 3 million years, effectively eliminating wear-out concerns in all known industrial applications.

Can the RTC operate independently when main power (VDD) is removed?

Yes - the RTC, event counters, and serial number retain functionality solely on VBAK (3 V battery or capacitor) when VDD falls below ~2.5 V. The device automatically switches to backup power without glitch, preserving time, counts, and configuration registers continuously across power loss events.

Is the 64-bit serial number truly one-time programmable and irreversible?

Yes - once the lock bit (bit 7 of RTC register 0Bh) is set, the 64-bit serial number area becomes permanently read-only. No hardware or software method exists to alter it thereafter, providing cryptographically verifiable device identity essential for anti-counterfeiting and secure firmware authentication.