STMicroelectronics M48T37V-10MH1F

Overview

M48T37V-10MH1F from STMicroelectronics is a monolithic TIMEKEEPER® SRAM integrating 256 Kbit (32 K × 8) non-volatile static RAM, real-time clock, power-fail control circuitry, watchdog timer, and battery-switchover logic in a single 44-pin SOIC package. It operates at 3.0–3.6 V, provides automatic WRITE protection below 2.7–3.0 V VPFD, and maintains timekeeping and data retention for ≥7 years on internal lithium battery during VCC loss. Used in industrial PLCs, telecom base station controllers, and medical diagnostic equipment requiring persistent time-stamped logging.

For engineers reviewing the M48T37V-10MH1F datasheet, M48T37V-10MH1F pinout, M48T37V-10MH1F application, or M48T37V-10MH1F equivalent, key selection criteria include battery-backed RTC accuracy (±20 ppm over –40°C to +85°C), guaranteed 7-year data retention at 25°C, VPFD window (2.7–3.0 V), and SNAPHAT®-compatible 44-pin SOH44 mechanical interface with gold-plated top-socket contacts.

Technical Context

The device implements a BiPORT™ dual-port memory architecture where clock registers (7FF1h–7FFFh) reside in user-accessible SRAM space and are updated once per second by dedicated clock chain logic. The 32.768 kHz crystal oscillator feeds a precision divider chain with programmable calibration register (7FF8h D0–D5) enabling software fine-tuning of timing drift.

Power management integrates voltage-sense comparators for VPFD (2.7–3.0 V) and VSO (2.5 V typ.) thresholds, triggering automatic chip deselect, WRITE disable, and seamless battery switchover without external components. The open-drain IRQ/FT pin supports both alarm interrupts and frequency test output for real-time calibration verification.

Key Specifications

Pinout & Package

The M48T37V-10MH1F uses a 44-pin SOH44 plastic small outline package (330 mil width) with gold-plated top-socket contacts for mating with SNAPHAT® battery/crystal housing (e.g., M4T32-BR12SH). The package supports surface-mount reflow before snap-on assembly, preventing thermal damage to the lithium cell and crystal.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar battery-backed RTC+SRAM applications.

Compared with DS1307+AT24C256, M48T37V-10MH1F reduces component count by 2×, eliminates external power supervision ICs, and guarantees atomic time+data updates. Against M48T59Y-70MH1E, it enables lower-power 3.3 V system integration but trades off memory density for voltage compatibility.

Availability

M48T37V-10MH1F is available at Aetrix Electronics and suitable for industrial PLC data logging, telecom base station timing, and medical diagnostic equipment requiring stable component supply across extended product lifecycles.

Supply support for M48T37V-10MH1F 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 microcontrollers, power management ICs, and timing solutions for industrial, automotive, and consumer markets.

M48T37V belongs to the TIMEKEEPER® family of integrated RTC+SRAM devices engineered specifically for mission-critical applications demanding guaranteed timekeeping and data persistence during power loss.

FAQ

What is the function of the SNAPHAT® top and is it included with M48T37V-10MH1F?

The SNAPHAT® top (e.g., M4T32-BR12SH) contains the 120 mAh lithium coin cell and 32.768 kHz crystal, and mounts directly onto the SOH44 package after reflow soldering. It is not included with M48T37V-10MH1F - the SOIC and SNAPHAT® are shipped separately in anti-static tubes or tape-and-reel to prevent battery discharge during handling.

How does the M48T37V-10MH1F handle leap year calculation and month-end date rollover?

The internal clock logic automatically corrects for 28-, 29- (leap year through 2100), 30-, and 31-day months by updating the date register based on stored month-length rules. This occurs transparently during the 1 Hz update cycle and requires no firmware intervention beyond initial time setup.

Can the watchdog timer be disabled, and what happens when it times out?

The watchdog timer cannot be fully disabled but can be configured for infinite timeout by clearing all BMB bits (7FF7h D0–D4 = 0). When active and not fed, timeout asserts either RST (if WDS = 0) or IRQ/FT (if WDS = 1), providing flexible system recovery options without requiring external reset ICs.

What is the significance of the "H1F" suffix in M48T37V-10MH1F?

The "H1F" denotes the SOH44 package variant with 4-socket SNAPHAT® interface and RoHS-compliant lead-free finish. "10M" specifies 100 ns maximum access time; "V" indicates 3.0–3.6 V operation; "F" confirms industrial temperature grade (–40°C to +85°C).