STMicroelectronics M48T37V-10MH6E

Overview

M48T37V-10MH6E from STMicroelectronics is a 32 Kbit × 8 (256 Kbit) battery-backed TIMEKEEPER® SRAM integrating real-time clock, ultra-low-power static RAM, power-fail control, watchdog timer, and microprocessor reset-operating at 3.0–3.6 V with VPFD of 2.7–3.0 V and factory-calibrated 32.768 kHz crystal. It delivers non-volatile timekeeping and memory retention for >7 years on internal lithium battery during VCC loss, used in industrial control panels requiring persistent timestamping and configuration storage.

For engineers reviewing the M48T37V-10MH6E datasheet, M48T37V-10MH6E pinout, M48T37V-10MH6E application, or M48T37V-10MH6E equivalent, key selection criteria include battery-backed RTC accuracy (±20 ppm over –40°C to +85°C), write-protection voltage threshold (VPFD = 2.7–3.0 V), SOH44 package compatibility with SNAPHAT® top, and alarm interrupt capability active in backup mode.

Technical Context

The M48T37V integrates a BiPORT™ SRAM array (32,752 × 8) with dedicated TIMEKEEPER registers mapped to addresses 7FF1h–7FFFh in BCD format, updated once per second by an on-chip oscillator circuit. Clock data-including century, year, month, date, day, hour, minute, second-is accessed as standard memory reads/writes, with separate READ/WRITE bits (D6/D7 of register 7FF8h) enabling atomic clock freeze and update.

Its power management includes autonomous switchover to internal lithium battery below VSO (2.5 V typ.), VPFD-triggered write protection (2.7–3.0 V), and CMOS standby mode with <1 μA current draw. The IRQ/FT pin provides dual-function open-drain output: programmable alarm interrupt or frequency test signal for software calibration of crystal drift.

Key Specifications

Pinout & Package

Package: SOH44 - 44-pin plastic small outline (330 mil width), designed for direct mating with 4-pin SNAPHAT® housing (e.g., M4T28-BR12SH) containing crystal and battery. Gold-plated sockets enable post-reflow top-mount assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with DS1743-120+, M48T37V-10MH6E enables compact 3.3 V designs with post-reflow battery integration; versus M48T37Y-10MH6E, it offers lower voltage operation but zero supply voltage interchangeability-requiring strict BOM segregation by VCC domain.

Availability

M48T37V-10MH6E is available at Aetrix Electronics and suitable for industrial PLCs, medical infusion pumps, smart energy meters, and telecom base station controllers requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for M48T37V-10MH6E 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 sensor solutions for industrial, automotive, and consumer markets.

M48T37V belongs to the TIMEKEEPER® family-engineered specifically for embedded systems demanding integrated, battery-backed real-time clock and non-volatile SRAM in a single monolithic IC with robust power-fail resilience.

FAQ

What is the role of the SNAPHAT® top, and is it included with M48T37V-10MH6E?

The SNAPHAT® top (e.g., M4T28-BR12SH) is a separate 4-pin housing containing the 32.768 kHz crystal and lithium battery; it mounts directly onto the SOH44 package after reflow soldering. M48T37V-10MH6E ships as the bare SOIC only-SNAPHAT® must be ordered separately and is not included in the M48T37V-10MH6E unit shipment.

How does the M48T37V handle clock updates during a READ operation?

The M48T37V uses a BiPORT™ architecture where clock registers (7FF1h–7FFFh) are memory-mapped but updated independently by hardware. To prevent reading inconsistent values, users must set the READ bit (D6 of 7FF8h) to halt updates before reading; registers then hold static values until the bit is cleared, ensuring atomic time capture without disrupting oscillator operation.

Can the watchdog timer generate both reset and interrupt outputs?

Yes-the WDS bit (D7 of 7FF7h) selects watchdog behavior: when cleared (0), timeout asserts RST (open-drain reset); when set (1), timeout asserts IRQ/FT (open-drain interrupt). This dual-mode capability allows flexible system-level fault recovery strategies without external logic.

What happens to SRAM data integrity during rapid VCC transients?

During VCC noise or negative-going transients entering the VPFD window (2.7–3.0 V), the M48T37V may enter unintended power-fail deselect. ST recommends 100 nF ceramic decoupling at VCC/VSS pins and avoiding conductive foam contact with SNAPHAT® to maintain deterministic write protection and prevent spurious high-Z transitions.