STMicroelectronics M48T08Y-10MH1F

Overview

M48T08Y-10MH1F from STMicroelectronics is a 5 V, 64 Kbit (8 Kb × 8) non-volatile TIMEKEEPER® SRAM integrating ultra-low-power static RAM, real-time clock, power-fail control circuitry, and on-board lithium battery and 32.768 kHz crystal in a CAPHAT™ DIP-28 package. It delivers ±1 minute/month clock accuracy at 25 °C, supports BYTEWIDE™ RAM-like access to BCD-coded time registers (year/month/day/hour/minute/second), and provides automatic write protection during VCC drop below VPFD (4.2–4.5 V). It is used in industrial control panels requiring persistent time-stamped event logging under intermittent power.

For engineers reviewing the M48T08Y-10MH1F datasheet, M48T08Y-10MH1F pinout, M48T08Y-10MH1F application, or M48T08Y-10MH1F equivalent, this page details its integrated RTC+SRAM architecture, battery-backed data retention behavior, power-fail interrupt timing, and compatibility with JEDEC 8K×8 SRAM sockets and DS1643 designs.

Technical Context

The M48T08Y-10MH1F integrates a BiPORT™ SRAM array (8184 × 8) and a quartz-controlled oscillator chain on a single die, with clock registers mapped to memory addresses 1FF8h–1FFFh. Time data is stored in 24-hour BCD format and updated once per second by dedicated clock control logic-not directly from counter latches-enabling atomic read/write without halting timekeeping.

Its dual-chip-enable (E1/E2) and output-enable (G) interface implements standard SRAM timing with tAVQV ≤ 150 ns and supports both WRITE-enable– and chip-enable–controlled write cycles. A voltage-sense circuit monitors VCC continuously, triggering INT (open-drain) within microseconds of crossing VPFD, then asserting write protection and switching to battery backup when VCC falls below VSO (typ. 4.25 V).

Key Specifications

Pinout & Package

PCDIP28 CAPHAT™ package: 28-pin plastic DIP (600 mil width) with integrated lithium button cell and 32.768 kHz quartz crystal housed in the molded cap. No external battery or crystal required.

Key Features

Applications

Equivalent & Alternatives

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

Compared with DS1643-100+, M48T08Y-10MH1F reduces bill-of-materials and improves long-term reliability via integrated battery/crystal; compared with M48T35Y-10MH1F, it offers optimal cost/performance balance for applications needing only 64 Kbit of persistent storage.

Availability

M48T08Y-10MH1F is available at Aetrix Electronics and suitable for industrial HMI panels, medical device loggers, and energy metering gateways requiring stable component supply, long-lifecycle support, and guaranteed CAPHAT™ package authenticity.

Supply support for M48T08Y-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 ICs, sensors, and timing solutions for industrial, automotive, and consumer markets.

M48T08Y-10MH1F belongs to the TIMEKEEPER® family-engineered specifically for embedded systems demanding autonomous, battery-backed timekeeping and non-volatile data storage without external support components.

FAQ

What is the purpose of the INT pin, and how should it be connected?

The INT pin is an open-drain power-fail interrupt output that asserts when VCC enters the VPFD window (4.2–4.5 V). It must be pulled up externally with a 4.7 kΩ resistor to VCC or a compatible logic rail. INT signals imminent write protection and battery switchover, allowing the host MCU to complete critical writes before memory lockout occurs. It remains asserted until VCC rises above VPFD(max).

How does the M48T08Y-10MH1F handle leap years and month-end date rollovers?

The internal clock logic automatically compensates for 28-, 29- (leap year), 30-, and 31-day months through year 2100 using hardwired calendar arithmetic. No host software intervention is required-the RTC registers update correctly on February 28 → 29 (leap) or March 1 regardless of MCU activity. This behavior is implemented in silicon and verified per AN923.

Can the integrated battery be replaced or recharged?

No. The CAPHAT™ package contains a non-replaceable, non-rechargeable 48 mAh lithium button cell. It is sealed during manufacture and designed for ≥10 years of data retention in backup mode. Attempting physical replacement voids the hermetic seal and invalidates RTC accuracy and data integrity guarantees. ST recommends M4T28-BR12SH for SOIC-based designs requiring field-serviceable battery tops.

Is the M48T08Y-10MH1F RoHS compliant and lead-free?

Yes. M48T08Y-10MH1F complies with RoHS Directive 2011/65/EU and features lead-free second-level interconnects. The PCDIP28 package uses matte tin (Sn) termination finish and meets JEDEC J-STD-020 moisture sensitivity level 3 (MSL3) requirements. Full compliance documentation is available in ST's Environmental Reports (Doc ID: CD002457).