STMicroelectronics M48Z58Y-70MH1F

Overview

M48Z58Y-70MH1F from STMicroelectronics is a 64 kbit (8 k × 8) non-volatile zero-power SRAM with integrated lithium battery, power-fail detection circuitry, and automatic write protection. It operates at 4.5–5.5 V, features 70 ns read/write cycle time, and provides ≥10 years data retention in battery backup mode. It serves as a drop-in replacement for standard JEDEC 8 k × 8 SRAMs in real-time clock (RTC), metering, and industrial control systems requiring persistent memory without external backup components.

For engineers reviewing the M48Z58Y-70MH1F datasheet, M48Z58Y-70MH1F pinout, M48Z58Y-70MH1F application, or M48Z58Y-70MH1F equivalent, key selection criteria include VPFD window (4.2–4.5 V), SOH28 package compatibility with SNAPHAT® top M4Z28-BR00SH1, battery-backed data retention under VCC < 3.0 V, and CMOS/TTL-compatible control timing (tELQV = 70 ns, tGLQV = 35 ns).

Technical Context

The M48Z58Y-70MH1F integrates a monolithic 8 k × 8 SRAM array, voltage-sense switching circuitry, and lithium cell management logic on a single die. Its power-fail detection triggers automatic chip deselect and write protection when VCC falls within the 4.2–4.5 V VPFD window, and switches to internal battery supply at VSO = 3.0 V.

It supports three operational modes: active READ/WRITE (E low, W high/low), CMOS standby (E high), and battery backup (VCC ≤ VSO). The SOH28 package enables post-reflow mounting of the SNAPHAT® battery top via gold-plated socket contacts, preventing thermal damage during SMT assembly.

Key Specifications

Pinout & Package

The M48Z58Y-70MH1F is housed in a 28-pin SOH28 (small outline) package designed for surface-mount assembly and subsequent top-mounting of the SNAPHAT® battery housing (M4Z28-BR00SH1). The package features gold-plated contacts on both top and bottom surfaces to enable reliable mechanical and electrical connection to the battery module after reflow soldering.

Key Features

Applications

Equivalent & Alternatives

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

Compared with M48Z58-70PC1, the M48Z58Y-70MH1F offers SMT manufacturability and thermal safety via SNAPHAT® top-mounting, while DS1248W-120+T&R trades speed for broader VPFD overlap but demands layout revision and lacks ST's SOH28 mechanical integration.

Availability

M48Z58Y-70MH1F is available at Aetrix Electronics and suitable for smart metering, industrial PLCs, RTC backup, and medical event logging requiring stable component supply across multi-year production cycles.

Supply support for M48Z58Y-70MH1F 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, sensors, and memory solutions for industrial, automotive, and consumer markets.

The M48Z58Y belongs to ST's ZEROPOWER® SRAM product line, engineered specifically for applications demanding seamless, maintenance-free non-volatility in space-constrained, thermally sensitive, or mission-critical embedded systems.

FAQ

What is the purpose of the SNAPHAT® top and how is it installed?

The SNAPHAT® top (e.g., M4Z28-BR00SH1) contains a 48 mAh lithium button cell and mounts directly onto the SOH28 package after reflow soldering. Its keyed mechanical design prevents reverse insertion, and gold-plated contacts ensure low-resistance connection. This post-reflow installation avoids exposing the battery to peak reflow temperatures (>255 °C), which would degrade cell capacity or cause venting.

How does the M48Z58Y-70MH1F handle power transitions during WRITE operations?

If VCC drops into the VPFD window (4.2–4.5 V) during a WRITE cycle, the device immediately disables writes and places all outputs in high-impedance state. Data at the addressed location may be corrupted, but the remainder of the 8 kbyte array remains intact. Recovery requires VCC to rise above VPFD(max) (4.5 V) for ≥40 ms before normal operation resumes, ensuring stable power restoration.

Can the M48Z58Y-70MH1F be used in place of standard SRAMs without circuit modifications?

Yes - it is pin- and function-compatible with JEDEC-standard 28-pin 8 k × 8 SRAMs (e.g., 62256-class devices). No timing or voltage interface changes are needed. However, the VCC decoupling network must include a 0.1 µF ceramic capacitor, and a Schottky diode (e.g., MBRS120T3) is recommended from VCC to VSS to suppress negative transients that could corrupt data in battery mode.

What is the expected lifetime of the integrated battery and how is it affected by temperature?

The integrated lithium carbon monofluoride battery provides ≥10 years of data retention at 25 °C with VCC < VSO (3.0 V). At 70 °C, retention drops to ~5 years due to accelerated chemical degradation. Storage at –40 °C to +85 °C is rated, but continuous operation above 70 °C is not recommended. Battery capacity is not user-replaceable; end-of-life requires full component replacement.