STMicroelectronics M48Z35Y-70MH1F

Overview

M48Z35Y-70MH1F from STMicroelectronics is a 256 Kbit (32 K × 8) non-volatile ZEROPOWER® 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, VPFD of 4.2–4.5 V, and delivers 11-year data retention in battery backup mode. It serves as a drop-in replacement for standard JEDEC 32K×8 SRAMs in real-time clock and configuration memory applications.

For engineers reviewing the M48Z35Y-70MH1F datasheet, M48Z35Y-70MH1F pinout, M48Z35Y-70MH1F application, or M48Z35Y-70MH1F equivalent, this page provides verified package mapping (SOH28), validated pin functions, confirmed battery switchover voltage (VSO = 3.0 V), exact power-fail window (VPFD min/max), and real-world timing behavior under VCC decay conditions.

Technical Context

The M48Z35Y integrates a 32 K × 8 SRAM array, voltage-sense comparator, battery switch, and write-protection logic on a single die. Its power-fail detection triggers chip deselect when VCC falls between VPFD(min) and VPFD(max), forcing all I/O into high-impedance and disabling writes before battery switchover at VSO = 3.0 V.

It supports standard asynchronous SRAM timing: tAVQV = 70 ns, tGLQV = 35 ns, and tWHAX = 0 ns, with dual control via E (chip enable) and W (write enable). The SOH28 package enables post-reflow SNAPHAT® battery mounting, isolating the 48 mAh lithium cell from solder thermal stress.

Key Specifications

Pinout & Package

Package: SOH28 - 28-pin plastic small-outline package with gold-plated contacts for direct mating with SNAPHAT® battery housing (M4Z28-BR00SH1). Designed for surface-mount assembly followed by top-mounted battery insertion post-reflow.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6900 and CAT24C512, M48Z35Y-70MH1F delivers parallel-byte access, hardware-triggered write protection, and fully integrated battery backup-enabling deterministic real-time operation without firmware intervention or external support components.

Availability

M48Z35Y-70MH1F is available at Aetrix Electronics and suitable for real-time clock backup, industrial PLC configuration storage, medical event logging, and point-of-sale transaction buffering requiring stable component supply across multi-year production cycles.

Supply support for M48Z35Y-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.

M48Z35Y belongs to ST's ZEROPOWER® SRAM product line, engineered specifically for applications demanding seamless, maintenance-free non-volatility in space-constrained, mission-critical systems where battery integration and power-fail resilience are mandatory.

FAQ

What is the battery chemistry and capacity used in M48Z35Y-70MH1F?

The M48Z35Y-70MH1F uses a non-rechargeable lithium carbon monofluoride (LiCFₓ) button cell with 48 mAh capacity, housed separately in the SNAPHAT® top (M4Z28-BR00SH1). This chemistry ensures stable voltage output and 11+ years of data retention at 25 °C with zero self-discharge-induced data loss.

Can M48Z35Y-70MH1F operate without the SNAPHAT® battery installed?

Yes - the SOH28 package functions as a standard 32K×8 SRAM when VCC is present and within specification (4.5–5.5 V). However, data retention during power loss is disabled without the SNAPHAT® battery; the device will lose all stored data once VCC drops below VSO = 3.0 V.

How does the VPFD window differ between M48Z35 and M48Z35Y variants?

M48Z35 specifies VPFD = 4.5–4.75 V (for 4.75–5.5 V VCC), while M48Z35Y specifies VPFD = 4.2–4.5 V (for 4.5–5.5 V VCC). This lower VPFD threshold allows earlier write protection activation in systems with looser 5 V rail regulation, improving robustness against marginal power supplies.

Is M48Z35Y-70MH1F RoHS compliant and lead-free?

Yes - M48Z35Y-70MH1F meets RoHS Directive 2011/65/EU and is manufactured with lead-free second-level interconnects. The SOH28 package uses Pb-free terminations compatible with standard reflow profiles (peak 260 °C, time above 255 °C ≤ 30 s).