Infineon Technologies FM21LD16-60-BG

Overview

FM21LD16-60-BG from Cypress Semiconductor is a 2-Mbit (128 K × 16) ferroelectric RAM (F-RAM) with SRAM-compatible parallel interface, 60-ns access time, 10¹⁴ read/write endurance, and 151-year data retention. It operates from 2.7 V to 3.6 V across –40 °C to +85 °C and is packaged in a 48-ball FBGA for industrial nonvolatile memory applications requiring rapid, frequent writes without backup batteries.

For engineers reviewing the FM21LD16-60-BG datasheet, FM21LD16-60-BG pinout, FM21LD16-60-BG application, or FM21LD16-60-BG equivalent, key selection criteria include NoDelay™ write capability, software-configurable block-level write protection, page-mode 30-ns cycle time, and drop-in compatibility with 128 K × 16 SRAM footprints in metering, automotive black boxes, and industrial PLCs.

Technical Context

The FM21LD16-60-BG implements a parallel 17-bit address bus (A16–A0) and 16-bit bidirectional data bus (DQ15–DQ0), with CE/WE/OE control logic enabling SRAM-like timing. Its ferroelectric memory array is partitioned into eight 16 K × 16 blocks, each independently software write-protectable via a deterministic six-read/three-write address/command sequence.

It supports two operational modes: CE-initiated access (faster than address-access time) and WE-controlled write cycles, both delivering true NoDelay™ writes-no internal write latency, no polling, and no erase-before-write. The device includes a low-voltage monitor that blocks memory access when VDD drops below 2.7 V, preventing data corruption during brown-out conditions.

Key Specifications

Pinout & Package

FM21LD16-60-BG is housed in a 48-ball fine-pitch ball grid array (FBGA) package with 0.8 mm pitch, optimized for high-density PCB layouts and thermal performance in industrial modules.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar nonvolatile parallel memory applications.

Compared with FM21LD16-60-BG, FM22LD16-60-BG doubles capacity without altering timing or protection logic, while FM23MLD16-60-BG provides quadruple density with identical reliability and interface behavior-both retain full backward compatibility for migration paths in long-lifecycle industrial programs.

Availability

FM21LD16-60-BG is available at Aetrix Electronics and suitable for smart metering, automotive event recording, and industrial PLC data logging requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for FM21LD16-60-BG 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

Cypress Semiconductor (now part of Infineon Technologies) is a global leader in high-performance, reliable semiconductor solutions for embedded systems, connectivity, and memory.

The FM21LD16 belongs to Cypress's F-RAM product line, engineered specifically to replace battery-backed SRAM in mission-critical nonvolatile data logging applications where endurance, speed, and zero-maintenance reliability are essential.

FAQ

Is FM21LD16-60-BG pin-compatible with standard 128 K × 16 SRAMs?

Yes. FM21LD16-60-BG uses an industry-standard 128 K × 16 SRAM pinout with identical signal names (A0–A16, DQ0–DQ15, CE, WE, OE, UB, LB, VDD, VSS). No PCB redesign is needed for drop-in replacement, though firmware must account for its nonvolatile behavior and lack of initialization requirement.

How does the software write-protection mechanism work?

Protection is configured by issuing a precise six-read address sequence (12555h, 1DAAAh, 01333h, 0ECCCh, then two more defined addresses), followed by a write of the 8-bit protection byte to DQ0–DQ7 and its complement. Each bit controls one of eight 16 K × 16 blocks; '1' locks, '0' enables writes. Settings persist without power.

What happens during power loss below 2.7 V?

The integrated low-voltage monitor disables memory access when VDD falls below 2.7 V, placing the device in a high-impedance state and preventing partial writes or data corruption. This ensures atomicity of the last completed write and preserves all previously stored data intact.

Can FM21LD16-60-BG operate in 8-bit mode?

Yes. By asserting LB only (for lower byte) or UB only (for upper byte), and tying the inactive byte select to ground, the device functions as a 256 K × 8 memory. Address lines remain unchanged; DQ0–DQ7 or DQ8–DQ15 are active accordingly, maintaining full timing compliance and endurance.