Microchip Technology 48L640T-I/MNY

Overview

48L640T-I/MNY from Microchip Technology Inc. is a 64-Kbit SPI serial EERAM integrating an 8,192 × 8-bit SRAM core with cell-based hidden EEPROM backup. It operates at up to 66 MHz over SPI, supports symmetrical read/write timing, and delivers 5 mA active current, 200 μA standby current, and 3 μA hibernate current. It is used in industrial data logging systems requiring persistent memory without software-managed backup.

For engineers reviewing the 48L640T-I/MNY datasheet, 48L640T-I/MNY pinout, 48L640T-I/MNY application, or 48L640T-I/MNY equivalent, key selection considerations include automatic power-loss data retention, VCAP capacitor dependency, SPI Mode 0/3 compatibility, and STATUS register-controlled write protection levels.

Technical Context

The 48L640T-I/MNY implements a dual-memory architecture where SRAM serves as the primary volatile interface while EEPROM provides invisible, parallel cell-for-cell backup. Its AutoStore/AutoRecall logic monitors VCC against a 2.30–2.65 V trip threshold and uses energy stored on the external VCAP capacitor (10–50 μF) to complete full-array transfer within 10 ms.

It supports SPI Modes 0 and 3 with MSb-first framing, requires WREN/WRSR for write enable and STATUS register control, and includes dedicated commands for secure CRC-protected reads/writes, nonvolatile user space (2 bytes), and last-written address tracking. The HOLD pin enables mid-sequence pause without clock reset.

Key Specifications

Pinout & Package

48L640T-I/MNY is packaged in an 8-lead TDFN (3 mm × 2 mm, 0.5 mm pitch) with exposed pad (optional VSS connection). Pin functions are electrically identical to the SOIC variant but arranged in compact top-view layout.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar serial EERAM applications.

Compared with 48L640T-I/MNY, the SOIC variant offers easier hand-soldering and thermal margin at the expense of size, while the FM25V05-G eliminates capacitor dependency and extends write endurance by four orders of magnitude - making it preferable for ultra-high-cycle applications despite higher unit cost.

Availability

48L640T-I/MNY is available at Aetrix Electronics and suitable for industrial data loggers, smart metering endpoints, and PLC I/O modules requiring stable component supply with guaranteed long-term manufacturability.

Supply support for 48L640T-I/MNY 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

Microchip Technology Inc. is a U.S.-based semiconductor manufacturer specializing in microcontrollers, analog devices, and memory solutions for industrial, automotive, and communications markets.

The 48L640T-I/MNY belongs to Microchip's EERAM product line, designed specifically to replace battery-backed SRAM and simplify nonvolatile data logging in resource-constrained embedded systems.

FAQ

What is the function of the VCAP pin on the 48L640T-I/MNY?

The VCAP pin on the 48L640T-I/MNY connects to an external 10–50 μF capacitor that supplies energy during VCC dropout. When system voltage falls below 2.30–2.65 V, the 48L640T-I/MNY isolates itself from VCC and uses stored charge on the VCAP capacitor to autonomously transfer the entire 8,192 × 8-bit SRAM contents to its internal EEPROM - ensuring zero-data-loss backup without host involvement.

Does the 48L640T-I/MNY require a write-enable command before every SRAM write operation?

Yes, the 48L640T-I/MNY requires execution of the WREN (06h) instruction before each WRITE or WRSR command. This sets the Write Enable Latch (WEL) bit in the STATUS register to '1'. The WEL bit resets to '0' after any write completes, on power-up, or upon WRDI execution - meaning WREN must be issued prior to every discrete write sequence to the SRAM array or STATUS register.

Can the 48L640T-I/MNY operate in SPI Mode 1 or Mode 2?

No, the 48L640T-I/MNY only supports SPI Modes 0 and 3. In both modes, data is latched on the rising edge of SCK and output on the falling edge. Mode 0 uses low-idle SCK; Mode 3 uses high-idle SCK. Attempting Mode 1 or Mode 2 will result in incorrect data sampling or communication failure because the 48L640T-I/MNY's internal timing logic is hardwired for these two specific phase/polarity combinations.

How does the HOLD pin affect ongoing operations in the 48L640T-I/MNY?

The HOLD pin on the 48L640T-I/MNY suspends SPI communication mid-sequence without resetting internal state - allowing resumption from the exact point of pause. However, it does not interrupt active internal operations: if a STORE or RECALL is in progress, HOLD has no effect and the operation completes normally. HOLD must be asserted during SCK low to take effect, and SO enters high-Z immediately upon HOLD low assertion.

What is the purpose of the nonvolatile user space in the 48L640T-I/MNY?

The 48L640T-I/MNY includes a dedicated 2-byte nonvolatile user space that persists across power cycles independently of the main SRAM array. It is written via WRNUR (C2h) and read via RDNUR (C3h) commands. This space is intended for storing immutable device-specific values such as calibration coefficients, manufacturing lot codes, or unique identifiers - and is automatically backed up alongside SRAM and STATUS register during AutoStore events.