Microchip Technology 25LC020AT-E/ST

Overview

25LC020AT-E/ST from Microchip Technology Inc. is a 2 Kbit (256 × 8) SPI Serial EEPROM with 16-byte page write capability, 10 MHz max clock frequency at 4.5–5.5 V, and industrial-temperature operation (−40°C to +85°C). It features hardware write protection via WP pin, HOLD input for bus pause, and block-level write protection (none/¼/½/all array). Used in embedded system configuration storage, sensor calibration data retention, and firmware parameter backup.

For engineers reviewing the 25LC020AT-E/ST datasheet, 25LC020AT-E/ST pinout, 25LC020AT-E/ST application, or 25LC020AT-E/ST equivalent, key selection criteria include VCC range (2.5–5.5 V), page write timing (≤5 ms), endurance (1,000,000 cycles), data retention (>200 years), and SOIC-8 package compatibility with legacy SPI designs.

Technical Context

The 25LC020AT-E/ST implements a standard SPI Mode 0,0/Master-Slave interface with separate SI (data in) and SO (data out) lines, requiring CS, SCK, and optional HOLD/WP control. It uses an internal high-voltage generator for EEPROM programming and includes a nonvolatile STATUS register with WIP, WEL, BP0, and BP1 bits for real-time write status and configurable block protection.

Write operations require explicit WREN instruction followed by CS high-to-low transition to initiate self-timed internal write cycle (TWC ≤ 5 ms); reads support sequential addressing with automatic address wraparound. The HOLD function suspends ongoing serial transfers without resetting state, enabling interrupt servicing on shared SPI buses.

Key Specifications

Pinout & Package

25LC020AT-E/ST is supplied in 8-lead SOIC (ST) package per Microchip's Device Selection Table. Pin mapping matches standard SOIC-8 footprint with 1.27 mm pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 25AA020AT-I/ST, the 25LC020AT-E/ST trades lower-voltage support for tighter VCC min specification (2.5 V), simplifying power design in 3.3 V/5 V systems; versus AT25020B-SSHL-T, it lacks AEC-Q100 qualification but delivers identical functionality at lower cost for non-automotive applications.

Availability

25LC020AT-E/ST is available at Aetrix Electronics and suitable for industrial sensor nodes, medical device configuration storage, and automotive body control modules requiring stable component supply and long-term obsolescence management.

Supply support for 25LC020AT-E/ST 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 leading provider of microcontroller, analog, and Flash-IP solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 25LC020A family targets cost-sensitive, space-constrained embedded systems needing reliable, low-power serial EEPROM for configuration, calibration, and event logging - optimized for seamless integration with PIC® and other SPI-capable MCUs.

FAQ

What is the maximum clock frequency supported by the 25LC020AT-E/ST?

The 25LC020AT-E/ST supports up to 10 MHz clock frequency when VCC is between 4.5 V and 5.5 V. At 2.5 V ≤ VCC < 4.5 V, the maximum clock frequency drops to 5 MHz. These limits are defined in Table 1-2 of the DS21833G datasheet and ensure reliable setup/hold timing across voltage and temperature ranges. The 25LC020AT-E/ST must be operated within these AC specifications to guarantee correct SPI communication.

Does the 25LC020AT-E/ST support page write operations, and what is the page size?

Yes, the 25LC020AT-E/ST supports page write mode with a fixed page size of 16 bytes. This allows up to 16 consecutive bytes to be loaded into the page buffer before initiating the internal write cycle. Writing across a page boundary causes wraparound within the same page - software must enforce alignment. The 25LC020AT-E/ST completes each page write in ≤5 ms, and the WIP bit in the STATUS register indicates completion.

How does the WP pin function on the 25LC020AT-E/ST?

The WP (Write-Protect) pin on the 25LC020AT-E/ST is a hardware-level disable for all write operations. When WP is low, writes to both memory array and STATUS register are blocked regardless of WEL state. Pulling WP high restores full write capability. Critically, WP low resets the write enable latch and inhibits new writes, but does not abort an already-started internal write cycle. This behavior is documented in Table 2-4 and Section 2.3 of the 25LC020AT-E/ST datasheet.

What is the endurance and data retention specification for the 25LC020AT-E/ST?

The 25LC020AT-E/ST guarantees 1,000,000 erase/write cycles and data retention exceeding 200 years at 25°C. Endurance is characterized at 25°C and VCC = 5.5 V (Note 2, Table 1-3), while retention is extrapolated from accelerated testing. These figures apply to the entire 256-byte array and are valid across the industrial temperature range (−40°C to +85°C). Real-world endurance may vary with voltage, temperature, and usage pattern - consult Microchip's Total Endurance™ Model for application-specific estimates.

Is the 25LC020AT-E/ST pin-compatible with other members of the 25XX020A family?

Yes, the 25LC020AT-E/ST shares identical pinout and electrical interface with all 25XX020A variants (e.g., 25AA020A, 25LC020A) in the same package type - including SOIC-8 (ST). All variants use the same CS/SO/WP/VSS/SI/SCK/HOLD/VCC pin assignments and SPI protocol. Functional differences (e.g., VCC range, temp grade) do not affect pin compatibility or PCB layout. The 25LC020AT-E/ST can be substituted on existing boards designed for 25AA020AT-I/ST or 25LC020AT-I/ST, provided voltage and temperature requirements align.