Microchip Technology 25LC020AT-H/SN

Overview

25LC020AT-H/SN from Microchip Technology is a 2 Kbit (256 × 8) SPI serial EEPROM with high-temperature operation (−40°C to +150°C), 5 MHz max clock speed, 16-byte page write capability, and hardware write protection via WP pin. It operates from 2.5V to 5.5V and supports byte/page writes with self-timed internal erase/write cycles (≤6 ms). It is used in automotive engine control units for storing calibration data under thermal stress.

For engineers reviewing the 25LC020AT-H/SN datasheet, 25LC020AT-H/SN pinout, 25LC020AT-H/SN application, or 25LC020AT-H/SN equivalent, key selection criteria include extended temperature compliance, SPI interface timing at 150°C, page boundary handling, and hardware-based block write protection configuration.

Technical Context

The 25LC020AT-H/SN implements a standard SPI Mode 0,0 (CPOL = 0, CPHA = 0) interface with separate SI (data-in) and SO (data-out) lines, requiring CS assertion and SCK synchronization for all operations. Its internal architecture includes an 8-bit instruction register, status register with WIP/WEL/BP bits, and EEPROM array segmented into four blocks for configurable protection.

It supports sequential read, HOLD pin suspension of ongoing transfers without sequence reset, and power-on default write-disable state. All write operations require explicit WREN instruction followed by CS deassertion to latch enable, and internal write cycle initiation occurs on CS rising edge after valid command completion.

Key Specifications

Pinout & Package

25LC020AT-H/SN is housed in an 8-lead Pb-free SOIC package (SN), 3.90 mm body width, RoHS compliant, with standard JEDEC MS-012AC footprint and 1.27 mm pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 25LC020AT-H/SN, AT25DF021-SSH-T offers higher density and faster quad-SPI but sacrifices temperature range and HOLD functionality, while BR25H020FJ-WE2 matches density and package but lacks 150°C rating and HOLD - making 25LC020AT-H/SN uniquely suitable for thermally demanding automotive control nodes.

Availability

25LC020AT-H/SN is available at Aetrix Electronics and suitable for automotive engine management, industrial sensor logging, medical diagnostic calibration, and aerospace subsystem configuration requiring stable component supply across extended temperature ranges.

Supply support for 25LC020AT-H/SN 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 products, with global design and manufacturing infrastructure.

The 25LCXXXA family was designed specifically for high-reliability, extended-temperature SPI EEPROM applications in automotive, industrial, and medical systems where data integrity under thermal stress is critical.

FAQ

What is the maximum clock frequency supported by the 25LC020AT-H/SN across its full voltage and temperature range?

The 25LC020AT-H/SN supports up to 5 MHz clock frequency when VCC is 4.5V–5.5V and ambient temperature is −40°C to +150°C. At VCC = 2.5V–4.5V, the maximum clock drops to 3 MHz. These AC timing limits are fully characterized and guaranteed per DS22136B-page 4 Table 1-2, ensuring reliable SPI communication in high-temp automotive environments.

How does the HOLD pin function during an active SPI read or write sequence in the 25LC020AT-H/SN?

In the 25LC020AT-H/SN, the HOLD pin suspends ongoing SPI communication without resetting internal state: when pulled low while SCK is low, SI/SO/SCK inputs are ignored, SO enters high-impedance, and the device pauses mid-transfer. Resuming requires bringing HOLD high while SCK remains low. This enables MCU interrupt servicing without retransmitting commands - a key feature for real-time deterministic systems.

Can the 25LC020AT-H/SN be used as a direct replacement for the 25LC020A-H/SN, and what is the functional difference?

Yes - the 25LC020AT-H/SN is the tape-and-reel variant of the 25LC020A-H/SN, sharing identical electrical specifications, pinout, timing, and temperature rating. The "T" suffix denotes packaging format only (tape/reel vs. tube), with no functional or parametric differences. Both parts use the same die, SOIC-8 (SN) package, and are interchangeable in design and production.

What protection mechanisms prevent unintended writes to the 25LC020AT-H/SN memory array?

The 25LC020AT-H/SN employs four layered protections: (1) Power-on reset clears the write-enable latch (WEL); (2) Explicit WREN instruction required before any write; (3) WP pin hardware disable (low = all writes blocked); (4) STATUS register BP bits allow nonvolatile software-defined block protection. These ensure robust immunity against noise-induced or firmware-error writes in harsh ECU environments.

What is the page size of the 25LC020AT-H/SN, and why does crossing a page boundary during a page write cause data wraparound?

The 25LC020AT-H/SN has a fixed 16-byte page size. During page write, the internal address counter increments from the starting address; upon reaching the last byte of the page (e.g., address XX0F), the next byte wraps to the page start (XX00) instead of advancing to the next page. This hardware behavior - documented in DS22136B-page 9 - requires firmware to split multi-page writes, or risk overwriting earlier data in the same page.