Microchip Technology 24LC01B-I/ST

Overview

24LC01B-I/ST from Microchip Technology Inc. is a 1 Kbit I²C-compatible serial EEPROM organized as 128 × 8-bit memory with hardware write-protection, 400 kHz max clock frequency, and operation from 2.5V to 5.5V. It supports page writes (up to 8 bytes), features Schmitt-trigger inputs and slope-controlled outputs, and is rated for industrial temperature (–40°C to +85°C). It is commonly used in embedded system configuration storage where low-power nonvolatile memory is required.

For engineers reviewing the 24LC01B-I/ST datasheet, 24LC01B-I/ST pinout, 24LC01B-I/ST application, or 24LC01B-I/ST equivalent, this page provides verified technical context, package-specific pin definitions, real-world use cases, and validated alternative parts for design-in and supply continuity planning.

Technical Context

The 24LC01B-I/ST implements a 2-wire I²C interface compliant with standard-mode (100 kHz) and fast-mode (400 kHz) timing, with internal address pointer auto-increment for sequential reads. Its EEPROM array uses charge-pump-based programming and supports byte and page write operations with self-timed erase/write cycles.

It integrates Schmitt-trigger inputs on SDA and SCL for noise immunity, output slope control to suppress ground bounce, and a dedicated WP pin that enables full-array hardware write-protection when tied to VCC. The device requires no external high-voltage programming supply and operates with only a single VCC rail.

Key Specifications

Pinout & Package

24LC01B-I/ST is supplied in an 8-lead SOIC (Small Outline Integrated Circuit) package with 1.27 mm pitch, 3.90 mm body width, and surface-mount footprint. Pin 1 is marked by a beveled corner or notch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24LC01B-I/ST, the 24AA01-I/ST offers wider voltage flexibility but no extended temp support, while the AT24C01C-SSHM-T removes hardware write-protection in favor of software control - making 24LC01B-I/ST the preferred choice for safety-critical or industrial environments requiring guaranteed write-disable at power-on.

Availability

24LC01B-I/ST is available at Aetrix Electronics and suitable for industrial sensor calibration storage, consumer appliance configuration memory, medical device serial number registry, and automotive body control module NVM requiring stable component supply and long-term lifecycle assurance.

Supply support for 24LC01B-I/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 U.S.-based semiconductor company specializing in microcontrollers, analog devices, and memory products, with global manufacturing and quality certifications including ISO 9001 and IATF 16949.

The 24LC01B-I/ST belongs to Microchip's legacy 24XX01 EEPROM family, designed specifically for cost-sensitive, low-power embedded systems requiring simple, reliable, and pin-compatible nonvolatile storage with minimal external components.

FAQ

What is the maximum clock frequency supported by the 24LC01B-I/ST?

The 24LC01B-I/ST supports a maximum I²C clock frequency of 400 kHz when VCC is 2.5V or higher. At voltages below 2.5V, the device is not rated for operation - unlike the 24AA01 which supports 100 kHz down to 1.7V. This 400 kHz limit directly determines the fastest achievable write throughput in page mode, approximately 400 bytes per second under ideal conditions. The 24LC01B-I/ST does not support 1 MHz operation like the 24FC01 variant.

Does the 24LC01B-I/ST require external pull-up resistors on SDA and SCL lines?

Yes, the 24LC01B-I/ST requires external pull-up resistors on both SDA and SCL lines because its I/O pins are open-drain. For 400 kHz operation, a 2 kΩ pull-up is recommended; for 100 kHz, 10 kΩ is typical. These resistors ensure proper signal rise times and bus arbitration. The 24LC01B-I/ST itself contains no internal pull-ups, and omitting external ones will result in communication failure. Pull-up voltage must match the VCC rail (2.5–5.5V).

How does the Write-Protect (WP) pin function on the 24LC01B-I/ST?

The WP pin on the 24LC01B-I/ST is a hardware-level write-inhibit control: when tied to VCC, it disables all write operations (byte and page) to the entire 128-byte memory array (addresses 00h–7Fh), while read operations remain fully functional. When tied to VSS or left floating, normal read/write access is enabled. This feature provides deterministic, power-on-safe protection independent of firmware state - a key differentiator from software-lock EEPROMs like the AT24C01C. The 24LC01B-I/ST does not support partial-page or block-level write protection.

What is the page size and write buffer capacity of the 24LC01B-I/ST?

The 24LC01B-I/ST has an 8-byte page write buffer and enforces strict 8-byte page boundaries (e.g., addresses 00–07, 08–0F). A page write command can load up to 8 bytes into the buffer before issuing a Stop condition - after which the internal 5 ms write cycle begins. If more than 8 bytes are sent before Stop, the address pointer rolls over within the same page, overwriting earlier data. This page structure limits burst efficiency but ensures predictable timing; the 24LC01B-I/ST does not support cross-page writes or variable buffer sizes.

Is the 24LC01B-I/ST qualified for automotive applications?

Yes, the 24LC01B-I/ST is AEC-Q100 qualified for automotive applications, specifically Grade 3 (–40°C to +85°C), matching its industrial temperature rating. This qualification covers stress testing for thermal cycling, humidity, ESD, and electrical performance under automotive operating conditions. While not rated for extended temperature (–40°C to +125°C) like the 24LC01B-E/ST variant, the 24LC01B-I/ST is approved for use in body control modules, infotainment peripherals, and other non-engine-bay automotive subsystems requiring certified reliability and traceability.