Microchip Technology 24LC08B-I/ST

Overview

24LC08B-I/ST from Microchip Technology Inc. is an 8-Kbit I²C-compatible serial EEPROM organized as four 256 × 8-bit memory blocks, operating from 2.5V to 5.5V with 400 kHz max clock frequency, 16-byte page write buffer, and hardware write-protect via WP pin - used for nonvolatile parameter storage in industrial sensor nodes and embedded control modules.

For engineers reviewing the 24LC08B-I/ST datasheet, 24LC08B-I/ST pinout, 24LC08B-I/ST application, or 24LC08B-I/ST equivalent, key selection criteria include VCC range (2.5–5.5V), I²C timing compliance at 400 kHz, industrial temperature rating (−40°C to +85°C), SOIC-8 package footprint, and hardware write-protection functionality.

Technical Context

The 24LC08B-I/ST implements a two-wire I²C interface with Schmitt-trigger inputs and slope-controlled outputs to suppress noise and eliminate ground bounce. Its internal architecture includes a 16-byte page latch, HV generator for EEPROM programming, and address pointer logic supporting current-address, random, and sequential read modes.

It supports standard I²C protocol with Start/Stop conditions, 7-bit client addressing (1010xxxR/W), block-select bits (B1/B0) for 4×256-byte memory segmentation, and ACK polling to detect end of self-timed 5 ms write cycle - all compliant with I²C bus electrical and timing specifications at 400 kHz over −40°C to +85°C.

Key Specifications

Pinout & Package

24LC08B-I/ST is supplied in an 8-lead SOIC (SN) package per Microchip drawing C04-057-SN Rev F, with 3.90 mm body width, 1.27 mm pitch, and matte tin (Sn) lead finish. Pin 1 is marked with 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 24LC08B-I/ST, the 24AA08-I/ST offers lower-voltage flexibility but reduced speed below 2.5V, while the AT24C08D-SSHM-T provides higher clock rate and broader voltage support but uses a different I²C address - both require firmware validation for address and timing compatibility.

Availability

24LC08B-I/ST is available at Aetrix Electronics and suitable for industrial sensor calibration, embedded system configuration, and power meter data logging requiring stable component supply and long-term manufacturing continuity.

Supply support for 24LC08B-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 24LC08B belongs to Microchip's 24XX08 family of I²C EEPROMs, designed specifically for reliable, low-power nonvolatile storage in space-constrained industrial and automotive applications where write-protection and extended temperature operation are critical.

FAQ

What is the minimum VCC required for reliable operation of the 24LC08B-I/ST?

The 24LC08B-I/ST requires a minimum VCC of 2.5V for full specification compliance, including 400 kHz I²C operation and guaranteed write functionality. Operation below 2.5V is not supported and may result in data corruption or communication failure. This distinguishes it from the 24AA08 variant, which supports down to 1.7V.

Does the 24LC08B-I/ST support page write operations, and what is the maximum page size?

Yes, the 24LC08B-I/ST supports page write operations with a maximum buffer size of 16 bytes. Writes crossing a 16-byte page boundary will wrap within the current page instead of advancing to the next, so firmware must enforce alignment. Each page write completes in ≤5 ms and counts as one of the 1 million rated endurance cycles.

How does the WP pin function on the 24LC08B-I/ST, and what happens when it is left floating?

The WP pin on the 24LC08B-I/ST enables hardware write-protection: tied to VCC, it disables all write operations (memory becomes read-only); tied to VSS, full read/write access is enabled. The pin is not internally pulled - leaving it floating results in undefined behavior and is strictly prohibited per Microchip's design guidelines for 24LC08B-I/ST.

What I²C address does the 24LC08B-I/ST use, and how is memory block selection handled?

The 24LC08B-I/ST uses a base I²C address of 1010xxx, where the three least-significant bits (xxx) are "don't care" - resulting in a fixed 7-bit address of 0x50 for write and 0x51 for read. Block selection (four 256-byte segments) is controlled by bits B1 and B0 in the control byte, allowing firmware to access any block without changing the device address.

Is the 24LC08B-I/ST RoHS compliant and qualified for automotive use?

Yes, the 24LC08B-I/ST is RoHS compliant and AEC-Q100 qualified for Grade 3 (−40°C to +85°C), making it suitable for under-hood and industrial control applications. Its qualification includes stress testing for temperature cycling, humidity, and ESD (>4 kV HBM), ensuring reliability in harsh environments where the 24LC08B-I/ST is deployed.