Microchip Technology 24LC08B-E/MC

Overview

24LC08B-E/MC from Microchip Technology Inc. is an 8-Kbit I²C-compatible serial EEPROM organized as four 256 × 8-bit blocks, operating from 2.5V to 5.5V with 400 kHz max clock frequency, 16-byte page write buffer, and hardware write-protection via WP pin. It supports industrial (–40°C to +85°C) and extended (–40°C to +125°C) temperature ranges in 8-lead SOIC package and is used for nonvolatile parameter storage in embedded controllers and sensor modules.

For engineers reviewing the 24LC08B-E/MC datasheet, 24LC08B-E/MC pinout, 24LC08B-E/MC application, or 24LC08B-E/MC equivalent, key selection criteria include VCC range compatibility (2.5–5.5V), I²C timing compliance at 400 kHz, WP-enabled memory protection, endurance (>1M cycles), and data retention (>200 years) under extended temperature conditions.

Technical Context

The 24LC08B-E/MC 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 uses a fixed 4-bit control code (1010) with 2-bit block select (B1/B0) for addressing four 256-word blocks, and supports acknowledge polling to detect write-cycle completion. Write protection is implemented via dedicated WP pin tied to VCC or VSS - active-high inhibit for full-array protection.

Key Specifications

Pinout & Package

24LC08B-E/MC is supplied in an 8-lead SOIC (SN) package per Microchip drawing C04-057-SN Rev F, with standard 1.27 mm pitch, 3.90 mm body width, and matte tin (Sn) lead finish. The exposed pad is not present in SOIC variant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24LC08B-E/MC, the 24AA08-I/MC offers broader voltage flexibility but sacrifices guaranteed 400 kHz performance at 2.5V, while the AT24C08D-SSHM-T provides addressable multi-drop capability at the cost of losing hardware-based memory lockout - making 24LC08B-E/MC optimal for safety-critical, single-node, write-protected configurations.

Availability

24LC08B-E/MC is available at Aetrix Electronics and suitable for industrial sensor calibration, automotive body control modules, medical infusion pump settings, and smart energy meter firmware patch storage requiring stable component supply across extended temperature and long product lifecycles.

Supply support for 24LC08B-E/MC 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 centers and ISO 9001-certified manufacturing.

The 24LC08B belongs to Microchip's 24XX08 family of I²C serial EEPROMs, designed specifically for reliable, low-power nonvolatile data storage in space-constrained, thermally demanding embedded systems.

FAQ

What is the minimum VCC voltage required for reliable operation of the 24LC08B-E/MC?

The 24LC08B-E/MC requires a minimum VCC of 2.5V for guaranteed functionality across its full temperature range (–40°C to +125°C). Operation below 2.5V is not specified and may result in timing violations, incomplete writes, or loss of I²C communication - unlike the 24AA08 which supports 1.7V. This 2.5V floor ensures robust noise margin and EEPROM programming voltage stability in harsh environments where the 24LC08B-E/MC is deployed.

Does the 24LC08B-E/MC support multi-master I²C bus configurations?

Yes, the 24LC08B-E/MC fully supports multi-master I²C bus operation as defined by the I²C specification. Its open-drain SDA/SCL pins, built-in arbitration logic, and clock stretching capability (via ACK polling during write cycles) allow seamless coexistence with other masters. However, the 24LC08B-E/MC itself never acts as a bus master - it operates exclusively as a slave device responding to addresses 1010xxx0/1, with no internal clock generation or bus control logic.

Can the A0, A1, and A2 pins on the 24LC08B-E/MC be used to configure device addressing?

No - the A0, A1, and A2 pins on the 24LC08B-E/MC are explicitly stated as "not connected" in the official datasheet (DS20001710M, Section 2.1). They have no internal bond wires and serve no addressing function. Device addressing is fixed to the 4-bit control code '1010' plus 2-bit block select (B1/B0), yielding four hardwired sub-block addresses. Leaving these pins floating or tying them to VSS/VCC has zero effect on I²C address resolution.

How does the hardware write-protect (WP) feature behave during power transitions?

The WP pin on the 24LC08B-E/MC is sampled asynchronously at the start of each I²C transaction. If WP is high (VCC) at the moment the Start condition is detected, all subsequent write commands - including byte, page, and control register writes - are ignored and return no ACK. During power-up or brown-out, WP state must be stabilized before the first I²C command; tying WP directly to VCC (not through a resistor divider) ensures deterministic protection even during unstable supply conditions.

Is the 24LC08B-E/MC compatible with 1 MHz I²C buses?

No - the 24LC08B-E/MC is rated for a maximum clock frequency of 400 kHz across its full VCC (2.5–5.5V) and temperature (–40°C to +125°C) operating range. Attempting 1 MHz operation will violate AC timing parameters including THIGH (min 600 ns), TLOW (min 1300 ns), and TAA (max 900 ns), leading to unreliable ACK generation, data corruption, or bus lockup. For 1 MHz support, Microchip's 24FC08 is the designated alternative in the same family.