Microchip Technology 24LC04BT-E/MS

Overview

24LC04BT-E/MS from Microchip Technology Inc. is a 4-Kbit I²C-compatible serial EEPROM organized as two 256 × 8-bit blocks, operating from 2.5V to 5.5V with 400 kHz max clock frequency, 5 ms max page write time, and industrial-extended temperature range (–40°C to +125°C). It delivers low-power operation (1 µA standby, 1 mA read), hardware write-protection via WP pin, and 1 million erase/write cycles - used in embedded system configuration storage and calibration data retention.

For engineers reviewing the 24LC04BT-E/MS datasheet, 24LC04BT-E/MS pinout, 24LC04BT-E/MS application, or 24LC04BT-E/MS equivalent, key selection considerations include its MSOP-8 package, I²C address structure (1010xxxR/W), page write buffer (16 bytes), Schmitt-trigger inputs for noise immunity, and compatibility with 100/400 kHz I²C buses under extended temperature conditions.

Technical Context

The 24LC04BT-E/MS implements a two-wire I²C interface with fixed 4-bit control code (1010) and block-select bit (B0), enabling access to either 256-byte memory block. Its internal Address Pointer auto-increments during sequential reads and supports current-address, random, and sequential read modes.

Write operations use self-timed erase/write cycles with ACK polling support; page writes are limited to 16-byte boundaries within a single physical page. The device features Schmitt-trigger inputs, output slope control, and hardware write-protection via the WP pin tied to VCC or VSS - no internal connection to A0–A2 pins.

Key Specifications

Pinout & Package

24LC04BT-E/MS is supplied in an 8-lead MSOP (Micro Small Outline Package) with 0.65 mm pitch, 3.0 mm × 3.0 mm body, and wettable flanks for automated optical inspection. Pin 1 is marked with a dot; pin numbering follows standard MSOP convention (counterclockwise from mark).

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24LC04BT-E/MS, the 24AA04T-I/MS offers wider voltage range but lacks extended temperature support, while the AT24C04D-MAHM-T provides higher speed and SOIC-8 availability but replaces hardware write-protection with software-based security - making 24LC04BT-E/MS optimal for automotive and industrial applications demanding guaranteed physical write-locking.

Availability

24LC04BT-E/MS is available at Aetrix Electronics and suitable for automotive body electronics, industrial PLCs, medical infusion pumps, and smart energy metering requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for 24LC04BT-E/MS 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 microcontrollers, analog devices, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 24LC04B series was designed specifically for robust, low-power nonvolatile data storage in automotive and industrial systems - emphasizing extended temperature operation, hardware write-protection, and AEC-Q100 qualification.

FAQ

What is the I²C address format used by the 24LC04BT-E/MS?

The 24LC04BT-E/MS uses a 7-bit I²C client address with fixed 4-bit control code '1010', two don't-care bits, and one block-select bit (B0), resulting in two possible base addresses: 1010xxx0 for Block 0 and 1010xxx1 for Block 1. The R/W bit is appended separately. Pins A0–A2 are not internally connected and do not affect addressing - the 24LC04BT-E/MS always responds to these two base addresses regardless of A0–A2 state.

Does the 24LC04BT-E/MS support 1 MHz I²C operation?

No, the 24LC04BT-E/MS supports up to 400 kHz I²C operation at VCC ≥ 2.5V. It is not rated for 1 MHz - that speed is specified only for the 24FC04 variant. Attempting 1 MHz communication with the 24LC04BT-E/MS may result in timing violations, failed ACKs, or unreliable data transfer. For 1 MHz applications, consider the 24FC04 or alternative EEPROMs explicitly qualified at that rate.

How does the WP pin function on the 24LC04BT-E/MS?

The WP (Write-Protect) pin on the 24LC04BT-E/MS is a dedicated hardware control: when tied to VCC, it disables all write operations (byte and page) to the entire memory array (addresses 000h–1FFh), while read operations remain fully functional. When tied to VSS (or left floating, though not recommended), full read/write access is enabled. This provides deterministic, glitch-immune protection independent of firmware state - a key safety feature in the 24LC04BT-E/MS.

What is the maximum page write size supported by the 24LC04BT-E/MS?

The 24LC04BT-E/MS supports a maximum page write size of 16 bytes. Its on-chip page buffer holds up to 16 bytes, and writes crossing a 16-byte boundary will wrap around within the same physical page instead of advancing to the next. To avoid data corruption, host firmware must ensure page write commands begin at addresses aligned to 16-byte boundaries (e.g., 0x00, 0x10, 0x20) - a constraint explicitly defined in the 24LC04BT-E/MS datasheet.

Is the 24LC04BT-E/MS AEC-Q100 qualified?

Yes, the 24LC04BT-E/MS is AEC-Q100 qualified for Grade 1 (–40°C to +125°C), as confirmed in the official Microchip datasheet DS20001708P. This qualification covers stress testing for temperature cycling, humidity bias, ESD, and other automotive-relevant reliability parameters - making the 24LC04BT-E/MS suitable for under-hood and chassis-mounted electronic control units where the 24LC04BT-E/MS operates as trusted configuration memory.