Microchip Technology 24LC04B-I/MS

Overview

24LC04B-I/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 temperature range (–40°C to +85°C). It features hardware write-protection via the WP pin and is packaged in an 8-lead MSOP.

For engineers reviewing the 24LC04B-I/MS datasheet, 24LC04B-I/MS pinout, 24LC04B-I/MS application, or 24LC04B-I/MS equivalent, key selection considerations include its 16-byte page buffer, Schmitt-trigger inputs for noise immunity, 1 µA standby current, I²C bus compatibility up to 400 kHz, and support for current-address, random, and sequential read modes.

Technical Context

The 24LC04B-I/MS implements a two-wire I²C interface with open-drain SDA/SCL pins requiring external pull-ups, and uses a client-server protocol where it acts solely as a slave device responding to host-generated Start/Stop conditions and address commands. Its internal architecture includes a 16-byte page latch, EEPROM array, HV generator, and memory control logic managing self-timed erase/write cycles.

Addressing uses a fixed 4-bit control code (1010) followed by two "don't care" bits and a block-select bit (B0), enabling access to either 256-word memory block; the R/W bit determines operation direction. Write protection is implemented via the dedicated WP pin tied to VCC to inhibit all writes while permitting reads.

Key Specifications

Pinout & Package

24LC04B-I/MS is housed in an 8-lead MSOP (Micro Small Outline Package) with exposed pad option, measuring 3.0 mm × 3.0 mm × 1.1 mm. Pin 1 is marked with a dot or bevel; A0–A2 are not internally connected and may be left floating or tied to VSS/VCC.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24LC04B-I/MS, the 24AA04-I/MS offers broader voltage flexibility at the cost of reduced speed below 2.5V, while the AT24C04-PU trades automotive qualification and longevity for lower unit cost in non-critical applications.

Availability

24LC04B-I/MS is available at Aetrix Electronics and suitable for industrial sensor calibration storage, consumer appliance configuration memory, medical device usage logs, and automotive body control module settings requiring stable component supply, long-term data integrity, and automotive-grade reliability.

Supply support for 24LC04B-I/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 components, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 24LC04B-I/MS belongs to Microchip's 24XX04 family of I²C serial EEPROMs, designed specifically for reliable, low-power nonvolatile data storage in space-constrained embedded systems across industrial, automotive, and consumer markets.

FAQ

What is the maximum I²C clock frequency supported by the 24LC04B-I/MS?

The 24LC04B-I/MS supports a maximum I²C clock frequency of 400 kHz when operated within its specified VCC range of 2.5V to 5.5V. This is defined in the AC characteristics table of the DS20001708P datasheet. Frequencies above 400 kHz are not guaranteed and fall outside the device's validated specification.

Does the 24LC04B-I/MS require external pull-up resistors on SDA and SCL lines?

Yes, the 24LC04B-I/MS requires external pull-up resistors on both SDA and SCL lines because these pins are open-drain. For 400 kHz operation, a typical value is 2 kΩ to VCC; for 100 kHz, 10 kΩ is commonly used. The exact value depends on bus capacitance and rise-time requirements per I²C specification.

How does the WP pin function on the 24LC04B-I/MS?

The WP (Write-Protect) pin on the 24LC04B-I/MS is an active-high input: when tied to VCC, it disables all write operations to the entire memory array (000h–1FFh), allowing only read access; when tied to VSS, full read/write functionality is enabled. No internal pull-up or pull-down is present, so the pin must be externally biased.

What is the page write capability of the 24LC04B-I/MS?

The 24LC04B-I/MS supports a 16-byte page write buffer, allowing up to 16 bytes to be loaded into the on-chip latch and written to memory in a single self-timed cycle. Page writes must remain within a single 16-byte physical boundary (e.g., addresses 00h–0Fh); crossing boundaries causes wraparound within the page.

Is the 24LC04B-I/MS qualified for automotive applications?

Yes, the 24LC04B-I/MS is AEC-Q100 qualified for automotive applications. It is rated for the extended temperature range (–40°C to +125°C) and meets stress testing requirements for automotive electronic components, making it suitable for use in body control modules, infotainment systems, and other vehicle subsystems.