Microchip Technology 24LC04B-I/ST

Overview

24LC04B-I/ST 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 delivers low-power operation (1 µA standby, 1 mA read), hardware write-protection via WP pin, and Schmitt-trigger inputs for noise immunity in embedded control and sensor calibration applications.

For engineers reviewing the 24LC04B-I/ST datasheet, 24LC04B-I/ST pinout, 24LC04B-I/ST application, or 24LC04B-I/ST equivalent, key selection considerations include its 8-pin SOIC package, I²C address structure (1010xxxR/W), 16-byte page buffer, endurance of 1 million cycles, and compatibility with standard 2-wire bus timing requirements at 400 kHz under 2.5V–5.5V supply.

Technical Context

The 24LC04B-I/ST implements a two-wire I²C interface with open-drain SDA/SCL pins, internal address pointer, and block-select addressing using the B0 bit in the control byte. Its memory architecture supports byte and page writes (up to 16 bytes per page), with automatic wrap-around on page boundary overflow and self-timed erase/write cycles.

It features Schmitt-trigger inputs and output slope control to suppress ground bounce and bus noise, ensuring reliable communication in electrically noisy environments. The WP pin provides hardware-level write protection for the full 4-Kbit array (addresses 000h–1FFh), independent of software commands.

Key Specifications

Pinout & Package

24LC04B-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 gull-wing leads. 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 24LC04B-I/ST, the 24AA04-I/ST extends voltage flexibility at the cost of reduced speed below 2.5V, while the AT24C04-10PU-2.7 trades endurance and retention for higher-speed operation - making each suitable for distinct power, timing, and lifetime requirements.

Availability

24LC04B-I/ST is available at Aetrix Electronics and suitable for industrial automation, medical instrumentation, and automotive body electronics requiring stable component supply, long-term manufacturability, and AEC-Q100 compliance.

Supply support for 24LC04B-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 nonvolatile memory solutions for embedded systems.

The 24LC04B belongs to Microchip's 24XX04 family of I²C EEPROMs, designed specifically for reliable, low-power parameter storage in space-constrained, noise-prone environments across industrial, medical, and automotive applications.

FAQ

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

The 24LC04B-I/ST supports a maximum I²C clock frequency of 400 kHz when operated within its specified VCC range of 2.5V to 5.5V. This is confirmed in the Device Selection Table and AC Characteristics section of the DS20001708P datasheet. Operation below 2.5V is not permitted for this variant, distinguishing it from the 24AA04 which supports 100 kHz down to 1.7V.

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

Yes, the 24LC04B-I/ST requires external pull-up resistors on both SDA and SCL lines because these pins are open-drain. The datasheet recommends 2 kΩ for 400 kHz operation. Without pull-ups, the bus cannot achieve valid HIGH states, preventing Start/Stop detection and data transmission - a fundamental requirement of I²C bus operation.

How many write cycles can the 24LC04B-I/ST endure before failure?

The 24LC04B-I/ST is rated for more than 1,000,000 erase/write cycles at +25°C and 5.5V in page mode, as specified in Table 1-2 (Param. No. 18) of the DS20001708P datasheet. This endurance level ensures robust performance in applications requiring frequent updates, such as logging or calibration adjustment, over extended service life.

What is the function of the A0, A1, and A2 pins on the 24LC04B-I/ST?

The A0, A1, and A2 pins on the 24LC04B-I/ST are not internally connected and serve no functional purpose. As stated in Section 2.1 and Table 2-1 of the datasheet, they may be left floating or tied to VSS or VCC without affecting device behavior, addressing, or I²C communication - unlike higher-density variants (e.g., 24LC256) where these pins configure device address.

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

Yes, the 24LC04B-I/ST is explicitly listed as Automotive AEC-Q100 Qualified in the Features section of the DS20001708P datasheet. This qualification covers the industrial temperature grade (–40°C to +85°C), confirming reliability under automotive thermal, vibration, and electrical stress conditions - making it suitable for body control modules and other non-safety-critical vehicle subsystems.