Microchip Technology 24LC04BT-I/ST

Overview

24LC04BT-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, 1 µA standby current, and industrial temperature range (–40°C to +85°C). It supports page writes up to 16 bytes and hardware write-protection via the WP pin for embedded system configuration storage.

For engineers reviewing the 24LC04BT-I/ST datasheet, 24LC04BT-I/ST pinout, 24LC04BT-I/ST application, or 24LC04BT-I/ST equivalent, key selection criteria include VCC voltage compatibility (2.5V min), I²C timing compliance at 400 kHz, SOIC-8 package footprint, WP-controlled memory protection, and endurance of 1 million erase/write cycles.

Technical Context

The 24LC04BT-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 address pointer supports current-address, random, and sequential read modes, while the 16-byte page buffer enables efficient burst writes without host-side byte-by-byte handshaking.

It uses an on-chip high-voltage generator for EEPROM programming and features acknowledge polling to detect write-cycle completion. The device does not use A0–A2 pins-addressing is fixed to control code '1010' with block-select bit B0 and R/W bit, enabling access to either 256-word block without external address lines.

Key Specifications

Pinout & Package

24LC04BT-I/ST is supplied in an 8-lead SOIC (SN) package per Microchip drawing C04-057-SN Rev F, with 150-mil body width and 1.27 mm pitch. Pin 1 is marked by a beveled corner or notch; package meets JEDEC MS-012 standards.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24LC04BT-I/ST, 24AA04T-I/ST extends voltage flexibility at the cost of reduced max clock speed under 2.5V, while 24LC04B-I/P offers identical performance in a through-hole package - choice depends strictly on board assembly method and supply rail constraints.

Availability

24LC04BT-I/ST is available at Aetrix Electronics and suitable for industrial sensor calibration, medical device configuration, and automotive body control modules requiring stable component supply, long-term data retention, and AEC-Q100-aligned reliability.

Supply support for 24LC04BT-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 leading provider of microcontrollers, analog devices, and memory solutions, headquartered in Chandler, Arizona, with global manufacturing and support infrastructure.

The 24LC04B family is designed for cost-sensitive, low-power embedded systems requiring reliable nonvolatile storage of configuration data, calibration values, and user preferences in I²C-based architectures.

FAQ

What is the maximum I²C clock frequency supported by the 24LC04BT-I/ST?

The 24LC04BT-I/ST supports a maximum I²C clock frequency of 400 kHz across its full VCC range (2.5V–5.5V). It is not rated for 1 MHz operation - that capability is exclusive to the 24FC04 variant. Timing parameters such as THIGH (600 ns min) and TLOW (1300 ns min) are specified to ensure reliable communication at this rate.

Does the 24LC04BT-I/ST require external pull-up resistors on SDA and SCL lines?

Yes, the 24LC04BT-I/ST requires external pull-up resistors on both SDA and SCL lines because its I²C interface uses open-drain outputs. For 400 kHz operation, a 2 kΩ resistor to VCC is recommended. Pull-up strength directly affects rise time and bus noise immunity, so values must be selected based on bus capacitance and speed requirements.

How does the WP pin function on the 24LC04BT-I/ST?

The WP (Write-Protect) pin on the 24LC04BT-I/ST is an active-high input. When tied to VCC, it disables all write operations to the entire memory array (addresses 000–1FF hex), while read operations remain fully functional. When tied to VSS or left floating (not recommended), full read/write access is enabled. This provides hardware-level protection against unintended firmware or configuration overwrites.

Can the 24LC04BT-I/ST be used in automotive applications?

Yes, the 24LC04BT-I/ST is AEC-Q100 qualified for automotive applications and rated for the industrial temperature range (–40°C to +85°C). Its 1 million erase/write cycles, 200-year data retention, and robust ESD protection (>4 kV) meet key reliability requirements for body control, infotainment, and comfort systems in passenger vehicles.

What is the purpose of the A0, A1, and A2 pins on the 24LC04BT-I/ST?

The A0, A1, and A2 pins on the 24LC04BT-I/ST have no internal connection and are unused. They may be left floating or tied to VSS or VCC without affecting device operation. This simplifies PCB layout and eliminates the need for external address configuration resistors - unlike higher-density EEPROMs, the 24LC04B uses a fixed I²C address (1010xxx) with only block-select bit B0 determining memory access.