Microchip Technology 24AA04-I/ST

Overview

24AA04-I/ST from Microchip Technology Inc. is a 4-Kbit I²C-compatible serial EEPROM organized as two 256 × 8-bit blocks, operating from 1.7V to 5.5V with 400 kHz max clock frequency, 1 µA standby current, and industrial temperature range (–40°C to +85°C). It features hardware write-protection, 16-byte page write buffer, and Schmitt-trigger inputs for noise immunity in embedded control and sensor calibration applications.

For engineers reviewing the 24AA04-I/ST datasheet, 24AA04-I/ST pinout, 24AA04-I/ST application, or 24AA04-I/ST equivalent, this device supports low-voltage I²C systems requiring reliable nonvolatile storage with fast page writes, robust ESD protection (>4 kV), and AEC-Q100-qualified variants for automotive subsystems.

Technical Context

The 24AA04-I/ST implements a two-wire I²C interface with fixed 4-bit device code '1010', block-select addressing via B0 bit, and no internal connection to A0–A2 pins. Its memory architecture uses an on-chip address pointer and page latches to enable byte and 16-byte page writes with self-timed erase/write cycles.

It incorporates Schmitt-trigger inputs on SDA/SCL, output slope control to suppress ground bounce, and ACK polling support to determine write completion without fixed delay timing - all compliant with standard I²C protocol timing requirements at 100 kHz (VCC < 2.5V) and 400 kHz (VCC ≥ 2.5V).

Key Specifications

Pinout & Package

24AA04-I/ST is supplied in an 8-lead SOIC (SN) package with 3.90 mm body width and standard 1.27 mm pitch. Pin 1 is marked with a notch or dot; orientation follows JEDEC MS-012.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24AA04-I/ST, the 24LC04B-I/ST offers identical packaging and function but excludes ultra-low-voltage capability, while AT24C04-PU provides basic EEPROM functionality at lower cost but without automotive qualification or enhanced noise immunity features.

Availability

24AA04-I/ST is available at Aetrix Electronics and suitable for industrial sensor calibration, medical device configuration, and automotive body control module designs requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for 24AA04-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 design and manufacturing operations.

The 24AA04 belongs to Microchip's serial EEPROM product line, engineered for robust, low-power nonvolatile storage in space-constrained embedded systems where I²C compatibility, extended voltage range, and industrial reliability are critical.

FAQ

What is the maximum I²C clock frequency supported by the 24AA04-I/ST?

The 24AA04-I/ST supports up to 400 kHz when VCC is 2.5V or higher. At VCC between 1.7V and 2.49V, the maximum clock frequency is reduced to 100 kHz to ensure reliable timing margins. This dual-speed capability allows seamless integration across mixed-voltage systems without protocol translation.

Does the 24AA04-I/ST require external pull-up resistors on SDA and SCL lines?

Yes, the 24AA04-I/ST has open-drain SDA and SCL pins and requires external pull-up resistors. For 400 kHz operation, a 2 kΩ resistor to VCC is recommended; for 100 kHz, 10 kΩ is typical. Pull-up values must be selected based on bus capacitance and rise-time requirements per I²C specification.

How does the WP pin function on the 24AA04-I/ST?

When the WP pin on the 24AA04-I/ST is tied to VCC, all write operations (byte and page) are inhibited - the entire 4-Kbit array becomes read-only. When tied to VSS or left floating, full read/write access is enabled. No internal pull-up or pull-down is present, so explicit connection is required for deterministic behavior.

Can the 24AA04-I/ST be used in automotive applications?

The 24AA04-I/ST itself is not AEC-Q100 qualified; however, the broader 24XX04 family includes AEC-Q100-qualified variants like 24AA04T-I/ST (tape-and-reel, automotive grade). For automotive use, specify the 'T' suffix part number and confirm qualification status via Microchip's official documentation before design-in.

What is the purpose of the A0, A1, and A2 pins on the 24AA04-I/ST?

The A0, A1, and A2 pins on the 24AA04-I/ST are not internally connected and serve no functional role. They may be left floating, tied to VSS, or tied to VCC without affecting device operation - unlike higher-density EEPROMs, the 24AA04 uses only the B0 bit for block selection and has no address-pin decoding logic.