Microchip Technology 24AA16T-I/ST

Overview

24AA16T-I/ST from Microchip Technology Inc. is a 16-Kbit I²C-compatible serial EEPROM organized as eight 256 × 8-bit blocks, operating from 1.7V to 5.5V with 400 kHz max clock frequency (100 kHz below 2.5V), 1 μA standby current, and hardware write-protection via the WP pin. It supports page writes of up to 16 bytes and is rated for industrial temperature (–40°C to +85°C) in an 8-lead SOIC package.

For engineers reviewing the 24AA16T-I/ST datasheet, 24AA16T-I/ST pinout, 24AA16T-I/ST application, or 24AA16T-I/ST equivalent, key selection criteria include low-voltage operation down to 1.7V, I²C bus compatibility with Schmitt-trigger inputs and slope control, 1 million write cycles, 200-year data retention, and hardware-based memory protection - all critical for embedded system configuration storage, calibration data logging, and firmware parameter backup.

Technical Context

The 24AA16T-I/ST functions as a slave device on a two-wire I²C bus, using a 7-bit slave address format (1010xxxR/W) where the three block-select bits (B2–B0) determine one of eight 256-byte memory blocks. Its internal architecture includes a 16-byte page latch, HV generator for EEPROM programming, and dedicated I/O control logic that enforces strict timing compliance per I²C specification - including start/stop condition detection, acknowledge polling during write cycles, and noise-suppressed SDA/SCL inputs.

It implements a fixed 8-pin SOIC package with no internal connection to A0–A2 pins, requiring only VCC, VSS, SDA, SCL, and WP terminals for full functionality. Write protection is binary: WP = VSS enables full read/write access; WP = VCC locks the entire 16-Kbit array (addresses 000h–7FFh). The device performs self-timed erase/write operations with a maximum 5 ms cycle time and supports byte, page, current-address, random, and sequential read modes.

Key Specifications

Pinout & Package

8-Lead SOIC (SN) package with gull-wing leads, 1.27 mm pitch, 3.90 mm body width, and JEDEC MS-012AC compliant footprint. Pin 1 marked by notch or bevel; exposed pad not present in SOIC variant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24LC16BT-I/ST, the 24AA16T-I/ST enables true 1.8V system integration, while versus AT24C16C-SSHM-T, it offers automotive qualification and fixed-address simplicity - making it optimal for safety-critical or ultra-low-power embedded designs where reliability and voltage headroom are primary constraints.

Availability

24AA16T-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-lifecycle support, and RoHS-compliant packaging.

Supply support for 24AA16T-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, FPGA, and memory solutions, serving industrial, automotive, and consumer markets with vertically integrated silicon and development tools.

The 24AA16T-I/ST belongs to Microchip's 24XX16 family of I²C EEPROMs, designed specifically for robust, low-power nonvolatile data storage in space-constrained embedded systems where voltage flexibility and data integrity are critical.

FAQ

What is the maximum I²C clock frequency supported by the 24AA16T-I/ST?

The 24AA16T-I/ST supports up to 400 kHz when VCC is 2.5V or higher. At VCC between 1.7V and 2.5V, the maximum clock frequency is reduced to 100 kHz to ensure reliable timing margins. This dual-speed capability allows seamless integration into both 1.8V and 3.3V/5V systems without protocol changes. The 24AA16T-I/ST automatically adapts to the applied VCC level without external configuration.

Does the 24AA16T-I/ST require external pull-up resistors on SDA and SCL lines?

Yes, the 24AA16T-I/ST requires external pull-up resistors on both SDA and SCL lines because its I²C interface uses open-drain outputs. Recommended values are 10 kΩ for 100 kHz operation, 2 kΩ for 400 kHz, and lower values for 1 MHz (though 24AA16T-I/ST does not support 1 MHz). These resistors ensure proper signal rise times and bus contention resolution in multi-device I²C networks.

How does hardware write-protection work on the 24AA16T-I/ST?

Hardware write-protection on the 24AA16T-I/ST is controlled by the WP pin: when tied to VCC, all write operations (byte, page, or erase) to the entire 16-Kbit memory array (000h–7FFh) are disabled, while read operations remain fully functional. When WP is tied to VSS, normal read/write access is enabled. This pin-level control operates independently of software commands and persists across power cycles, providing tamper-resistant memory lockdown.

Can the 24AA16T-I/ST be used in automotive applications?

Yes, the 24AA16T-I/ST is AEC-Q100 qualified for automotive use and specified for industrial temperature range (–40°C to +85°C), making it suitable for body control modules, infotainment systems, and ADAS subsystems. Its 1.7V operation supports cold-crank scenarios, and features like Schmitt-trigger inputs, slope-controlled outputs, and >4 kV ESD protection enhance robustness in electrically noisy vehicle environments.

What is the purpose of the unused A0, A1, and A2 pins on the 24AA16T-I/ST?

The A0, A1, and A2 pins on the 24AA16T-I/ST have no internal connection and serve no functional purpose. They may be left floating or tied to VSS or VCC without affecting device operation. This design simplifies PCB layout by eliminating address pin routing and avoids conflicts in multi-device I²C buses - unlike competing EEPROMs that require these pins to configure slave addresses.