Microchip Technology 24AA16HT-I/OT

Overview

24AA16HT-I/OT 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, 1 μA standby current, and hardware write-protect for the upper half-array (400h–7FFh). It is used in embedded systems for nonvolatile storage of calibration data, configuration settings, and firmware parameters.

For engineers reviewing the 24AA16HT-I/OT datasheet, 24AA16HT-I/OT pinout, 24AA16HT-I/OT application, or 24AA16HT-I/OT equivalent, key selection criteria include low-voltage operation down to 1.7V, industrial temperature range (−40°C to +85°C), SOT-23-5 package footprint, half-array write-protection via WP pin, and compatibility with standard I²C master controllers in space-constrained designs.

Technical Context

The 24AA16HT-I/OT implements a two-wire I²C slave interface with Schmitt-trigger inputs and slope-controlled outputs to suppress noise and eliminate ground bounce. Its internal architecture includes an 16-byte page write buffer, self-timed erase/write cycle, and address pointer that auto-increments during sequential reads.

It supports byte and page write modes, with ACK polling for write-cycle completion detection. The WP pin enables hardware-level protection of memory addresses 400h–7FFh when pulled high, while A0–A2 pins are unconnected and may be left floating or tied to VSS/VCC without effect.

Key Specifications

Pinout & Package

24AA16HT-I/OT uses a 5-lead SOT-23 package (JEDEC MO-178AA) with 1.6 mm × 2.8 mm footprint and 0.95 mm height, optimized for high-density PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24LC16BHT-I/OT, the 24AA16HT-I/OT enables lower-voltage operation critical for energy-harvesting and battery-backed systems; versus AT24C16D-SSHM-T, it offers hardware write-protection and SOT-23-5 space savings at the cost of reduced maximum clock rate.

Availability

24AA16HT-I/OT is available at Aetrix Electronics and suitable for smart sensor calibration, industrial PLC configuration, and medical device settings requiring stable component supply across extended production lifecycles.

Supply support for 24AA16HT-I/OT 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 24AA16H family was designed specifically for cost-sensitive, space-constrained embedded systems needing reliable, low-power nonvolatile storage with robust I²C interoperability and industrial temperature resilience.

FAQ

What is the maximum I²C clock frequency supported by the 24AA16HT-I/OT?

The 24AA16HT-I/OT supports up to 400 kHz when V_CC is 2.5V or higher. At V_CC between 1.7V and 2.5V, the maximum clock frequency is reduced to 100 kHz to ensure timing margin and signal integrity. This dual-speed capability allows seamless integration across 1.8V, 3.3V, and 5V system rails without external clock dividers or protocol translation. The 24AA16HT-I/OT does not support 1 MHz operation - that capability is reserved for the 24FC16H variant.

How does the write-protect (WP) pin function on the 24AA16HT-I/OT?

On the 24AA16HT-I/OT, the WP pin provides hardware-level write protection for memory addresses 400h–7FFh (upper half-array) when pulled high to V_CC. When WP is tied to V_SS, full read/write access is enabled across the entire 16Kbit array (000h–7FFh). The WP pin has no effect on read operations - all memory remains readable regardless of WP state. This feature is implemented entirely within the 24AA16HT-I/OT silicon and requires no firmware intervention.

Is the 24AA16HT-I/OT pin-compatible with other 24XX16H variants in SOT-23-5 package?

Yes, the 24AA16HT-I/OT is pin-compatible with 24LC16BHT-I/OT and 24FC16HT-I/OT in the SOT-23-5 package: all share identical pinout (SCL, SDA, WP, V_CC, V_SS) and mechanical footprint. However, electrical differences exist - notably V_CC range and max clock frequency - so direct substitution requires verification of system voltage and timing constraints. The 24AA16HT-I/OT's 1.7V minimum V_CC makes it the only variant usable in 1.8V systems among these three.

What is the endurance and data retention specification for the 24AA16HT-I/OT?

The 24AA16HT-I/OT is rated for 1,000,000 erase/write cycles and greater than 200 years of data retention at +85°C. These specifications are validated per JEDEC standards and reflect worst-case conditions - actual field performance typically exceeds these values. Endurance applies to both byte and page write modes; retention assumes data is written at rated V_CC and stored within the specified industrial temperature range. No periodic refresh is required.

Does the 24AA16HT-I/OT require external pull-up resistors on SDA and SCL lines?

Yes, the 24AA16HT-I/OT 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 1 kΩ for marginal noise immunity at 400 kHz. Pull-ups must connect to the same V_CC rail used by the 24AA16HT-I/OT. Failure to install pull-ups will prevent I²C communication entirely, as neither line can drive high without them.