Microchip Technology 24AA01HT-I/OT

Overview

24AA01HT-I/OT from Microchip Technology Inc. is a 1 Kbit (128 × 8) I²C-compatible serial EEPROM optimized for ultra-low-voltage operation down to 1.7V, featuring hardware write-protect for the upper half-array (40h–7Fh), 1 μA max standby current, and 400 kHz clock support at V_CC ≥ 2.5V. It serves as nonvolatile configuration storage in space-constrained industrial sensors and embedded control modules.

For engineers reviewing the 24AA01HT-I/OT datasheet, 24AA01HT-I/OT pinout, 24AA01HT-I/OT application, or 24AA01HT-I/OT equivalent, this page delivers verified electrical specs, validated SOT-23 pin mapping, confirmed half-array write-protection behavior, and real-world use cases aligned with I²C bus timing constraints and low-power design requirements.

Technical Context

The 24AA01HT-I/OT implements a fixed 128-word × 8-bit memory array organized as a single block, with no internal address pins (A0–A2 are unconnected). Its I²C slave interface uses open-drain SDA/SCL with Schmitt-trigger inputs and slope control to suppress ground bounce and noise spikes.

Write operations support byte and page modes (up to 8 bytes per page write), with typical 3 ms page write time and 5 ms max write cycle time. Hardware write-protection is controlled solely by the WP pin state-tied to V_CC to lock addresses 40h–7Fh, while permitting full read access regardless of WP state.

Key Specifications

Pinout & Package

24AA01HT-I/OT is supplied in a Pb-free, RoHS-compliant 5-lead SOT-23 package (tape-and-reel). Pin 1 is SCL; Pin 2 is V_SS; Pin 3 is SDA; Pin 4 is V_CC; Pin 5 is WP. A0, A1, and A2 are not internally connected and must be left floating or tied to V_SS/V_CC per layout convenience.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24AA01HT-I/OT, the 24LC01BHT-I/OT offers identical form/fit/function at ≥2.5V but excludes sub-2.5V operation, while the AT24C01D-SSHM-T trades write-protection and pin compatibility for higher speed and broader vendor availability-making 24AA01HT-I/OT optimal for cost-sensitive, low-voltage, write-protected designs.

Availability

24AA01HT-I/OT is available at Aetrix Electronics and suitable for industrial sensor calibration, embedded controller configuration, and IoT edge node identity storage requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for 24AA01HT-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 microcontroller, mixed-signal, analog, and Flash-IP solutions, headquartered in Chandler, Arizona, with global design, manufacturing, and sales operations.

The 24AA01H family was designed specifically for ultra-low-voltage, space-constrained embedded systems needing reliable, low-power nonvolatile storage with hardware-based data integrity safeguards.

FAQ

What is the minimum V_CC required for reliable operation of the 24AA01HT-I/OT?

The 24AA01HT-I/OT operates reliably down to 1.7V V_CC across its full industrial temperature range (–40°C to +85°C). Below 1.7V, the internal voltage threshold detector disables erase/write logic to prevent corrupted writes. This 1.7V minimum enables direct interfacing with 1.8V microcontrollers and battery-powered systems without regulators or level shifters, making the 24AA01HT-I/OT uniquely suited for ultra-low-power designs where every millivolt matters.

How does the WP pin function on the 24AA01HT-I/OT, and what memory regions does it protect?

When the WP pin of the 24AA01HT-I/OT is tied to V_CC, write operations to memory addresses 40h through 7Fh (upper 512 bits) are inhibited; reads remain fully functional across the entire 00h–7Fh range. If WP is tied to V_SS, full read/write access is enabled. This hardware-based half-array protection is implemented entirely within the silicon and requires no software intervention, ensuring robust safeguarding of critical firmware or calibration data even during unexpected resets or firmware faults.

Is the 24AA01HT-I/OT compatible with standard I²C bus speeds, and what are the timing limits?

Yes, the 24AA01HT-I/OT supports standard-mode (100 kHz) and fast-mode (400 kHz) I²C operation. At V_CC ≥ 2.5V, it meets full 400 kHz timing specifications including THIGH ≥ 600 ns and TLOW ≥ 1300 ns. At 1.7V ≤ V_CC < 2.5V, maximum clock frequency drops to 100 kHz with relaxed timing (THIGH ≥ 4000 ns). These dual-speed capabilities ensure interoperability with legacy and modern I²C masters while maintaining signal integrity under varying supply conditions.

What is the endurance rating of the 24AA01HT-I/OT, and how is it validated?

The 24AA01HT-I/OT is rated for more than 1 million erase/write cycles per memory location, validated through characterization testing at 25°C and V_CC = 5.5V using block-mode stress patterns. This endurance specification ensures reliable operation in applications requiring frequent parameter updates-such as usage logging or dynamic calibration-without premature wear-out. Field reliability is further enhanced by the device's >200-year data retention guarantee, which applies across the full industrial temperature range.

Does the 24AA01HT-I/OT require external pull-up resistors on the SDA and SCL lines, and what values are recommended?

Yes, the 24AA01HT-I/OT requires external pull-up resistors on both SDA and SCL because these pins are open-drain outputs. For 100 kHz operation, a 10 kΩ resistor to V_CC is typical; for 400 kHz, a 2 kΩ resistor is recommended to meet rise-time requirements (TR ≤ 300 ns at V_CC ≥ 2.5V). The exact value depends on bus capacitance and V_CC; designers should verify timing margins using the AC characteristics table in DS22104A, especially under worst-case voltage and temperature conditions.