Microchip Technology 24AA08HT-I/OT

Overview

24AA08HT-I/OT from Microchip Technology is an 8 Kbit I²C-compatible serial EEPROM organized as four 256 × 8-bit blocks, operating from 1.7V to 5.5V with industrial temperature range (−40°C to +85°C), 400 kHz max clock frequency, and hardware write-protect for memory addresses 200h–3FFh. It is used in embedded system configuration storage, sensor calibration data retention, and power-fail-safe parameter backup.

For engineers reviewing the 24AA08HT-I/OT datasheet, 24AA08HT-I/OT pinout, 24AA08HT-I/OT application, or 24AA08HT-I/OT equivalent, key selection criteria include low-voltage operation down to 1.7V, 16-byte page write buffer, Schmitt-trigger I²C inputs for noise immunity, and SOT-23-5 package compatibility with space-constrained PCB layouts.

Technical Context

The 24AA08HT-I/OT implements a slave-only I²C interface with fixed 4-bit device code '1010', block-select addressing (B2–B0) for selecting one of four 256-word memory blocks, and internal address pointer auto-increment for sequential reads. It supports byte and page write modes, with self-timed erase/write cycles and acknowledge polling for bus efficiency.

Its architecture includes Schmitt-trigger inputs on SDA/SCL, output slope control to suppress ground bounce, VCC threshold detection disabling writes below 1.5V, and hardware write-protection activated when WP = VCC. The device uses CMOS technology with max 1 mA active current and 1 µA standby current.

Key Specifications

Pinout & Package

24AA08HT-I/OT is supplied in a 5-lead SOT-23 package (JEDEC MO-178AA), measuring 2.9 mm × 1.6 mm × 1.1 mm, optimized for high-density PCB layouts. Pin 1 = SCL, Pin 2 = VSS, Pin 3 = SDA, Pin 4 = VCC, Pin 5 = WP. A0, A1, A2 are not connected and may be left floating.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24AA08HT-I/OT, the 24LC08BHT-I/OT offers identical packaging and interface but lacks 1.7V support, while the AT24C08D-SSHM-T provides broader temperature tolerance but removes hardware-based memory segmentation - making the 24AA08HT-I/OT optimal for cost-sensitive, low-voltage industrial designs requiring robust write protection.

Availability

24AA08HT-I/OT is available at Aetrix Electronics and suitable for industrial sensor calibration, smart meter configuration storage, and embedded system bootloader settings requiring stable component supply across extended product lifecycles.

Supply support for 24AA08HT-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, analog, and Flash-IP solutions, founded in 1989 and headquartered in Chandler, Arizona.

The 24AA08H family was designed specifically for ultra-low-power, space-constrained embedded systems needing reliable nonvolatile storage with minimal external components and robust noise immunity in harsh electrical environments.

FAQ

What is the minimum operating voltage for the 24AA08HT-I/OT?

The 24AA08HT-I/OT operates down to 1.7V, enabling direct integration with 1.8V logic families and battery-powered devices without voltage translation. This specification is confirmed in the Device Selection Table and Electrical Characteristics section of DS20002084B, where VCC min is explicitly stated as 1.7V for 24AA08H devices. Operation below this threshold disables internal write logic via the VCC detector circuit.

Does the 24AA08HT-I/OT support page write operations, and what is the buffer size?

Yes, the 24AA08HT-I/OT supports page write operations with a 16-byte buffer, as documented in the Features list and Section 4.2 Page Write. This allows up to 16 sequential bytes to be loaded into the on-chip buffer before initiating the internal write cycle, reducing I²C bus overhead and improving firmware efficiency compared to byte-write mode.

How does the write-protect (WP) pin function on the 24AA08HT-I/OT?

When WP is tied to VCC, the 24AA08HT-I/OT hardware write-protects memory addresses 200h–3FFh (half the array); all other addresses remain writable. When WP is tied to VSS, full-array read/write access is enabled. This behavior is defined in Section 6.0 Write Protection and verified in the Pin Descriptions table (DS20002084B, page 11).

Is the 24AA08HT-I/OT pin-compatible with other SOT-23 EEPROMs like the AT24C08D?

No - while both use SOT-23-5 packages, the 24AA08HT-I/OT assigns SCL to Pin 1, VSS to Pin 2, SDA to Pin 3, VCC to Pin 4, and WP to Pin 5, whereas AT24C08D-SSHM-T uses Pin 1 = VCC, Pin 2 = SCL, Pin 3 = SDA, Pin 4 = WP, Pin 5 = VSS. This pinout mismatch prevents direct replacement without PCB redesign.

What is the endurance rating and data retention specification for the 24AA08HT-I/OT?

The 24AA08HT-I/OT is rated for more than 1 million erase/write cycles and guarantees data retention exceeding 200 years at +25°C, as specified in the Features list and Table 1-2 AC Characteristics (Note 4). These values are ensured by characterization and apply across the full industrial temperature range per Microchip's Total Endurance™ Model.