Microchip Technology 24AA08T-I/OT

Overview

24AA08T-I/OT from Microchip Technology Inc. is an 8-Kbit I²C-compatible serial EEPROM organized as four 256 × 8-bit blocks, operating from 1.7V to 5.5V with 400 kHz max clock frequency, 1 µA standby current, and hardware write-protection via the WP pin. It supports industrial temperature range (–40°C to +85°C) and is packaged in SOT-23-5.

For engineers reviewing the 24AA08T-I/OT datasheet, 24AA08T-I/OT pinout, 24AA08T-I/OT application, or 24AA08T-I/OT equivalent, key selection criteria include low-voltage operation down to 1.7V, 16-byte page write buffer, Schmitt-trigger inputs for noise immunity, self-timed erase/write cycle, and RoHS-compliant SOT-23-5 packaging for space-constrained embedded systems.

Technical Context

The 24AA08T-I/OT implements a two-wire I²C interface with fixed 4-bit device code (1010b), block-select addressing (B1/B0 bits), and R/W bit control. Its internal architecture includes a 16-byte page latch, HV generator for EEPROM programming, and memory control logic managing address pointer increment and wraparound during sequential access.

It features Schmitt-trigger inputs on SDA/SCL with 0.05×VCC hysteresis, output slope control to suppress ground bounce, and ACK polling support to detect write-cycle completion. The WP pin enables full-array hardware write-protection when tied to VCC; no internal connection exists for A0/A1/A2 pins.

Key Specifications

Pinout & Package

24AA08T-I/OT is housed in a 5-lead SOT-23 package (JEDEC MO-178AA), with 1.6 mm × 2.9 mm footprint and 1.1 mm height. Pin 1 is SCL; pin 2 is VSS; pin 3 is SDA; pin 4 is VCC; pin 5 is WP. A0, A1, and A2 are not connected internally and must be left floating or tied to VSS/VCC per layout requirements.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24LC08BT-I/OT, the 24AA08T-I/OT enables lower-voltage operation critical for modern ultra-low-power designs; compared with 24FC08T-I/OT, it trades 1 MHz speed and extended temp for lower unit cost and proven qualification in industrial-grade applications.

Availability

24AA08T-I/OT is available at Aetrix Electronics and suitable for industrial sensor calibration, medical device configuration, automotive body control modules, and consumer IoT firmware patch storage requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for 24AA08T-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, serving industrial, automotive, communications, and consumer markets with high-reliability semiconductor products.

The 24AA08T-I/OT belongs to Microchip's 24XX08 family of I²C serial EEPROMs, designed specifically for robust, low-power nonvolatile data storage in space-constrained embedded systems where write-protection, noise immunity, and wide supply voltage range are critical.

FAQ

What is the maximum clock frequency supported by the 24AA08T-I/OT?

The 24AA08T-I/OT 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 across 1.8V, 3.3V, and 5V system buses without external clock dividers or protocol translation.

Does the 24AA08T-I/OT require external pull-up resistors on SDA and SCL lines?

Yes, the 24AA08T-I/OT uses open-drain outputs on both SDA and SCL pins and requires external pull-up resistors to VCC. Typical values are 10 kΩ for 100 kHz operation and 2 kΩ for 400 kHz. The resistor value must be selected based on bus capacitance and desired rise time to meet I²C specification timing requirements.

How does the write-protection feature work on the 24AA08T-I/OT?

The WP pin on the 24AA08T-I/OT enables hardware-level write protection: when tied to VCC, all write operations (byte and page) to the entire 8-Kbit memory array (addresses 000h–3FFh) are inhibited, while read operations remain fully functional. When tied to VSS, normal read/write access is enabled. This provides deterministic, non-software-dependent protection against accidental or malicious overwrites.

What is the purpose of the A0, A1, and A2 pins on the 24AA08T-I/OT?

The A0, A1, and A2 pins on the 24AA08T-I/OT are not internally connected and serve no functional role. They may be left floating or tied to VSS or VCC without affecting device operation. This design simplifies PCB layout and eliminates address conflicts in single-device I²C configurations, as the 24AA08T-I/OT uses a fixed 4-bit device code (1010b) with block-select bits instead of hardware address pins.

Can the 24AA08T-I/OT be used in automotive applications?

The 24AA08T-I/OT is qualified for industrial temperature range (–40°C to +85°C) and is RoHS-compliant, but it is not AEC-Q100 qualified. For automotive applications requiring AEC-Q100 Grade 2 or Grade 3 qualification, Microchip recommends the 24LC08B or 24FC08 variants, which are explicitly certified. The 24AA08T-I/OT remains suitable for non-safety-critical automotive subsystems where industrial-grade reliability suffices.