Microchip Technology 24AA025T-I/ST

Overview

24AA025T-I/ST from Microchip Technology Inc. is a 2 Kbit I²C-compatible serial EEPROM organized as 256 × 8-bit memory, operating from 1.7V to 5.5V with industrial temperature range (–40°C to +85°C). It features 16-byte page write buffer, 400 kHz max clock speed, and Schmitt-trigger inputs for noise immunity - deployed in embedded system configuration storage, sensor calibration data retention, and secure device identity storage.

For engineers reviewing the 24AA025T-I/ST datasheet, 24AA025T-I/ST pinout, 24AA025T-I/ST application, or 24AA025T-I/ST equivalent, key selection considerations include its 6-lead SOT-23 package, absence of hardware write-protect (WP) pin, 1 μA standby current, and compatibility with standard I²C bus timing at 100/400 kHz across full VCC range.

Technical Context

The 24AA025T-I/ST implements a two-wire I²C interface with open-drain SDA/SCL pins requiring external pull-ups. Its internal address pointer auto-increments during sequential reads and supports byte/page writes with self-timed 5 ms erase/write cycles. The device uses Schmitt-trigger inputs and input filtering (50 ns spike suppression) to ensure robust operation on noisy buses.

Unlike the 24AA024 variant, the 24AA025T-I/ST omits the WP pin internally - confirmed by datasheet Note: "WP pin is not internally connected on the 24XX025" and Pin Function Table showing WP as unconnected in SOT-23. Addressing uses A0/A1 pins only (A2 not bonded), enabling up to four devices per bus with 3-bit slave address (1010xx0).

Key Specifications

Pinout & Package

24AA025T-I/ST is housed in a 6-lead SOT-23 package (3.0 mm × 1.7 mm × 1.3 mm), optimized for space-constrained PCB layouts. Pin 1 is laser-marked; no thermal pad or exposed metal.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24AA025-I/ST, the 24AA025T-I/ST offers identical functionality with optimized packaging for pick-and-place; versus AT24C02C-SSHM-T, it trades higher clock speed and register-based WP for proven Microchip reliability and simpler firmware integration in cost-sensitive industrial designs.

Availability

24AA025T-I/ST is available at Aetrix Electronics and suitable for industrial automation, IoT endpoint configuration, and medical device calibration data storage requiring stable component supply across extended production lifecycles.

Supply support for 24AA025T-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 components, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 24AA025T-I/ST belongs to Microchip's legacy 24AAxx serial EEPROM family, designed specifically for low-power, space-constrained embedded systems needing reliable nonvolatile storage with minimal external components.

FAQ

What is the function of the WP pin on the 24AA025T-I/ST?

The WP (Write-Protect) pin is not internally connected on the 24AA025T-I/ST - confirmed in the datasheet's Pin Function Table and Section 2.4. Unlike the 24AA024, this variant lacks hardware write protection; write-enable logic is entirely controlled by I²C command sequence. System-level protection must be implemented in firmware or upstream controller logic. The 24AA025T-I/ST pinout contains only SCL, SDA, VSS, VCC, A0, and A1 terminals.

Can the 24AA025T-I/ST operate at 1.7V supply voltage?

Yes, the 24AA025T-I/ST is fully specified for operation from 1.7V to 5.5V across the industrial temperature range (–40°C to +85°C). At 1.7V, the maximum I²C clock frequency is 100 kHz per Table 1-2; performance scales to 400 kHz above 1.8V. Internal voltage detection prevents write operations below 1.5V to ensure data integrity, making it suitable for single-cell Li-ion or energy-harvesting applications where supply voltage varies.

How many 24AA025T-I/ST devices can share the same I²C bus?

Up to four 24AA025T-I/ST devices can be connected to a single I²C bus. Because the SOT-23 package lacks the A2 pin (as stated in Section 2.3 and Figure 2-1), only A0 and A1 are available for chip-select addressing, yielding four unique slave addresses (1010000 through 1010011). This enables compact multi-sensor nodes or modular peripherals without bus contention, provided each device has distinct A0/A1 strap configurations.

What is the maximum page write size supported by the 24AA025T-I/ST?

The 24AA025T-I/ST supports a 16-byte page write buffer, as documented in the Features list and Section 6.2. Page writes must remain within physical page boundaries (addresses 0x00–0x0F, 0x10–0x1F, etc.); crossing boundaries causes wraparound to the start of the current page. Software must validate address alignment before initiating multi-byte writes. Each page write completes in ≤5 ms, during which the device does not acknowledge I²C commands until internally timed programming finishes.

Does the 24AA025T-I/ST support standard I²C repeated-start conditions?

Yes, the 24AA025T-I/ST fully complies with standard I²C protocol including repeated-start conditions, as defined in Section 4.0 and illustrated in Figures 4-1 and 4-2. It correctly interprets repeated-start sequences for random reads (Section 8.2) and supports acknowledge polling (Section 7.0) to detect write completion. The Schmitt-trigger inputs and 50 ns input filtering ensure robust recognition of repeated-start edges even under bus noise, meeting I²C specification timing requirements for THD:STA, TSU:STA, and TBUF.