Microchip Technology 24AA512T-I/ST

Overview

24AA512T-I/ST from Microchip Technology Inc. is a 512 Kbit I²C-compatible serial EEPROM organized as 64K × 8-bit memory, operating from 1.7V to 5.5V with 400 µA max read current, 1 µA max standby current, and 128-byte page write buffer. It supports industrial temperature range (−40°C to +85°C) and is housed in an 8-lead SOIC package with hardware write-protection via the WP pin.

For engineers reviewing the 24AA512T-I/ST datasheet, 24AA512T-I/ST pinout, 24AA512T-I/ST application, or 24AA512T-I/ST equivalent, key selection criteria include low-voltage operation down to 1.7V, 400 kHz I²C clock compatibility, Schmitt-trigger noise immunity on SDA/SCL, cascading support for up to eight devices on one bus, and 1 million erase/write cycles with >200-year data retention.

Technical Context

The 24AA512T-I/ST implements a two-wire I²C interface with open-drain SDA/SCL pins requiring external pull-ups, and uses A0–A2 address inputs to enable up to eight devices on a shared bus. Its internal architecture includes a 128-byte page latch, HV generator for EEPROM programming, and memory control logic supporting byte and page writes with self-timed erase/write cycles.

It features Schmitt-trigger inputs on SDA and SCL for robust noise suppression, output slope control to minimize ground bounce, and hardware write-protection via the WP pin-sampled at the Stop bit-to disable writes when tied to VCC. The device supports random, sequential, and current-address read modes with automatic address pointer incrementation and wraparound at 64K boundary.

Key Specifications

Pinout & Package

24AA512T-I/ST is supplied in an 8-lead SOIC (Small Outline Integrated Circuit) package, 3.90 mm body width, with standard JEDEC MS-012AC footprint and gull-wing leads. Pin 1 is marked with a notch or dot; device orientation follows standard SOIC top-view convention.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24LC512-I/ST and AT24C512BN-SH-T, the 24AA512T-I/ST uniquely supports 1.7V operation and AEC-Q100 qualification-making it the only option for ultra-low-voltage or automotive-grade deployments where both features are mandatory.

Availability

24AA512T-I/ST is available at Aetrix Electronics and suitable for industrial sensor calibration storage, medical device configuration memory, and automotive body control modules requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 24AA512T-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 microcontroller, analog, FPGA, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 24AA512T-I/ST belongs to Microchip's 24XX512 family of I²C serial EEPROMs, designed specifically for reliable, low-power nonvolatile data storage in cost-sensitive, space-constrained embedded systems across industrial, automotive, and medical markets.

FAQ

What is the minimum supply voltage required for reliable operation of the 24AA512T-I/ST?

The 24AA512T-I/ST operates reliably down to 1.7V across its full industrial temperature range (−40°C to +85°C). This low-voltage capability enables direct interfacing with 1.8V logic families and battery-powered systems without voltage translation. Below 1.7V, read/write functionality is not guaranteed per datasheet DS20001754Q, and the device may fail to acknowledge I²C commands or complete write cycles. Always verify VCC stability during brown-out conditions using the WP pin's sampling point at the Stop bit.

How does the WP pin function on the 24AA512T-I/ST, and when is it sampled?

The WP (Write-Protect) pin on the 24AA512T-I/ST is sampled only at the Stop condition of each I²C write command. When tied to VCC, it disables all write operations-including byte and page writes-while permitting unlimited reads. If WP is pulled low (VSS), writes are enabled. Critically, toggling WP after the Stop bit has no effect on an ongoing write cycle. This behavior ensures that partial writes cannot occur during power transitions, making the 24AA512T-I/ST suitable for safety-critical applications where data integrity is paramount.

Can multiple 24AA512T-I/ST devices share the same I²C bus, and how is addressing managed?

Yes, up to eight 24AA512T-I/ST devices can share a single I²C bus using the A0, A1, and A2 address pins. These three pins form the three least-significant bits of the 7-bit I²C client address (base 1010xxx), allowing unique addressing from 1010000 to 1010111. Each pin must be hard-wired to either VSS or VCC-floating connections are undefined. This cascading capability simplifies multi-node sensor networks and modular system designs without requiring additional I²C multiplexers or GPIO-controlled bus switching.

What is the maximum page write size supported by the 24AA512T-I/ST, and what happens if more than 128 bytes are sent?

The 24AA512T-I/ST supports a maximum page write size of 128 bytes, aligned to physical page boundaries starting at addresses divisible by 128 (e.g., 0x0000, 0x0080). If more than 128 bytes are transmitted before the Stop condition, the internal address counter rolls over within the same page, overwriting previously loaded data. This behavior is intentional and documented in Section 6.2 of DS20001754Q. To avoid data corruption, application firmware must segment writes at 128-byte boundaries and verify address alignment prior to initiating page writes.

Does the 24AA512T-I/ST support 1 MHz I²C communication, and what limits its speed?

No, the 24AA512T-I/ST is rated for a maximum I²C clock frequency of 400 kHz under all valid operating conditions (VCC = 1.7–5.5V, TA = −40°C to +85°C). While the 24FC512 variant supports 1 MHz, the "AA" suffix denotes the 400 kHz version. Speed is limited by internal timing parameters including THIGH (min 600 ns), TLOW (min 1300 ns), and TR/TF (max 300 ns rise/fall times at VCC ≥2.5V). Attempting 1 MHz operation will violate setup/hold times and result in NACK responses or bus lockup-verified in Table 1-2 AC Characteristics of DS20001754Q.