Microchip Technology 24AA515-I/SM

Overview

24AA515-I/SM from Microchip Technology Inc. is a 64K × 8 (512 Kbit) I²C-compatible serial EEPROM with 1.7V–5.5V supply operation, 400 kHz max clock frequency (100 kHz below 2.5V), and industrial temperature range (–40°C to +85°C). It features 64-byte page write buffer, hardware write protection via WP pin, and Schmitt-trigger inputs for noise immunity - deployed in embedded system configuration storage, sensor calibration data retention, and power-meter firmware parameter backup.

For engineers reviewing the 24AA515-I/SM datasheet, 24AA515-I/SM pinout, 24AA515-I/SM application, or 24AA515-I/SM equivalent, key selection considerations include low-voltage operation down to 1.7V, page write time ≤5 ms, 1 million erase/write cycles, 200+ year data retention, and compatibility with I²C bus systems requiring cascaded EEPROMs up to four devices.

Technical Context

The 24AA515-I/SM implements a two-wire I²C interface with fixed 7-bit slave address prefix '1010', block-select bit B0 replacing A15 for 256K-bit segment addressing, and user-configurable chip select pins A0/A1 enabling up to four devices on one bus. Its internal architecture includes a 64-byte page latch, HV generator for EEPROM programming, and memory control logic supporting byte and page writes with self-timed erase/write cycles.

It uses Schmitt-trigger inputs on SDA/SCL for noise suppression, slope-controlled outputs to minimize ground bounce, and supports both random and sequential reads across two 256K-bit address blocks (0000h–7FFFh and 8000h–FFFFh). Write-protect functionality is implemented via dedicated WP pin tied to VCC or VSS, sampled at Stop condition.

Key Specifications

Pinout & Package

24AA515-I/SM is housed in an 8-lead SOIJ (Small Outline Integrated Circuit, J-bend) package, 5.28 mm wide, RoHS-compliant and Pb-free. Pin 1 is A0 (chip select), pin 8 is VCC, and pin 4 is VSS (ground).

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24LC515-I/SM and AT24C512-10PU-2.7, the 24AA515-I/SM uniquely supports 1.7V operation and includes mandatory A2-to-VCC requirement for deterministic addressing - making it the only option for ultra-low-voltage, multi-device I²C EEPROM systems requiring guaranteed initialization behavior.

Availability

24AA515-I/SM is available at Aetrix Electronics and suitable for smart metering, industrial sensor calibration, medical diagnostics, automotive body control, and battery-powered IoT endpoint applications requiring stable component supply and long-term lifecycle assurance.

Supply support for 24AA515-I/SM 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 nonvolatile memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 24AA515 belongs to Microchip's 24XX515 family of I²C serial EEPROMs engineered specifically for low-power, wide-voltage-range embedded systems requiring high endurance and long-term data retention in harsh environments.

FAQ

What is the minimum operating voltage for the 24AA515-I/SM?

The 24AA515-I/SM operates down to 1.7V, enabling direct use in single-cell Li-ion, LiFePO₄, or energy-harvesting systems without voltage boosting. This is a key differentiator from the 24LC515-I/SM (2.5V min) and supports brown-out resilience during battery discharge cycles - a critical feature verified in DS21673G Section 1.0.

How many 24AA515-I/SM devices can be connected on a single I²C bus?

Up to four 24AA515-I/SM devices can be cascaded on one I²C bus using combinations of A0 and A1 pins (A2 is fixed to VCC). Each device responds only to its unique 2-bit chip select code, allowing shared SDA/SCL lines and consolidated memory addressing - confirmed in Device Selection Table and Section 2.1 of DS21673G.

Does the 24AA515-I/SM support page write operations, and what is the maximum page size?

Yes, the 24AA515-I/SM supports page write with a 64-byte buffer. Writes must remain within a single physical page boundary (addresses aligned to 64-byte multiples); crossing boundaries causes wraparound. This behavior is explicitly defined in Section 6.2 and Figure 6-2 of DS21673G, and limits effective burst writes to ≤64 bytes per transaction.

What is the function of the A2 pin on the 24AA515-I/SM?

The A2 pin on the 24AA515-I/SM is a non-configurable chip select input that must be hardwired to VCC for device operation. If left floating or tied to VSS, the device will not respond to I²C commands - a safety mechanism ensuring deterministic initialization, as specified in Section 2.2 and Table 2-1 of DS21673G.

How does hardware write protection work on the 24AA515-I/SM?

Hardware write protection on the 24AA515-I/SM is controlled by the WP pin: tying it to VCC disables all write operations (byte/page) while preserving read functionality; tying it to VSS enables full read/write access. The pin state is sampled only at the Stop condition, making it immune to mid-transaction changes - detailed in Section 2.5 and Section 6.3 of DS21673G.