Microchip Technology 24LC515T-I/SM

Overview

24LC515T-I/SM from Microchip Technology Inc. is a 64K × 8 (512 Kbit) I²C-compatible serial EEPROM with 2.5–5.5 V supply range, 400 kHz max clock frequency, and industrial temperature rating (–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 systems requiring nonvolatile parameter storage, such as industrial sensor calibration and power meter firmware configuration.

For engineers reviewing the 24LC515T-I/SM datasheet, 24LC515T-I/SM pinout, 24LC515T-I/SM application, or 24LC515T-I/SM equivalent, key selection criteria include guaranteed 1 million erase/write cycles, 200+ year data retention, I²C bus compatibility up to four cascaded devices, and SOIJ-8 package suitability for space-constrained PCB layouts.

Technical Context

The 24LC515T-I/SM implements a two-wire I²C slave interface with fixed 7-bit address prefix '1010', block-select bit B0 enabling access across two 256 Kbit memory segments, and user-configurable chip select pins A0/A1 supporting up to four devices on one bus. Its internal address pointer auto-increments during sequential reads within 0000h–7FFFh or 8000h–FFFFh boundaries.

Write operations are self-timed: byte writes complete in ≤5 ms; page writes (up to 64 bytes) also require ≤5 ms. The device samples the WP pin at the Stop condition to enable/disable writes - no effect occurs if WP toggles mid-cycle. Acknowledge polling is supported using the original write control byte.

Key Specifications

Pinout & Package

24LC515T-I/SM uses an 8-lead SOIJ package with J-bend leads. Pin functions are electrically identical to PDIP but differ mechanically in lead form and footprint.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24AA515-I/SM, the 24LC515T-I/SM trades low-voltage flexibility for stricter 2.5 V minimum and better noise immunity at nominal rails; versus AT24C512-MAHM-T, it offers deterministic A2-enforced device enable but lacks 1 MHz capability - making it optimal for cost-sensitive industrial control where 400 kHz suffices and write-protection rigor is critical.

Availability

24LC515T-I/SM is available at Aetrix Electronics and suitable for industrial sensor calibration, smart meter firmware storage, and medical device configuration requiring stable component supply across multi-year production cycles.

Supply support for 24LC515T-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 U.S.-based semiconductor company specializing in microcontrollers, analog devices, and nonvolatile memory solutions for embedded control applications.

The 24LC515T-I/SM belongs to Microchip's 24XX515 family of I²C EEPROMs, designed specifically for reliable, low-power, long-life data storage in industrial, medical, and consumer electronics where write endurance and data integrity are mission-critical.

FAQ

What is the minimum supply voltage required for reliable operation of the 24LC515T-I/SM?

The 24LC515T-I/SM requires a minimum VCC of 2.5 V for guaranteed functionality across its full specification range. Unlike the 24AA515 variant, it is not rated for operation below 2.5 V - attempting to power it at 1.8 V may result in undefined behavior, failed writes, or communication timeouts. Always maintain VCC within 2.5–5.5 V per the DS21673G datasheet.

How does the A2 pin function on the 24LC515T-I/SM, and what happens if it is left unconnected?

The A2 pin on the 24LC515T-I/SM is a non-configurable chip select that must be hard-wired to VCC for device operation. If left floating or tied to VSS, the 24LC515T-I/SM will not respond to I²C commands and remains inactive. This differs from A0/A1, which are user-configurable address inputs - A2 enforces strict hardware enablement to prevent accidental activation in multi-device systems.

Can the 24LC515T-I/SM perform sequential reads across the full 64K address space without interruption?

No. Sequential reads on the 24LC515T-I/SM are limited to 256 Kbit segments: addresses 0000h–7FFFh and 8000h–FFFFh. When reading past 7FFFh, the internal address pointer rolls over to 0000h; past FFFFh, it rolls over to 8000h. To read the entire memory linearly, software must issue separate read commands for each segment - no automatic wrap-around across the 32K-word boundary.

What is the maximum number of 24LC515T-I/SM devices that can share a single I²C bus, and how is addressing managed?

Up to four 24LC515T-I/SM devices can share one I²C bus using the A0 and A1 pins to configure unique 2-bit chip select codes. Combined with the fixed 4-bit control code '1010', this yields four distinct 7-bit slave addresses (1010000, 1010001, 1010010, 1010011). The A2 pin is not used for addressing - it must be tied high, so only A0/A1 determine device identity on the bus.

Does the 24LC515T-I/SM support page write operations across memory page boundaries?

No. Page write operations on the 24LC515T-I/SM are strictly confined within physical 64-byte pages. Attempting to write across a boundary (e.g., starting at address 003Fh with 64 bytes) causes the address counter to wrap within the same page - overwriting earlier data instead of advancing to the next page. Application firmware must align page writes to 64-byte boundaries (0000h, 0040h, 0080h, etc.) to ensure correct data placement.