Microchip Technology 24FC515-I/P

Overview

24FC515-I/P from Microchip Technology Inc. is a 64K × 8 (512 Kbit) I²C-compatible serial EEPROM with 2.5–5.5 V supply range, 1 MHz maximum 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-used in embedded systems for firmware parameter storage, calibration data retention, and configuration backup.

For engineers reviewing the 24FC515-I/P datasheet, 24FC515-I/P pinout, 24FC515-I/P application, or 24FC515-I/P equivalent, key selection considerations include its 1 MHz I²C speed advantage over 24LC515, PDIP-8 package compatibility with legacy through-hole designs, endurance of 1 million erase/write cycles, and support for cascaded multi-device addressing up to 2 Mbit total memory.

Technical Context

The 24FC515-I/P implements a slave-mode I²C interface with fixed 4-bit control code (1010b), block-select bit (B0), and two chip-select bits (A0, A1) enabling up to four devices on one bus. Its internal address counter supports current-address, random, and sequential reads across two 256 Kbit segments (0000h–7FFFh and 8000h–FFFFh).

Write operations use self-timed erase/write cycles with 5 ms max page write time; page writes are limited to 64-byte boundaries and wrap on overflow. The WP pin disables all writes when tied to VCC, while A2 must be hardwired to VCC for operation-no floating or low states permitted.

Key Specifications

Pinout & Package

24FC515-I/P is housed in an 8-lead plastic dual in-line package (PDIP) with 300-mil body width, compatible with standard through-hole PCB assembly and socket-based prototyping.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24LC515-I/P, the 24FC515-I/P delivers 2.5× faster configuration writes and maintains full PDIP-8 compatibility; versus AT24C512-10PU-2.7, it offers broader 2.5 V VCC support and through-hole packaging for serviceability and prototyping.

Availability

24FC515-I/P is available at Aetrix Electronics and suitable for industrial sensor calibration, medical device configuration, and smart energy metering requiring stable component supply across extended product lifecycles.

Supply support for 24FC515-I/P 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, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 24FC515 belongs to Microchip's 24XX515 family of I²C serial EEPROMs, designed specifically for robust, low-power nonvolatile data storage in space-constrained embedded systems requiring high endurance and long-term data integrity.

FAQ

What is the maximum I²C clock frequency supported by the 24FC515-I/P?

The 24FC515-I/P supports up to 1 MHz I²C clock frequency when VCC is between 2.5 V and 5.5 V. This is a key differentiator from the 24LC515-I/P (400 kHz max) and enables faster configuration writes in time-critical applications. The 24FC515-I/P datasheet specifies minimum high/low times of 500 ns each at this speed, requiring careful PCB layout for signal integrity.

Can the 24FC515-I/P operate at 1.8 V?

No, the 24FC515-I/P requires a minimum VCC of 2.5 V and is not rated for 1.8 V operation. For sub-2.5 V applications, engineers should consider the 24AA515 variant, which supports down to 1.7 V. Using the 24FC515-I/P below 2.5 V may result in unreliable read/write behavior or failure to acknowledge I²C commands.

How does the WP pin function on the 24FC515-I/P?

The WP (Write-Protect) pin on the 24FC515-I/P disables all write operations-including byte and page writes-when held at VCC. When tied to VSS, writes are enabled. The pin is sampled only at the Stop condition of each write command; toggling WP during a write cycle has no effect. This provides hardware-level protection against accidental firmware corruption.

What is the purpose of the A2 pin on the 24FC515-I/P?

The A2 pin on the 24FC515-I/P is a non-configurable chip select that must be hardwired to VCC for proper operation. If left floating or pulled low, the device will not respond to I²C commands. Unlike A0 and A1, A2 is not used for address selection-it serves as an enable signal ensuring correct initialization and preventing unintended device activation.

Does the 24FC515-I/P support sequential reads across the full 64K address space?

No, sequential reads on the 24FC515-I/P are limited to 256 Kbit segments: addresses 0000h–7FFFh and 8000h–FFFFh. Attempting to read past 7FFFh will roll over to 0000h, and reading past FFFFh will roll over to 8000h. To access the full memory linearly, software must issue separate read commands for each segment, respecting these internal addressing boundaries.