Microchip Technology 24LC512-I/ST

Overview

24LC512-I/ST from Microchip Technology Inc. is a 512 Kbit I²C-compatible serial EEPROM organized as 64K × 8-bit, operating from 2.5V to 5.5V with industrial temperature range (–40°C to +85°C), 400 µA max read current, 1 µA max standby current, and 128-byte page write buffer. It serves as nonvolatile configuration storage in embedded controllers, power management units, and sensor calibration modules.

For engineers reviewing the 24LC512-I/ST datasheet, 24LC512-I/ST pinout, 24LC512-I/ST application, or 24LC512-I/ST equivalent, key selection criteria include its 400 kHz I²C clock support at 2.5V+, hardware write-protect (WP) pin, cascading capability for up to eight devices on one bus, and guaranteed >1 million erase/write cycles with >200-year data retention.

Technical Context

The 24LC512-I/ST implements a two-wire I²C interface with Schmitt-trigger inputs on SDA and SCL for noise immunity, slope-controlled outputs to suppress ground bounce, and internal address pointer logic enabling sequential, random, and current-address read modes. Its memory array is partitioned into 4096 pages of 128 bytes each, with page-write buffering and self-timed erase/write cycles.

Write protection is enforced via the dedicated WP pin-tied to VCC to inhibit all writes while permitting reads-and device addressing uses three hardware-configurable chip-select pins (A0–A2), allowing up to eight 24LC512-I/ST devices on a shared bus with unique 7-bit client addresses derived from the '1010' control code plus A2:A0 bits.

Key Specifications

Pinout & Package

24LC512-I/ST is supplied in an 8-lead SOIC package (ST suffix per Microchip's packaging nomenclature), with 150 mil body width, gull-wing leads, and JEDEC MS-012AC compliant footprint. Pin 1 is marked with a beveled corner or dot.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT24C512BN-SH-B and BR24G512FJ-3GE2, the 24LC512-I/ST offers proven industrial temperature reliability and strict 2.5V minimum VCC compliance - making it optimal for legacy 3.3V/5V systems where voltage margin is constrained and qualification traceability is mandatory.

Availability

24LC512-I/ST is available at Aetrix Electronics and suitable for industrial sensor calibration, embedded system configuration storage, and automotive body control module applications requiring stable component supply across multi-year production cycles.

Supply support for 24LC512-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 manufacturing and support infrastructure.

The 24LC512 belongs to Microchip's 24XX512 family of I²C serial EEPROMs, designed specifically for reliable, low-power nonvolatile data storage in space-constrained embedded systems where write endurance, data retention, and bus scalability are critical.

FAQ

What is the minimum supply voltage required for reliable operation of the 24LC512-I/ST?

The 24LC512-I/ST requires a minimum supply voltage of 2.5V for guaranteed operation across its full industrial temperature range (–40°C to +85°C). Below 2.5V, functionality is not assured - unlike the 24AA512 or 24FC512 variants, which support down to 1.7V. This makes the 24LC512-I/ST ideal for stable 3.3V or 5V rail systems where voltage droop is minimal.

How does the WP pin function on the 24LC512-I/ST, and what happens if it's left floating?

The WP (Write-Protect) pin on the 24LC512-I/ST is active-high: tying it to VCC disables all write operations (byte and page), while tying it to VSS enables them. The pin is sampled at the STOP bit of each write command. If left floating, the internal state is undefined and may result in intermittent or failed writes - Microchip explicitly requires WP to be hard-wired to either VSS or VCC. The 24LC512-I/ST does not include internal pull-up/down on WP.

Can multiple 24LC512-I/ST devices share the same I²C bus, and how is addressing managed?

Yes, up to eight 24LC512-I/ST devices can share one I²C bus using hardware address pins A0, A1, and A2. Each device's 7-bit client address is formed as '1010' + A2:A0, allowing unique addressing without software configuration. All devices respond only to commands matching their A0–A2 logic levels, enabling scalable storage expansion - e.g., eight 24LC512-I/ST units provide 4 Mbit contiguous address space when used with proper address-bit mapping.

What is the maximum page write time for the 24LC512-I/ST, and how should hosts handle write completion?

The maximum page write time for the 24LC512-I/ST is 5 ms. Hosts must not issue new commands until this cycle completes. The recommended method is ACK polling: after sending a STOP to initiate the write, the host repeatedly sends a START + write control byte (R/W = 0); the 24LC512-I/ST responds with an ACK only when ready. This avoids fixed delays and maximizes bus utilization - no timeout is needed since the device will eventually ACK once the internal cycle finishes.

Does the 24LC512-I/ST support 1 MHz I²C communication, and what limits its speed?

No, the 24LC512-I/ST does not support 1 MHz I²C. Its maximum clock frequency is 400 kHz when VCC ≥ 2.5V. The 24FC512 variant supports 1 MHz, but the 24LC512-I/ST is rated only to 400 kHz due to internal timing constraints in its EEPROM write controller and HV generation circuitry. Attempting 1 MHz operation may cause ACK failures, data corruption, or incomplete writes - always adhere to the 400 kHz limit specified in DS20001754Q.