Microchip Technology AT24C512C-XHD-B

Overview

AT24C512C-XHD-B from Microchip Technology is a 512-Kbit I²C-compatible serial EEPROM organized as 65,536 × 8 bits, operating from 1.7V to 3.6V or 2.5V to 5.5V, with industrial temperature range (−40°C to +85°C), 1 MHz Fast Mode Plus support, and hardware write protection via WP pin - used for nonvolatile configuration storage in embedded controllers and power management systems.

For engineers reviewing the AT24C512C-XHD-B datasheet, AT24C512C-XHD-B pinout, AT24C512C-XHD-B application, or AT24C512C-XHD-B equivalent, key selection criteria include voltage-grade compatibility (1.7–3.6V / 2.5–5.5V), 128-byte page write capability, 1,000,000 write endurance, 100-year data retention, and 8-lead SOIC package pin mapping with A0/A1/A2 address inputs.

Technical Context

The AT24C512C-XHD-B implements a two-wire I²C slave interface with Schmitt-triggered, noise-filtered SDA/SCL inputs and internal pull-downs on A0/A1/A2/WP pins. It supports Standard (100 kHz), Fast (400 kHz), and Fast Mode Plus (1 MHz) timing across dual VCC ranges.

Internally organized as 512 pages × 128 bytes, it uses hardware address inputs (A0–A2) to enable up to eight devices on one bus, and features self-timed write cycles ≤5 ms, random/sequential read modes, and hardware write protection that disables all writes when WP = VCC.

Key Specifications

Pinout & Package

AT24C512C-XHD-B is supplied in an 8-lead Small Outline Integrated Circuit (SOIC) package with 1.27 mm pitch, JEDEC MS-012AC compliant, body size 4.9 mm × 3.9 mm × 1.75 mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT24C512BN-SH-T, the AT24C512C-XHD-B offers identical functionality in a more mechanically robust SOIC package ideal for high-reliability industrial use; versus M24512-RMN6TP, it delivers guaranteed 1 MHz operation down to 2.5V and stronger noise immunity via integrated Schmitt triggers.

Availability

AT24C512C-XHD-B is available at Aetrix Electronics and suitable for industrial PLCs, medical diagnostics equipment, smart energy meters, and automotive body control modules requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.

Supply support for AT24C512C-XHD-B 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 is a U.S.-based semiconductor company specializing in microcontrollers, analog devices, and memory solutions, with ISO 9001-certified manufacturing and global distribution.

The AT24C512C-XHD-B belongs to Microchip's AT24Cxx family of I²C serial EEPROMs, designed specifically for reliable, low-power nonvolatile data storage in industrial, medical, and automotive applications demanding extended data retention and high write endurance.

FAQ

What voltage ranges does the AT24C512C-XHD-B support, and how do they affect interface speed?

The AT24C512C-XHD-B supports two distinct VCC ranges: 1.7V–3.6V (low-voltage grade) and 2.5V–5.5V (standard-voltage grade). At 1.7V–2.5V, maximum I²C speed is 400 kHz (Fast mode); above 2.5V, it supports 1 MHz Fast Mode Plus. This dual-range design allows seamless integration into both modern ultra-low-power systems and legacy 3.3V/5V platforms without compromising performance. The AT24C512C-XHD-B datasheet specifies timing parameters separately for each range to ensure timing compliance.

How does the write-protect (WP) pin function on the AT24C512C-XHD-B, and what happens if it's left unconnected?

When the WP pin on the AT24C512C-XHD-B is driven to VCC, all write operations to the entire memory array are inhibited - preventing accidental overwrites during power-up or firmware updates. If left floating, the pin is internally pulled down to GND, enabling normal writes; however, Microchip explicitly warns that capacitive coupling in real-world PCB layouts may cause intermittent WP assertion, risking unintended protection. Therefore, the AT24C512C-XHD-B design guidelines require tying WP to a defined logic level (GND for write-enable, VCC for lock) using ≤10 kΩ resistors.

What is the memory organization of the AT24C512C-XHD-B, and how does it impact page write efficiency?

The AT24C512C-XHD-B organizes its 65,536 bytes of memory into 512 pages of 128 bytes each. This structure enables 128-byte page write mode, allowing up to 128 bytes to be written in a single I²C transaction with ≤5 ms self-timed completion - significantly faster than byte-write sequences. Partial page writes are supported, so writing 10 bytes to an aligned 128-byte boundary still consumes only one write cycle. This architecture directly improves firmware update throughput and reduces I²C bus occupancy in the AT24C512C-XHD-B.

Does the AT24C512C-XHD-B require external pull-up resistors on SDA and SCL, and what values are recommended?

Yes, the AT24C512C-XHD-B requires external pull-up resistors on both SDA and SCL because these pins are open-drain. Recommended values depend on I²C speed and bus capacitance: 10 kΩ for 100 kHz, 4 kΩ for 400 kHz, and 1.3 kΩ for 1 MHz operation - all referenced to VCC. The AT24C512C-XHD-B datasheet specifies maximum pull-up resistance to ensure VOL ≤ 0.4 V at IOL = 2.1 mA (VCC = 5.0V), and notes that exceeding 10 kΩ may violate timing in high-speed modes due to RC rise-time limitations.

How does the AT24C512C-XHD-B handle power-up sequencing, and what is the minimum delay before issuing commands?

The AT24C512C-XHD-B incorporates an internal Power-on Reset (POR) circuit that holds the device in reset until VCC crosses a 1.5 V threshold and stabilizes. After VCC reaches its final value, the host controller must wait at least 100 µs (tPUP) before sending the first I²C command - this delay ensures internal circuits fully initialize. Failure to observe tPUP may result in NACK responses or corrupted writes. This requirement is explicitly defined in the AT24C512C-XHD-B electrical specifications and applies regardless of VCC ramp rate or final voltage level.