Microchip Technology AT24CM01-XHD-B

Overview

AT24CM01-XHD-B from Microchip Technology is a 1-Mbit I²C-compatible serial EEPROM organized as 131,072 × 8, operating from 1.7V 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, power management units, and sensor calibration modules.

For engineers reviewing the AT24CM01-XHD-B datasheet, AT24CM01-XHD-B pinout, AT24CM01-XHD-B application, or AT24CM01-XHD-B equivalent, key selection criteria include voltage flexibility (1.7–5.5V), page-write capability (256-byte pages), ultra-low standby current (≤6 µA), built-in error detection/correction, and compatibility with multi-device I²C bus topologies using A1/A2 address inputs.

Technical Context

The AT24CM01-XHD-B implements a true two-wire I²C slave interface with Schmitt-triggered, noise-filtered SDA/SCL inputs, supporting Standard (100 kHz), Fast (400 kHz), and Fast Mode Plus (1 MHz) timing across overlapping VCC ranges. Its internal architecture includes a 512-page × 256-byte memory array, hardware address decoding (A1/A2), and a dedicated write-protect circuit that disables all writes when WP = VCC.

It features a self-timed write cycle completing in ≤5 ms, automatic power-on reset (POR) with 100 µs tPUP delay, and open-drain bidirectional SDA with external pull-up requirement (≤10 kΩ). The device uses internal high-voltage generation for EEPROM programming and incorporates built-in error detection and correction logic for enhanced data integrity.

Key Specifications

Pinout & Package

AT24CM01-XHD-B is supplied in an 8-lead SOIC package (XHD suffix per Microchip marking convention), with gull-wing leads, 1.27 mm pitch, and JEDEC MS-012AC compliant outline. Pin 1 is marked by a beveled corner or notch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT24C1024-SSHD-T, AT24CM01-XHD-B offers broader voltage range and faster I²C timing; versus M95M01-RDW6TP, it provides native I²C compatibility and hardware write protection - making AT24CM01-XHD-B optimal for mixed-voltage, noise-prone industrial I²C systems requiring guaranteed write safety.

Availability

AT24CM01-XHD-B is available at Aetrix Electronics and suitable for industrial sensor calibration, embedded controller configuration, and power management unit settings requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant sourcing.

Supply support for AT24CM01-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 AT24CM01-XHD-B belongs to Microchip's AT24Cxx family of I²C serial EEPROMs, designed specifically for reliable, low-power nonvolatile storage in space-constrained industrial and automotive subsystems.

FAQ

What is the maximum I²C clock frequency supported by the AT24CM01-XHD-B?

The AT24CM01-XHD-B supports up to 1 MHz Fast Mode Plus (FM+) operation when VCC is between 2.5V and 5.5V. At lower voltages (1.7V–5.5V), it operates in Fast Mode (400 kHz) or Standard Mode (100 kHz). This multi-speed capability allows the AT24CM01-XHD-B to adapt to host controller capabilities and system noise conditions without requiring hardware changes.

Does the AT24CM01-XHD-B require external pull-up resistors on SDA and SCL lines?

Yes, the AT24CM01-XHD-B requires external pull-up resistors on both SDA and SCL lines because its SDA pin is open-drain and SCL is an input-only pin. Microchip specifies a maximum value of 10 kΩ for pull-up resistors; typical values range from 2.2 kΩ to 4.7 kΩ depending on bus capacitance and target I²C speed. Without proper pull-ups, the AT24CM01-XHD-B will not communicate reliably on the I²C bus.

How does the write-protect (WP) pin function on the AT24CM01-XHD-B?

The WP pin on the AT24CM01-XHD-B is an active-high hardware lock: when tied to VCC, it disables all write operations to the entire memory array; when tied to GND, normal writes are enabled. If left floating, the pin is internally pulled down to GND, enabling writes - but Microchip recommends explicit connection to avoid noise-induced glitches. This feature ensures fail-safe protection of critical configuration data in the AT24CM01-XHD-B.

What is the memory organization of the AT24CM01-XHD-B?

The AT24CM01-XHD-B organizes its 1-Mbit capacity as 131,072 words × 8 bits (131,072 bytes), structured into 512 pages of 256 bytes each. This page-based layout enables efficient 256-byte burst writes and supports partial-page writes. Addressing uses a 17-bit word address, with the upper bit (A16) encoded in the device address byte and the remaining 16 bits transmitted as two sequential address bytes - a structure fully compatible with standard I²C EEPROM drivers.

Is the AT24CM01-XHD-B compatible with legacy AT24C series EEPROMs?

Yes, the AT24CM01-XHD-B maintains full software and pinout compatibility with earlier AT24Cxx devices (e.g., AT24C512, AT24C1024) in the same SOIC-8 package. It uses identical I²C addressing (1010b prefix), A1/A2 hardware address inputs, and command protocol. However, the AT24CM01-XHD-B adds Fast Mode Plus support and improved low-voltage operation - enhancements that do not break backward compatibility but extend functionality in upgraded systems.