Microchip Technology AT24CS01-XHM-B

Overview

AT24CS01-XHM-B from Microchip Technology is a 1-Kbit (128 × 8) I²C-compatible serial EEPROM with factory-programmed 128-bit unique serial number, operating from 1.7V to 5.5V, supporting 100/400 kHz and 1 MHz Fast Mode Plus, and rated for -40°C to +85°C industrial temperature range. It delivers ultra-low standby current (6 μA max) and integrates hardware write protection via WP pin for secure firmware storage in embedded control modules.

For engineers reviewing the AT24CS01-XHM-B datasheet, AT24CS01-XHM-B pinout, AT24CS01-XHM-B application, or AT24CS01-XHM-B equivalent, this device serves as a secure, low-voltage, serialized memory solution for asset tracking, calibration data storage, and device authentication where guaranteed uniqueness and robust I²C timing compliance are required.

Technical Context

The AT24CS01-XHM-B implements a two-wire I²C slave interface with Schmitt-triggered, noise-filtered SDA/SCL inputs and internal pull-downs on A0–A2 and WP pins. It supports standard (100 kHz), fast (400 kHz), and Fast Mode Plus (1 MHz) operation across 1.7–5.5V, with strict AC timing compliance including tLOW ≤ 500 ns and tBUF ≤ 500 ns at VCC ≥ 2.5V.

Its memory architecture comprises 16 pages of 8 bytes each, enabling partial page writes and sequential reads. The dedicated 128-bit serial number block is read-only, physically isolated from user memory, and guaranteed globally unique across all Microchip CS-series EEPROMs - no user address space is consumed.

Key Specifications

Pinout & Package

AT24CS01-XHM-B is packaged in an 8-lead SOIC (Small Outline Integrated Circuit) with standard 1.27 mm pitch. This surface-mount package supports automated assembly and provides mechanical stability for industrial PCB environments.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT24CS01-XHM-B, AT24C01D-SSHM-T offers lower unit cost but forfeits hardware-enforced uniqueness and FM+ timing headroom, while M24C01-RMN6TP trades package compatibility and power efficiency for alternate sourcing flexibility - neither provides the integrated, globally unique 128-bit serial number that defines the CS-series value proposition.

Availability

AT24CS01-XHM-B is available at Aetrix Electronics and suitable for industrial sensor nodes, medical calibration modules, smart energy meters, and asset tracking tags requiring stable component supply, long-term lifecycle assurance, and guaranteed serialization capability.

Supply support for AT24CS01-XHM-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 Inc. is a leading provider of microcontroller, analog, FPGA, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The AT24CS01-XHM-B belongs to Microchip's CS-series Serial EEPROM product line, engineered specifically for applications demanding factory-assigned, globally unique identifiers alongside robust, low-voltage nonvolatile storage - targeting industrial, medical, and IoT markets where traceability and security are foundational.

FAQ

What is the factory-programmed serial number format and access method for AT24CS01-XHM-B?

The AT24CS01-XHM-B contains a permanent, read-only 128-bit serial number programmed during wafer fabrication. It is accessed via I²C using device address 0xB0–0xB7 (1011xxxx binary), distinct from the main memory address 0xA0–0xA7. No user memory space is consumed, and the value is guaranteed unique across all Microchip CS-series EEPROMs.

Does AT24CS01-XHM-B support 1 MHz I²C communication, and what are the voltage requirements?

Yes, AT24CS01-XHM-B supports Fast Mode Plus (FM+) at up to 1 MHz, but only when VCC is between 2.5V and 5.5V. At 1.7V–2.5V, maximum speed is limited to 400 kHz. This dual-speed capability allows designers to optimize timing margins based on system voltage rails without changing components.

How does the write-protect (WP) pin function on AT24CS01-XHM-B, and what happens if it's left unconnected?

When WP is tied to VCC, AT24CS01-XHM-B disables all write operations to its entire memory array. If left floating, the pin is internally pulled down to GND, enabling writes - however, Microchip recommends hardwiring WP to a known state due to potential noise-induced misbehavior from capacitive coupling in real-world layouts.

What is the memory organization and page-write capability of AT24CS01-XHM-B?

AT24CS01-XHM-B organizes its 1-Kbit memory as 16 pages of 8 bytes each. It supports 8-byte page writes with partial-page capability - meaning fewer than 8 bytes can be written in a single cycle, provided they reside within the same page boundary. This enables efficient small-data updates without erasing adjacent bytes.

Is AT24CS01-XHM-B RoHS compliant and what package type does it use?

Yes, AT24CS01-XHM-B is RoHS compliant, halide-free, and lead-free. It is supplied in an 8-lead SOIC package (XHM suffix denotes SOIC-8), with 1.27 mm lead pitch and JEDEC-standard dimensions - compatible with standard reflow profiles and automated optical inspection systems.