Microchip Technology AT24C01C-XHM-B

Overview

AT24C01C-XHM-B from Microchip Technology is a 1-Kbit (128 × 8) I²C-compatible serial EEPROM with low-voltage operation (1.7V–5.5V), industrial temperature range (−40°C to +85°C), and hardware write protection via the WP pin. It supports Standard (100 kHz), Fast (400 kHz), and Fast Mode Plus (1 MHz) I²C speeds and delivers ultra-low standby current (6 μA max) for battery-powered sensor nodes and embedded control systems.

For engineers reviewing the AT24C01C-XHM-B datasheet, AT24C01C-XHM-B pinout, AT24C01C-XHM-B application, or AT24C01C-XHM-B equivalent, key selection criteria include its 8-pin UDFN package, I²C address configuration via A0–A2 pins, page-write capability (8-byte pages), self-timed 5 ms max write cycle, and guaranteed 1,000,000 write endurance with 100-year data retention.

Technical Context

The AT24C01C-XHM-B operates as an I²C slave device with open-drain SDA/SCL interfaces, Schmitt-triggered inputs, and integrated spike filtering for noise immunity in noisy industrial environments. Its memory is organized as 16 pages of 8 bytes each, supporting both random and sequential read modes plus partial page writes.

It implements a hardware-based write-protection scheme where WP = VCC inhibits all writes to the full array, while WP = GND enables normal operation. Internal pull-downs on A0–A2 and WP ensure defined logic states when unconnected, but Microchip recommends hard-wiring them for robustness in production designs.

Key Specifications

Pinout & Package

AT24C01C-XHM-B is packaged in an 8-pad UDFN (2 mm × 3 mm, 0.5 mm pitch) with wettable flanks, RoHS-compliant and halide-free. The exposed pad is optional and may be connected to GND or left floating.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT24C01C-XHM-B, the AT24C01D-XHM-B offers measurable improvements in ESD tolerance and timing consistency, while the M24C01-RMN6TP trades package size and speed for broader distributor availability and lower unit cost in legacy TSSOP-based designs.

Availability

AT24C01C-XHM-B is available at Aetrix Electronics and suitable for smart metering, industrial PLCs, medical wearables, and automotive body control modules requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.

Supply support for AT24C01C-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 microcontrollers, analog components, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The AT24Cxx series is designed specifically for low-power, I²C-based nonvolatile data storage in space-constrained embedded systems - emphasizing reliability, wide voltage operation, and industrial-grade temperature performance.

FAQ

What is the maximum I²C clock frequency supported by the AT24C01C-XHM-B?

The AT24C01C-XHM-B supports up to 1 MHz in Fast Mode Plus, but only when VCC is ≥2.5V. At 1.7V–2.5V, maximum speed is 400 kHz (Fast mode), and at any VCC within 1.7V–5.5V, it supports 100 kHz Standard mode. These limits are defined by AC timing parameters tLOW, tHIGH, and tR/tF in the official datasheet DS20006111A.

Does the AT24C01C-XHM-B require external pull-up resistors on SDA and SCL lines?

Yes, the AT24C01C-XHM-B requires external pull-up resistors on both SDA and SCL lines because these pins are open-drain. Microchip specifies maximum values of 10 kΩ for SDA and recommends matching pull-up strength to bus capacitance and target I²C speed - e.g., 4 kΩ for 400 kHz operation with 100 pF load.

How does the write-protect (WP) pin function on the AT24C01C-XHM-B?

When WP is tied to VCC, the AT24C01C-XHM-B disables all write operations to its entire memory array. When WP is grounded, normal read/write access is enabled. If left floating, WP is internally pulled down to GND, enabling writes - but Microchip strongly recommends hard-wiring WP to avoid noise-induced state ambiguity.

What is the memory organization of the AT24C01C-XHM-B?

The AT24C01C-XHM-B contains 1,024 bits organized as 128 words of 8 bits each, structured into 16 pages of 8 bytes. This layout enables efficient page-write operations and supports both random and sequential read addressing without wraparound constraints across page boundaries.

Is the AT24C01C-XHM-B compatible with standard I²C protocol implementations?

Yes, the AT24C01C-XHM-B is fully compliant with the NXP I²C-bus specification for Standard, Fast, and Fast Mode Plus modes. It implements proper Start/Stop detection, ACK/NACK handshaking, 7-bit slave addressing (with A0–A2 hardware bits), and clock stretching compatibility - verified across multiple MCU platforms including STM32, PIC, and ESP32.