Microchip Technology AT24C08C-XHM-T

Overview

AT24C08C-XHM-T from Microchip Technology is an 8-Kbit (1,024 × 8) I²C-compatible serial EEPROM in an 8-pad UDFN package, operating from 1.7V to 5.5V with industrial temperature range (−40°C to +85°C), 1 MHz Fast Mode Plus support at ≥2.5V, and hardware write protection via the WP pin - used for nonvolatile parameter storage in embedded controllers, power supply monitors, and sensor calibration modules.

For engineers reviewing the AT24C08C-XHM-T datasheet, AT24C08C-XHM-T pinout, AT24C08C-XHM-T application, or AT24C08C-XHM-T equivalent, key selection criteria include I²C bus voltage compatibility (1.7–5.5V), page write timing (≤5 ms), standby current (≤6 μA), and hardware address configuration (A2 only; A1 is NC on AT24C08C).

Technical Context

The AT24C08C-XHM-T implements a two-wire I²C interface with Schmitt-triggered, noise-filtered SDA and SCL inputs, supporting Standard (100 kHz), Fast (400 kHz), and Fast Mode Plus (1 MHz) speeds depending on VCC level. It uses an internal high-voltage generation circuit for EEPROM programming and features automatic power-on reset (POR) with tPUP = 100 µs delay before command acceptance.

Memory is organized as 64 pages of 16 bytes each, enabling partial-page writes and sequential/random reads. Device addressing uses a fixed 4-bit identifier (1010b) plus one hardware address bit (A2), allowing up to two AT24C08C devices on a shared bus; A1 is not connected on this variant.

Key Specifications

Pinout & Package

AT24C08C-XHM-T is packaged in an 8-pad UDFN (Ultra Thin Dual Flat No-lead) with exposed pad, rated for industrial temperature operation and RoHS-compliant. Pin 1 is NC; pins 2–8 correspond to A2, GND, VCC, WP, SCL, SDA, and NC respectively (top view).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT24C08D-XHM-T, the AT24C08C-XHM-T offers identical functionality but slightly lower ESD rating and looser AC timing margins; versus M24C08-RMN6TP, it provides hardware write protection and faster I²C operation but requires different PCB layout and firmware handling for WP control.

Availability

AT24C08C-XHM-T is available at Aetrix Electronics and suitable for industrial sensor calibration, power supply configuration, and embedded controller settings requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for AT24C08C-XHM-T 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 leading provider of microcontrollers, analog components, and memory solutions, with a focus on embedded control and connectivity.

The AT24C08C belongs to Microchip's serial EEPROM product line, designed specifically for low-voltage, low-power nonvolatile data storage in space-constrained industrial and commercial systems.

FAQ

What is the maximum I²C clock frequency supported by the AT24C08C-XHM-T?

The AT24C08C-XHM-T supports up to 1 MHz (Fast Mode Plus) when VCC is 2.5V or higher. At 1.7–2.5V, maximum clock frequency is 400 kHz (Fast Mode). Standard Mode (100 kHz) operates across the full 1.7–5.5V range. These modes are automatically selected based on VCC level and host controller configuration - no internal register setting is required to enable FM+.

Is the A1 pin functional on the AT24C08C-XHM-T?

No, the A1 pin is not functional on the AT24C08C-XHM-T. Per Microchip's datasheet DS20006127B, A1 is designated as "NC" (No Connect) for the AT24C08C family. Only the A2 pin serves as a hardware address input, allowing up to two AT24C08C devices on the same I²C bus. This differs from the AT24C04C, where both A1 and A2 are active address inputs.

How does the Write-Protect (WP) pin function on the AT24C08C-XHM-T?

When the WP pin of the AT24C08C-XHM-T is driven high (to VCC), all write operations to the entire memory array are inhibited - reads remain fully functional. When WP is low (GND), normal byte and page writes are enabled. If left floating, WP is internally pulled down to GND, enabling writes; however, Microchip recommends hardwiring WP to a defined state to prevent noise-induced corruption during system operation.

What is the memory organization of the AT24C08C-XHM-T?

The AT24C08C-XHM-T contains 8,192 bits organized as 1,024 words of 8 bits each, physically structured as 64 pages of 16 bytes. This layout enables efficient 16-byte page writes and supports both random and sequential read operations. The internal address counter auto-increments during sequential reads, eliminating the need for repeated address transmission by the host controller.

Does the AT24C08C-XHM-T require an external pull-up resistor on the SDA and SCL lines?

Yes, the AT24C08C-XHM-T requires external pull-up resistors on both SDA and SCL lines because both pins are open-drain. Microchip specifies maximum values of 10 kΩ for SDA/SCL pull-ups. Recommended values depend on bus capacitance and target I²C speed: e.g., 4 kΩ for 400 kHz, 1.3 kΩ for 1 MHz. Failure to install pull-ups will prevent proper I²C communication and device recognition.