Microchip Technology 24FC04HT-I/Q4B

Overview

24FC04HT-I/Q4B from Microchip Technology Inc. is a 4-Kbit I²C-compatible serial EEPROM organized as two 256 × 8-bit blocks, supporting 1 MHz clock operation down to 1.7V supply, with 16-byte page write buffer, hardware half-array write-protection (100h–1FFh), and >1 million erase/write cycles. It serves as nonvolatile configuration storage in embedded controllers requiring low-power, noise-immune bus interfacing.

For engineers reviewing the 24FC04HT-I/Q4B datasheet, 24FC04HT-I/Q4B pinout, 24FC04HT-I/Q4B application, or 24FC04HT-I/Q4B equivalent, key selection criteria include its 1 MHz I²C speed at 1.7V, extended temperature support (–40°C to +125°C), Q4B TDFN-8 package footprint, and half-array write-protect functionality for firmware parameter partitioning.

Technical Context

The 24FC04HT-I/Q4B implements a two-wire I²C interface with Schmitt-trigger inputs and slope-controlled outputs to suppress ground bounce and bus noise. Its internal address pointer supports current-address, random, and sequential read modes, while ACK polling enables precise timing of write-cycle completion without fixed delays.

It uses an on-chip 16-byte page buffer to batch up to 16 bytes per write command, with automatic wraparound handling within physical page boundaries (00h–0Fh, 10h–1Fh, etc.). Write protection is controlled solely by the WP pin state-tied to VCC to lock addresses 100h–1FFh-and does not require software configuration.

Key Specifications

Pinout & Package

24FC04HT-I/Q4B is packaged in an 8-lead TDFN (Thin Dual Flat No-lead) with 2 mm × 3 mm body and exposed pad. Pin 1 is marked by a dot; the exposed pad may be connected to VSS or left floating per layout requirements.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24FC04HT-I/Q4B, the 24AA04HT-I/MS trades speed for broader legacy compatibility, while the AT24C04D-SSHM-T omits hardware half-array protection - making 24FC04HT-I/Q4B uniquely suited for applications requiring guaranteed, pin-controlled safeguarding of critical configuration regions.

Availability

24FC04HT-I/Q4B is available at Aetrix Electronics and suitable for industrial automation, automotive electronics, and medical device design requiring stable component supply, extended temperature operation, and high-reliability nonvolatile storage.

Supply support for 24FC04HT-I/Q4B 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 devices, and memory solutions, serving automotive, industrial, and consumer markets with high-reliability silicon and development tools.

The 24FC04HT-I/Q4B belongs to Microchip's 24XX04H family of serial EEPROMs, designed specifically for low-voltage, noise-immune configuration storage in space-constrained embedded systems requiring extended temperature resilience and robust write-cycle management.

FAQ

What is the maximum I²C clock frequency supported by the 24FC04HT-I/Q4B?

The 24FC04HT-I/Q4B supports up to 1 MHz I²C clock frequency across its full 1.7V–5.5V supply range. This is confirmed in the Device Selection Table and AC Characteristics section of DS20002119C, distinguishing it from the 24AA04H (max 400 kHz) and 24LC04BH (max 400 kHz, min 2.5V). The 24FC04HT-I/Q4B maintains this speed even at 1.7V, enabling faster configuration loads in low-power systems.

How does the hardware write-protect feature work on the 24FC04HT-I/Q4B?

The 24FC04HT-I/Q4B uses the WP pin to enable hardware write protection: tying WP to VCC locks addresses 100h–1FFh (half the array), permitting reads but blocking writes to that region; tying WP to VSS disables protection entirely. This is implemented in silicon - no software initialization or command sequence is required. The 24FC04HT-I/Q4B datasheet explicitly confirms this behavior applies to all variants in the 24XX04H family, including the Q4B package.

Is the 24FC04HT-I/Q4B compatible with standard I²C protocol implementations?

Yes, the 24FC04HT-I/Q4B is fully I²C-compatible, supporting standard Start/Stop conditions, 7-bit addressing (client address 1010xxxR/W), ACK/NACK signaling, and repeated Start sequences. It adheres to I²C timing specifications including THD:STA, TSU:DAT, and TBUF, with validated operation at 100 kHz, 400 kHz, and 1 MHz. Its Schmitt-trigger inputs and filtered SDA/SCL lines ensure robust interoperability with diverse I²C masters.

What package type does the 24FC04HT-I/Q4B use, and what are its key mechanical features?

The 24FC04HT-I/Q4B uses the Q4B package: an 8-lead TDFN (Thin Dual Flat No-lead) with 2 mm × 3 mm body, 0.5 mm pitch, and exposed thermal pad. Per Microchip Drawing C04-2057-Q4B, the exposed pad may be connected to VSS or left floating. Pin 1 is marked by a dot; the package is RoHS-compliant and qualified for reflow soldering per J-STD-020.

Does the 24FC04HT-I/Q4B require external pull-up resistors on SDA and SCL lines?

Yes, the 24FC04HT-I/Q4B requires external pull-up resistors on both SDA and SCL lines because its I/O pins are open-drain. For 1 MHz operation, a 2 kΩ pull-up to VCC is recommended per the datasheet; for lower speeds (e.g., 100 kHz), 10 kΩ is typical. These resistors establish valid high logic levels and ensure proper bus arbitration - omission will cause communication failure.