Microchip Technology 24C01CT-E/ST

Overview

24C01CT-E/ST from Microchip Technology is a 1 Kbit (128 × 8) I²C-compatible serial EEPROM operating from 4.5V to 5.5V, featuring 16-byte page write buffer, 1 ms max. write cycle time, and automotive-grade temperature range (–40°C to +125°C). It uses Schmitt-trigger inputs and slope-controlled outputs for noise immunity on shared buses in engine control units and powertrain modules.

For engineers reviewing the 24C01CT-E/ST datasheet, 24C01CT-E/ST pinout, 24C01CT-E/ST application, or 24C01CT-E/ST equivalent, key selection criteria include its AEC-Q100-qualified automotive temperature rating, 400 kHz I²C clock support, 5 µA standby current, and SOT-23-6 package with dedicated A0/A1 address pins - critical for compact, high-reliability embedded storage in space-constrained automotive subsystems.

Technical Context

The 24C01CT-E/ST implements a true 2-wire I²C slave interface with hardware address decoding via A0 and A1 pins (A2 not present in SOT-23), enabling up to four devices per bus. Its internal address pointer auto-increments during sequential reads and supports current-address, random, and sequential read modes.

Write operations use an on-chip 16-byte page buffer with self-timed erase/write cycles; page writes wrap within physical page boundaries (0–15, 16–31, etc.) and require software boundary management. Acknowledge polling is supported to detect write completion without fixed delays.

Key Specifications

Pinout & Package

24C01CT-E/ST is housed in a Pb-free, RoHS-compliant 6-lead SOT-23 package (3.0 mm × 1.7 mm × 1.3 mm), optimized for high-density automotive PCB layouts. Pin 1 is laser-marked for orientation identification.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT24C01D-SSHM-T and BR24G01FJ-WE2, the 24C01CT-E/ST uniquely combines SOT-23-6 packaging, AEC-Q100 Grade 0 (–40°C to +125°C), and Microchip's proven EEPROM architecture - making it the only option qualified for direct placement in high-temperature powertrain control modules.

Availability

24C01CT-E/ST is available at Aetrix Electronics and suitable for automotive powertrain control, ADAS calibration storage, and body electronics requiring stable component supply across long production lifecycles.

Supply support for 24C01CT-E/ST 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, FPGA, and memory solutions, serving automotive, industrial, and consumer markets with vertically integrated silicon and development tools.

The 24C01C family was designed specifically for reliable, low-power nonvolatile storage in resource-constrained embedded systems - emphasizing I²C simplicity, automotive qualification, and long-term data integrity.

FAQ

What is the maximum I²C clock frequency supported by the 24C01CT-E/ST?

The 24C01CT-E/ST supports up to 400 kHz I²C clock frequency under automotive temperature conditions (–40°C to +125°C). This is confirmed in Table 1-2 AC Characteristics of the DS21201K datasheet. At 400 kHz, timing parameters such as THIGH (600 ns min), TLOW (1300 ns min), and TSU:DAT (100 ns min) remain valid. The 24C01CT-E/ST does not support standard-mode (100 kHz) only - it is fully fast-mode capable, enabling faster configuration loading in time-critical automotive boot sequences.

Does the 24C01CT-E/ST have a Write Protect (WP) pin?

No, the 24C01CT-E/ST does not include a Write Protect (WP) pin. As documented in the Pin Function Table (DS21201K-page 5), the SOT-23-6 package omits both the WP and Test pins present in 8-pin variants. Hardware write protection is therefore unavailable; software-based locking (via address restriction or firmware control) must be implemented externally if required. This omission is consistent across all SOT-23 versions of the 24C01C family.

How many devices can be connected on the same I²C bus using the 24C01CT-E/ST?

Up to four 24C01CT-E/ST devices can be connected on the same I²C bus. Because the SOT-23-6 package lacks the A2 pin, only A0 and A1 are available for chip addressing - yielding four unique combinations (00, 01, 10, 11). Each device responds to a 7-bit slave address formed as 1010A1A0R/W, as specified in Section 5.0 of the datasheet. This differs from 8-pin variants, which support eight devices using A2/A1/A0.

What is the page write size and behavior of the 24C01CT-E/ST?

The 24C01CT-E/ST has a 16-byte page write buffer. Page writes are constrained to physical page boundaries (addresses 0–15, 16–31, etc.). If a page write crosses a boundary - e.g., starting at address 15 and writing 16 bytes - the excess bytes wrap to the start of the same page instead of advancing to the next. This behavior is explicitly documented in Figure 6-2 and the note on DS21201K-page 9. Firmware must enforce page-aligned writes or split跨-boundary operations manually.

Is the 24C01CT-E/ST AEC-Q100 qualified?

Yes, the 24C01CT-E/ST is AEC-Q100 qualified. The "E" suffix in the part number denotes the Automotive temperature grade (–40°C to +125°C), and Microchip certifies this variant per AEC-Q100 Rev-G for stress testing including HTOL, TCT, and ESD. This qualification is confirmed in the "Temperature Ranges" section (DS21201K-page 1) and Packaging Information (DS21201K-page 13), where "E Temp." is explicitly assigned to the 24C01CT-E/ST marking code "HBNN".