Microchip Technology 24CW320T-E/ST66KVAO

Overview

24CW320T-E/ST66KVAO from Microchip Technology is a 32-Kbit I²C serial EEPROM organized as 4096 × 8-bit memory, supporting byte/page writes (up to 32 bytes), self-timed write cycles ≤5 ms, and operation across 1.6V–5.5V supply. It features programmable hardware client address bits (A2–A0), software write protection via WPR register, and AEC-Q100 qualification for automotive use.

For engineers reviewing the 24CW320T-E/ST66KVAO datasheet, 24CW320T-E/ST66KVAO pinout, 24CW320T-E/ST66KVAO application, or 24CW320T-E/ST66KVAO equivalent, this page delivers verified electrical specs, I²C timing compliance (1 MHz max), ESD robustness (>4 kV), extended temperature support (–40°C to +125°C), and real-world configuration register behavior for reliable nonvolatile storage in constrained embedded systems.

Technical Context

The 24CW320T-E/ST66KVAO implements a two-wire I²C interface with Schmitt-trigger inputs and slope-controlled outputs to suppress noise and eliminate ground bounce. Its internal architecture includes dual configuration registers - Write Protection Register (WPR) for selective array locking and Hardware Address Register (HAR) for configuring A2/A1/A0 bits - both permanently lockable after programming.

It supports up to eight devices on a shared bus using unique 7-bit client addresses derived from Device Type Identifier (1010b) and HAR-configured bits. Memory access uses two-word addressing with bit-7 flagging EEPROM vs. configuration register space, and page boundaries are fixed at 32-byte intervals with automatic address rollover within pages.

Key Specifications

Pinout & Package

24CW320T-E/ST66KVAO is packaged in an 8-lead UDFN (ST package code) with exposed pad, measuring 2.0 mm × 1.6 mm × 0.55 mm. Pin 1 is SCL; pins 4 and 7 are NC; VSS (pin 3) and VCC (pin 8) provide power; SDA (pin 5) is bidirectional open-drain I²C data line.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT24C32D-SSHM-T and BR24G32FJ-3GE2, the 24CW320T-E/ST66KVAO uniquely integrates both hardware address programmability and software-configurable write protection in a single 8-lead UDFN package - enabling scalable multi-device I²C networks and fine-grained memory security without additional components.

Availability

24CW320T-E/ST66KVAO is available at Aetrix Electronics and suitable for automotive body control modules, industrial PLC configuration storage, and medical infusion pump calibration requiring stable component supply across extended temperature and long-lifecycle programs.

Supply support for 24CW320T-E/ST66KVAO 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 global semiconductor company specializing in microcontrollers, analog devices, and memory solutions, with emphasis on embedded control and automotive-grade reliability.

The 24CW Series was designed specifically for automotive and industrial applications demanding wide-voltage I²C EEPROMs with configurable addressing and robust data protection - targeting systems where AEC-Q100 compliance and extended temperature operation are mandatory.

FAQ

What is the exact memory organization of the 24CW320T-E/ST66KVAO?

The 24CW320T-E/ST66KVAO contains 32 Kbits of EEPROM memory organized as 4096 words × 8 bits. Internally, it is structured as 128 pages of 32 bytes each. This layout enables efficient page-write operations within fixed 32-byte boundaries and supports byte-level random access. The device uses two-word addressing, with the first word byte selecting the upper address bits and the second providing the lower 8 bits - consistent across all densities in the 24CW family.

Does the 24CW320T-E/ST66KVAO support 1 MHz I²C communication reliably?

Yes, the 24CW320T-E/ST66KVAO fully supports 1 MHz I²C operation across its entire specified voltage range (1.6V–5.5V) and temperature range (–40°C to +125°C). Its AC characteristics guarantee minimum clock high/low times (THIGH ≥260 ns, TLOW ≥500 ns) and rise/fall time limits (TR ≤1000 ns, TF ≤300 ns) that meet standard-mode plus (FM+) timing requirements. Slope control on SDA/SCL outputs further ensures signal integrity at high speeds.

How is hardware addressing configured on the 24CW320T-E/ST66KVAO?

Hardware addressing on the 24CW320T-E/ST66KVAO is controlled by the Hardware Address Register (HAR), which sets the A2, A1, and A0 bits used in the 7-bit I²C client address. These bits combine with the fixed Device Type Identifier (1010b) to form a unique address. The HAR is programmable via I²C and can be permanently locked to prevent accidental reconfiguration - enabling up to eight identical 24CW320T-E/ST66KVAO devices on a single bus without external strapping.

Can the 24CW320T-E/ST66KVAO be used in systems powered by 1.8V logic?

Yes, the 24CW320T-E/ST66KVAO operates down to 1.6V, making it fully compatible with 1.8V systems. At 1.8V, its ICCREAD is ≤0.3 mA (400 kHz) and ICCWRITE is ≤1 mA, while VOL remains ≤0.2 V at IOL = 0.15 mA - ensuring clean logic-level compatibility with 1.8V MCUs. Its VIH/VIL thresholds scale with VCC (VIH ≥0.7×VCC, VIL ≤0.3×VCC), eliminating level-shifter requirements in mixed-voltage designs.

What write protection mechanisms does the 24CW320T-E/ST66KVAO offer?

The 24CW320T-E/ST66KVAO provides two complementary write protection mechanisms: (1) Software write protection via the Write Protection Register (WPR), allowing selective locking of memory address ranges, and (2) Permanent lock capability for both WPR and HAR registers to prevent runtime modification. Unlike basic EEPROMs with only a WP# pin, the 24CW320T-E/ST66KVAO enables granular, firmware-defined protection policies - e.g., locking calibration sectors while leaving logging areas writable.