Microchip Technology 24CW320T-E/OT66KVAO

Overview

24CW320T-E/OT66KVAO 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. 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/OT66KVAO datasheet, 24CW320T-E/OT66KVAO pinout, 24CW320T-E/OT66KVAO application, or 24CW320T-E/OT66KVAO equivalent, key selection criteria include extended temperature support (–40°C to +125°C), 1 MHz I²C interface compliance, 32-byte page size, permanent configuration register locking, and SOT-23-5 package compatibility with space-constrained automotive control modules.

Technical Context

The 24CW320T-E/OT66KVAO 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 dedicated Write Protection Register (WPR) and Hardware Address Register (HAR), both configurable and lockable to prevent runtime modification.

It supports up to eight devices on a shared bus via three programmable address bits (A2–A0), uses open-drain SDA/SCL with external pull-ups, and enters low-power standby mode after Stop condition receipt-unless an internal write cycle is active. Power-on reset (VPOR ≤1.5 V) ensures reliable initialization without spurious writes.

Key Specifications

Pinout & Package

24CW320T-E/OT66KVAO is packaged in a 5-lead SOT-23 (OT) with exposed pad (not electrically connected). Pin 1 = SCL, Pin 2 = VSS, Pin 3 = SDA, Pin 4 = NC, Pin 5 = VCC. The NC pin provides mechanical stability and thermal relief; no circuit connection required.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar I²C EEPROM applications.

Compared with AT24C32D-SSHM-T and BR24G32FJ-3GE2, the 24CW320T-E/OT66KVAO uniquely combines AEC-Q100 Grade 0 qualification, 1 MHz I²C, programmable hardware addressing, and dual configuration registers-making it the only option qualified for next-generation automotive control units demanding extended temperature, high-speed configuration access, and secure parameter locking.

Availability

24CW320T-E/OT66KVAO is available at Aetrix Electronics and suitable for automotive ECU calibration storage, ADAS sensor configuration, and EV battery management systems requiring stable component supply across multi-year production lifecycles.

Supply support for 24CW320T-E/OT66KVAO 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, serving automotive, industrial, and consumer markets with vertically integrated silicon and development tools.

The 24CW Series was designed specifically for automotive-grade nonvolatile memory applications requiring extended temperature operation, robust I²C communication, and configurable write protection-targeting ECU, ADAS, and electrification subsystems.

FAQ

What is the exact memory organization of the 24CW320T-E/OT66KVAO?

The 24CW320T-E/OT66KVAO contains 32 Kbits of EEPROM organized as 4096 bytes (4096 × 8-bit), internally structured into 128 pages of 32 bytes each. This layout enables efficient page-write operations within a single physical page boundary, and the device uses two 8-bit word address bytes to access any location. The first word address byte includes MSb bits dependent on density, with bit 7 indicating EEPROM (0) or configuration register (1) access.

Does the 24CW320T-E/OT66KVAO support 1 MHz I²C operation across its full voltage range?

Yes, the 24CW320T-E/OT66KVAO supports 1 MHz I²C clock frequency (FCLK) across its entire specified operating voltage range of 1.6V to 5.5V, as confirmed in Table 1-2 of DS20005772D. This capability is enabled by internal slope control on SDA/SCL outputs and Schmitt-trigger inputs, ensuring signal integrity even at high speeds and low voltages-critical for fast parameter loading in automotive microcontrollers.

How is hardware addressing configured on the 24CW320T-E/OT66KVAO?

Hardware addressing on the 24CW320T-E/OT66KVAO is controlled by the three-bit Hardware Address Register (HAR), which sets the A2, A1, and A0 bits used in the 7-bit device address (1010 A2 A1 A0 R/W). These bits are programmable in-system and can be permanently locked to prevent modification. The preset address is encoded in the part number suffix (e.g., "0" = 000, "1" = 001); for 24CW320T-E/OT66KVAO, the "0" indicates A2:A1:A0 = 0:0:0, yielding base address 0x50 for write operations.

What write protection mechanisms does the 24CW320T-E/OT66KVAO provide?

The 24CW320T-E/OT66KVAO implements two complementary write protection mechanisms: (1) Software write protection via the Write Protection Register (WPR), which allows selective locking of memory address ranges, and (2) Permanent locking of both WPR and HAR registers after configuration. Once locked, neither register can be modified-even by power cycle-ensuring immutable calibration data and secure device addressing in deployed automotive systems.

Is the 24CW320T-E/OT66KVAO pin-compatible with other members of the 24CWXX family?

Yes, the 24CW320T-E/OT66KVAO shares identical pinout and electrical characteristics with other 24CWXX devices in the SOT-23-5 (OT) package, including 24CW16X and 24CW64X variants. All use the same 5-pin assignment (SCL, VSS, SDA, NC, VCC), enabling drop-in replacement within the same density family-provided software accounts for differences in memory size and page boundaries during read/write operations.