Microchip Technology 93C46X/SN

Overview

93C46X/SN from Microchip Technology is a 1K-bit serial EEPROM organized as 64 words × 16 bits, featuring a 3-wire SPI-compatible interface, 5.5 V max operating voltage, and 1 million write cycles endurance. It operates across -40°C to +85°C and is used in industrial control systems for parameter storage and calibration data retention.

For engineers reviewing the 93C46X/SN datasheet, 93C46X/SN pinout, 93C46X/SN application, or 93C46X/SN equivalent, key selection criteria include its 16-bit word width, 3-wire serial interface timing, write cycle time (10 ms typical), endurance rating, and SOIC-8 package compatibility with legacy 93Cxx designs.

Technical Context

The 93C46X/SN implements a serial EEPROM architecture with dual-word addressing (64 × 16-bit), supporting both ORG pin-selectable 8-bit and 16-bit word configurations. It uses CMOS technology with built-in write protection via WP pin and software-controlled write enable/disable sequences.

It supports standard SPI clock polarity (CPOL = 0) and phase (CPHA = 0), with read/write operations initiated by command opcodes (e.g., 0x03 for read, 0x02 for write). Data retention is rated at 200 years at +25°C.

Key Specifications

Pinout & Package

93C46X/SN is housed in an 8-pin SOIC (Small Outline Integrated Circuit) package with 150 mil body width and standard JEDEC MS-012AC footprint.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 93C46X/SN, the 93C46B/SN removes organization flexibility but simplifies layout, while the AT93C46-10SU-2.7 trades voltage range for lower minimum supply and shorter retention - selection depends on MCU voltage, word-width needs, and product lifecycle.

Availability

93C46X/SN is available at Aetrix Electronics and suitable for industrial sensor calibration, legacy MCU configuration storage, and power meter firmware settings requiring stable component supply and long-term obsolescence management.

Supply support for 93C46X/SN 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 U.S.-based semiconductor company specializing in microcontrollers, analog devices, and nonvolatile memory solutions for embedded control applications.

The 93Cxx family was designed for cost-sensitive, space-constrained systems needing reliable, low-pin-count serial EEPROM with flexible organization and industrial-grade environmental tolerance.

FAQ

What is the maximum clock frequency supported by the 93C46X/SN?

The 93C46X/SN supports a maximum serial clock frequency of 2 MHz at V_CC = 5.0 V and 1 MHz at V_CC = 2.5 V. This timing allows direct interfacing with common 8-bit and 16-bit microcontrollers without external clock dividers. The 93C46X/SN datasheet specifies setup and hold times relative to this clock, and exceeding these limits may cause read/write failures. Always verify timing margins using the 93C46X/SN's published AC characteristics table.

Does the 93C46X/SN require external pull-up resistors on its I/O pins?

The 93C46X/SN does not require external pull-ups on DI, DO, or CLK - these pins are actively driven. However, CS and WP are active-low inputs with internal weak pull-ups disabled by default; external pull-ups (typically 10 kΩ to V_CC) are recommended unless driven actively by the host controller. This ensures deterministic state during power-up and reset, preventing unintended writes to the 93C46X/SN.

How is write protection implemented on the 93C46X/SN?

The 93C46X/SN provides dual-layer write protection: hardware-based via the WP pin (high = write disabled), and software-based via WREN/WRDI command sequences. When WP is high, all write/erase commands are ignored regardless of software state. When WP is low, the 93C46X/SN accepts writes only after a valid WREN command. This layered approach prevents accidental writes during noise events or firmware glitches affecting the 93C46X/SN.

Can the 93C46X/SN be used in place of a 93C46 without modification?

Yes - the 93C46X/SN is a direct replacement for the legacy 93C46 in SOIC-8 packages, sharing identical pinout, timing, and command set. The 'X' suffix denotes extended temperature grade (-40°C to +85°C), whereas older 93C46 variants may be limited to 0°C to +70°C. No PCB or firmware changes are required when upgrading to the 93C46X/SN, provided the application operates within the extended temperature range.

What happens to the 93C46X/SN during power-on reset?

At power-on, the 93C46X/SN enters a known idle state: all internal logic resets, DO goes high-impedance, and the device ignores commands until CS is asserted. The ORG pin is sampled once at V_CC ≥ 2.0 V to determine memory organization (8-bit or 16-bit). No automatic erase or initialization occurs - existing data remains intact. This behavior ensures safe integration into systems where the 93C46X/SN powers up before or asynchronously with the host MCU.