Microchip Technology 93C46AX-I/SN

Overview

93C46AX-I/SN from Microchip Technology Inc. is a 1 Kbit (128 × 8-bit) low-voltage serial EEPROM with Microwire-compatible 3-wire interface, 4.5–5.5 V supply range, industrial temperature rating (−40°C to +85°C), and 1,000,000 erase/write cycles. It provides nonvolatile memory storage for configuration data in embedded microcontroller systems requiring reliable, low-power, pin-efficient memory.

For engineers reviewing the 93C46AX-I/SN datasheet, 93C46AX-I/SN pinout, 93C46AX-I/SN application, or 93C46AX-I/SN equivalent, key selection criteria include its fixed 8-bit organization (no ORG pin), SOIC-8 package, 2 ms write cycle time, Ready/Busy status signaling via DO, and compatibility with legacy Microwire controllers in space-constrained industrial control and sensor modules.

Technical Context

The 93C46AX-I/SN implements a synchronous serial interface using CS, CLK, and DI/DO pins with start-bit detection and opcode-based command decoding. It supports READ, WRITE, ERASE, ERAL, WRAL, EWEN, and EWDS instructions with self-timed internal erase-before-write operation.

Its architecture includes an on-chip address counter, output buffer with high-impedance control, and power-on/off protection circuitry that inhibits all operations below 3.8 V. The device enters EWDS mode at power-up and requires explicit EWEN before any programming sequence.

Key Specifications

Pinout & Package

93C46AX-I/SN is supplied in an 8-lead SOIC package (SN suffix), with standard pinout matching industry Microwire EEPROMs. Pin 1 is CS, Pin 2 is CLK, Pin 3 is DI, Pin 4 is DO, Pin 5 is VSS, Pin 6 is NC (no internal connection), Pin 7 is NC, and Pin 8 is VCC.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 93C46B-I/SN, the 93C46AX-I/SN delivers native 8-bit compatibility without data packing; compared with 93LC46A-I/SN, it offers higher noise immunity and tighter 5 V timing but lacks 3.3 V operation - making it optimal for legacy 5 V industrial control upgrades.

Availability

93C46AX-I/SN is available at Aetrix Electronics and suitable for industrial sensor calibration, microcontroller configuration storage, and legacy equipment retrofit requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.

Supply support for 93C46AX-I/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 Inc. is a leading provider of microcontrollers, analog components, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 93C46A/B/C series was designed specifically for cost-sensitive, space-constrained industrial and automotive applications needing robust, low-pin-count serial EEPROMs with hardware data protection and wide temperature operation.

FAQ

What is the memory organization of the 93C46AX-I/SN?

The 93C46AX-I/SN has a fixed 128 × 8-bit (1 Kbit) organization. Unlike 'C' variants, it lacks an ORG pin and is not configurable - it operates exclusively in x8 mode. This simplifies interface design for 8-bit microcontrollers and eliminates external pull-up/pull-down requirements for memory width selection. The 93C46AX-I/SN matches the timing and instruction set of other 93C46A devices in the family.

Does the 93C46AX-I/SN support 3.3 V operation?

No, the 93C46AX-I/SN does not support 3.3 V operation. Its specified V_CC range is strictly 4.5 V to 5.5 V. Attempting to operate it below 4.5 V may result in undefined behavior or failure to execute commands due to its 3.8 V power-on reset threshold. For 3.3 V systems, consider the 93LC46A-I/SN, which supports 2.5–5.5 V and shares the same 8-bit organization and SOIC-8 package as the 93C46AX-I/SN.

How is Ready/Busy status monitored on the 93C46AX-I/SN?

Ready/Busy status is monitored on the DO pin: logic low indicates an erase or write operation is in progress; logic high indicates completion. To read status, CS must be brought high after being low for ≥250 ns (TCSL), then the DO level is sampled. The 93C46AX-I/SN does not require continuous clocking during the self-timed 2 ms write cycle - DO transitions automatically upon completion. After status read, issuing a Start bit followed by CS low clears the status flag.

What is the purpose of the EWEN and EWDS commands in the 93C46AX-I/SN?

The EWEN (Erase/Write Enable) and EWDS (Erase/Write Disable) commands provide hardware-level write protection. The 93C46AX-I/SN powers up in EWDS mode, blocking all erase/write operations until EWEN is issued. After programming, executing EWDS disables further writes - preventing accidental overwrites from noise, glitches, or software errors. READ operations remain fully functional regardless of EWEN/EWDS state, ensuring configuration data remains always accessible.

Is the 93C46AX-I/SN pin-compatible with other 93C46x SOIC-8 variants?

Yes, the 93C46AX-I/SN is pin-compatible with all 93C46x variants in SOIC-8 (SN) package, including 93C46B-I/SN and 93C46C-I/SN. All share identical pinout: CS (1), CLK (2), DI (3), DO (4), VSS (5), NC (6), NC (7), VCC (8). However, functional compatibility depends on organization (x8 vs. x16) and ORG pin presence - the 93C46AX-I/SN has no ORG pin and is x8-only, so firmware must match this fixed configuration.