Microchip Technology 93LC46XT-I/SN

Overview

93LC46XT-I/SN from Microchip Technology Inc. is a 1K-bit (128 × 8 or 64 × 16) low-voltage serial EEPROM with Microwire™ interface, ORG-pin-selectable memory organization, and industrial temperature range (−40°C to +85°C). It operates down to 2.5V, features self-timed erase/write cycles, 1 million endurance cycles, and >200-year data retention. Used for configuration storage in embedded controllers, sensor calibration, and power management systems.

For engineers reviewing the 93LC46XT-I/SN datasheet, 93LC46XT-I/SN pinout, 93LC46XT-I/SN application, or 93LC46XT-I/SN equivalent, key selection considerations include its 3-wire serial interface timing (max 2 MHz at VCC < 4.5V), standby current of 3 µA at 2.5V, programmable x8/x16 organization via ORG pin, and rotated SOIC-8 (SN) package compatibility with space-constrained PCB layouts.

Technical Context

The 93LC46XT-I/SN implements a synchronous 3-wire Microwire interface with CS, CLK, and bidirectional DI/DO lines. Its instruction set includes READ, WRITE, ERASE, EWEN/EWDS, ERAL, and WRAL - all initiated by a Start bit followed by opcode, address, and optional data bits clocked on CLK rising edges.

Memory organization is dynamically selected by the ORG pin: tied to VCC for 64 × 16-bit mode (18-clock READ), tied to VSS for 128 × 8-bit mode (10-clock READ). During programming, DO provides Ready/Busy status polling; self-timed write/erase cycles require no external timing control and complete in 4 ms (per word), 8 ms (ERAL), or 16 ms (WRAL) at 5V ±10%.

Key Specifications

Pinout & Package

8-pin rotated SOIC (SN) package per JEDEC MS-012, with pin 1 at bottom-left corner when notch faces up. Pin rotation differs from standard SOIC: CS=pin3, CLK=pin4, DI=pin5, DO=pin6, VSS=pin7, ORG=pin8, NU=pin1, VCC=pin2.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 93LC46XT-I/SN, the 93LC46C-I/SN offers drop-in replacement with higher ESD immunity and lifecycle support, while the AT93C46-10SU-2.7 trades lower voltage operation for faster clocking - both require verification of ORG-pin behavior and WRAL timing compliance in target applications.

Availability

93LC46XT-I/SN is available at Aetrix Electronics and suitable for industrial sensor calibration, embedded controller configuration, and automotive body control modules requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for 93LC46XT-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 microcontroller, analog, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 93LC46XT-I/SN belongs to Microchip's legacy 93LC serial EEPROM family, designed specifically for cost-sensitive, low-power embedded systems needing simple, reliable nonvolatile storage with minimal pin count and firmware overhead.

FAQ

What is the function of the ORG pin on the 93LC46XT-I/SN?

The ORG pin on the 93LC46XT-I/SN selects memory organization: tied to VCC enables 64 × 16-bit mode (18-clock READ), tied to VSS enables 128 × 8-bit mode (10-clock READ). It must be solidly pulled - floating is only permitted at ≤1 MHz in x16 mode. This pin directly determines address width and data bus width, making it essential for matching the host MCU's memory access model. The 93LC46XT-I/SN uses this pin to maintain backward compatibility across diverse 8-bit and 16-bit system architectures.

Does the 93LC46XT-I/SN support sequential read operations?

Yes, the 93LC46XT-I/SN supports sequential read: when CS remains high after a READ instruction, the device automatically increments the internal address counter and outputs subsequent memory locations on DO without requiring new opcodes or addresses. This reduces host MCU overhead for reading contiguous configuration blocks. The 93LC46XT-I/SN performs sequential reads in both x8 and x16 modes, with data toggling on each CLK rising edge and stable within 400 ns (TPD) at CL = 100 pF.

How does the 93LC46XT-I/SN protect against accidental writes during power transitions?

The 93LC46XT-I/SN incorporates hardware power-on/power-off protection: programming modes are inhibited until VCC exceeds 1.4V at power-up, and disabled when VCC falls below 1.4V at power-down. Additionally, it powers up in EWDS (Erase/Write Disable) state, requiring an explicit EWEN command before any ERASE or WRITE. These dual safeguards ensure that the 93LC46XT-I/SN cannot corrupt stored data during brown-out conditions or uncontrolled power cycling - critical for safety-critical and maintenance-free applications.

What is the maximum clock frequency supported by the 93LC46XT-I/SN?

The 93LC46XT-I/SN supports up to 2 MHz clock frequency when VCC < 4.5V, and up to 3 MHz when VCC ≥ 4.5V, per AC specifications. All timing parameters - including TCKH (250 ns min), TCKL (250 ns min), and TDIS (100 ns min) - are guaranteed across the industrial temperature range (−40°C to +85°C). Host firmware must respect these limits to ensure reliable command execution; exceeding them risks incomplete instruction latching or status misreads on the 93LC46XT-I/SN DO pin.

Is the 93LC46XT-I/SN pin-compatible with standard SOIC-8 footprints?

No, the 93LC46XT-I/SN uses a rotated SOIC-8 (SN) package where pin 1 is at the bottom-left corner (not top-left), resulting in reversed pin order versus standard SOIC-8. Its pin mapping is: pin1=NU, pin2=VCC, pin3=CS, pin4=CLK, pin5=DI, pin6=DO, pin7=VSS, pin8=ORG. PCB layout must use the rotated footprint defined in Microchip drawing C04-057; using a standard SOIC-8 land pattern will cause functional failure. This rotation is exclusive to the "X" series variants like the 93LC46XT-I/SN.