Microchip Technology 93C46C-I/MS

Overview

93C46C-I/MS from Microchip Technology Inc. is a 1 Kbit (128 × 8 or 64 × 16) low-voltage serial EEPROM with Microwire-compatible 3-wire interface, ORG pin for runtime word-size selection, and industrial temperature range (–40°C to +85°C). It supports self-timed erase/write cycles, automatic ERAL/WRAL, and Ready/Busy status via DO pin. Used in microcontroller configuration storage, sensor calibration data retention, and power-management parameter backup.

For engineers reviewing the 93C46C-I/MS datasheet, 93C46C-I/MS pinout, 93C46C-I/MS application, or 93C46C-I/MS equivalent, this page delivers verified electrical specs, package mapping to MSOP-8, functional timing behavior, real-world use scenarios, and two validated alternative parts with documented technical and application differences.

Technical Context

The 93C46C-I/MS implements a synchronous serial Microwire interface with CS, CLK, DI, and DO signals, where instruction execution is triggered by a Start bit (CS high + DI high on CLK rising edge). Its dual-word-size capability (8-bit or 16-bit) is controlled solely by the logic level on the dedicated ORG pin - tied to VCC for x16, VSS for x8 - and is not software-configurable.

It features hardware-based data protection: power-on/off detection (VPOR = 3.8 V), automatic EWDS at power-up, and mandatory EWEN before any erase/write. Erase/write cycles are self-timed (2 ms for 93C versions), with status signaled via DO pin polling during CS high after ≥250 ns low time (TCSL), and requires VCC ≥4.5 V for ERAL/WRAL operations.

Key Specifications

Pinout & Package

93C46C-I/MS is housed in an 8-lead MSOP (Mini Small Outline Package) with 0.65 mm pitch, 3.0 mm × 3.0 mm body, and exposed pad option (not connected per datasheet). Pin 1 is marked by laser dot; package is Pb-free (Matte Tin finish).

Key Features

Applications

Equivalent & Alternatives

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

Compared with 93LC46C-I/MS and 93AA46C-I/MS, the 93C46C-I/MS offers narrower VCC tolerance optimized for stable 5 V rails, higher VPOR for robustness against marginal supplies, and industrial-grade qualification - making it ideal for fixed-voltage industrial control where cost and simplicity outweigh wide-VCC flexibility.

Availability

93C46C-I/MS is available at Aetrix Electronics and suitable for industrial automation, automotive body electronics, and medical device manufacturing requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for 93C46C-I/MS 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 93C46C-I/MS belongs to Microchip's legacy 93XX serial EEPROM family, designed specifically for cost-sensitive, low-pin-count embedded systems requiring reliable nonvolatile storage with minimal external components and industry-standard Microwire compatibility.

FAQ

What is the function of the ORG pin on the 93C46C-I/MS?

The ORG pin on the 93C46C-I/MS selects memory organization: logic high (VCC) configures 64 × 16-bit mode; logic low (VSS) configures 128 × 8-bit mode. This hardware-selectable feature eliminates firmware dependency for word-width adaptation. The 93C46C-I/MS requires a stable logic level on ORG at power-up and during operation - floating or undefined states may cause unpredictable behavior. No internal pull-up/down is provided.

Does the 93C46C-I/MS support true SPI communication?

No, the 93C46C-I/MS implements Microwire protocol - a subset of SPI - with strict 3-wire (CS, CLK, DI/DO) half-duplex operation and fixed instruction encoding. It lacks SPI mode bits (CPOL/CPHA), bidirectional MISO/MOSI separation, and standard SPI opcodes. Host firmware must follow Microwire timing (e.g., TCSL ≥250 ns, Start bit detection) and instruction set (READ=10b, WRITE=01b) defined in DS20001749K. Using an SPI peripheral in Microwire-compatible mode is possible but requires precise clock polarity/phase alignment.

What is the minimum VCC required for ERAL and WRAL operations on the 93C46C-I/MS?

The 93C46C-I/MS requires VCC ≥4.5 V for proper execution of ERAL (Erase All) and WRAL (Write All) commands, as explicitly specified in DS20001749K pages 8 and 11. Below 4.5 V, these commands will fail silently or produce incomplete erasure - no error flag is generated. This threshold is higher than the general operating range (4.5–5.5 V) and reflects the elevated voltage needed to drive internal charge pumps during bulk array operations. Always verify VCC stability before issuing ERAL/WRAL.

How does the Ready/Busy status work on the 93C46C-I/MS DO pin?

During erase or write cycles, the DO pin of the 93C46C-I/MS outputs Ready/Busy status only when CS is brought high after being low for ≥250 ns (TCSL). While busy, DO is logic low; when ready, DO goes high. DO returns to High-Z on CS falling edge. Status is invalid if CS remains low throughout the cycle. To poll correctly: assert CS high post-TCSL, sample DO on CLK rising edge, and repeat until high. The 93C46C-I/MS does not support interrupt-driven status - polling is mandatory.

Is the 93C46C-I/MS pin-compatible with other 93XX46C variants in MSOP-8 package?

Yes, the 93C46C-I/MS is pin-compatible with all 93XX46C variants (e.g., 93AA46C-I/MS, 93LC46C-I/MS) in the MSOP-8 package - same pin count, layout, and signal assignment (CS, CLK, DI, DO, VSS, ORG, NC, VCC). However, electrical differences exist: VCC ranges, VPOR thresholds, and temperature grades vary. Swapping requires validation of supply voltage, reset behavior, and ambient operating conditions - e.g., substituting 93C46C-I/MS with 93AA46C-I/MS risks malfunction below 4.5 V.