Microchip Technology 93C56CT-I/MS

Overview

93C56CT-I/MS from Microchip Technology Inc. is a 2 Kbit (256 × 8-bit) low-voltage serial EEPROM with Microwire-compatible 3-wire interface, operating at 4.5–5.5 V, rated for industrial temperature range (−40°C to +85°C), and housed in an 8-lead MSOP package. It provides nonvolatile storage for configuration data in embedded microcontroller systems requiring reliable, low-power memory with automatic erase-before-write and hardware-level power-on/off protection.

For engineers reviewing the 93C56CT-I/MS datasheet, 93C56CT-I/MS pinout, 93C56CT-I/MS application, or 93C56CT-I/MS equivalent, key selection considerations include its fixed 8-bit organization (no ORG pin), 2 ms typical write cycle time, 1 million erase/write endurance, 200-year data retention, and compatibility with legacy Microwire-based host controllers in space-constrained industrial designs.

Technical Context

This device implements a synchronous serial interface using CS, CLK, and DI/DO signals with start-bit detection and opcode-driven command execution. It supports READ, WRITE, ERASE, ERAL, WRAL, EWEN, and EWDS instructions - all clocked on the rising edge of CLK, with DO providing Ready/Busy status during programming cycles.

Unlike C-variant parts, the 93C56T series lacks an ORG pin and is permanently configured for 8-bit word access. Its internal power-on reset circuitry enforces write protection below 3.8 V, and it enters Erase/Write Disable (EWDS) mode at power-up - requiring explicit EWEN before any programming operation.

Key Specifications

Pinout & Package

8-lead MSOP (150 mil) package with exposed pad (optional VSS connection), RoHS-compliant matte tin finish. Pin 1 marked by laser dot; pin 1 location confirmed per Microchip DS21794G-page 17.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 93LC56BT-I/MS and AT25020B-MAHL-T, the 93C56CT-I/MS offers guaranteed Microwire compatibility and deterministic 2 ms write timing at 5 V, making it optimal for cost-sensitive industrial controllers where pin count, firmware simplicity, and voltage margin are prioritized over multi-voltage flexibility or SPI integration.

Availability

93C56CT-I/MS is available at Aetrix Electronics and suitable for industrial sensor calibration, motor drive configuration storage, and medical device settings backup requiring stable component supply, long-term obsolescence management, and RoHS-compliant packaging.

Supply support for 93C56CT-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 microcontroller, mixed-signal, analog, and Flash-IP solutions, headquartered in Chandler, Arizona.

The 93Cxx family was designed specifically for cost-effective, low-pin-count nonvolatile memory in resource-constrained embedded systems relying on Microwire-compatible interfaces and industrial-grade reliability.

FAQ

What is the memory organization of the 93C56CT-I/MS?

The 93C56CT-I/MS is a fixed 256 × 8-bit (2 Kbit) EEPROM with no ORG pin - unlike C-variant parts, it does not support 16-bit mode. Its organization is permanently x8, matching the 'A' version designation in Microchip's 93C56A/B/C family. This simplifies address decoding and eliminates external ORG pin routing, making it ideal for space-constrained PCB layouts where pin count is critical. The 93C56CT-I/MS datasheet confirms this in the Device Selection Table and Pin Function Table.

Does the 93C56CT-I/MS support 3.3 V operation?

No, the 93C56CT-I/MS does not support 3.3 V operation. Its specified V_CC range is strictly 4.5 V to 5.5 V, and its internal power-on reset circuit activates write protection below ~3.8 V. Attempting to operate at 3.3 V will result in unreliable communication and inhibited erase/write functions. For 3.3 V systems, consider the 93LC56A-I/MS (2.5–5.5 V) or SPI-based alternatives like the AT25020B-MAHL-T.

How is write protection implemented on the 93C56CT-I/MS?

Write protection on the 93C56CT-I/MS operates at two levels: hardware and software. Hardware protection is enforced by an internal voltage detector that disables all programming modes when V_CC falls below ~3.8 V. Software protection requires issuing an EWEN (Erase/Write Enable) command before any ERASE, WRITE, ERAL, or WRAL instruction - the device powers up in EWDS (Erase/Write Disable) state. This dual-layer scheme prevents accidental writes during power transitions or firmware errors.

What is the purpose of the NC pins on the 93C56CT-I/MS MSOP package?

Pins 6 and 7 on the 93C56CT-I/MS MSOP package are designated NC (No Internal Connection). They are physically present but unconnected to die circuitry - confirming the absence of an ORG pin in this 'T' variant. These pins must be left floating or tied to V_SS/V_CC per PCB design rules (e.g., for thermal relief or EMI control), but they serve no functional role in memory operation or configuration. Their presence aligns with Microchip's standardized 8-lead MSOP footprint across the 93XX56 family.

Can the 93C56CT-I/MS be used in automotive applications?

No, the 93C56CT-I/MS is rated only for industrial temperature range (−40°C to +85°C) and is not qualified for automotive use. Automotive-grade variants (e.g., 93C56CT-E/MS) carry an 'E' suffix and are tested to −40°C to +125°C with extended reliability screening. Using the 93C56CT-I/MS in under-hood or dashboard environments risks parametric drift, reduced endurance, and premature failure. Always verify temperature grade suffixes and consult Microchip's automotive qualification documentation before deployment.