Microchip Technology 93C56AT-I/MS

Overview

93C56AT-I/MS from Microchip Technology Inc. is a 2 Kbit (256 × 8-bit) low-voltage serial EEPROM with Microwire-compatible 3-wire interface, 4.5–5.5 V supply range, and industrial temperature grade (–40°C to +85°C). It features self-timed erase/write cycles, automatic erase-all before write-all, power-on/off data protection, and 1,000,000 endurance cycles. Used in microcontroller-based systems for parameter storage, calibration data retention, and configuration memory.

For engineers reviewing the 93C56AT-I/MS datasheet, 93C56AT-I/MS pinout, 93C56AT-I/MS application, or 93C56AT-I/MS equivalent, key selection considerations include its fixed 8-bit organization (no ORG pin), MSOP-8 package, 2 ms program cycle time, Ready/Busy status signaling via DO, and compatibility with legacy Microwire controllers in space-constrained industrial designs.

Technical Context

The 93C56AT-I/MS implements a synchronous serial Microwire interface with CS, CLK, and DI/DO pins - no ORG pin present, confirming fixed 256 × 8-bit organization. Its internal logic enforces power-on write protection, requiring explicit EWEN command prior to any erase or write operation, and automatically enters EWDS mode after power-up or reset.

Timing behavior is defined by strict AC parameters: max 3 MHz clock frequency at VCC ≥ 4.5 V, 250 ns minimum CS low time between instructions, and 2 ms typical erase/write cycle duration. Device status is actively signaled on DO during programming - low = busy, high = ready - enabling efficient polling without external timers.

Key Specifications

Pinout & Package

8-pin MSOP (Micro Small Outline Package), 3.0 mm × 3.0 mm body, 0.65 mm pitch, exposed pad optional (VSS or floating). Pin 1 marked by laser dot; pin 1 location confirmed per DS21794G-page 17.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 93LC56AT-I/MS and AT25020B-MAHL-T, the 93C56AT-I/MS offers tighter write timing (2 ms vs. 5–6 ms) and hardware-enforced 4.5 V minimum for robustness in noisy 5 V environments, but lacks low-voltage flexibility and SPI compatibility.

Availability

93C56AT-I/MS is available at Aetrix Electronics and suitable for industrial control systems, medical instrumentation, smart metering, and automotive body electronics requiring stable component supply, long-term obsolescence management, and RoHS-compliant packaging.

Supply support for 93C56AT-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 devices, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 93Cxx EEPROM family was designed specifically for cost-sensitive, space-constrained embedded systems requiring reliable nonvolatile storage with minimal external components and legacy Microwire interface compatibility.

FAQ

What is the memory organization of the 93C56AT-I/MS?

The 93C56AT-I/MS has a fixed 256 × 8-bit organization. Unlike 'C' variants, it lacks an ORG pin and therefore does not support configurable word size - it operates exclusively in x8 mode. This is confirmed in the Device Selection Table and Pin Function Table of DS21794G, where 93C56A entries show "No" under ORG Pin and "8-bit" under Word Size.

Does the 93C56AT-I/MS require an external pull-up resistor on the DO pin?

No, the 93C56AT-I/MS does not require an external pull-up on DO. The DO pin actively drives high/low during read or status polling and enters High-Z when inactive. However, if DI and DO are shorted (shared bus), a series resistor (e.g., 10 kΩ) is recommended to prevent bus conflict during dummy-zero read phases, as noted in Section 2.2 of DS21794G.

What is the minimum VCC required to execute write operations on the 93C56AT-I/MS?

The 93C56AT-I/MS requires VCC ≥ 4.5 V to enable write operations. Its power-on reset (VPOR) threshold is specified as 3.8 V (max), meaning all erase/write functions are hardware-disabled below this voltage. This ensures data integrity during brown-out conditions and is distinct from the wider 2.5–5.5 V range of the 93LC56A variant.

How is Ready/Busy status monitored on the 93C56AT-I/MS?

Ready/Busy status is monitored by reading the DO pin while CS is high and after ensuring CS has been low for ≥250 ns (TCSL). DO = low indicates active erase/write; DO = high indicates completion. The status remains valid until CS is brought low again, and issuing a Start bit followed by CS low clears the status flag, as described in Sections 2.4–2.9 of DS21794G.

Is the 93C56AT-I/MS pin-compatible with other 93XX56 variants in MSOP-8 package?

Yes, the 93C56AT-I/MS is pin-compatible with all 93XX56A/B/C variants offered in MSOP-8 ('MS' suffix), including 93AA56A, 93LC56A, and 93C56B. All share identical pin numbering, functions, and NC assignments per Table 3-1 and Package Types diagrams in DS21794G. However, functional differences (e.g., ORG presence, VCC range) must be verified per part number.