Microchip Technology 93C56AT-I/MC

Overview

93C56AT-I/MC 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, industrial temperature rating (–40°C to +85°C), and 1 million erase/write cycles. It serves as nonvolatile configuration storage in microcontroller-based systems requiring reliable parameter retention across power cycles.

For engineers reviewing the 93C56AT-I/MC datasheet, 93C56AT-I/MC pinout, 93C56AT-I/MC application, or 93C56AT-I/MC equivalent, key selection criteria include its dedicated 8-bit organization (no ORG pin), TSSOP-8 package with exposed pad (MC), 2 ms write cycle time, Ready/Busy status via DO pin, and compatibility with legacy Microwire controllers in space-constrained industrial control modules.

Technical Context

This device implements a synchronous serial interface with CS, CLK, and DI/DO pins operating at up to 3 MHz (VCC ≥ 4.5 V). It uses self-timed erase/write cycles initiated by CLK rising edge on final data bit - a timing behavior distinct from 93AA/93LC variants that trigger on CS falling edge.

Power-on data protection is enforced via internal voltage detection (VPOR = 3.8 V typical); programming is disabled below this threshold. The device powers up in EWDS (Erase/Write Disable) mode and requires explicit EWEN command before any WRITE or ERASE operation - a hardware-enforced safety mechanism preventing accidental overwrites during brown-out or reset conditions.

Key Specifications

Pinout & Package

93C56AT-I/MC is housed in an 8-lead 3×3 mm DFN (Dual Flat No-lead) package with exposed thermal pad (MC suffix), compatible with reflow soldering and offering improved thermal performance over SOIC. Pin 1 is marked by laser dot; exposed pad may be connected to VSS or left floating per Microchip packaging spec.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 93LC56AT-I/MC, the 93C56AT-I/MC offers faster write timing and tighter VCC tolerance ideal for stable 5 V rails, while the AT25020B-MAHL-T provides SPI compatibility at the cost of losing hardware Ready/Busy signaling - impacting real-time response in fault-critical logging.

Availability

93C56AT-I/MC is available at Aetrix Electronics and suitable for industrial sensor calibration, embedded controller configuration, and power meter firmware patch storage requiring stable component supply across multi-year production cycles.

Supply support for 93C56AT-I/MC 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 manufacturing and support infrastructure.

The 93Cxx EEPROM family was designed specifically for cost-sensitive, space-constrained industrial and automotive applications requiring robust nonvolatile storage with minimal external components and proven Microwire compatibility.

FAQ

What is the function of the ORG pin on the 93C56AT-I/MC?

The ORG pin on the 93C56AT-I/MC is a no-connect (NC) terminal - it has no internal connection and must be left floating or tied to VSS per Microchip's layout recommendations. This distinguishes the 93C56A variant from the 93C56C, which uses ORG to select between 8-bit and 16-bit word organization. The 93C56AT-I/MC implements fixed 256 × 8-bit memory mapping without configurable word size.

Does the 93C56AT-I/MC support 3.3 V operation?

No, the 93C56AT-I/MC does not support 3.3 V operation. Its absolute minimum VCC is 4.5 V, with a typical power-on reset threshold of 3.8 V. Attempting to operate below 4.5 V will disable write functionality and may cause unpredictable read behavior. For 3.3 V systems, consider the 93LC56AT-I/MC (2.5–5.5 V range) or AT25020B-MAHL-T (2.5–5.5 V, SPI interface) as alternatives.

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

Ready/Busy status on the 93C56AT-I/MC is monitored via the DO pin: during an active erase or write cycle, DO outputs logic low (busy); when the operation completes, DO transitions to logic high (ready). To sample status, CS must be brought high for ≥250 ns after the initial CS low pulse, then DO is sampled on subsequent CLK edges. The 93C56AT-I/MC does not require external pull-ups for this function.

What is the maximum clock frequency supported by the 93C56AT-I/MC?

The 93C56AT-I/MC supports a maximum clock frequency of 3 MHz when VCC is between 4.5 V and 5.5 V. This is specified in Table 1-2 (A1 parameter) of the DS21794G datasheet. At lower voltages (not applicable to 93C56A), timing margins relax; however, since the 93C56AT-I/MC is rated only for 4.5–5.5 V, 3 MHz is its guaranteed maximum operational clock rate.

Is the exposed pad on the 93C56AT-I/MC (DFN package) required to be connected to ground?

The exposed pad on the 93C56AT-I/MC DFN package (MC suffix) may be connected to VSS or left electrically floating, as stated in Microchip's DS21794G-page 12 footnote. However, for optimal thermal performance and EMI reduction in industrial environments, Aetrix recommends soldering the pad to a dedicated PCB ground plane with multiple thermal vias - a practice confirmed in Microchip's packaging specification documents.