Microchip Technology 93AA56C-I/SN

Overview

93AA56C-I/SN from Microchip Technology is a 2 Kbit low-voltage serial EEPROM with configurable 8-bit or 16-bit word organization selected via the ORG pin, 1.8–5.5 V supply range, industrial temperature rating (–40°C to +85°C), and Microwire-compatible 3-wire serial interface. It delivers 1 million erase/write cycles and >200 years data retention for nonvolatile storage in microcontroller peripherals, power management systems, and sensor calibration modules.

For engineers reviewing the 93AA56C-I/SN datasheet, 93AA56C-I/SN pinout, 93AA56C-I/SN application, or 93AA56C-I/SN equivalent, key selection criteria include ORG-pin-configurable memory width, self-timed erase/write with ERAL/WRAL support, Ready/Busy status signaling on DO, and compatibility with 1.8 V logic systems requiring robust data retention and low standby current.

Technical Context

The 93AA56C-I/SN implements a synchronous Microwire-compatible serial interface with CS, CLK, DI, and DO signals, where instruction execution begins upon detection of a Start condition (CS high and DI high on CLK rising edge). Memory organization is dynamically selected: ORG = VSS enables 256 × 8-bit mode; ORG = VCC enables 128 × 16-bit mode.

Internal control logic enforces power-on write protection, automatic ERAL before WRAL, and EWEN/EWDS command-based programming enable/disable. The DO pin serves dual function-serial data output during READ and Ready/Busy status indicator during erase/write cycles-with status valid after minimum TCSL (250 ns) and detectable via polling.

Key Specifications

Pinout & Package

93AA56C-I/SN is packaged in 8-lead SOIC (SN), with lead finish Pb-free matte tin. Pin 1 is CS; pin 2 is CLK; pin 3 is DI; pin 4 is DO; pin 5 is VSS; pin 6 is ORG; pin 7 is NC; pin 8 is VCC.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 93LC56C-I/SN, the 93AA56C-I/SN adds 1.8 V operation for ultra-low-power designs; compared with AT25020B-MAHL-T, it retains Microwire compatibility and ORG flexibility but requires different host driver logic.

Availability

93AA56C-I/SN is available at Aetrix Electronics and suitable for industrial sensor calibration, microcontroller configuration storage, and power management unit settings requiring stable component supply, long-term obsolescence planning, and RoHS-compliant sourcing.

Supply support for 93AA56C-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 microcontrollers, analog devices, and memory solutions, headquartered in Chandler, Arizona.

The 93XX56 series was designed specifically for cost-sensitive, low-power embedded systems requiring reliable serial nonvolatile memory with flexible word-width configuration and robust data integrity features.

FAQ

What is the function of the ORG pin on the 93AA56C-I/SN?

The ORG pin on the 93AA56C-I/SN selects memory organization: tied to VSS (logic low) configures 256 × 8-bit mode; tied to VCC (logic high) configures 128 × 16-bit mode. This pin is not present on A/B variants and must be externally biased - the 93AA56C-I/SN does not include internal pull-up or pull-down. Incorrect ORG biasing results in undefined memory access behavior.

Does the 93AA56C-I/SN require an external pull-up resistor on the DO pin?

No, the 93AA56C-I/SN does not require an external pull-up on DO. During READ, DO actively drives data; during READY/READY polling, DO drives low (busy) or high (ready); and during idle or CS low, DO is in High-Z state. A pull-up would conflict with active drive and is unnecessary per DS21794G electrical specifications.

How does the 93AA56C-I/SN handle power loss during a write cycle?

The 93AA56C-I/SN incorporates hardware power-loss protection: if V_CC falls below ~1.5 V during erase/write, the internal circuitry aborts the operation and holds memory contents intact. No data corruption occurs, and the device resumes normal operation after V_CC stabilizes above threshold. This behavior is intrinsic to the 93AA56C-I/SN design and requires no host firmware intervention.

Can the 93AA56C-I/SN be used with a 3.3 V microcontroller operating at 1.8 V I/O levels?

Yes, the 93AA56C-I/SN supports 1.8 V to 5.5 V operation and meets VIH1/VIL1 thresholds at V_CC ≥ 2.7 V, and VIH2/VIL2 thresholds at V_CC < 2.7 V. When powered at 3.3 V, it accepts 1.8 V logic-high inputs (VIH2 = 0.2 × V_CC = 0.66 V max) - thus interoperates directly with 1.8 V I/O banks without level translation, provided V_CC remains ≥2.5 V for reliable timing margins.

What is the purpose of the NC pin (pin 7) on the 93AA56C-I/SN SOIC package?

Pin 7 of the 93AA56C-I/SN in SOIC (SN) package is designated NC (No Connection) and has no internal die connection. It must remain unconnected in the PCB layout. While some designs tie NC pins to ground for mechanical stability, Microchip's DS21794G explicitly lists it as "No Internal Connection" - grounding pin 7 provides no electrical benefit and may risk unintended coupling in high-noise environments.