Microchip Technology 93AA56C-I/MS

Overview

93AA56C-I/MS from Microchip Technology Inc. is a 2 Kbit low-voltage serial EEPROM with configurable 8-/16-bit word organization via the ORG pin, 1.8–5.5 V supply range, and Industrial temperature grade (–40°C to +85°C). It uses Microwire-compatible 3-wire serial interface (CS, CLK, DI, DO), supports self-timed erase/write cycles, and delivers 1,000,000 endurance cycles with >200 years data retention. It is used in microcontroller-based systems for parameter storage, calibration data, and configuration settings.

For engineers reviewing the 93AA56C-I/MS datasheet, 93AA56C-I/MS pinout, 93AA56C-I/MS application, or 93AA56C-I/MS equivalent, key selection criteria include ORG-pin-configurable memory width, industrial-temperature operation, MSOP-8 packaging, Microwire protocol compliance, and power-on/off data protection circuitry.

Technical Context

The 93AA56C-I/MS implements a synchronous serial Microwire interface with start-bit detection, opcode-driven command set (READ, WRITE, ERASE, ERAL, WRAL, EWEN/EWDS), and Ready/Busy status polling via the DO pin. Its dual-word-size capability (256 × 8-bit or 128 × 16-bit) is selected by logic level on the ORG pin - high for x16, low for x8.

It features automatic erase-before-write, integrated power-on reset detection (VPOR = 1.5 V), and hardware write protection via EWEN/EWDS commands. All programming operations are self-timed: TWC = 6 ms for erase/write, TEC = 6 ms for ERAL, TWL = 15 ms for WRAL - all valid at VCC ≥ 4.5 V for bulk operations.

Key Specifications

Pinout & Package

Package: 8-lead MSOP (150 mil), Pb-free Matte Tin finish, footprint compatible with SOIC-8 but with 3.0 mm × 3.0 mm body and 0.65 mm lead pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 93LC56C-I/MS, the 93AA56C-I/MS supports lower-voltage operation down to 1.8 V, enabling compatibility with ultra-low-power MCUs; compared with AT25020B-MAHL-T, it retains Microwire simplicity and ORG configurability but trades off maximum clock speed for broader voltage flexibility and legacy interface support.

Availability

93AA56C-I/MS is available at Aetrix Electronics and suitable for smart metering, industrial PLCs, and automotive body control modules requiring stable component supply, long-lifecycle assurance, and RoHS-compliant packaging.

Supply support for 93AA56C-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, analog, and Flash-IP solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 93XX series EEPROMs were designed for cost-sensitive, low-power embedded systems requiring reliable nonvolatile storage with minimal pin count and simple firmware drivers - especially where Microwire compatibility and voltage flexibility are critical.

FAQ

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

The ORG pin on the 93AA56C-I/MS selects memory organization: tied to VCC (logic high) configures 128 × 16-bit mode; tied to VSS (logic low) configures 256 × 8-bit mode. This allows a single 93AA56C-I/MS part to serve both 8-bit and 16-bit host systems. The ORG pin must be externally biased - floating is not permitted. No ORG pin exists on A/B variants; only C-series devices like the 93AA56C-I/MS support this feature.

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

No, the 93AA56C-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 CS is low or during non-read operations. However, if DI and DO are shorted (common-bus configuration), a series resistor (e.g., 10 kΩ) is recommended to prevent bus conflict during the dummy-zero phase of read commands - as specified in DS21794G Section 2.2.

What is the maximum clock frequency supported by the 93AA56C-I/MS at 1.8 V?

At VCC = 1.8 V, the 93AA56C-I/MS supports a maximum clock frequency (FCLK) of 1 MHz, as specified in Table 1-2 (A1). This is lower than the 3 MHz maximum at 4.5–5.5 V. Timing parameters including TCKH (450 ns min), TCKL (450 ns min), and TPD (400 ns max) scale accordingly to ensure reliable operation across the full 1.8–5.5 V range. The 93AA56C-I/MS maintains full functionality - including ERAL and WRAL - at 1.8 V, though WRAL requires VCC ≥ 4.5 V per datasheet note.

How does write protection work on the 93AA56C-I/MS?

Write protection on the 93AA56C-I/MS is implemented via EWEN (Erase/Write Enable) and EWDS (Erase/Write Disable) commands. The device powers up in EWDS mode - all erase/write operations are blocked until EWEN is issued. After EWEN, writes remain enabled until EWDS is sent or VCC is cycled. READ operations are always allowed regardless of EWEN/EWDS state. This provides firmware-level control to prevent accidental overwrites during normal operation - a key safety feature in the 93AA56C-I/MS.

Is the 93AA56C-I/MS pin-compatible with other 93XX56 variants in MSOP-8 package?

Yes, the 93AA56C-I/MS is pin-compatible with all 93XX56A/B/C variants in the MSOP-8 package (e.g., 93LC56C-I/MS, 93C56C-I/MS), sharing identical pinout: CS(1), CLK(2), DI(3), DO(4), VSS(5), ORG(6), NC(7), VCC(8). However, functional differences exist - notably VCC ranges (1.8–5.5 V for 93AA vs. 2.5–5.5 V for 93LC), POR threshold (1.5 V vs. 3.8 V), and AC timing. Thus, while PCB layout is interchangeable, electrical validation is required when substituting across families.