Microchip Technology 93AA76B-I/SN

Overview

93AA76B-I/SN from Microchip Technology Inc. is an 8Kbit, low-voltage, serial EEPROM with fixed 16-bit memory organization (512 × 16), operating across 1.8–5.5V supply, rated for industrial temperature (−40°C to +85°C), and packaged in 8-lead SOIC (SN). It implements Microwire-compatible 3-wire serial interface (CS/CLK/DI/DO) and supports self-timed erase/write cycles with 1M endurance and >200-year data retention - used for nonvolatile parameter storage in embedded control systems.

For engineers reviewing the 93AA76B-I/SN datasheet, 93AA76B-I/SN pinout, 93AA76B-I/SN application, or 93AA76B-I/SN equivalent, key selection considerations include its fixed x16 organization (no ORG pin), absence of PE/ORG pins, industrial-grade voltage and temperature operation, and compatibility with legacy Microwire controllers requiring sequential read and Ready/Busy polling via DO.

Technical Context

The 93AA76B-I/SN operates as a synchronous serial EEPROM using a 3-wire Microwire interface: CS enables device selection, CLK synchronizes bit transfers on rising edges, and DI/DO handle half-duplex command/data flow. Its fixed 512 × 16-bit array eliminates configuration logic - unlike 'C' variants, it lacks ORG and PE pins, simplifying design but removing runtime word-size switching or hardware write-protection.

Internal logic includes auto-erase-before-write, ERAL/WRAL bulk operations, EWEN/EWDS enable/disable control, and power-on/off data protection. The DO pin serves dual roles: outputting read data and signaling Ready/Busy status during programming - verified by polling after CS reassertion with ≥250 ns low time (TCSL).

Key Specifications

Pinout & Package

8-lead SOIC package (SN suffix), 3.9 mm × 4.9 mm body, 1.27 mm pitch, RoHS-compliant matte tin finish. Pin 1 marked by laser dot; pin 1 ID corner matches standard SOIC orientation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 93AA76B-I/SN, the 93AA76A-I/SN trades word-width efficiency for byte-addressability, while the 93LC76B-I/SN extends operational voltage and temperature ranges at the cost of reduced low-voltage capability - all three share identical pinout and instruction set.

Availability

93AA76B-I/SN is available at Aetrix Electronics and suitable for industrial sensor calibration, automotive body control modules, medical infusion pump settings, and smart energy meter firmware parameters requiring stable component supply across long production lifecycles.

Supply support for 93AA76B-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, FPGA, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 93XX76 series was designed specifically for cost-sensitive, low-power embedded systems requiring reliable nonvolatile storage - emphasizing Microwire compatibility, wide voltage operation, and robust data retention without external support circuitry.

FAQ

What memory organization does the 93AA76B-I/SN implement?

The 93AA76B-I/SN implements a fixed 512 × 16-bit (8Kbit) memory organization. Unlike 'C' variants, it has no ORG pin - the x16 structure is hardwired, eliminating configuration complexity but precluding runtime switching to x8 mode. This matches 16-bit MCU data buses and ADC output widths directly, reducing software bit-packing overhead.

Does the 93AA76B-I/SN include hardware write-protection pins?

No, the 93AA76B-I/SN does not include Program Enable (PE) or ORG pins. Write protection is implemented exclusively through firmware commands: EWEN must precede any erase/write operation, and EWDS disables further programming until the next power cycle or explicit EWEN. This differs from 93AA76C-I/SN, which uses PE for hardware-level inhibit.

What is the maximum clock frequency supported by the 93AA76B-I/SN at 3.3 V operation?

At VCC = 3.3 V, the 93AA76B-I/SN supports a maximum clock frequency of 2 MHz, as specified in Table 1-2 (A1). This is derived from the 2.5 V ≤ VCC < 4.5 V bin, where FCLK max = 2 MHz. Operating above this violates AC timing - TCKH (clock high time) would fall below the guaranteed 250 ns minimum, risking command misreads.

How is Ready/Busy status monitored on the 93AA76B-I/SN?

Ready/Busy status is monitored by polling the DO pin after reasserting CS high following ≥250 ns low time (TCSL). During erase/write, DO = low indicates ongoing operation; DO = high confirms completion. The status remains latched until cleared by issuing a Start bit and pulling CS low - no external interrupt or dedicated status register is required.

Is the 93AA76B-I/SN compatible with standard SPI interfaces?

The 93AA76B-I/SN uses a Microwire-compatible 3-wire interface (CS/CLK/DI/DO), not standard 4-wire SPI. It lacks separate MISO/MOSI lines - DI and DO share bidirectional functionality on a single pin, requiring half-duplex timing. While many SPI peripherals can emulate Microwire via GPIO-controlled bit-banging, hardware SPI master modes expecting full-duplex transfers will require firmware adaptation.