Microchip 93LC86CT-E/SN: A Comprehensive Guide to the 16K Microwire Serial EEPROM

In the realm of embedded systems and electronic design, reliable non-volatile memory is a cornerstone for storing critical data. The Microchip 93LC86CT-E/SN stands out as a robust and versatile solution, offering 16K bits of organized as 2K x 8 memory space. This device utilizes the efficient Microwire serial interface, making it an ideal choice for applications where board space, power consumption, and cost are significant constraints.

Key Features and Electrical Characteristics

The 93LC86CT-E/SN is designed for endurance and longevity, supporting over 1 million erase/write cycles and featuring a data retention period of more than 200 years. It operates across a broad voltage range from 2.5V to 5.5V, accommodating various system power designs from low-power battery-operated devices to standard 5V systems. The device is offered in an 8-lead SOIC (SN) package, which is well-suited for automated PCB assembly and space-constrained applications.

Its Microwire interface requires only a minimal number of I/O pins—typically just three (CS, SK, DI) for writing and four (adding DO) for reading—freeing up valuable microcontroller resources. The interface includes support for both sequential read operations, enabling rapid data access, and essential software data protection mechanisms to prevent accidental writes.

Internal Organization and Command Set

The memory array is logically divided into 256 registers, each containing 8 bits. Communication with the EEPROM is accomplished through a simple yet powerful command set sent via the serial data input (DI) line. Key instructions include:

EWEN (Erase/Write Enable): Must be issued before any programming operation.

WRITE: Programs a specific memory location.

READ: Reads data from a specified address.

ERASE: Sets all bits in a given address to a logical '1'.

ERAL (Erase All): Erases the entire memory array.

WRAL (Write All): Writes a common value to all locations.

This straightforward command structure simplifies software driver development and integration.

Application Guide and Circuit Implementation

The primary application for the 93LC86CT-E/SN is storing configuration parameters, calibration constants, user settings, or historical data logs in a vast array of products, including:

Industrial control and automation systems

Automotive electronics (e.g., dashboards, sensors)

Consumer appliances

Telecommunications equipment

Medical devices

A typical application circuit involves connecting the EEPROM's CS (Chip Select), SK (Serial Clock), DI (Data In), and DO (Data Out) lines directly to general-purpose I/O pins of a host microcontroller. Pull-up resistors are often recommended on the DI and DO lines for signal integrity. The software driver toggles the CS and SK lines while shifting data in and out according to the Microwire timing specifications outlined in the datasheet. Critical design considerations include implementing proper power-on reset timing and ensuring that the minimum clock pulse widths are adhered to for reliable communication.

ICGOOODFIND

The Microchip 93LC86CT-E/SN is a highly reliable and easy-to-integrate serial EEPROM, offering a perfect balance of density, performance, and cost-effectiveness for a multitude of embedded design needs. Its Microwire serial interface ensures broad microcontroller compatibility with minimal pin overhead.

Keywords:

1. Microwire Serial Interface

2. Non-Volatile Memory

3. EEPROM

4. 2K x 8 Organization

5. Low-Power Operation