Microchip 93LC56B-I/OT Serial EEPROM: Features, Applications, and Interface Guide
The Microchip 93LC56B-I/OT is a 2K-bit Microwire serial Electrically Erasable Programmable Read-Only Memory (EEPROM) organized as 128 x 8-bit or 64 x 16-bit. Housed in a space-saving SOT-23-6 package, this non-volatile memory device is designed for applications requiring reliable data storage with low power consumption and simple serial interfacing. Its combination of features makes it a versatile component across a wide range of industries.
Key Features
The 93LC56B boasts an impressive set of characteristics that contribute to its widespread adoption:
Non-Volatile Storage: Retains data without power, ensuring critical information is preserved.
Microwire Serial Interface: A simple, 3-wire (CS, SK, DI) serial protocol for easy communication with microcontrollers (MCUs), reducing pin count and board space.
Wide Voltage Operation: Supports a broad range from 2.5V to 5.5V, making it suitable for both 3.3V and 5V systems.
Low Power Consumption: Features a low standby current and active current, which is critical for battery-powered and portable devices.
High Reliability: Offers 1,000,000 erase/write cycles and data retention of over 200 years, ensuring long-term data integrity.
Software and Hardware Write Protection: Provides safeguards against accidental data corruption.
Extended Temperature Range (Industrial): The -I suffix denotes an operating temperature range of -40°C to +85°C, suitable for industrial environments.
Primary Applications
The robust feature set of the 93LC56B-I/OT allows it to serve in numerous applications, including:
Consumer Electronics: Storing calibration data, user settings, and configuration parameters in devices like smart TVs, set-top boxes, and audio equipment.
Automotive Systems: Used for storing mileage data, radio presets, and other non-critical vehicle settings in modules that do not require AEC-Q100 qualification.
Industrial Control: Ideal for storing calibration constants, device identifiers, and operational parameters in sensors, PLCs, and measurement equipment.
Medical Devices: Employed in portable medical monitors and instruments to store device configuration and user data reliably.
PC Peripherals: Commonly found in keyboards, printers, and mice to store default settings and manufacturer data.
Interface Guide (Microwire Protocol)
Interfacing the 93LC56B with a microcontroller is straightforward. The primary control pins are:
CS (Chip Select): Activated high to initiate a command session.
SK (Serial Clock): Provides the timing for data shifting; data is sampled on the rising edge.
DI (Data In): The line for writing instructions and data into the EEPROM.
DO (Data Out): The line for reading data from the EEPROM.
A typical communication sequence involves:
1. Taking CS high to select the device.
2. Sending a Start Bit (`1`), followed by a 2- or 3-bit Opcode (e.g., `10` for a Write instruction, `11` for a Read).
3. Sending the 6- or 7-bit Address (depending on memory organization).
4. For a Write operation, sending the 8- or 16-bit Data to be stored. The device then enters an internally timed write cycle (`~3ms`).
5. For a Read operation, reading the data back on the DO pin immediately after the address is sent.
It is crucial to check the Ready/Busy status by polling the DO pin after a write command is issued before sending a new instruction.
ICGOODFIND Summary
The Microchip 93LC56B-I/OT is a highly reliable and versatile 2K-bit serial EEPROM, prized for its simple Microwire interface, wide voltage range, and exceptional endurance. Its small form factor and low power needs make it an ideal choice for storing critical data in space-constrained and power-sensitive designs across consumer, industrial, and automotive applications.
Keywords: Serial EEPROM, Microwire Interface, Non-Volatile Memory, Low-Power, Data Storage
