Microchip 93C56AT-E/SN: A Comprehensive Guide to the 1K 5V SPI Serial EEPROM
In the realm of embedded systems and electronics, reliable non-volatile memory is a cornerstone for storing critical configuration data, calibration constants, or operational logs. The Microchip 93C56AT-E/SN stands out as a robust and versatile solution, offering 1K bits of serial EEPROM memory organized as 128 x 8-bit or 64 x 16-bit. This guide delves into its datasheet, pinout, and a practical application circuit to facilitate seamless integration into your designs.
Datasheet Overview and Key Features
The 93C56AT-E/SN is a member of Microchip's extensive 93 Series SPI Serial EEPROM family. Operating from a single 4.5V to 5.5V power supply, it is ideally suited for 5V system environments. Its core strength lies in its simple 3-wire serial interface (SPI-compatible), which includes Chip Select (CS), Serial Clock (SK), and Data Input/Output (DI/DO) lines, enabling communication with a vast array of microcontrollers and processors with minimal I/O pin requirements.
A critical feature detailed in the datasheet is its built-in erase/write cycle endurance of 1,000,000 cycles and a data retention period of over 200 years, ensuring long-term reliability. The device also supports sequential read operations for faster data throughput. It includes essential write protection capabilities, activated via the Organization (ORG) pin, which controls the memory structure (8-bit or 16-bit) and provides a hardware write-lock function when set to a specific state.
Pinout Configuration
The 93C56AT-E/SN is available in an 8-lead SOIC (SN) package. Its pinout is crucial for correct PCB layout:
1. CS (Chip Select): Active-high input that enables the device for communication.
2. SK (Serial Clock): Input for the synchronous serial clock, which shifts data in and out.
3. DI (Data In): Serial data input for instructions, addresses, and data to be written.
4. DO (Data Out): Serial data output for read operations.
5. GND (Ground): System ground reference.
6. ORG (Organization): This pin determines the memory organization. Connecting it to VCC sets the x16 organization, while connecting it to GND sets the x8 organization and enables write protection.
7. NC (No Connect): This pin is not internally connected and can be left floating.
8. VCC (Power Supply): +5V power supply input.
Application Circuit Guide
A typical application circuit for interfacing the 93C56AT-E/SN with a microcontroller (MCU) is straightforward, emphasizing signal integrity and stability.
1. Power Decoupling: Place a 100nF ceramic decoupling capacitor as close as possible between the VCC (Pin 8) and GND (Pin 5) pins to filter high-frequency noise.
2. MCU Interface: Connect the CS, SK, and DI pins of the EEPROM directly to any digital I/O pins of the MCU. The DO pin connects to an MCU input pin.
3. Organization Setting: Hardwire the ORG pin (Pin 6) based on the desired data format. For 16-bit mode, connect it to VCC. For 8-bit mode and hardware write protection, connect it to GND.
4. Pull-Up Resistors: While the SPI lines often have internal MCU pull-ups, adding external 4.7kΩ to 10kΩ pull-up resistors on the CS, SK, and DI lines can enhance noise immunity in electrically noisy environments.
This simple hookup allows the MCU to perform byte/word write, read, and erase operations by toggling the CS pin and generating the appropriate SPI clock and data sequences as specified in the datasheet's instruction set.
ICGOOODFIND Summary
The Microchip 93C56AT-E/SN is an exceptionally reliable and easy-to-use serial EEPROM, perfect for 5V applications requiring modest non-volatile storage. Its simple 3-wire SPI interface, configurable memory organization, and robust write protection features make it a go-to choice for designers. The straightforward application circuit ensures quick implementation, saving valuable development time and reducing design complexity.
Keywords: Serial EEPROM, SPI Interface, Non-Volatile Memory, Microcontroller, Hardware Write Protection
