24LC256-I-SN Detailed explanation of pin function specifications and circuit principle instructions

The component 24LC256-I/SN is a part of Microchip Technology's EEPROM series. Specifically, it is a 256Kb (32K x 8) I2C-compatible EEPROM with low-voltage operation.

Pin Function Specifications

This device comes in a 8-pin SOIC (Small Outline Integrated Circuit) package.

Below is a detailed explanation of each pin’s function:

Pin Number Pin Name Pin Description 1 Vcc Power Supply Pin: Connect to the positive power supply voltage, typically 2.5V to 5.5V for this device. 2 SCL ( Clock ) I2C Clock Pin: The clock signal for I2C communication. It synchronizes the data transfer between the EEPROM and the microcontroller. 3 SDA (Data) I2C Data Pin: The data signal for I2C communication, carrying the read/write data between the EEPROM and the controller. 4 WP (Write Protect) Write Protect Pin: If connected to Vcc, it disables write operations to the memory, providing data protection. If connected to GND, writing to the EEPROM is allowed. 5 A0 (Address Pin 0) Device Address Pin 0: A part of the I2C address, can be connected to GND or Vcc to set the most significant bit of the I2C address. 6 A1 (Address Pin 1) Device Address Pin 1: Another part of the I2C address. Can also be tied to GND or Vcc to set the address bit. 7 A2 (Address Pin 2) Device Address Pin 2: Part of the I2C address, similar to A0 and A1. 8 GND Ground Pin: Connect to the ground of the circuit.

Pin Count and Package Type

Pin Count: The 24LC256-I/SN has 8 pins in total. Package Type: It is typically available in an 8-pin SOIC package.

Pin Function List and Explanation (Complete List)

Vcc (Pin 1): Function: Provides the power supply voltage for the device. The chip operates on voltages between 2.5V and 5.5V. This voltage is essential for the chip's internal operations and communication via the I2C protocol. Use: Always connect this pin to the positive supply rail. SCL (Pin 2): Function: The clock signal for I2C communication. It allows the master device (usually a microcontroller) to synchronize data transfer with the EEPROM. Use: Connect this pin to the SCL line of the I2C bus. SDA (Pin 3): Function: The data line used for I2C communication. Data is transmitted over this line in both directions between the EEPROM and the master device. Use: Connect this pin to the SDA line of the I2C bus. WP (Pin 4): Function: Write protection for the EEPROM. If this pin is connected to Vcc, it disables all write operations to the memory, ensuring the data cannot be modified. If connected to GND, writing to memory is allowed. Use: To prevent accidental data corruption, you may choose to tie this pin to Vcc. A0 (Pin 5): Function: This pin is part of the device's unique I2C address. It sets the least significant bit of the device address when combined with other address pins A1 and A2. This allows multiple 24LC256 devices to be used on the same I2C bus by assigning unique addresses. Use: Connect to Vcc or GND to set the address bit accordingly. A1 (Pin 6): Function: Another address pin for the I2C address. Together with A0 and A2, it defines the complete address of the device. Use: Connect to Vcc or GND to configure the address. A2 (Pin 7): Function: The final address pin for the device. With A0 and A1, this pin helps define the I2C address of the EEPROM. Use: Can be tied to Vcc or GND to set the device's address. GND (Pin 8): Function: Ground pin for the device. Use: Always connect this pin to the ground of your circuit.

Commonly Asked Questions (FAQ) for 24LC256-I/SN

Q: What is the maximum operating voltage for the 24LC256-I/SN? A: The maximum operating voltage for the 24LC256-I/SN is 5.5V.

Q: How do I enable write protection on the 24LC256-I/SN? A: You can enable write protection by connecting the WP pin to Vcc.

Q: Can I use multiple 24LC256-I/SN devices on the same I2C bus? A: Yes, you can use multiple devices by setting different combinations of address pins (A0, A1, A2) for each device.

Q: What is the storage capacity of the 24LC256-I/SN? A: The 24LC256-I/SN has a capacity of 256Kb, which equals 32,768 bytes of memory.

Q: What is the write cycle time for the 24LC256-I/SN? A: The typical write cycle time is 5 ms.

Q: How do I read data from the 24LC256-I/SN? A: You can read data by sending the device address and memory location via the I2C interface , then receiving the data bytes.

Q: How do I write data to the 24LC256-I/SN? A: Write data by sending the device address and memory location, followed by the data bytes to be written.

Q: What is the I2C address for the 24LC256-I/SN? A: The default I2C address is 0xA0 for the write operation and 0xA1 for the read operation. This address can be adjusted using the A0, A1, and A2 pins.

Q: Can the 24LC256-I/SN be used with a 3.3V system? A: Yes, the 24LC256-I/SN can operate with a supply voltage as low as 2.5V, making it compatible with 3.3V systems.

Q: How do I initialize the 24LC256-I/SN on the I2C bus? A: Initialization involves selecting the appropriate I2C address and performing a read or write operation based on your application.

Q: What is the purpose of the A0, A1, and A2 pins on the 24LC256-I/SN? A: These pins determine the I2C address of the device, allowing multiple EEPROMs to share the same I2C bus.

Q: Can I write protect only a portion of the memory? A: No, write protection applies to the entire memory block when the WP pin is tied to Vcc.

Q: How long does it take to write data to the 24LC256-I/SN? A: The write cycle typically takes around 5 milliseconds.

Q: What is the maximum number of 24LC256-I/SN devices I can use on an I2C bus? A: You can connect up to 8 devices by configuring the address pins A0, A1, and A2.

Q: What happens if the Vcc pin is not connected? A: The device will not function properly, as the Vcc pin is required to power the EEPROM.

Q: Is the 24LC256-I/SN compatible with both 3.3V and 5V systems? A: Yes, it works with both 3.3V and 5V I2C systems.

Q: What is the maximum clock frequency for the I2C communication with the 24LC256-I/SN? A: The maximum clock frequency is 400 kHz (Fast-mode I2C).

Q: Does the 24LC256-I/SN support fast write operations? A: Yes, the 24LC256-I/SN supports fast write operations with a write cycle time of approximately 5 ms.

Q: Can the 24LC256-I/SN be used for storing configuration data? A: Yes, the 24LC256-I/SN is ideal for storing configuration data due to its non-volatile memory.

Q: How do I clear the EEPROM memory? A: You can clear the memory by writing zeros or specific data to the entire address space.

This should cover a comprehensive explanation of the pin functions, circuit principles, and FAQ related to the 24LC256-I/SN EEPROM. Let me know if you need further details!