24C64 I2C-Compatible EEPROM Technical Summary

Overview

The 24C64 is a 64-Kbit electrically erasable programmable read-only memory (EEPROM) device that operates over an I2C-compatible interface. This non-volatile memory component is designed for applications requiring reliable data storage with low power consumption. The 24C64 is organized as 8,192 words of 8 bits each, making it suitable for storing configuration data, calibration settings, and other critical parameters in embedded systems.

With its robust architecture and industry-standard interface, the 24C64 provides an optimal balance of performance, density, and cost-effectiveness for a wide range of applications. The device supports both industrial and commercial temperature ranges, ensuring reliable operation in various environments.

Key Features

• Memory Capacity: 64 Kbits organized as 8K × 8
• Interface: I2C-compatible two-wire serial interface
• Operating Voltage: 1.7V to 5.5V wide voltage range
• Write Protection: Hardware write-protect pin for data security
• Endurance: 1,000,000 write cycles minimum
• Data Retention: 100 years minimum
• Page Write Mode: 32-byte page write buffer
• Operating Temperature: -40°C to +85°C (industrial grade)
• Packages: Available in PDIP, SOIC, TSSOP, and MSOP packages

Applications

The 24C64 is widely used in various electronic systems requiring non-volatile memory storage:

• Consumer electronics (TVs, set-top boxes, audio systems)
• Industrial control systems
• Medical equipment
• Automotive subsystems
• Networking equipment
• Smart meters and IoT devices
• Computer peripherals
• Gaming systems

The device's small footprint and low power consumption make it particularly suitable for portable and battery-powered applications where space and energy efficiency are critical.

Electrical Characteristics

Absolute Maximum Ratings

• Supply Voltage: -0.6V to +6.5V
• Input Voltage: -0.6V to V_CC + 0.6V
• Operating Temperature: -40°C to +85°C
• Storage Temperature: -65°C to +150°C

DC Characteristics

• Supply Current (Read): 1 mA (typical) at 100 kHz
• Supply Current (Write): 3 mA (typical) at 100 kHz
• Standby Current: 1 µA (typical)
• Input Low Voltage: 0.3V_CC (max)
• Input High Voltage: 0.7V_CC (min)

AC Characteristics

• Clock Frequency: 100 kHz (standard mode), 400 kHz (fast mode)
• Write Cycle Time: 5 ms (max)
• Clock Low Period: 4.7 µs (standard mode)
• Clock High Period: 4.0 µs (standard mode)
• Start Condition Hold Time: 4.0 µs

Functional Description

Memory Organization

The 24C64 memory array is organized as 8,192 bytes, each byte being individually addressable. The device uses a 13-bit address space (A12-A0) to access all memory locations. Memory accesses can be performed in sequential or random modes, with automatic address incrementing during sequential reads.

I2C Interface

The device implements a bi-directional two-wire bus protocol compatible with the I2C standard. The interface consists of:

• Serial Data (SDA) - Bidirectional data line
• Serial Clock (SCL) - Clock input

Communication is initiated by a Start condition and terminated by a Stop condition. The device supports 7-bit slave addressing with the ability to connect up to eight devices on the same bus using the A0, A1, and A2 address pins.

Write Operations

The 24C64 supports two write modes:

• Byte Write: Writes a single byte to a specified address
• Page Write: Writes up to 32 bytes in a single operation

An internal write cycle (t_WR) begins after each write command. During this time, the device will not acknowledge further commands.

Read Operations

The device supports three read modes:

• Current Address Read: Reads from the last accessed address +1
• Random Read: Reads from any specified address
• Sequential Read: Reads multiple bytes sequentially

Package Information

Available Packages

• 8-lead PDIP: 300 mil body width, through-hole package
• 8-lead SOIC: 150 mil body width, surface mount package
• 8-lead TSSOP: 4.4 mm body width, thin shrink small outline package
• 8-lead MSOP: 3 mm body width, micro small outline package

Pin Configuration

All packages share the same pinout:

• Pin 1: A0 - Chip Address Input
• Pin 2: A1 - Chip Address Input
• Pin 3: A2 - Chip Address Input
• Pin 4: VSS - Ground
• Pin 5: SDA - Serial Data
• Pin 6: SCL - Serial Clock
• Pin 7: WP - Write Protect
• Pin 8: VCC - Power Supply

Ordering Information

The 24C64 is available in various package options and temperature grades. The complete ordering code includes:

• Device density (64 for 64 Kbit)
• Technology (C for I2C interface)
• Package type (P for PDIP, S for SOIC, etc.)
• Temperature range (I for industrial)

Example: 24C64-I/P for industrial temperature PDIP package.

Design Considerations

Power Supply Decoupling

A 0.1 µF ceramic capacitor should be placed as close as possible between VCC and VSS pins to minimize power supply noise.

Pull-up Resistors

The I2C bus requires pull-up resistors on both SDA and SCL lines. Typical values range from 1 kΩ to 10 kΩ, depending on bus speed and capacitive loading.

Write Protect Function

The WP pin provides hardware protection against accidental writes:

• WP