DS1744-70

Product Overview

Category: Integrated Circuits (ICs)

Use: Real-Time Clock (RTC) with Non-Volatile RAM (NVRAM)

Characteristics: - Low-power CMOS technology - 32K x 8 non-volatile static RAM - Serial interface - Battery backup - Automatic power-fail detect and switch circuitry - Industrial temperature range (-40°C to +85°C) - DIP package

Essence: The DS1744-70 is an integrated circuit that combines a real-time clock and non-volatile RAM. It provides accurate timekeeping and data storage capabilities in various applications.

Packaging/Quantity: The DS1744-70 is available in a 24-pin dual in-line package (DIP). It is typically sold in quantities of one unit.

Specifications

• Supply Voltage: 4.5V to 5.5V
• Timekeeping Current: 500nA (typical)
• Operating Temperature Range: -40°C to +85°C
• Data Retention: >10 years
• Memory Organization: 32K x 8 bits
• Serial Interface: SPI-compatible, 3-wire bus

Pin Configuration

The DS1744-70 has a total of 24 pins. The following table provides a detailed pin configuration:

| Pin Number | Pin Name | Description | |------------|----------|-------------| | 1 | VCC | Power supply voltage input | | 2 | GND | Ground | | 3 | X1 | Crystal oscillator input | | 4 | X2 | Crystal oscillator output | | 5 | VBAT | Battery backup input | | 6-13 | NC | No connection | | 14 | CE | Chip enable input | | 15 | SCLK | Serial clock input | | 16 | SI | Serial data input | | 17 | SO | Serial data output | | 18-21 | NC | No connection | | 22 | RST | Reset input | | 23 | VCC2 | Power supply voltage input | | 24 | GND2 | Ground |

Functional Features

1. Real-Time Clock: The DS1744-70 provides accurate timekeeping capabilities, including seconds, minutes, hours, day, date, month, and year information.

2. Non-Volatile RAM: It features a 32K x 8 non-volatile static RAM for data storage, ensuring that the stored information is retained even during power loss.

3. Battery Backup: The device includes a battery backup input (VBAT) to maintain timekeeping and data retention when the main power supply is disconnected.

4. Automatic Power-Fail Detect and Switch Circuitry: The DS1744-70 automatically detects power failures and switches to the battery backup, ensuring uninterrupted operation.

Advantages and Disadvantages

Advantages: - Accurate timekeeping - Non-volatile data storage - Low-power consumption - Wide operating temperature range - Easy integration with serial interface

Disadvantages: - Limited memory capacity (32K x 8 bits) - Requires an external crystal oscillator for clock accuracy

Working Principles

The DS1744-70 combines a real-time clock and non-volatile RAM using low-power CMOS technology. It utilizes a crystal oscillator for accurate timekeeping and a battery backup for data retention during power loss. The device communicates with the host system through a serial interface, allowing easy integration into various applications.

Detailed Application Field Plans

The DS1744-70 is commonly used in applications that require accurate timekeeping and non-volatile data storage, such as:

1. Embedded Systems: The device is suitable for embedded systems that need to maintain accurate time and store critical data, such as event logs or configuration settings.

2. Industrial Automation: It can be utilized in industrial automation systems to synchronize processes, record timestamps, and store important parameters.

3. Medical Equipment: The DS1744-70 finds application in medical devices where precise timekeeping and data retention are crucial, such as patient monitoring systems or medical recorders.

4. Energy Management: It can be integrated into energy management systems to track power consumption, record energy usage patterns, and schedule operations.

Detailed and Complete Alternative Models

1. DS1744W-120+: Similar to DS1744-70 but operates in a wider temperature range (-40°C to +125°C).

2. DS1744P-120+: Provides additional features like tamper detection and timestamping capabilities.

3. DS1744-100+: Offers increased memory capacity (64K x 8 bits) compared to the DS1744-70.

4. DS1744Z