Real-time clocks (RTCs)
Compare DS1302 vs DS1307 vs DS3231 RTC – Real-time clocks (RTCs) are integrated circuits that keep track of the current date and time even when there is a power outage. There are several types of RTCs available in the market, but among the most popular are the DS1302, DS1307, and DS3231. In this article, we will compare these three RTCs and see what makes them unique from each other.
Dallas Semiconductor (now a part of Maxim Integrated) is the original manufacturer of the DS1302, DS1307, and DS3231 real-time clock (RTC) integrated circuits. These RTCs are widely used in various electronic projects and are available from many electronic component distributors.
DS1302 Arduino
The DS1302 is a simple RTC that uses a 32.768kHz crystal oscillator to keep accurate time. It has a small number of pins, making it easy to use, and it has a simple serial interface that can be used to communicate with a microcontroller. The DS1302 also has a trickle-charge feature that allows it to be powered by a small battery even when the main power supply is off.
DS1307 Arduino
The DS1307 is an improved version of the DS1302, featuring a more accurate crystal oscillator and a larger number of pins. Like the DS1302, the DS1307 has a simple serial interface that can be used to communicate with a microcontroller. The DS1307 also has an internal battery-backed SRAM, allowing it to store data even when the main power supply is off.
DS3231 Arduino
The DS3231 is a more advanced RTC that offers much better accuracy and features compared to the DS1302 and DS1307. It uses a temperature-compensated crystal oscillator (TCXO) that provides an accuracy of ±2ppm. The DS3231 also has a higher operating temperature range, making it suitable for use in harsh environments. Additionally, the DS3231 has an I2C interface, making it easier to interface with microcontrollers compared to the serial interface of the DS1302 and DS1307.
Comparison Table
here’s a more in-depth comparison table between the DS1302, DS1307, and DS3231 RTCs:
Feature DS1302 DS1307 DS3231 Pin Configuration 
Interface Serial I2C I2C Oscillator 32.768kHz 32.768kHz Temperature-compensated crystal oscillator (TCXO) Accuracy ±2.5% at 25°C ±2.0% at 25°C ±2ppm Operating Voltage 2.0V to 5.5V 2.0V to 5.5V 2.3V to 5.5V Operating Temperature Range -40°C to +85°C -55°C to +125°C -40°C to +85°C Battery-backed SRAM No 56 bytes No Pin Count 8 8 8 Date/Time Registers 8 7 8 Trickle-charge feature Yes No No Cost Low Medium High
Note: The above table is a general comparison and the actual specifications may vary depending on the manufacturer.
As can be seen from the table, the DS3231 offers the highest accuracy, thanks to its temperature-compensated crystal oscillator (TCXO). It also has a wider operating voltage range compared to the DS1302 and DS1307. On the other hand, the DS1307 offers battery-backed SRAM, which can be useful for storing data during power outages. The DS1302 has the advantage of being low cost and having a trickle-charge feature, which allows it to be powered by a small battery even when the main power supply is off.
Arduino Tutorial
If you need a tutorial about this RTC, here I provide some links that can help you find the best program code you need:
- Display Time Every Second Arduino RTC
- OLED SSD1306 and DS1307 Problem and Fix it
- DS3231 arduino RTC Tutorial Using Adafruit Library
- ESP8266 NodeMCU RTC DS3231 Code
In conclusion, the choice between DS1302, DS1307, and DS3231 will depend on the specific needs of the project. If a simple and low-cost solution is required, the DS1302 may be the best choice. For projects that require more accuracy and features, the DS3231 is the way to go. The DS1307 offers a good balance between cost and features, making it a good choice for many projects.
I hope this DS1302 DS1307 DS3231 RTC Comparison Table article is useful.
