Part Number: DS3231MZ+TRL

Manufacturer: Analog Devices Inc./Maxim Integrated


Shipped from: Shenzhen/HK Warehouse

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Technical Specifications of DS3231MZ+TRL

Datasheet  DS3231MZ+TRL datasheet
Category Integrated Circuits (ICs)
Family Clock/Timing – Real Time Clocks
Manufacturer Maxim Integrated
Packaging Tape & Reel (TR)
Part Status Active
Type Clock/Calendar
Features Alarm, Leap Year, Square Wave Output
Memory Size
Time Format HH:MM:SS (12/24 hr)
Date Format YY-MM-DD-dd
Interface I2C, 2-Wire Serial
Voltage – Supply 2.3 V ~ 5.5 V
Voltage – Supply, Battery 2.3 V ~ 5.5 V
Current – Timekeeping (Max) 130μA ~ 200μA @ 3.63V ~ 5.5V
Operating Temperature -40°C ~ 85°C
Mounting Type Surface Mount
Package / Case 8-SOIC (0.154″, 3.90mm Width)
Supplier Device Package 8-SOIC

General Description

The DS3231M is a highly accurate and affordable I2C real-time clock (RTC). In a power outage, the device’s battery backup maintains time accurately. Microelectromechanical systems (MEMS) resonators lessen the number of parts required for production while enhancing the device’s long-term precision. The DS3231M is available in the same compact form factor as the DS3231 RTC, its predecessor. Through seconds, minutes, hours, days, dates, months, and years, the RTC records the passing of time.

The last day of the month is automatically modified to accommodate leap year adjustments for months with fewer than 31 days. It includes an AM/PM indicator for convenience, and the time can be shown in a 12- or 24-hour format. Included are two programmable time-of-day warnings and a 1Hz output. A bidirectional serial bus for transmitting data and addresses is the I2C bus. A precise temperature-compensated voltage reference and comparator circuit is used to monitor VCC to perform power monitoring, power failure detection, and automatic backup supply switching. The RST pin is also watched as a pushbutton input, which produces a microprocessor reset. Please check the Block Diagram for further details.

Detailed Description

The DS3231M is a microelectromechanical system (MEMS) resonator-driven serial real-time clock (RTC). The oscillator keeps the RTC accurate to within Q0.432 seconds per day from -45NC to +85NC by providing a stable and accurate reference clock. The RTC is a low-power clock/calendar that can be set to sound two separate alarms at certain times. The INT/ SQW output might be an alert interrupt signal or a 1Hz square wave. The clock/calendar displays the current time, date, month, and year.

For months with fewer than 31 days, the last day of the month is changed automatically, considering leap year adjustments. The time can be displayed in either the 12- or 24-hour format, and there is an AM/PM indicator for convenience. The onboard registers can be accessed via the I2C bus. To identify power outages and switch to the backup supply automatically, the level of VCC is monitored using a temperature-compensated voltage reference and comparator circuit. The RST pin serves as an external pushbutton and a power-fail indicator.


● High-Accuracy Time Base

A temperature sensor, an oscillator, and digital adjustment controller circuitry make up the exceptionally accurate time foundation. The controller evaluates the temperature sensor information and adjusts the final 1Hz output. The device’s accuracy is fine-tuned in the manufacturing facility to be consistent over the course of its usable temperature range.

The device’s settings are changed once every second when powered by VCC. The adjustment is done every ten seconds using a VBAT power source. The frequency of 1Hz time base adjustments can be decreased without affecting the device’s long-term timekeeping accuracy. The device contains an Aging Offset register where a constant offset (positive or negative) can be input in addition to the factory-tuned adjustment value.

● Initial VBAT Attachment

Contact bounce must be avoided when connecting a battery for the first time to the DS3231M. If the connection between the battery and the attachment mechanism is initially bouncy while connecting a battery, it will eventually become attached. If the DS3231power M’s is suddenly interrupted due to the bounce, memory recall corruption may result. There are two ways to stop contact bounce from causing the device to malfunction. The recommended method is power sequencing, in which VCC is provided to the component before the battery is installed. A modest capacitor linked between VBAT and the ground can be used as a filter to prevent contact bounce. 0.1nf to 1nf are recommended for the supply filtering capacitor values in this method.

● VBAT Operation

The number of operating modes impacts how much VBAT current is drawn. The active battery current IBATA is used while the serial interface is engaged, and VBAT powers the device. The timekeeping current IBATT, including the, averaged temperature-conversion current IBATTC, is utilized when the serial link is not in use. The system needs to support the periodic increased current pulse while maintaining a stable voltage level. Hence the temperature-conversion current IBATTC is defined. When the oscillator turns off (EOSC = 1), the device’s current draw is known as the data-retention current (IBATDR). When preserving the time and date are unnecessary, such as when the finished system is being supplied to a customer, this mode can reduce battery usage.

● Pushbutton Reset Function

The device’s RST input/output pin is designed to be connected to a pushbutton switch. The device constantly checks RST for a falling edge while not in a reset cycle. If the device detects an edge transition, it debounces the switch by lowering RST. The gadget keeps watching the RST line even after its internal timer has run out (PBDB). If the line has not yet begun to rise, the gadget will continue to do so. The device detects release and drives RST low, maintaining that state for tRST. The RST signal can also indicate a power outage. An internal power-fail signal is created when VCC is less than VPF, which compels RST to go low.

During around 250ms (tREC), RST is kept at a low value after VCC rises above VPF so that the power grid can settle. When VCC is provided but the oscillator is inactive, tREC is skipped, and RST is set to high. When the RST output is asserted, either manually or in response to a power failure, the device continues to function normally. Power from VCC is required for RST output functionality and pushbutton monitoring.

● Real-Time Clock (RTC)

The RTC uses the 1Hz signal from the temperature-compensated oscillator to display the current time, date, month, and year. For months with fewer than 31 days, the last day of the month is changed automatically, considering leap year adjustments. The clock can display the time in either the 12-hour or 24-hour style and tell you if it is AM or PM. Two time-of-day alarms can be set on the clock. When activated, INT/SQW will produce either an alarm condition interrupt or a 1Hz square wave. The INTCN bit of the Control register decides which option is used.

● I2C Interface

The I2C interface can be accessed when either VCC or VBAT are at the appropriate level. If the microcontroller attached to the device resets due to a lack of VCC or another event, such as when the microcontroller resets while receiving data from the device, the I2C communications between the microcontroller and the device will likely get out of sync. When the microcontroller is reset, the device’s I2C interface can be placed into a known state by switching SCL until SDA is observed at a high level. To create a START condition, the microcontroller should make SDA low and SCL high.


The DS3231M is an exceptional real-time clock with a very accurate and cost-effective I2C interface, MEMS resonator technology, customizable time-of-day warnings, and power monitoring capabilities, to name a few. It makes a great choice for various applications thanks to its push-button reset mechanism and constant accuracy over a wide temperature range. To assist your project needs, we suggest ICRFQ if you’re looking for a reliable source of electronic components. We provide the DS3231MZ+TRL at a competitive price, with a knowledgeable crew and quick delivery. Explore ICRFQ today to see how we may help with your upcoming project.

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