DS1341U+

Real Time Clock Overview

The DS1341U+ is a low-current real-time clock (RTC) from Analog Devices/Maxim Integrated, housed in an 8-pin µSOP package. It operates within a voltage range of +1.8V to +5.5V and maintains time down to +1.15V with a typical standby current of 250nA at +3.0V. The device supports high-ESR crystals up to 100kΩ and utilizes a 6pF load capacitance crystal. It features a fast-mode I2C interface operating at 400kHz with bus timeout protection. The RTC provides calendar data through 2099, two alarms, interrupt outputs, and external clock synchronization capabilities.

Real Time Clock Feature Summary

• Low timekeeping current of 250nA (typical) extending battery life
• Compatible with high-ESR crystals up to 100kΩ and 6pF load capacitance
• Fast-mode I2C interface at 400kHz with serial bus timeout mechanism
• Calendar counts seconds through year with leap-year compensation valid through 2099

Real Time Clock Applications

• Medical devices
• Point of Sale (POS) systems
• Telematics equipment
• Portable instruments
• Portable audio devices

Real Time Clock Procurement Notes

Verify the specific ordering suffix for packaging requirements. The base part number DS1341U+ indicates surface-mount packaging in an 8-pin µSOP. Confirm RoHS compliance status and lead-free specifications against the latest manufacturer documentation before procurement.

Real Time Clock Selection Notes

Select the DS1341U+ when a 6pF load capacitance crystal is required. Ensure the application environment stays within the -40°C to +85°C temperature range. Verify that the system voltage remains above 1.8V for full functionality or above 1.15V for timekeeping maintenance only.

Real Time Clock Part Context

This component belongs to the DS1341/DS1342 family of low-current I2C real-time clocks. The 'U+' suffix denotes the 8-pin µSOP package variant. The DS1342 counterpart uses a 12.5pF crystal load capacitance. Both variants share identical electrical characteristics and pinouts except for the internal oscillator loading configuration.

Real Time Clock Replacement Considerations

The DS1342U+ is a functional substitute if the design accommodates a 12.5pF crystal instead of 6pF. Other Maxim Integrated RTCs may require register mapping adjustments and different power supply configurations.

Real Time Clock FAQ

What is the maximum crystal ESR supported by the DS1341U+?

The DS1341U+ supports crystals with a series resistance (ESR) up to 100kΩ.

How does the device handle external clock synchronization?

It accepts an external clock reference via the CLKIN pin. If the external signal is present and within ±0.8% tolerance, the RTC locks to it; otherwise, it reverts to the internal crystal oscillator.

What is the minimum voltage for maintaining time?

The device maintains time down to a typical voltage of +1.15V.