DS1343E-18+

Real Time Clock Overview

The DS1343E-18+ is a low-current real-time clock (RTC) from Analog Devices/Maxim Integrated, housed in a 20-pin TSSOP package. It provides timekeeping with seconds, minutes, hours, day, date, month, and year information, including leap year compensation through 2099. The device supports SPI or 3-wire serial interfaces and includes two programmable alarms with interrupt outputs. It features 96 bytes of battery-backed NV RAM. Operating voltage ranges from 1.71V to 5.5V, with standby current as low as 250nA typical. It maintains time down to 1.15V and operates within an industrial temperature range of -40°C to +85°C.

Real Time Clock Feature Summary

• Extremely low standby current of 250nA typical, extending backup supply life.
• Supports high-ESR crystals up to 100kΩ, broadening crystal selection.
• Includes 96-byte battery-backed nonvolatile RAM for data storage.
• Two programmable time-of-day alarms with flexible interrupt output configurations.

Real Time Clock Applications

• Medical devices requiring precise timestamping.
• Handheld devices with limited power budgets.
• Telematics systems needing reliable timekeeping.
• Embedded systems requiring data logging with calendar functions.

Real Time Clock Procurement Notes

Verify component authenticity due to potential availability issues. Confirm RoHS compliance status via official documentation. Check for end-of-life notices as some distributors list this part as obsolete. Ensure proper handling for ESD-sensitive components during installation.

Real Time Clock Selection Notes

Select the DS1343E-18+ when low power consumption is critical and SPI or 3-wire interface compatibility is required. Choose this model over the DS1344 variant if the application utilizes crystals with a 6pF load capacitance rather than 12.5pF. Ensure the system voltage aligns with the 1.71V to 5.5V operating range.

Real Time Clock Part Context

This component belongs to the DS1343/DS1344 family of low-current RTCs. The 'E' suffix indicates an extended industrial temperature range (-40°C to +85°C). The '18' suffix specifies the 1.8V nominal operating voltage version. The '+' suffix denotes lead-free/RoHS-compliant packaging. It is distinct from the DS1344 which supports different crystal load capacitances.

Real Time Clock Replacement Considerations

The DS1344E-18+ is a pin-compatible alternative but supports 12.5pF crystals instead of 6pF. Verify crystal load capacitance requirements before substitution. Other Maxim RTCs may require interface or register mapping changes.