DS1344D-18+

Real Time Clock Overview

The DS1344D-18+ is a low-current real-time clock (RTC) from Analog Devices/Maxim Integrated. 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 interfaces and includes two programmable alarms with interrupt outputs. It features 96 bytes of battery-backed NV RAM. Electrical specifications include an operating voltage range of 1.71V to 5.5V for VCC and 1.3V to 5.5V for VBAT. Typical standby current is 250nA. The device operates in the -40°C to +85°C temperature range and is available in a 14-pin TDFN package.

Real Time Clock Feature Summary

• Low Timekeeping Current: 250nA typical
• High ESR Crystal Support: Compatible with crystals up to 100kΩ ESR
• Integrated Capacitive Loading: Designed for 12.5pF load capacitance crystals
• Dual Alarms and Interrupts: Two time-of-day alarms with configurable interrupt outputs

Real Time Clock Applications

• Medical devices
• Handheld devices
• Telematics systems
• Embedded timestamping

Real Time Clock Procurement Notes

Verify the specific suffix 'D-18+' corresponds to the 1.8V nominal voltage variant and 14-pin TDFN package as per the official datasheet. Confirm RoHS compliance status and lead-free material declarations directly from the manufacturer's documentation before procurement.

Real Time Clock Selection Notes

Select the DS1344D-18+ when a 12.5pF crystal load capacitance is required, distinguishing it from the DS1343 series which supports 6pF. Ensure the system power supply allows for the 1.71V minimum operating voltage. Verify that the application requires the specific 14-pin TDFN footprint rather than the 20-pin TSSOP option.

Real Time Clock Part Context

The DS1344D-18+ belongs to the DS1343/DS1344 family of low-current RTCs. The 'D' indicates the 14-pin TDFN package, while '18' specifies the 1.8V nominal operating voltage version. This part is functionally similar to the DS1343 but differs in integrated crystal load capacitance (12.5pF vs 6pF).

Real Time Clock Replacement Considerations

The DS1343D-18+ is a direct functional substitute if the design accommodates a 6pF crystal load instead of 12.5pF. Other variants like DS1344D-3+ differ in operating voltage (3.0V nominal) and must be evaluated for power supply compatibility.