DS1344D-18+T&R

Real Time Clock Overview

The DS1344D-18+T&R is a low-current real-time clock (RTC) from Analog Devices/Maxim Integrated, designed for precise timekeeping with minimal power consumption. It features an integrated oscillator supporting crystals with up to 100kΩ ESR and includes capacitive loading for 12.5pF crystals. The device provides BCD clock/calendar data, two programmable alarms, and 96 bytes of battery-backed NV RAM. It operates via SPI or 3-wire interfaces and maintains time down to 1.15V. Key electrical parameters include a VCC range of 1.71V to 5.5V, typical standby current of 250nA, and operation in the -40°C to +85°C industrial temperature range.

Real Time Clock Feature Summary

• Ultra-low timekeeping current of 250nA (typical) extends backup battery life.
• Supports high-ESR crystals up to 100kΩ and integrates 12.5pF load capacitance.
• Includes 96-byte battery-backed non-volatile RAM for data storage.
• Features two programmable time-of-day alarms with interrupt outputs.

Real Time Clock Applications

• Medical devices requiring accurate timestamping
• Handheld portable electronics
• Telematics systems
• Embedded timestamping applications

Real Time Clock Procurement Notes

Verify that the ordering suffix 'D' confirms the TDFN package and '+T&R' indicates tape-and-reel packaging. Confirm the '-18' suffix specifies the 1.8V operating voltage variant. Ensure the component meets RoHS compliance standards as indicated by the '+' suffix. Cross-reference the manufacturer part number with official Analog Devices documentation to validate specifications.

Real Time Clock Selection Notes

Select this model if the application requires support for crystals with high equivalent series resistance (up to 100kΩ). Choose the DS1344 over DS1343 when the system utilizes 12.5pF load capacitors rather than 6pF. Ensure the design accommodates the 1.8V nominal supply voltage range (1.71V to 5.5V) and requires the specific TDFN form factor.

Real Time Clock Part Context

This component belongs to the DS1343/DS1344 family of low-current RTCs. The DS1344 variant is distinguished by its internal 12.5pF capacitive loading, whereas the DS1343 supports 6pF loads. Both share identical functionality regarding alarms, RAM, and interfaces, differing primarily in crystal compatibility.

Real Time Clock Replacement Considerations

Publicly confirmed substitutes include DS1343, DS1344, MAX31341C, MAX31343, and MAX31341B. Verify pinout and register compatibility before substitution, particularly regarding the crystal load capacitance differences between DS1343 and DS1344 variants.