DS1339U-33

Real Time Clock Overview

The DS1339U-33 is a low-power, I2C serial real-time clock (RTC) manufactured by Analog Devices Inc./Maxim Integrated. It provides seconds, minutes, hours, day, date, month, and year information with automatic leap-year compensation up to the year 2200. The device operates within a supply voltage range of 2.97V to 5.5V and features an automatic power-fail detect and switch circuitry that maintains timekeeping via a backup supply. Key specifications include a maximum current consumption of 200µA at 5.5V, operation in either 12-hour or 24-hour formats, and two programmable time-of-day alarms. It is housed in an 8-pin uSOP package.

Real Time Clock Feature Summary

• I2C Serial Interface: Address and data are transferred serially through a standard I2C bus.
• Automatic Power-Fail Detection: Built-in circuit detects power failures and switches to backup supply automatically.
• Programmable Alarms: Includes two user-programmable time-of-day alarms.
• Leap-Year Compensation: Automatically adjusts for months with fewer than 31 days and leap years.

Real Time Clock Applications

• GPS devices
• Point-of-Sale (POS) terminals
• Set-top boxes
• Digital consumer electronics

Real Time Clock Procurement Notes

Verify the specific suffix against official datasheets to confirm voltage ranges and packaging types. The 'U' indicates the uSOP package, while the '-33' typically denotes the operating temperature range. Confirm RoHS compliance status and lead times directly with authorized distributors, as availability may vary by region.

Real Time Clock Selection Notes

Select this component when a low-current RTC with I2C interface is required for space-constrained designs. Ensure the system voltage falls within the 2.97V to 5.5V range. Consider the 8-pin uSOP footprint constraints during PCB layout. Verify if the integrated trickle charger capability is needed for battery backup maintenance.

Real Time Clock Part Context

This part belongs to the Maxim DS1339 family of real-time clocks. It serves as a drop-in replacement for earlier versions like the DS1339. The manufacturer is Analog Devices Inc., which acquired Maxim Integrated. The device is categorized under Clock & Timer ICs.

Real Time Clock Replacement Considerations

The DS1339A is documented as a drop-in replacement for the DS1339 series. Verify pin compatibility and electrical parameters before substitution. Other variants in the family may differ in package type or additional features such as NV SRAM.