MAX6909EO30+

Real Time Clock Overview

The MAX6909EO30+ is an I2C-compatible real-time clock (RTC) with a microprocessor supervisor and NV RAM controller. It provides timekeeping for seconds, minutes, hours, date, month, day of week, and year, including leap year compensation up to 2100. The device features 31 bytes of static RAM for scratchpad storage and operates on a single 2-wire serial bus. Electrical characteristics specify an operating voltage range of 2.7V to 3.6V for the EO30 suffix. It includes a watchdog timer, manual reset input, power-fail comparator, and piezo transducer output. The component is housed in a 20-pin QSOP package and functions within a temperature range of -40°C to +85°C.

Real Time Clock Feature Summary

• I2C-compatible RTC with calendar and 31-byte NV RAM
• Microprocessor supervisor with open-drain and push-pull reset outputs
• Watchdog timer and manual reset input with debounce
• Power-fail comparator and crystal fail detection

Real Time Clock Applications

• Point-of-sale equipment
• Programmable logic controllers
• Handheld instruments
• Medical instrumentation

Real Time Clock Procurement Notes

Verify the specific EO30 ordering suffix to confirm the 2.7V minimum operating voltage threshold. Confirm package integrity for the 20-pin QSOP format. Check current availability status as this component may be subject to obsolescence or limited supply conditions.

Real Time Clock Selection Notes

Select the MAX6909EO30+ when a 2.7V minimum supply voltage is required, distinguishing it from the EO33 variant which requires 3.0V. Ensure the application utilizes a standard 32.768kHz crystal with a 6pF load capacitance. Verify that the 20-pin QSOP footprint matches the PCB layout constraints.

Real Time Clock Part Context

This part belongs to the MAX6909/MAX6910 family of I2C-compatible real-time clocks. The MAX6909 variant lacks the trickle charger found in the MAX6910. The EO30 suffix specifically denotes the lower voltage operating range compared to the EO33 suffix. Both share identical pinouts and functional registers.

Real Time Clock Replacement Considerations

The MAX6909EO33+ serves as a direct pin-compatible alternative if the system voltage does not drop below 3.0V. Other MAX6909 variants in the QSOP-20 package should be evaluated for voltage threshold compatibility.