MAX31342EWA+T

Real Time Clock Overview

The MAX31342EWA+T is a low-current real-time clock (RTC) from Analog Devices/Maxim Integrated, housed in an 8-bump WLP package measuring 1mm x 2mm. It operates within a supply voltage range of +1.6V to +3.6V and supports temperatures from -40°C to +85°C. The device provides timekeeping with a typical current consumption of 150nA at 3.0V. It features an I2C serial interface, two programmable alarms, interrupt outputs, and a countdown timer. The RTC includes automatic date adjustments for leap years through 2199 and supports external clock synchronization via the CLKIN pin.

Real Time Clock Feature Summary

• Ultra-low power consumption with 150nA typical timekeeping current at 3.0V
• Integrated load capacitors for 6pF crystals, supporting ESR up to 100kΩ
• I2C interface with bus timeout mechanism to prevent lockup
• Programmable square-wave output and two time-of-day alarms

Real Time Clock Applications

• Medical devices
• Wearable electronics
• Point-of-Sale (POS) systems
• Telematics units
• Portable instruments

Real Time Clock Procurement Notes

Verify the component is the lead-free/RoHS-compliant version indicated by the '+' suffix. Confirm the package is the 8-bump WLP with 0.5mm pitch. Ensure the operating environment stays within the specified -40°C to +85°C temperature range and voltage limits of 1.6V to 3.6V.

Real Time Clock Selection Notes

Select this part when board space is limited due to its 1mm x 2mm footprint. It is suitable for designs requiring long battery life given the low standby current. Use if external crystal compatibility with high ESR or specific load capacitance is required without additional components.

Real Time Clock Part Context

This device is part of the Maxim Integrated RTC family, designed for applications needing precise timekeeping with minimal power draw. It complements other Maxim RTCs by offering a balance of low cost, small size, and robust features like data retention mode and external clock sync.

Real Time Clock Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation. Consult Analog Devices/Maxim Integrated for direct replacements or cross-reference guides.

Real Time Clock FAQ

How does the MAX31342 handle external clock synchronization?

When the enable external clock input bit (ECLK) is set to 1, the device locks to an external reference clock (e.g., 32kHz, 50Hz/60Hz, GPS 1PPS) applied to the CLKIN pin, with accuracy determined by that source.

What is the purpose of the data retention mode?

Data retention mode shuts down internal functional blocks including the oscillator while retaining register contents, consuming only 6nA typically. This allows the device to preserve time/date values during main power loss.

Can the MAX31342 operate without an external crystal?

No, the MAX31342 requires an external 32.768kHz crystal. However, it integrates the necessary load capacitors for a 6pF crystal, eliminating the need for external capacitors.