PCA21125T/Q900/1,1

Real Time Clock Overview

The PCA21125T/Q900/1,1 is an AEC-Q100 compliant CMOS Real-Time Clock (RTC) and calendar designed for automotive applications. It operates with a supply voltage range of 1.3 V to 5.5 V and supports an operating temperature up to 125 °C. The device features a 4-line SPI-bus interface with a maximum data rate of 6.0 Mbit/s. Key electrical parameters include a typical supply current of 0.8 µA at 25 °C. It provides timekeeping based on a 32.768 kHz quartz crystal with integrated oscillator capacitors.

Real Time Clock Feature Summary

• AEC-Q100 qualified for automotive reliability
• SPI-bus interface supporting up to 6.0 Mbit/s
• Low power consumption: typical 0.8 µA at 25 °C
• Integrated oscillator capacitor and internal Power-On Reset (POR)

Real Time Clock Applications

• Automotive time keeping
• Metering

Real Time Clock Procurement Notes

Verify the specific ordering suffix /1,1 indicates tape and reel packaging in a 13-inch format. Confirm that the Q900 designation aligns with the required automotive qualification standards for the target application environment before finalizing procurement.

Real Time Clock Selection Notes

Select this component when an SPI interface is preferred over I²C for RTC functionality in automotive systems. Ensure the system voltage falls within the 1.3 V to 5.5 V range and that the operating temperature requirements do not exceed 125 °C. The integrated capacitor simplifies board layout compared to external crystal solutions.

Real Time Clock Part Context

This part belongs to the PCA21125 family from NXP Semiconductors. It is specifically the automotive-grade variant (Q900) packaged in TSSOP14 (SOT402-1). The '/1,1' suffix denotes the delivery form as tape and reel, distinguishing it from tube-packaged versions like the PCA21125TS.

Real Time Clock Replacement Considerations

Direct replacements must maintain AEC-Q100 compliance and SPI interface compatibility. Verify pinout compatibility with the TSSOP14 package if substituting with other NXP RTCs such as the PCA2125 or PCF8563, noting that bus interfaces may differ.