DS1340Z-33+T&R

Real Time Clock Overview

The DS1340Z-33+T&R is a low-power real-time clock (RTC) and calendar integrated circuit manufactured by Analog Devices Inc./Maxim Integrated. It operates within a supply voltage range of 2.97V to 5.5V, with a backup supply range of 1.3V to 5.5V. The device maintains timekeeping functions using an external 32.768kHz crystal and features automatic power-fail detection to switch between primary and backup supplies. Key electrical parameters include a maximum standby current of 150µA at 5.5V and a typical backup current of 1150nA. It utilizes a fast-mode I²C interface operating up to 400kHz and is housed in an 8-SOIC package.

Real Time Clock Feature Summary

• Integrated trickle charger for battery or supercapacitor charging via VBACKUP pin
• Software-based clock calibration capability with ±10.7 seconds/month adjustment range
• Oscillator Stop Flag (OSF) to detect oscillator failure or stop conditions
• Automatic power-fail detection and seamless switching to backup supply

Real Time Clock Applications

• Portable instruments requiring precise timekeeping
• Point-of-sale equipment systems
• Medical equipment with data retention needs
• Telecommunications infrastructure components

Real Time Clock Procurement Notes

Verify the specific suffix Z-33 corresponds to the 3.3V nominal voltage variant and SOIC package when sourcing. Confirm RoHS compliance status as indicated by the '+' designation in the part number. Ensure the ordering information matches the required temperature range of -40°C to +85°C for industrial applications.

Real Time Clock Selection Notes

Select this component when a low-profile 8-pin surface-mount RTC with integrated charging capabilities is required. The 3.3V variant is suitable for systems powered by standard 3.3V logic buses. Consider the software calibration feature if high accuracy is needed without expensive crystals. Ensure the application can accommodate an external 32.768kHz crystal on pins X1 and X2.

Real Time Clock Part Context

This part belongs to the DS1340 family of serial real-time clocks. It is functionally equivalent to the ST M41T00 but includes additional features like the trickle charger and oscillator stop flag. The 'Z' indicates the SOIC package, while '33' denotes the 3.3V operating voltage range. It serves as a drop-in replacement for legacy RTCs in space-constrained designs.

Real Time Clock Replacement Considerations

The DS1340 is explicitly noted as an enhanced second source for the ST M41T00. Pin compatibility allows for direct substitution in existing designs. Verify that the target system supports the I²C protocol and has sufficient voltage headroom for the backup supply switching thresholds.