LTC2640ACTS8-HZ12#TRPBF

Overview

The LTC2640ACTS8-HZ12#TRPBF is a single-channel, 12-bit voltage-output digital-to-analog converter (DAC) from Analog Devices. It features an integrated precision reference providing a full-scale output of 4.096V and operates within a supply voltage range of 4.5V to 5.5V. The device incorporates a rail-to-rail output buffer guaranteed monotonic over temperature. It utilizes a 3-wire SPI/MICROWIRE compatible serial interface with clock rates up to 50MHz. Key specifications include a maximum integral nonlinearity (INL) error of ±1 LSB for the A-grade variant, a settling time of 4.6µs at 5V, and power-on reset functionality that clears the output to zero-scale upon initialization.

Feature Summary

• Integrated 10ppm/°C precision reference yielding a 4.096V full-scale output
• A-grade accuracy with maximum INL error of ±1 LSB
• Power-on reset circuit configured to clear DAC output to zero-scale
• Asynchronous CLR pin (Pin 8) for immediate hardware reset

Applications

• Process control and industrial automation systems
• Automatic test equipment requiring precise voltage generation
• Portable battery-powered instrumentation
• Optical networking signal conditioning

Procurement Notes

Verify the specific ordering suffix #TRMPBF against the datasheet documentation which defines it as a 500-piece tape and reel configuration. Confirm that the H-grade designation aligns with the required 4.5V to 5.5V supply voltage constraints and the –40°C to 125°C operating temperature range for the target application environment.

Selection Notes

Select this component when a 12-bit resolution with high accuracy (±1 LSB INL) is required in a compact 8-lead TSOT-23 package. Ensure the system supply voltage remains between 4.5V and 5.5V to support the internal 4.096V reference. Choose this part over the L-grade variants if the application demands a higher full-scale output voltage or extended automotive temperature performance.

Part Context

This part belongs to the LTC2640 family of single-channel DACs available in 8-, 10-, and 12-bit resolutions. The 'H' suffix denotes the automotive temperature grade (–40°C to 125V), while 'Z' indicates the zero-scale power-on reset option. The 'A' grade specifies the tighter linearity performance compared to standard grades. It shares the same pinout and interface protocol with other members of the series, facilitating design scalability.

Replacement Considerations

Direct replacements within the same package and specification profile include the LTC2640ACS8-HZ12#TRMPBF (tube packaging) or the LTC2640ITS8-HZ12#TRMPBF (industrial temperature grade). Verify that any substitute maintains the 4.5V minimum supply requirement and the zero-scale reset behavior if critical to the system startup sequence.

FAQ

What is the function of Pin 8 on the LTC2640ACTS8-HZ12?

Pin 8 serves as the Asynchronous Clear (CLR) input. Applying a logic low to this pin immediately clears all internal registers and forces the DAC output voltage to zero-scale.

How does the power-on reset behavior affect the initial output state?

The 'Z' suffix indicates that the device is configured to reset the DAC output to zero-scale upon power-up. This ensures a known, safe initial state for downstream circuits during system initialization.

What is the maximum clock frequency for the serial interface?

The serial interface supports clock frequencies (SCK) up to 50MHz with a 50% duty cycle, allowing for rapid data transfer to the 24-bit shift register.