AD650SD

Overview

The AD650SD is a monolithic voltage-to-frequency and frequency-to-voltage converter from Analog Devices, specified for the extended industrial temperature range of −55°C to +125°C. It operates with dual supplies ranging from ±9 V to ±18 V and supports full-scale frequencies up to 1 MHz. The device features very low nonlinearity, typically 0.002% at 10 kHz and guaranteed less than 0.1% at 1 MHz. It includes an input offset trimmable to zero and provides CMOS- or TTL-compatible output via an open-collector interface.

Feature Summary

• Provides high-resolution analog-to-digital conversion through inherent monotonicity in its voltage-to-frequency transfer function.
• Supports flexible input configurations including unipolar, bipolar, and differential voltage inputs, as well as unipolar current inputs.
• Features separate analog and digital ground pins to prevent ground loops and isolate precision analog signals from digital switching noise.

Applications

• Isolated analog signal transmission systems
• Precision stepper motor speed controllers
• Phase-locked loop circuits
• Precision tachometer applications
• FM demodulator circuits

Procurement Notes

Verify the specific suffix SD confirms the −55°C to +125°C temperature rating and ceramic package type. Confirm supply voltage requirements match the ±9 V to ±18 V operational range. Ensure external component selection aligns with the 1 MHz maximum frequency specifications for optimal linearity performance.

Selection Notes

Select this component when extended temperature operation is required alongside high-speed conversion capabilities. Consider the open-collector output for direct interfacing with various logic families without additional buffering. Evaluate the need for separate analog and digital grounding strategies to maintain high dynamic range in noisy environments.

Part Context

The AD650 series offers both plastic and ceramic packaging options across different temperature grades. The SD variant specifically targets harsh environments requiring wide thermal stability. It complements other data converters by providing a robust solution for applications demanding high linearity and fast response times over broad operating conditions.

Replacement Considerations

No public confirmed substitute part numbers are available in the provided documentation.