AD537KD/+

Overview

The AD537KD is a monolithic voltage-to-frequency converter manufactured by Analog Devices Inc. It integrates a high-impedance input amplifier, a precision oscillator system, an accurate internal reference generator, and a high-current output stage. The device operates on a single power supply ranging from 4.5 V to 36 V with a typical static current of 1.2 mA. It supports a maximum full-scale frequency of 100 kHz and accepts full-scale input voltages up to ±30 V. The component achieves a linearity error of ±0.05% at a 10 kHz full-scale frequency, ensuring a dynamic range exceeding 80 dB. It features a temperature coefficient of ±30 ppm/°C and provides a square wave output capable of driving multiple TTL loads.

Feature Summary

• Integrates a complete voltage-to-frequency conversion system requiring only external RC components for frequency setting
• Provides high linearity performance with low non-linearity error across the specified operating range
• Features a high-impedance input amplifier suitable for direct connection to small signal sources such as thermocouples
• Delivers a square wave output with sufficient drive capability to interface directly with digital logic circuits

Applications

• Precision analog-to-digital conversion systems utilizing voltage-to-frequency techniques
• Lock-phase loop circuits configured for frequency-to-voltage conversion
• Temperature sensing applications leveraging the proportional temperature output characteristic
• Industrial process control instrumentation requiring isolated signal transmission

Procurement Notes

Verify the specific suffix designation against official manufacturer documentation to confirm exact performance grades and temperature ranges. Confirm package type compatibility with intended PCB layout requirements. Ensure supply chain sources provide valid traceability records for military-grade specifications if applicable. Check current product status as distribution availability may vary due to lifecycle management policies.

Selection Notes

Select this component when high linearity and wide dynamic range are required for voltage-to-frequency conversion tasks. Consider the single-supply operation and low power consumption for battery-constrained or efficiency-sensitive designs. Evaluate the integrated reference and oscillator stability for applications demanding minimal external component count. Verify that the available temperature grades meet the environmental operating conditions of the target system.

Part Context

The AD537 series represents a family of high-performance voltage-to-frequency converters designed for precision measurement applications. The KD variant specifically denotes a military-grade version housed in a hermetically sealed ceramic dual in-line package. This packaging ensures reliability under harsh environmental conditions and strict thermal cycling requirements defined by military standards.

Replacement Considerations

Consult official manufacturer substitution guides for verified equivalent part numbers. Cross-reference pin configurations and electrical parameters before implementing any alternative components.