AD7740YRM

Overview

The AD7740YRM is a single-channel, synchronous Voltage-to-Frequency Converter (VFC) manufactured by Analog Devices Inc. It operates from a single supply of 3.0 V to 3.6 V or 4.75 V to 5.25 V, consuming typically 0.9 mA. The device features an internal 2.5 V bandgap reference and supports a maximum input frequency of 1 MHz. Integral Nonlinearity is specified at ±0.012% of span in unbuffered mode with a 1 MHz clock. The part is housed in an 8-lead MSOP package and is guaranteed for operation over the automotive temperature range of –40 °C to +105 °C.

Feature Summary

• Synchronous operation where full-scale output frequency is set by an external system clock signal on the CLKIN pin.
• Selectable high impedance buffered input mode via the BUF pin to minimize source loading effects.
• True bipolar input capability allowing analog signals down to –150 mV without requiring a charge pump.
• Minimal external component requirement as no resistors or capacitors are needed to set the output frequency.

Applications

• Isolation of high common-mode voltages using opto-isolators
• Low-cost analog-to-digital conversion systems
• Battery monitoring circuits
• Automotive sensing applications

Procurement Notes

Verify the specific ordering suffix to confirm the package type and RoHS compliance status. Confirm that the Y grade designation matches the required automotive temperature range specifications. Ensure the selected variant aligns with the intended power supply voltage and clock configuration requirements.

Selection Notes

Select this component when space-saving and low cost are primary design drivers. Choose the buffered mode for high source impedances and the unbuffered mode for true bipolar input ranges. Consider the external clock stability as it directly determines the transfer function accuracy and system drift characteristics.

Part Context

This device belongs to the AD7740 family of low-power synchronous voltage-to-frequency converters. It utilizes CMOS technology and charge-balance conversion techniques. The family includes variants such as the K grade for commercial temperatures and different package options like SOT-23 and MSOP.

Replacement Considerations

Public confirmed substitute part numbers: AD7740KRM, AD7740YRTZ-REEL7.