GENERAL DESCRIPTION

The AD7740 is a low-cost, ultrasmall synchronous Voltage-toFrequency Converter (VFC). It works from a single 3.0 V to 3.6 V or 4.75 V to 5.25 V supply consuming 0.9 mA. The AD7740 is available in an 8-lead SOT-23 and also in an 8-lead MSOP package. Small package, low cost and ease of use were major design goals for this product. The part contains an on-chip 2.5 V bandgap reference but the user may overdrive this using an external reference. This external reference range includes VDD.

FEATURES

Synchronous Operation

Full-Scale Frequency Set by External System Clock

8-Lead SOT-23 and 8-Lead MSOP Packages

3 V or 5 V Operation

Low Power: 3 mW (Typ)

Nominal Input Range: 0 to VREF

True –150 mV Capability Without Charge Pump

VREF Range: 2.5 V to VDD

Internal 2.5 V Reference

1 MHz Max Input Frequency

Selectable High Impedance Buffered Input

Minimal External Components Required

APPLICATIONS

Isolation of High Common-Mode Voltages

Low-Cost Analog-to-Digital Conversion

Battery Monitoring

Automotive Sensing