The AD7740KRMZ is a Low Power Synchronous Voltage to Frequency Converter that works from a single 3 to 5.25V supply consuming 0.9mA. The part contains an on-chip 2.5V bandgap reference but the user may overdrive this using an external reference. This external reference range includes VDD. The full-scale output frequency is synchronous with the clock signal on the CLKIN pin. This clock can be generated with the addition of an external crystal (or resonator) or supplied from a CMOS-compatible clock source. The part has a maximum input frequency of 1MHz. For an analogue input signal that goes from 0V to VREF, the output frequency goes from 10% to 90% of fCLKIN. There is also an unbuffered mode of operation that allows VIN to go from -0.15 to VDD +0.15V. The modes are interchangeable using the BUF pin.