The document describes the features and characteristics of Analog Devices' AD7741/AD7742 single-channel and multi-channel synchronous voltage-to-frequency converters. The product is available in versions with a single-ended input channel (AD7741) and differential or pseudo-differential input channels (AD7742). It has an integral nonlinearity of 0.012%, achieving a maximum frequency output of 2.75 MHz (AD7742) and 1.35 MHz (AD7741). The product is suitable for low-cost analog-to-digital conversion and signal isolation applications.
The AD7741 and AD7742 are synchronous voltage‑to‑frequency converters (VFCs) from Analog Devices. The AD7741 provides a single‑ended input in an 8‑lead package, while the AD7742 offers two differential or three pseudo‑differential inputs in a 16‑lead package. Both devices operate from a single +5 V supply, include an on‑chip 2.5 V reference, and feature power‑down capability.
The datasheet details functional block diagrams, pin functions, timing characteristics, absolute maximum ratings, and ordering information. It also defines the input ranges, output frequency limits, and performance parameters such as integral nonlinearity and power‑supply rejection.
| Supply voltage range (VDD) | +4.75 V to +5.25 V |
|---|---|
| Normal‑mode supply current (ID D) | 8 mA |
| Power‑down supply current (ID D) | 15 mA (AD7741) / 35 mA (AD7742) |
| Input voltage range | 0 V to VREF (+2.5 V) for AD7741; –VREF to +VREF for AD7742 |
| Maximum output frequency | 0.45 × fCLKIN |
| Operating temperature range (Industrial) | –40 °C to +85 °C |
| Operating temperature range (Automotive) | –40 °C to +105 °C |
Both devices operate from a supply voltage of +4.75 V to +5.25 V.
The AD7742 has four buffered inputs that can be configured as two fully‑differential channels or three pseudo‑differential channels.
In power‑down mode the AD7741 draws about 15 mA and the AD7742 about 35 mA.
The industrial (B) version is rated from –40 °C to +85 °C.