The AD7861 is a multichannel simultaneous sampling A/D Converter (ADC) configured for the acquisition of voltage inputs in a motor control solution or three-phase power system. The AD7861 combined with Analog Devices’ 16-bit fixed-point digital signal processor (DSP) provides a low cost 16-bit fixed-point microcontroller solution. The input stage has been designed to accommodate the types of voltage inputs that are found in these applications.
The AD7861 is a multichannel simultaneous‑sampling analog‑to‑digital converter designed for motor‑control and three‑phase power applications. It provides four analog inputs (VIN1, VIN2, VIN3, and AUX0‑AUX3) that can be sampled at the same time, preserving phase information, and offers flexible channel sequencing.
Key features include an 11‑bit resolution, internal 2.5 V reference, 5 V single‑supply operation, conversion times as low as 3.2 µs per channel, and a 6.25–12.5 MHz operating clock range. The device interfaces via a 12‑bit parallel bus compatible with Analog Devices DSPs and includes extensive register‑based I/O for easy integration.
| Resolution | 11 Bits |
|---|---|
| Internal Reference Voltage | 2.5 V ±5% |
| Supply Voltage | +5 V ±5% |
| Operating Clock Range | 6.25–12.5 MHz |
| Power Consumption (IDD) | 10 mA max |
| Signal‑to‑Noise Ratio | 60 dB min |
| Total Harmonic Distortion | –60 dB max |
The AD7861 operates from a single 5 V supply (VDD) with a tolerance of ±5 %.