AD7711A is a 24-bit analog front-end from AD company. It uses sigma-delta conversion technique, and can be applied to low frequency measurement applications. The device can directly accept the signal from the transducer and convert it into a serial digital signal.
The AD7711A is a complete analog front‑end for low‑frequency measurement applications. It provides a 24‑bit sigma‑delta conversion with programmable gain (1‑128), differential inputs, and an on‑chip 400 µA RTD excitation current. The device can operate from a single 5‑10 V supply or dual supplies and includes a low‑power mode (7 mW typical).
The datasheet details electrical specifications, pin configurations, timing characteristics, and calibration options. It also lists absolute maximum ratings, recommended operating conditions, and ESD sensitivity warnings for designers integrating the part into microcontroller‑based systems.
| Resolution | 24 bits |
|---|---|
| Supply Voltage (AVpp) | 5 V to 10 V |
| Typical Power Consumption (Normal Mode) | 25 mW |
| Gain Range | 1 to 128 |
| Input Noise (RMS) | <250 nV |
The input voltage range depends on the selected gain; for unipolar mode it is 0 to +VGG‑1 V, and for bipolar mode it is ±VGG‑1 V.
The AD7711A operates from a positive supply (AVpp) of 5 V to 10 V and a negative supply (Vss) that can be tied to AGND for single‑supply operation.