This document describes the AD7938/AD7939, an 8-channel, 1.5 MSPS, 12-bit and 10-bit parallel ADC. It features configurable analog input channels, accurate on-chip 2.5V reference, and a high-speed parallel interface.
The AD7938 (12‑bit) and AD7939 (10‑bit) are high‑speed, low‑power, successive‑approximation ADCs with eight analog input channels and a built‑in sequencer. They operate from a single 2.7 V to 5.25 V supply, offer up to 1.5 MSPS throughput, and include an accurate on‑chip 2.5 V reference.
The handbook contains a functional block diagram, detailed specifications, timing parameters, absolute maximum ratings, pin‑out tables, power‑mode options, PCB design guidelines, and an ordering guide for the 32‑lead LFCSP and TQFP packages.
| Throughput rate | 1.5 MSPS |
|---|---|
| Power consumption (3 V supply) | 6 mW max at 1.5 MSPS |
| Power consumption (5 V supply) | 13.5 mW max at 1.5 MSPS |
| Analog input channels | 8 channels with sequencer |
| On‑chip reference voltage | 2.5 V |
| SINAD | 70 dB at 50 kHz input |
| Resolution (AD7938) | 12 bits |
| Resolution (AD7939) | 10 bits |
The devices can sample at up to 1.5 MSPS.
It consumes up to 6 mW at 1.5 MSPS when powered from 3 V.
The ADCs include an accurate 2.5 V on‑chip reference.
The devices achieve 70 dB SINAD at a 50 kHz input frequency.