Which ADC IC Should I Pick? (Small-Batch Selection Guide)

Nominal bits rarely equal effective bits. Start from the smallest change you must resolve, convert it to %FS, and map to an ENOB target. Pick one to two bits of headroom and ensure reference noise stays well below ½ LSB(rms), otherwise resolution is wasted. Calibrate only after the front-end is quiet.

Don’t confuse the ADC’s fs with signal bandwidth. Budget a Nyquist guard (typically 20–30%) and set the anti-alias filter so out-of-band energy doesn’t fold back. Slow sensors still alias when switching noise leaks in. Decide by usable bandwidth, not a marketing max-rate.

Single-ended is simple; differential buys common-mode rejection and dynamic range. Choose full-scale range so codes are used efficiently. mV-level inputs usually need gain and a low-impedance driver; high source impedance calls for buffering. Match FSR and Vref to the real signal.

Quick check: throughput ≈ fs × bits × channels / efficiency. SPI is easy but hits limits early; LVDS adds lanes and immunity; JESD204 scales cleanly at very high rates with stricter clocking. Confirm framing overhead and firmware/FPGA resources before locking in.

Control loops, protection trips, and synchronized arrays care about group delay. SAR is low-latency; delta-sigma adds filtering delay; pipeline/flash can add cycles. Decide by loop stability and channel-alignment needs, then shortlist devices within that architecture class.

SNR reflects random noise; THD and SFDR expose harmonic distortion and spurs. Read datasheet FFT footnotes (input level, bandwidth, averaging) to avoid apples-to-oranges. If spectral purity matters, prioritize SFDR; for precision DC, focus on low noise density and ENOB.

Power scales with speed and channels. Rails set driver choices, input-range handling, and sequencing; leave thermal margin for hot environments. For battery or tight thermal budgets, compare energy-per-sample, not just “typical power” lines.

QFN is assembly-friendly and compact; BGA helps pin-count and signal integrity but complicates rework. Confirm stencil, paste, and reflow constraints, and choose the right temperature grade (Industrial or AEC-Q). Prefer families with footprint-compatible options.

Screen NRND/EOL and lifecycle stability early, and line up second-source candidates. Ask for indicative lead-time windows and MOQ/Cut-Tape options. Favor pin-compatible families and plan a swap test (timing, noise, codes) before committing a layout.

Aperture/clock jitter converts to SNR loss proportional to input frequency—harmless at low kHz, severe at MHz. Set a jitter budget from required SNR, isolate clocks from noisy loads, and keep references clean and well-decoupled.

Low-bandwidth sensing benefits from higher effective resolution and a quiet reference. Keep full-scale range close to the signal and budget an anti-alias RC even at low rates.

General DAQ and power/current monitoring favor SAR for low latency and easy bring-up. Size the driver and anti-alias filter so the source sees a stable load at the sampling instant.

High-throughput work needs Pipeline/Flash and a link that carries the data while keeping channels synchronized. Clock quality and lane timing dominate final performance.

Audio chains typically use audio-grade delta-sigma with I²S/TDM framing and well-managed references and clocks. This page doesn’t expand details—see the types overview.

Use isolated front-ends and differential inputs with isolated power and careful return paths. Validate CMTI and creepage/clearance early to avoid late-stage redesigns.

Architecture sets speed, latency, and noise behavior. Pick a direction before shortlisting parts.

Nameplate bits aren’t equal to effective bits. Relate ENOB and SNR to your accuracy target.

Stop out-of-band energy from folding into baseband. Even low-speed sensors need the right filter.

Make sure your link can move the data: throughput ≈ fs × bits × channels / efficiency.

When the internal converter isn’t enough—consider noise, bandwidth, latency, and isolation.

Understand what specs mean in practice and how to catch problems during bring-up.