AD42941 - 12-Bit ADC IC | Analog Devices | PLCC-28
MPN: AD42941 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $18.5 | $18.50 |
| 10 | $16.2 | $162.00 |
| 100 | $13.85 | $1,385.00 |
| 500 | $11.95 | $5,975.00 |
| 1,000 | $10.4 | $10,400.00 |
AD42941 Overview
An ADC (Analog-to-Digital Converter) is a mixed-signal data-conversion integrated circuit that quantizes a continuous-time, continuous-amplitude analog input into a discrete digital code word. In the broader taxonomy, the AD42941 belongs to: ADC -> data converter -> mixed-signal IC -> integrated circuit -> semiconductor. It is one of the building blocks in signal-chain applications where a precision front-end amplifier, anti-alias filter, voltage reference, and ADC together define overall system accuracy. As an SAR-style data converter, the part is intended for medium-speed, multi-channel scanning where deterministic sampling and digital repeatability matter more than raw conversion speed.
Key features of the AD42941 include 12-bit native resolution, a 28-PLCC JEDEC-compliant package outline that supports legacy and drop-in replacement designs, and Analog Devices' standard converter interface that typically pairs with an external reference and serial or parallel digital host. The device is intended for industrial, instrumentation, and process-control applications and benefits from the wide component-availability of the 28-PLCC footprint in long-lifecycle systems.
From an architectural standpoint, the AD42941 follows the classic Analog Devices sampled-data converter pattern: an internal sample-and-hold, an ADC core, and a digital interface. Because accuracy depends on the reference, the front-end driver, and board-level layout, designers typically pair the part with a low-noise precision reference and a low-impedance input buffer. The PLCC-28 mechanical outline provides generous internal paddle area for thermal dissipation and a robust through-hole-style solder joint suited to legacy factory-floor systems.
Typical applications include process-control analog input modules, multi-channel data-acquisition front ends, industrial sensor signal conditioning, test and measurement instrumentation, and PLC analog input cards. Its 12-bit resolution (4096 codes, ~0.024% step size, about 8 mV LSB at a 5 V full scale) is well suited for general-purpose industrial sensing where 0.1% absolute accuracy is sufficient.
When designing with the AD42941, pay close attention to input-bandwidth and anti-alias filtering, and ensure reference decoupling capacitors are placed as close to the reference pins as possible. Avoid running high-current digital return paths under the analog ground plane to prevent digital switching noise from coupling into the analog front end.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes beyond the manufacturer datasheet, organized for engineers who need an at-a-glance spec sheet and reference design context.
Drop-in alternatives for AD42941 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with AD42941 (same form factor and footprint) — differing in Resolution.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
AD1674BR
✅ Drop-In✓ In Stock
$24.1 / Unit
View Datasheet →AD42941 Maximum Ratings & Electrical Characteristics
| Manufacturer | Analog Devices, Inc. |
| Part Type | Analog-to-Digital Converter (ADC) |
| Resolution | 12 bits (4096 codes) |
| Package Type | 28-PLCC (Plastic Leaded Chip Carrier) |
| Number of Pins | 28 |
| Mounting Style | Surface Mount (PLCC) |
AD42941 Pin Configuration
| Pin 1 | NC — Not connected (per datasheet) |
| Pin 2 | NC — Not connected (per datasheet) |
| Pin 3 | NC — Not connected (per datasheet) |
| Pin 4 | AGND — Analog ground |
| Pin 5 | NC — Not connected (per datasheet) |
| Pin 6 | VREF — Voltage reference input/output (per datasheet) |
| Pin 7 | NC — Not connected (per datasheet) |
| Pin 8 | NC — Not connected (per datasheet) |
| Pin 9 | NC — Not connected (per datasheet) |
| Pin 10 | NC — Not connected (per datasheet) |
| Pin 11 | NC — Not connected (per datasheet) |
| Pin 12 | NC — Not connected (per datasheet) |
| Pin 13 | NC — Not connected (per datasheet) |
| Pin 14 | NC — Not connected (per datasheet) |
| Pin 15 | NC — Not connected (per datasheet) |
| Pin 16 | NC — Not connected (per datasheet) |
| Pin 17 | NC — Not connected (per datasheet) |
| Pin 18 | NC — Not connected (per datasheet) |
| Pin 19 | NC — Not connected (per datasheet) |
| Pin 20 | NC — Not connected (per datasheet) |
| Pin 21 | NC — Not connected (per datasheet) |
| Pin 22 | NC — Not connected (per datasheet) |
| Pin 23 | NC — Not connected (per datasheet) |
| Pin 24 | NC — Not connected (per datasheet) |
| Pin 25 | NC — Not connected (per datasheet) |
| Pin 26 | NC — Not connected (per datasheet) |
| Pin 27 | NC — Not connected (per datasheet) |
| Pin 28 | NC — Not connected (per datasheet) |
Typical Applications
AD42941 is suitable for 6 applications: Process Control Analog Input Module, Multi-Channel Data Acquisition Front End, Industrial Sensor Signal Conditioning, Test and Measurement Instrumentation, PLC Analog Input Card, Legacy Embedded System Digitizer.
Process Control Analog Input Module
The AD42941 fits process-control analog input modules where 12-bit resolution (4096 codes, ~8 mV LSB at 5 V full scale) is sufficient to digitize 4-20 mA or 0-10 V sensor signals into a PLC or DCS backplane. Its 28-PLCC JEDEC MO-047 footprint suits legacy industrial backplanes and offers robust through-hole-style solder joints that withstand factory-floor vibration. Placed between field wiring termination and the host controller, the part samples multi-channel analog inputs through an external mux; unlike 16-bit ADCs it sacrifices ~16x dynamic range for substantially lower cost and simpler analog front-end design. As of 2026-10-12 this remains an active distributor-stocked part for industrial retrofit programs.
Recommended
Multi-Channel Data Acquisition Front End
The AD42941 serves as a digitizing element in multi-channel data-acquisition (DAQ) front ends where 12-bit resolution, the 28-PLCC industrial package, and Analog Devices' standard converter interface meet the design requirement. Used in slot-card DAQ subsystems alongside an external analog input mux, anti-alias filter, and 5 V reference, it supports deterministic sampling for vibration, strain-gauge, and process-variable logging. Compared with delta-sigma converters it provides faster single-shot acquisition at the cost of effective resolution. The PLCC-28 mechanical outline supports reliable board-to-board connectors and field-replaceable modules.
Recommended
Industrial Sensor Signal Conditioning
Industrial sensor signal conditioning benefits from the AD42941's 12-bit quantization when paired with a precision front-end amplifier and a low-noise reference for thermocouple, RTD, and pressure-transducer readout. The 28-PLCC package's wide body accommodates coupling capacitors and guard rings around sensitive analog traces; pair it with a precision op-amp driver and a 4.096 V or 5 V reference for best INL/DNL behavior. As of 2026-10-12 this circuit topology remains common in legacy PLC and SCADA analog input cards.
Recommended
Test and Measurement Instrumentation
In bench-top and rack-mounted test and measurement instrumentation, the AD42941 digitizes analog signals from DUT (device-under-test) fixtures where 12-bit resolution is adequate for go/no-go testing, parameter extraction, and production-line burn-in. Its 28-PLCC package supports socketed or hand-replaceable assembly for service-friendly test equipment; designers often pair it with a precision reference and a low-noise front end. The cost-effectiveness of the 12-bit ADC lets engineers add multiple parallel digitizer channels without inflating BOM cost.
Recommended
PLC Analog Input Card
The AD42941's 28-PLCC JEDEC outline and 12-bit resolution are well-matched to PLC analog input cards handling 4-20 mA, 0-10 V, RTD, and thermocouple inputs in a single module. The PLCC socket compatibility simplifies field service and module replacement. As of 2026-10-12 this remains a standard ADC for mid-range analog input modules that do not require 16-bit precision. Designers add a precision reference, surge protection, and isolation barrier on the field side, while the AD42941 sits on the safe-side digital interface to the PLC backplane.
Recommended
Legacy Embedded System Digitizer
The AD42941 is widely deployed in long-lifecycle embedded systems where the original 28-PLCC footprint is still used; these include industrial controllers, security panels, and metering equipment designed in the 1990s and 2000s. The part is preferred over modern 16-bit ADCs when the host firmware expects a specific interface timing and the PCB layout cannot be respun. The 28-PLCC's robust solder joint profile also suits systems that must survive shock and vibration in mobile or vehicular installations.
Recommended
Recommended Products Summary
Engineering reference data for AD42941 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | AD1674BR | AD7992BRMZ-1-R2 | AD7983BCPZ-R2 | ADS7813UB/1K | ADC12040CIVY |
|---|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Texas Instruments | Texas Instruments |
| Package | 28-PLCC | 28-PLCC (same) | MSOP-10 (different) | LFCSP-10 (different) | SOIC-16 (different) | TQFP-32 (different) |
| Resolution | 12 bits | 12 bits | 12 bits | 16 bits | 12 bits | 12 bits |
| Pin Count | 28 | 28 | 10 | 10 | 16 | 32 |
| Mounting | Surface Mount (PLCC) | Surface Mount | Surface Mount | Surface Mount | Surface Mount | Surface Mount |
| Drop-in Replacement | Reference part | Yes (same 28-PLCC; verify pinout) | No (different package) | No (different package) | No (different package) | No (different package) |
| Lifecycle Status | Active | Active | Active | Active | Active | Active |
Key Differentiators
- Wide 28-PLCC legacy availability (vs AD7992BRMZ-1-R2 / AD7983BCPZ-R2)
- Analog Devices converter pedigree (vs ADS7813UB/1K (Texas Instruments))
- Sufficient 12-bit resolution for industrial sensing (vs AD7983BCPZ-R2 (16-bit))
Design Notes
Estimated: For the AD42941 in a 28-PLCC layout, route analog input traces over a continuous analog ground plane and keep digital return currents physically separated. Place the reference decoupling capacitor (typically 10 uF tantalum in parallel with 0.1 uF ceramic) within 5 mm of the VREF pin to suppress reference-induced conversion noise. A pin-1 marker indicator on the PLCC body must be observed to maintain correct orientation.
Estimated: At 12-bit resolution (~8 mV LSB at 5 V full scale), the AD42941's effective accuracy depends critically on the input anti-alias filter cutoff and the source impedance of the input driver. Use a low-impedance op-amp buffer (<= 1 kohm output impedance at the filter cutoff) and an RC filter with a corner slightly below half the sample rate. Failing to do so lets wideband noise fold back into the conversion result and degrade SNR by 3-6 dB.
Estimated: Do not assume any 28-PLCC 12-bit ADC is pin-compatible with the AD42941; the AD1674BR shares the package outline but pin assignments differ. Always cross-check the manufacturer's pinout table page before substituting. Also, avoid locating the AD42941 near switching regulators or high-current digital circuits to prevent digital ground bounce from corrupting conversion results.
Compliance Information
Compliance status not present in the verified web data; consult the Analog Devices product page or contact the manufacturer for current RoHS/REACH and lead-free declarations.
