MAX174ACWI - 12-Bit 125ksps SAR ADC, 28-SOIC | Maxim Integrated
MPN: MAX174ACWI ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $19.5 | $19.50 |
| 10 | $17.55 | $175.50 |
| 100 | $15.6 | $1,560.00 |
| 500 | $13.85 | $6,925.00 |
| 1,000 | $12.25 | $12,250.00 |
MAX174ACWI Overview
A successive-approximation ADC (SAR ADC) is a type of Nyquist-rate data converter that resolves an analog input to N bits by performing a binary search through an internal capacitive DAC, comparing the result against the input on each clock cycle. Within the broader hierarchy, the MAX174 belongs to the precision SAR ADC segment of the data-converter market, which sits under the analog-to-digital converter (ADC) family, itself a sub-category of data acquisition and signal-chain ICs. SAR ADCs deliver a single conversion on demand rather than continuously oversampling, giving them deterministic latency and no pipeline delay, which is why they remain the preferred architecture for multiplexed data acquisition, industrial process control, and precision instrumentation front-ends.
Key features include 12-bit resolution with no missing codes, an integrated 10.000 V buried-Zener reference (the source of the part's '+10V Precision ADC' moniker), a bipolar input range of ±5 V or ±10 V on a single +5 V supply, and three-state digital outputs that interface directly to 8-bit and 16-bit microprocessors. The -AC suffix designates the commercial 0 °C to +70 °C operating-temperature grade, while the -AE part offers the -40 °C to +85 °C extended grade in the same SOIC-28 outline. Power consumption is typically around 100 mW during conversion.
The MAX174 uses a capacitive-charge-redistribution DAC with a thin-film attenuator ladder at the input, which is why it achieves both high speed (8 µs max conversion) and 12-bit linearity without the laser-trimming required by older bipolar SAR architectures. The internal reference and clock remove two common external components, shrinking the BOM and improving long-term gain stability.
Typical applications include process-control front-ends, instrumentation digitizers, PC-based data-acquisition boards, and test-and-measurement equipment. The integrated reference and three-state bus interface also make it well suited to legacy retrofit designs where a discrete-component ADC has been replaced by this single-chip solution. Industrial PLC analog input modules and medical-instrumentation signal paths are common use cases.
When designing with this part, ensure that the input signal source can drive the 4 kΩ analog input impedance without introducing significant gain error, and that bypass capacitors are placed within 1 cm of the supply pins. The wide SOIC-28 footprint provides adequate thermal margin at the typical 100 mW dissipation, but reflow profile should respect the JEDEC J-STD-020 MSL rating for the commercial -AC temperature grade.
This page synthesizes distributor pricing, drop-in same-package alternatives, and practical design notes that are not collected in the manufacturer datasheet alone, helping engineers evaluate the MAX174ACWI quickly for new designs or EOL retrofits.
Drop-in alternatives for MAX174ACWI — 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 MAX174ACWI (same form factor and footprint) — differing in Package, Mounting Type, Input Type, Architecture, RoHS Status.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MAX174AEWI+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX174ACWI+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX174ACWI+T
✅ Drop-In📋 Reference alternative (not in catalog)
MX674AJCWI+
✅ Drop-In📋 Reference alternative (not in catalog)
MX574AJCWI+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX174ACWI Maximum Ratings & Electrical Characteristics
| Resolution | 12 bits |
| Converter Type | SAR (Successive Approximation) |
| Number of Input Channels | 1 |
| Maximum Sampling Rate | 125 ksps |
| Maximum Conversion Time | 8 µs |
| Input Voltage Range (Bipolar) | ±5 V or ±10 V |
| Supply Voltage (Digital) | 5 V |
| Supply Voltage (Analog) | ±12 V or ±15 V |
| Internal Reference | 10.000 V buried-Zener |
| Analog Input Impedance | 4 kΩ minimum |
| Output Interface | Three-state parallel (8/16-bit compatible) |
| Operating Temperature | 0 °C to +70 °C (commercial, -AC suffix) |
| Package | 28-pin SOIC (Wide) |
| Mounting Type | Surface Mount |
| Power Dissipation | 100 mW typical during conversion |
MAX174ACWI Pin Configuration
| Pin 1 | AGND — Analog ground |
| Pin 2 | REF OUT — Internal 10.000 V reference output |
| Pin 3 | REF IN — Reference input / external reference override |
| Pin 4 | ANALOG IN — Analog signal input |
| Pin 5 | RANGE — Input range select (pin strap ±5 V or ±10 V) |
| Pin 6 | BIP OFF — Bipolar offset adjustment |
| Pin 7 | 10V IN — +10 V reference input from RANGE ladder |
| Pin 8 | VEE — Negative analog supply (-12 V or -15 V) |
| Pin 9 | VCC — Positive analog supply (+12 V or +15 V) |
| Pin 10 | VREF — Reference trim node |
| Pin 11 | DB0 — Data bit 0 (LSB, three-state) |
| Pin 12 | DB1 — Data bit 1 (three-state) |
| Pin 13 | DB2 — Data bit 2 (three-state) |
| Pin 14 | DB3 — Data bit 3 (three-state) |
| Pin 15 | DB4 — Data bit 4 (three-state) |
| Pin 16 | DB5 — Data bit 5 (three-state) |
| Pin 17 | DB6 — Data bit 6 (three-state) |
| Pin 18 | DB7 — Data bit 7 (three-state) |
| Pin 19 | DB8 — Data bit 8 (three-state, high-byte mode) |
| Pin 20 | DB9 — Data bit 9 (three-state, high-byte mode) |
| Pin 21 | DB10 — Data bit 10 (three-state, high-byte mode) |
| Pin 22 | DB11 — Data bit 11 (MSB, three-state, high-byte mode) |
| Pin 23 | STS — Status output (conversion complete) |
| Pin 24 | HBEN — High-byte enable input |
| Pin 25 | CS — Chip select input (active low) |
| Pin 26 | R/C — Read/Convert input |
| Pin 27 | VLOGIC — Logic supply (+5 V) |
| Pin 28 | DGND — Digital ground |
Typical Applications
MAX174ACWI is suitable for 6 applications: Process Control Analog Input Modules, PC-Based Data Acquisition Boards, Precision Instrumentation Digitizers, Test and Measurement Equipment, Industrial PLC Analog Modules, Medical Instrumentation Signal Path.
Process Control Analog Input Modules
The MAX174ACWI fits process-control analog input modules because its 12-bit resolution, ±10 V bipolar input range, and 8 µs (125 ksps) conversion time match the speed and signal-level requirements of 4-20 mA-derived and thermocouple-conditioned signals in PLC analog front-ends. The integrated 10.000 V buried-Zener reference eliminates a precision external reference, while the three-state parallel output interfaces directly to the PLC's 8-bit or 16-bit data bus for low-latency register access. Compared with lower-speed ADC architectures such as integrating types, the SAR topology delivers deterministic single-shot conversion latency, which is critical for multiplexed channel scanning. Estimated: at VIN = ±10 V, an op-amp buffer with 4 kΩ-input-compatible drive and an RC anti-alias filter at 50 kHz keep the -3 dB bandwidth well above the sample rate, avoiding gain error in the digitized process variable.
Recommended
PC-Based Data Acquisition Boards
The MAX174ACWI fits PC-based data acquisition boards because its three-state parallel digital output bus maps directly to ISA or PCI-bus latches, and its 12-bit resolution with no-missing-codes meets the dynamic-range needs of general-purpose measurement at up to 125 ksps. The integrated 10 V reference and clock save board space, while the SOIC-28 wide-body footprint gives enough thermal margin at the 100 mW dissipation typical of multichannel boards. Compared with pipelined ADCs, the SAR topology gives single-cycle deterministic latency, which simplifies DMA-based acquisition. Estimated: at 100 ksps with a 50 kHz anti-alias filter, SNR degradation from aliasing is below 0.1 LSB, and the integrated reference keeps gain error under 0.5 LSB over the full 0-70C commercial temperature window.
Recommended
Precision Instrumentation Digitizers
The MAX174ACWI fits precision instrumentation digitizers because its 12-bit linearity, integrated low-drift 10 V reference, and 8 µs conversion time deliver repeatable measurements in benchtop multimeters, bench DMMs, and calibration equipment. The bipolar ±5 V or ±10 V input range accepts the standard instrument outputs directly without external scaling, while the SAR architecture's single-shot determinism supports triggered single-sample acquisitions required by digitizing multimeters. Compared with delta-sigma ADCs of equivalent resolution, the SAR topology provides lower latency per conversion, which suits calibration routines that scan reference voltages rapidly. Estimated: at 125 ksps with a 4 kΩ minimum source impedance, settling error is below 0.5 LSB for full-scale step inputs and the integrated reference contributes less than 10 ppm/°C gain drift.
Recommended
Test and Measurement Equipment
The MAX174ACWI fits test and measurement equipment such as oscilloscope auxiliary digitizers, signal-generator calibration loops, and rack-mounted data loggers because its 125 ksps throughput and integrated reference support repeatable acquisition at low BOM cost. The three-state parallel output and the standard 28-SOIC wide-body footprint simplify retrofit designs where a discrete ADC plus reference plus clock are replaced by this single chip. Compared with lower-precision 8/10-bit ADCs, the 12-bit resolution preserves margin for downstream DSP gain and offset correction. Estimated: at full-scale ±10 V input, the 4 kΩ minimum analog input impedance combined with a low-capacitance buffer op-amp keeps aperture-error contribution under 1 LSB at the maximum 125 ksps throughput.
Recommended
Industrial PLC Analog Modules
The MAX174ACWI fits industrial PLC analog input modules that demand rugged 12-bit conversion of ±10 V signals in a compact SOIC-28 footprint. Its integrated 10 V reference and SAR architecture allow the module BOM to shrink by eliminating an external reference IC, while the 8 µs conversion time supports multiplexed scanning of 8 to 16 channels per module within typical PLC scan budgets. Compared with discrete-component ADC solutions, this Maxim part reduces design complexity and improves channel-to-channel gain matching. Estimated: at a typical 16-channel multiplexed scan at 125 ksps aggregate, per-channel throughput averages 7.8 ksps, comfortably within PLC scan-cycle requirements.
Recommended
Medical Instrumentation Signal Path
The MAX174ACWI fits medical instrumentation such as patient-monitoring front-ends and bench-top diagnostic analyzers because its 12-bit resolution, integrated low-noise reference, and SAR topology support low-latency single-shot conversion of conditioned biosignals in the audio and low-frequency bands. The bipolar ±5 V input range matches the output of typical instrumentation-amp signal conditioning for ECG, EEG, or pulse-oximetry channels, while the wide SOIC-28 package simplifies hand-repair and prototyping workflows common in regulated medical-device development. Compared with delta-sigma converters of the same nominal resolution, the SAR architecture offers lower conversion latency which matters for triggered capture. Estimated: at 125 ksps with a 4 kHz anti-alias filter, the MAX174ACWI digitizes ECG bandwidth signals with better than 0.5 LSB integral nonlinearity and provides enough dynamic range for diagnostic-grade measurements.
Recommended
Recommended Products Summary
Engineering reference data for MAX174ACWI — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MAX174AEWI+ | MAX174ACWI+ | MAX174ACWI+T | MX674AJCWI+ | MX574AJCWI+ |
|---|---|---|---|---|---|---|
| Brand | Analog Devices (Maxim) | Analog Devices (Maxim) | Analog Devices (Maxim) | Analog Devices (Maxim) | Analog Devices (Maxim) | Analog Devices (Maxim) |
| Package | SOIC-28 (Wide) | SOIC-28 (Wide) - same | SOIC-28 (Wide) - same | SOIC-28 (Wide) - same | SOIC-28 (Wide) - same | SOIC-28 (Wide) - same |
| Resolution | 12 bits | 12 bits | 12 bits | 12 bits | 12 bits | 12 bits |
| Max Conversion Time | 8 µs | 8 µs | 8 µs | 8 µs | 15 µs (slower) | 25 µs (slowest, lowest power) |
| Sampling Rate | 125 ksps | 125 ksps | 125 ksps | 125 ksps | 66 ksps | 40 ksps |
| Operating Temperature | 0°C to +70°C | -40°C to +85°C | 0°C to +70°C | 0°C to +70°C | 0°C to +70°C | 0°C to +70°C |
| Internal Reference | 10.000 V buried-Zener | 10.000 V buried-Zener | 10.000 V buried-Zener | 10.000 V buried-Zener | 10.000 V buried-Zener | 10.000 V buried-Zener |
| Lead-Free Finish | No (SnPb) | Yes (Pb-free matte-tin) | Yes (Pb-free matte-tin) | Yes (Pb-free matte-tin) | Yes (Pb-free matte-tin) | Yes (Pb-free matte-tin) |
Key Differentiators
- Highest-speed member of industry-standard MAX174 ADC family (vs MX574AJCWI+)
- Single-chip integration of reference, clock, and three-state bus interface (vs MAX162ACNG+)
- Direct 8/16-bit microprocessor bus compatibility (vs MAX155ACPI+)
Design Notes
The MAX174ACWI requires three supplies: +5 V (VLOGIC), ±12 V or ±15 V analog (VCC/VEE). Estimated: at typical 100 mW dissipation the +5 V digital supply draws about 15 mA and the analog ±15 V draws approximately 3 mA per rail. Place 10 µF tantalum and 0.1 µF ceramic bypass capacitors within 1 cm of each supply pin to suppress switching noise from digital transitions coupling into the analog reference.
The MAX174ACWI uses separate analog ground (AGND, pin 1) and digital ground (DGND, pin 28) returns to avoid digital switching noise corrupting the analog input path. Recommended layout practice: connect AGND and DGND at a single point near the ADC package - typically under the device on the ground pour - and route the analog input trace as a guarded differential pair with the AGND plane on either side. Keep the digital bus traces (DB0-DB11, R/C, CS) routed away from the ANALOG IN pin to avoid capacitive coupling of logic transitions into the input.
The MAX174ACWI analog input presents a 4 kΩ minimum input impedance. Estimated: to keep gain error below 0.5 LSB at full-scale ±10 V input, the source impedance driving ANALOG IN must be below 50 Ω, which means a low-output-impedance op-amp buffer such as a MAX410 or MAX427 is required in front of the ADC for any source above 50 Ω. Add an RC anti-alias filter at the buffer output with a -3 dB cutoff at fc ≈ 50 kHz (5× the Nyquist bandwidth at 125 ksps) using a 100 Ω series resistor and 33 pF capacitor to ground.
Compliance Information
Base MAX174ACWI uses SnPb finish and is not RoHS compliant. RoHS-compliant '+' variants (MAX174ACWI+, MAX174AEWI+) are available with Pb-free matte-tin finish. AEC-Q100 qualification not applicable for this industrial/instrumentation-grade part; no automotive qualified variant exists.