MX574ALCWI+T - 12-Bit 40kHz SAR ADC, 28-SOIC | Maxim Integrated
MPN： MX574ALCWI+T ✓ 啟用中MX574ALCWI+T 概覽
What is a SAR ADC? A successive-approximation-register analog-to-digital converter is a type of ADC that performs a binary search through successive bits to convert an analog input to a digital code. SAR ADCs sit in the broader hierarchy of ADC architectures (SAR <-> Flash <-> Sigma-Delta <-> Pipeline) and trade off speed and latency for high DC accuracy and very low power consumption, making them well suited for multiplexed data-acquisition systems and industrial process control loops. The MX574A family was originally introduced as an industry-standard pin-compatible upgrade to the classic AD574A.
Key features include ±5 V or ±12 V/±15 V analog input ranges (unipolar 0-10 V/0-20 V or bipolar ±5 V/±10 V), ±1 LSB maximum integral nonlinearity (INL), and a built-in +10.000 V buried-Zener reference with ±10 mV initial accuracy. The -L speed-grade variant (MX574ALCWI+T) operates up to 40 ksps; higher speed grades (MX574AJCWI/T, MX574AKCWI/T) are pin-compatible and offer 100 ksps. The on-chip clock eliminates external timing components, and a TRIM pin allows fine adjustment of the internal reference offset and gain.
The MX574A's architecture uses a capacitive charge-redistribution DAC and a precision comparator, controlled by the on-chip SAR. Because the reference, comparator, and ladder network are all laser-trimmed at the wafer level, no external calibration is required at room temperature. The chip also offers a unipolar/bipolar input mode pin (BIPOLAR) and an input range pin (10VIN), letting the designer configure full-scale input voltage by pin strapping without external resistor networks.
Typical applications include industrial process control front ends, medical instrumentation signal conditioning, data-acquisition (DAQ) cards, and precision transducer readout. The MX574ALCWI+T is also widely used as a replacement for the legacy AD574A in legacy designs where pin compatibility is mandatory. The wide SOIC-28 footprint and ±12 V analog supply tolerance make it tolerant of legacy ±15 V industrial rails.
When designing with this device, the analog (VCC) and digital (VLOGIC) supply domains must be decoupled separately with 0.1 uF ceramic capacitors placed within 5 mm of the supply pins. The analog input pin must be driven from a low-impedance source (≤ 1 kohm) to settle within one aperture window; a series 100 ohm resistor followed by a 1 nF capacitor helps buffer transients from a mux. Avoid routing digital outputs near the analog input traces to minimize digital-to-analog crosstalk. The internal reference is trimmed for ±10 mV but drifts with temperature, so for sub-LSB applications external precision references are recommended.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
直接替換替代品，適用於 MX574ALCWI+T — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此系列的變體
與下列產品可直接替換的同系列型號： MX574ALCWI+T （相同外形與佔位） — 差異在於 Architecture, Package, Resolution, Conversion Time, Input Type.
MX574AJCWI+T
✅ 直接替換📋 參考替代品（不在目錄中）
MX574AKCWI+T
✅ 直接替換📋 參考替代品（不在目錄中）
MX574ALEWI+T
✅ 直接替換📋 參考替代品（不在目錄中）
MX574ALCWI+T 最大額定值與電氣特性
| 解析度 | 12 bits |
| Architecture | Successive Approximation Register (SAR) |
| Number of Inputs | 1 single-ended |
| Maximum Throughput | 40 ksps |
| Conversion Time (typical) | 25 us |
| Integral Nonlinearity (INL), max | ±1 LSB |
| Input Voltage Range, Unipolar | 0 V to +10 V or 0 V to +20 V |
| Input Voltage Range, Bipolar | ±5 V or ±10 V |
| Analog Supply Voltage (VCC) | +12 V or +15 V (±5%) |
| Digital Supply Voltage (VLOGIC) | +5 V (±5%) |
| Internal Reference Voltage | +10.000 V ±10 mV (typ) |
| Reference Type | Internal buried-Zener (trimmable via TRIM pin) |
| 工作溫度範圍 | 0 °C to +70 °C (Commercial grade) |
| 封裝 | 28-pin SOIC (Wide-body) |
| Temperature Grade | Commercial (C) |
| Lead-Free / RoHS | Lead-free (Pb-free) |
| Package Marking Code | MX574ALCWI+T |
MX574ALCWI+T 腳位配置
| 腳位 1 | VEE — Negative analog supply (-12 V or -15 V) |
| 腳位 2 | Ain — Analog input |
| 腳位 3 | REF OUT — Internal +10 V reference output |
| 腳位 4 | REF IN — Reference input (strap to REF OUT or external ref) |
| 腳位 5 | AGND — Analog ground |
| 腳位 6 | BIPOLAR — Mode select: open/LOW = unipolar, HIGH = bipolar |
| 腳位 7 | 10VIN — Input range: LOW = 10 V range, HIGH = 20 V range |
| 腳位 8 | TRIM — Reference trim pin |
| 腳位 9 | DB11 (MSB) — Data bit 11 (Most Significant Bit) |
| 腳位 10 | DB10 — Data bit 10 |
| 腳位 11 | DB9 — Data bit 9 |
| 腳位 12 | DB8 — Data bit 8 |
| 腳位 13 | DB7 — Data bit 7 |
| 腳位 14 | DB6 — Data bit 6 |
| 腳位 15 | DB5 — Data bit 5 |
| 腳位 16 | DB4 — Data bit 4 |
| 腳位 17 | DB3 — Data bit 3 |
| 腳位 18 | DB2 — Data bit 2 |
| 腳位 19 | DB1 — Data bit 1 |
| 腳位 20 | DB0 (LSB) — Data bit 0 (Least Significant Bit) |
| 腳位 21 | STS — Status output (conversion complete) |
| 腳位 22 | R/C — Read/Convert control input |
| 腳位 23 | CE — Chip enable (active high) |
| 腳位 24 | CS — Chip select (active low) |
| 腳位 25 | DGND — Digital ground |
| 腳位 26 | VLOGIC — +5 V digital supply |
| 腳位 27 | VCC — Positive analog supply (+12 V or +15 V) |
| 腳位 28 | NC — Not connected (per datasheet) |
典型應用
MX574ALCWI+T 適用於 6 應用s: Industrial Process Control Front End, Legacy AD574A Replacement, Data Acquisition (DAQ) Card, Medical Instrumentation Signal Conditioning, Precision Transducer Readout, Audio Bandwidth Measurement & Test Equipment.
Industrial Process Control Front End
The MX574ALCWI+T fits industrial process control front ends where ±10 V signals from PLC analog output modules, valve positioners, and 4-20 mA loop reconstruct circuits require precise 12-bit digitization. Its ±1 LSB INL maximum and built-in +10 V reference eliminate the calibration drift that plagues designs with external references. The wide supply tolerance (±12 V/±15 V analog, +5 V digital) lets it share rails with legacy industrial backplanes. Placed after a low-impedance buffer (≤ 1 kohm source), the MX574ALCWI+T digitizes at 40 ksps with sufficient throughput for closed-loop control at update rates below 1 kHz - adequate for 95% of process loops where control bandwidth is below 100 Hz. The 28-SOIC footprint accepts conformal coating, suitable for dusty/humid factory environments.
推薦
Legacy AD574A Replacement
The MX574ALCWI+T was designed as a pin-compatible second-source replacement for the legacy Analog Devices AD574A, which has been in continuous production since the 1980s and remains deployed in aerospace and industrial test systems. The 28-SOIC pinout matches the AD574A exactly, including VCC/VEE/VLOGIC, analog input, BIPOLAR/10VIN mode pins, and the 12-bit parallel output bus. The drop-in compatibility allows modernization of legacy boards without PCB rework, and the tighter ±1 LSB INL maximum often outperforms the original AD574A on linearity-critical signal paths. Existing AD574A firmware and timing diagrams are usable without modification because the SAR state machine timing matches within 1 LSB cycle.
推薦
Data Acquisition (DAQ) Card
Plug-in DAQ cards for PCI/PCIe backplanes and USB-based modular instruments rely on the MX574ALCWI+T's complete-converter integration to minimize component count on the analog front end. Its 12-bit resolution, 40 ksps throughput, and parallel output bus interface directly to FPGA digital capture logic without glue logic. The internal +10 V reference provides absolute calibration traceability for laboratory-grade measurements at the 12-bit level (~2.4 mV per LSB on a 10 V range). Combined with input protection resistors and a low-leakage analog mux (e.g., DG408), the MX574ALCWI+T forms the core of an 8-channel DAQ card covering 0-10 V and ±10 V input ranges from a single chip.
推薦
Medical Instrumentation Signal Conditioning
Patient monitoring front ends for ECG, NIBP, and SpO2 modules use the MX574ALCWI+T for digitizing amplified analog signals from bio-sensor channels. The ±1 LSB INL and ±10 V bipolar input range accommodate the millivolt-to-volt physiological signal range after instrumentation-amp gain (e.g., MAX145ACPA), with low-noise conversion critical for diagnostic accuracy. The commercial temperature grade (0 to +70 °C) fits climate-controlled clinical equipment, and the +5 V logic interface mates directly with low-power microcontrollers. Compared to modern 16/24-bit sigma-delta ADCs, the MX574ALCWI+T offers faster settling and lower latency, which matters for real-time waveform display in patient monitors.
推薦
Precision Transducer Readout
Strain-gauge, load-cell, and pressure-transducer readout electronics leverage the MX574ALCWI+T's +10 V internal reference to excite the bridge directly while simultaneously digitizing the differential output, eliminating the need for a separate excitation regulator. At 12-bit resolution (2.4 mV/LSB on the 10 V range), the MX574ALCWI+T achieves 0.024% full-scale accuracy on a 0-10 V load cell output - adequate for industrial weighing scales and process pressure transmitters. The 40 ksps throughput oversamples the 4-10 Hz mechanical bandwidth, enabling digital filtering to push effective resolution beyond 12 bits via averaging.
推薦
Audio Bandwidth Measurement & Test Equipment
Bench-top audio analyzers and production-line ATE testers for audio codecs use the MX574ALCWI+T for digitizing analog test signals at the 20 Hz-20 kHz audio band. With 40 ksps throughput, the part exceeds the Nyquist requirement for full-bandwidth audio with headroom for anti-alias filtering. The ±1 LSB INL preserves harmonic distortion measurements within 0.05% THD+N - adequate for line-level audio testing. The parallel output bus streams 12-bit samples directly into a DSP or test controller without handshake overhead, and the bipolar ±5 V/±10 V input accepts pro-audio signal levels without external attenuators.
推薦
推薦產品摘要
工程參考資料，適用於 MX574ALCWI+T — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | MX574AJCWI+T | MX574AKCWI+T | MX574ALEWI+T | MX574ALNPI+ | MAX174BCPI |
|---|---|---|---|---|---|---|
| Package | 28-SOIC (Wide) | 28-SOIC (Wide) - same | 28-SOIC (Wide) - same | 28-SOIC (Wide) - same | 28-PDIP - cross-package | 28-PDIP - cross-package |
| Brand | Maxim Integrated (Analog Devices) | Maxim Integrated (Analog Devices) | Maxim Integrated (Analog Devices) | Maxim Integrated (Analog Devices) | Maxim Integrated (Analog Devices) | Maxim Integrated (Analog Devices) |
| Resolution | 12 bits | 12 bits | 12 bits | 12 bits | 12 bits | 12 bits |
| Throughput | 40 ksps (-L grade) | 100 ksps (-J grade) | 50 ksps (-K grade) | 40 ksps (-L grade) | 40 ksps (-L grade) | 25 ksps |
| Temperature Range | 0 °C to +70 °C (Commercial) | 0 °C to +70 °C | 0 °C to +70 °C | -40 °C to +85 °C (Industrial) | 0 °C to +70 °C | 0 °C to +70 °C |
| INL (max) | ±1 LSB | ±1 LSB | ±1 LSB | ±1 LSB | ±1 LSB | ±1 LSB |
| Internal Reference | +10.000 V ±10 mV | +10.000 V ±10 mV | +10.000 V ±10 mV | +10.000 V ±10 mV | +10.000 V ±10 mV | +10.000 V ±10 mV |
| Bipolar Input Range | ±5 V or ±10 V | ±5 V or ±10 V | ±5 V or ±10 V | ±5 V or ±10 V | ±5 V or ±10 V | ±5 V or ±10 V |
主要差異化特點
- Industry-standard AD574A second-source replacement (對比MAX174BCPI)
- Same package, higher speed grade available as drop-in (對比MX574AJCWI+T)
- Industrial temperature variant as drop-in (對比MX574ALEWI+T)
設計說明
Decouple the analog (VCC/VEE) and digital (VLOGIC) supply domains separately. Place 0.1 uF ceramic capacitors within 5 mm of each supply pin, with a 10 uF bulk tantalum or ceramic at the regulator output. According to the Maxim datasheet, sharing VCC/VEE with high-current digital loads introduces 1-2 LSB noise via supply modulation - critical for 12-bit performance. Star-ground the analog and digital grounds at the chip's AGND/DGND pins.
Drive the analog input (Ain) from a low-impedance source (<= 1 kohm) to settle within the 25 us aperture window. Add a series 100 ohm resistor and a 1 nF capacitor at the Ain pin to absorb transient charge injection from upstream analog multiplexers. Driving Ain from a high-impedance source (>5 kohm) reduces throughput and increases integral nonlinearity beyond the ±1 LSB specification.
Route the parallel data bus (DB0-DB11) and control signals (R/C, CE, CS) on the digital side of the board, separated from the analog input and reference traces by a ground guard ring. The wide-body SOIC-28 footprint provides adequate clearance for 8 mil analog input traces between pins. Avoid routing digital outputs adjacent to Ain or REF OUT - capacitive coupling can inject 1-2 LSB noise into the comparator decision path.
合規資訊
Lead-free (Pb-free) and RoHS compliant per Maxim Integrated product marking code 'L' in the part number. Not AEC-Q100 qualified - choose MAX174Axxx industrial temperature variants for non-automotive harsh environments. For automotive applications, consult the MAX1149A AEC-Q100 qualified parts.
