MX574ALCWI+T - 12-Bit 40kHz SAR ADC, 28-SOIC | Maxim Integrated
MPN: MX574ALCWI+T ✓ Hoạt độngMX574ALCWI+T Tóm tắt
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.
Bộ thay thế dễ dàng lắp đặt cho MX574ALCWI+T — cùng gói, chân-to-chân tương thích. Các bộ phận yêu cầu hàn PCB bị loại trừ.
Các biến thể trong loạt này
Các mẫu cùng loạt có thể lắp đặt dễ dàng tương thích với MX574ALCWI+T (cùng hình factor và footprint) — khác nhau ở Architecture, Package, Resolution, Conversion Time, Input Type.
MX574AJCWI+T
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
MX574AKCWI+T
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
MX574ALEWI+T
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
MX574ALCWI+T Tỷ lệ tối đa & tính chất điện
| Độ phân giải | 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) |
| Khoảng nhiệt độ hoạt động | 0 °C to +70 °C (Commercial grade) |
| Hộp | 28-pin SOIC (Wide-body) |
| Temperature Grade | Commercial (C) |
| Lead-Free / RoHS | Lead-free (Pb-free) |
| Package Marking Code | MX574ALCWI+T |
Cấu hình chân MX574ALCWI+T
| Chân 1 | VEE — Negative analog supply (-12 V or -15 V) |
| Chân 2 | Ain — Analog input |
| Chân 3 | REF OUT — Internal +10 V reference output |
| Chân 4 | REF IN — Reference input (strap to REF OUT or external ref) |
| Chân 5 | AGND — Analog ground |
| Chân 6 | BIPOLAR — Mode select: open/LOW = unipolar, HIGH = bipolar |
| Chân 7 | 10VIN — Input range: LOW = 10 V range, HIGH = 20 V range |
| Chân 8 | TRIM — Reference trim pin |
| Chân 9 | DB11 (MSB) — Data bit 11 (Most Significant Bit) |
| Chân 10 | DB10 — Data bit 10 |
| Chân 11 | DB9 — Data bit 9 |
| Chân 12 | DB8 — Data bit 8 |
| Chân 13 | DB7 — Data bit 7 |
| Chân 14 | DB6 — Data bit 6 |
| Chân 15 | DB5 — Data bit 5 |
| Chân 16 | DB4 — Data bit 4 |
| Chân 17 | DB3 — Data bit 3 |
| Chân 18 | DB2 — Data bit 2 |
| Chân 19 | DB1 — Data bit 1 |
| Chân 20 | DB0 (LSB) — Data bit 0 (Least Significant Bit) |
| Chân 21 | STS — Status output (conversion complete) |
| Chân 22 | R/C — Read/Convert control input |
| Chân 23 | CE — Chip enable (active high) |
| Chân 24 | CS — Chip select (active low) |
| Chân 25 | DGND — Digital ground |
| Chân 26 | VLOGIC — +5 V digital supply |
| Chân 27 | VCC — Positive analog supply (+12 V or +15 V) |
| Chân 28 | NC — Not connected (per datasheet) |
Ứng dụng tiêu biểu
MX574ALCWI+T phù hợp cho 6 Áp dụngs: 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.
Được đề xuất
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.
Được đề xuất
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.
Được đề xuất
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.
Được đề xuất
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.
Được đề xuất
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.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho MX574ALCWI+T — so sánh, hướng dẫn thiết kế và thông tin tuân thủ.
Hướng dẫn chọn lựa
So sánh với các sản phẩm thay thế
| Tham số | Sản phẩm này | 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 |
Bảo phân biệt quan trọng
- Industry-standard AD574A second-source replacement (vsMAX174BCPI)
- Same package, higher speed grade available as drop-in (vsMX574AJCWI+T)
- Industrial temperature variant as drop-in (vsMX574ALEWI+T)
Ghi chú thiết kế
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.
Thông tin tuân thủ
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.
