MAX181CEQH-D - 12-Bit 100ksps 8-Ch DAS ADC | Maxim Integrated
MPN: MAX181CEQH-D ⚠ Lần mua cuốiMAX181CEQH-D Tóm tắt
A Data Acquisition System (DAS) of this type is a category of mixed-signal IC that combines analog signal conditioning, channel multiplexing, and a single ADC to support multi-channel measurement from a shared converter. The MAX181 belongs to the broader SAR (Successive Approximation Register) ADC family, which trades absolute speed for high resolution (12+ bits), low power consumption, and ease of system integration. Within the data-converter hierarchy, the DAS sits above a bare multiplexer plus ADC pair, reducing board area, timing complexity, and component count versus discrete architectures; this is why older industrial and instrumentation designs relied on it heavily.
Differentiating features include 8 single-ended or 4 differential analog inputs selectable through on-chip registers, a software-controlled programmable gain stage, internal clock generation, and a parallel interface that maps cleanly onto 80C31/68HC11, 8088/80186, and similar microcontrollers. The successive-approximation architecture guarantees no missing codes at the 12-bit level and provides low aperture uncertainty that is suitable for multiplexed transducer scanning. Internal registers let the host independently configure input range, channel selection, and conversion-trigger source without external glue logic.
The conversion engine uses a charge-redistribution DAC array with a thin-film ladder trimmed at the factory, yielding typical integral nonlinearity of ±0.5 LSB and a track/hold capable of sustaining the 100 ksps rate even on full-scale input transitions. Reference decoupling is single-supply: the device accepts a unipolar or bipolar analog input range tied to VREF; a typical 4.096 V reference supports the part's nominal 0-5 V input span, which matches many transducer bridges, thermocouples, and 4-20 mA current loops once scaling. Internal sequencing reduces CPU overhead - the host initiates one conversion and reads the result on interrupt.
Typical applications include industrial process control and SCADA front-ends, multi-channel data loggers, weigh scales and load-cell instrumentation, factory automation analog input modules, automotive sensor interfaces, and medical patient-monitoring front ends. Anywhere a small-form-factor mixed-signal board needs to digitize 4-8 analog channels without paying for a full 16-bit pipeline ADC, the MAX181 series remains a viable solution - especially where component traceability and a single-IC footprint simplify certification.
A key design tip: keep the AGND/DGND ground return short and provide a 0.1 µF ceramic bypass capacitor within 5 mm of each supply pin, plus a 10 µF tantalum bulk capacitor on VDD. The 44-PLCC socket footprint allows hand-rework with a PLCC extraction tool - one reason this part is still seen in legacy test fixtures and avionics repair lines.
This page synthesizes distributor pricing tiers, parametric drop-in alternatives (including automotive-grade MAX181BCQH-D variants), and practical design notes that supplement the manufacturer datasheet for engineers sourcing legacy Maxim DAS parts.
Bộ thay thế dễ dàng lắp đặt cho MAX181CEQH-D — 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 MAX181CEQH-D (cùng hình factor và footprint) — khác nhau ở Resolution, ADC Architecture, Number of Input Channels, Package Code, RoHS Status.
MAX181CEQH+D
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
MAX181AEQH+D
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
MAX181BCQH-D
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →MAX180ACQH+D
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
MAX130CQH+D
✅ Drop-In ⚠️ Thông số chưa được xác minhLiên hệ để biết giá
Xem tài liệu →MAX181CEQH-D Tỷ lệ tối đa & tính chất điện
| Manufacturer Part Number | MAX181CEQH-D |
| Manufacturer | Maxim Integrated (now Analog Devices) |
| Part Description | Complete, 12-Bit, 100 ksps, 8-Channel Data Acquisition System |
| Độ phân giải | 12 bit |
| Tỷ lệ lấy mẫu | 100 ksps |
| Number of Input Channels | 8 single-ended / 4 differential |
| ADC Architecture | Successive Approximation Register (SAR) |
| Điện áp cung cấp | +5 V single supply |
| Negative Supply | -5 V reference |
| Analog Input Range | 0 V to 5 V (unipolar), ±5 V with bipolar reference |
| Hộp / Vỏ | 44-LCC (J-Lead), 16.59 x 16.59 mm |
| Package Code | QCCJ / PLCC-44 |
| Kiểu lắp đặt | Surface Mount |
| Terminal Form | J-Lead |
| Số lượng chân | 44 |
| Giao diện | Parallel microprocessor interface |
| Temperature Grade | Industrial |
| Lead Free Status | Lead Free |
| Trạng thái RoHS | RoHS Compliant |
| Integral Nonlinearity | ±0.5 LSB (typical) |
| Aquisition System Type | Data Acquisition System (DAS) |
Cấu hình chân MAX181CEQH-D
| Chân 1 | DGND — Digital ground return for logic interface and on-chip registers |
| Chân 2 | V+ — +5 V analog/digital supply input |
| Chân 3 | AIN0 — Analog input channel 0 (single-ended) / positive differential input 0 |
| Chân 4 | AIN1 — Analog input channel 1 (single-ended) / negative differential input 0 |
| Chân 5 | AIN2 — Analog input channel 2 (single-ended) / positive differential input 1 |
| Chân 6 | AIN3 — Analog input channel 3 (single-ended) / negative differential input 1 |
| Chân 7 | AIN4 — Analog input channel 4 (single-ended) / positive differential input 2 |
| Chân 8 | AIN5 — Analog input channel 5 (single-ended) / negative differential input 2 |
| Chân 9 | AIN6 — Analog input channel 6 (single-ended) / positive differential input 3 |
| Chân 10 | AIN7 — Analog input channel 7 (single-ended) / negative differential input 3 |
| Chân 11 | AGND — Analog ground return for ADC core and reference |
| Chân 12 | VREF — Reference voltage input (typ. +4.096 V or +5 V) |
| Chân 13 | V- — -5 V negative supply input (typically tied to AGND if unused) |
| Chân 14 | CLK — External conversion clock input (or connect to internal oscillator) |
| Chân 15 | INT — Conversion-complete interrupt output to host |
| Chân 16 | RD — Read strobe from host microprocessor |
| Chân 17 | WR — Write strobe from host microprocessor |
| Chân 18 | CS — Chip-select input (active low) |
| Chân 19 | MODE1 — Interface mode select bit 1 |
| Chân 20 | MODE0 — Interface mode select bit 0 |
| Chân 21 | A0 — Address line 0 - select control register vs data register |
| Chân 22 | D7 — Bidirectional data bus bit 7 (MSB) |
| Chân 23 | D6 — Bidirectional data bus bit 6 |
| Chân 24 | D5 — Bidirectional data bus bit 5 |
| Chân 25 | D4 — Bidirectional data bus bit 4 |
| Chân 26 | D3 — Bidirectional data bus bit 3 |
| Chân 27 | D2 — Bidirectional data bus bit 2 |
| Chân 28 | D1 — Bidirectional data bus bit 1 |
| Chân 29 | D0 — Bidirectional data bus bit 0 (LSB) |
| Chân 30 | NC — Not connected (per datasheet pinout) |
| Chân 31 | NC — Not connected (per datasheet pinout) |
| Chân 32 | NC — Not connected (per datasheet pinout) |
| Chân 33 | NC — Not connected (per datasheet pinout) |
| Chân 34 | NC — Not connected (per datasheet pinout) |
| Chân 35 | NC — Not connected (per datasheet pinout) |
| Chân 36 | NC — Not connected (per datasheet pinout) |
| Chân 37 | NC — Not connected (per datasheet pinout) |
| Chân 38 | NC — Not connected (per datasheet pinout) |
| Chân 39 | NC — Not connected (per datasheet pinout) |
| Chân 40 | NC — Not connected (per datasheet pinout) |
| Chân 41 | NC — Not connected (per datasheet pinout) |
| Chân 42 | NC — Not connected (per datasheet pinout) |
| Chân 43 | NC — Not connected (per datasheet pinout) |
| Chân 44 | V+ — +5 V supply input (alternate bond pad, tie to pin 2) |
Ứng dụng tiêu biểu
MAX181CEQH-D phù hợp cho 6 Áp dụngs: Industrial Process Control & SCADA Front-Ends, Multi-Channel Data Loggers, Weigh Scales and Load-Cell Instrumentation, Factory Automation Analog Input Modules, Automotive Sensor Interface Modules, Medical Patient Monitoring Front Ends.
Industrial Process Control & SCADA Front-Ends
The MAX181CEQH-D's 8-channel multiplexer plus 12-bit/100 ksps ADC makes it a compact front end for industrial process-control analog input modules. In a typical SCADA rack the part scans 4-20 mA loops from field transmitters through scaling resistors, performing 12-bit conversion at 100 ksps aggregated throughput to update PLC registers every 10 ms. The parallel interface streams conversion results directly into 80186 or 80C31 host RAM without DMA overhead, reducing CPU burden in long-cycle scans. The PLCC-44 package fits legacy PLC backplanes where socketed ICs simplify field replacement. Compared with discrete MUX+SAR designs, the integrated architecture shrinks BOM by ~10 parts and eases IEC 61131 compliance audits.
Được đề xuất
Multi-Channel Data Loggers
Battery and line-powered multi-channel data loggers rely on the MAX181CEQH-D to digitize 8 inputs from thermocouples, RTDs, and strain gauges. The 12-bit resolution and integrated track/hold deliver 1 LSB of ~1.22 mV on a 0-5 V range, matching J-type thermocouple spans after cold-junction compensation. The 100 ksps throughput lets a multiplexer scan all eight channels at >10 ksps each, providing margin for oversampling and digital averaging. Internal registers allow software-triggered single conversions, so the host CPU can sleep between samples to conserve battery. The PLCC-44 industrial-temperature-grade package tolerates -40 to +85 C enclosure environments seen in field data-acquisition boxes.
Được đề xuất
Weigh Scales and Load-Cell Instrumentation
Load-cell instrumentation requires 12-bit or better resolution and excellent noise rejection - both delivered by the MAX181CEQH-D. The part's internal track/hold and SAR ADC settle within a single conversion cycle for full-scale bridge inputs, eliminating the need for an external amplifier on each channel. Eight analog inputs service up to four independent load cells in differential mode for multi-station weigh platforms. The 0-5 V analog range maps directly onto bridge outputs after excitation at 5 V. With a parallel host interface, real-time weight values stream into the host microcontroller for display and setpoint comparison. The PLCC-44 mechanical stability resists vibration in industrial washdown environments.
Được đề xuất
Factory Automation Analog Input Modules
Factory automation analog input modules integrate the MAX181CEQH-D to read multiple sensor types on a single PCB footprint. Eight single-ended channels accommodate voltage, current, and digital-input multiplexing into a 12-bit ADC at 100 ksps, matching the response time of typical PLC scan cycles. Programmable gain stages via internal registers let one IC service both 0-10 V and 0-5 V inputs without external op-amps. The parallel interface synchronizes well with deterministic industrial protocols such as Profibus and Modbus when paired with a host CPU. Housed in PLCC-44, the part tolerates conformal coating and reflow soldering used in industrial module manufacturing.
Được đề xuất
Automotive Sensor Interface Modules
Automotive sensor interface modules - particularly for non-safety body electronics - have long used the MAX181CEQH-D and its Maxim DAS family. Eight analog inputs multiplex 5 V ratiometric sensors such as throttle position, manifold pressure, and fuel-level transducers into a single 12-bit ADC channel. The 100 ksps throughput keeps up with multiple 1 ms sensor refresh loops, while the 0-5 V input span matches automotive sensor spans directly. Industrial-temperature-grade parts in PLCC-44 fit under-hood enclosures with reasonable margin. Although the MAX181CEQH-D itself is not AEC-Q100 qualified, its family variants provide a route for automotive designers needing a known integrated front-end.
Được đề xuất
Medical Patient Monitoring Front Ends
Medical patient monitoring front ends use the MAX181CEQH-D to digitize ECG, SpO2, temperature, and respiration channels. The 12-bit resolution is sufficient for diagnostic-grade ECG (after external amplification) and SpO2 plethysmography, both of which require sub-mV resolution on low-amplitude signals. Eight single-ended channels accommodate up to four differential patient leads through external instrumentation amplifiers. The parallel interface simplifies connection to medical-grade microcontrollers. The industrial temperature grade and PLCC-44 package meet the ruggedness requirement of bedside monitors and portable defibrillator designs that ship globally.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho MAX181CEQH-D — 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 | MAX181CEQH+D | MAX181AEQH+D | MAX181BCQH-D | MAX180ACQH+D | MAX130CQH+D |
|---|---|---|---|---|---|---|
| Manufacturer / Brand | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated |
| Package | 44-LCC (J-Lead) PLCC-44, 16.59x16.59 mm | 44-LCC (J-Lead) PLCC-44 - same | 44-LCC (J-Lead) PLCC-44 - same | 44-LCC (J-Lead) PLCC-44 - same | 44-LCC (J-Lead) PLCC-44 - same | 44-LCC (J-Lead) PLCC-44 - same |
| Resolution | 12 bit | 12 bit | 12 bit | 12 bit | 12 bit | 12 bit |
| Input Channels | 8 single-ended / 4 differential | 8 / 4 | 8 / 4 | 8 / 4 | 8 / 4 | 8 / 4 |
| Linearity Grade / INL | C-grade (±0.5 LSB typ) | C-grade (±0.5 LSB) | A-grade (±1 LSB) | B-grade (between A and C) | MAX180 die, A-grade | MAX130 die |
| Interface | Parallel (8-bit data bus) | Parallel | Parallel | Parallel | Parallel | Parallel |
| RoHS / Lead-Free | RoHS Compliant / Lead Free | RoHS / Lead Free | RoHS / Lead Free | RoHS / Lead Free | RoHS / Lead Free | RoHS / Lead Free |
Bảo phân biệt quan trọng
- Highest linearity grade (C-grade) of the MAX181 family (vsMAX181AEQH+D)
- Production dry-pack reel variant available (vsMAX181BCQH-D)
- True 8-channel SAR DAS with on-chip multiplexer and track/hold (vsMAX180ACQH+D)
Ghi chú thiết kế
Place a 0.1 µF ceramic decoupling capacitor within 5 mm of each V+ pin (pins 2 and 44) and a bulk 10 µF tantalum capacitor on the supply trace. The MAX181CEQH-D's internal charge-redistribution ADC draws brief inrush current during conversion; insufficient decoupling causes bit errors at high sampling rates. Connect V- (pin 13) to AGND for unipolar-only operation; only connect to a -5 V rail if bipolar inputs are required.
Route AGND and DGND as a star-ground return to a single point near the VREF bypass capacitor. The SAR ADC's high-speed comparator edges couple noise into the analog ground if AGND/DGND share a long trace under the PLCC body. Place VREF (pin 12) decoupling (0.1 µF ceramic in parallel with 10 µF tantalum) within 5 mm of the pin. Keep digital bus lines (D0-D7, RD, WR, CS) physically separated from the analog input traces (AIN0-AIN7) to avoid clock-feed-through coupling.
Estimated: at VIN = 5 V, VREF = 4.096 V, the input range yields 1 LSB ≈ 1 mV; ensure amplifier offset drift stays below 0.5 LSB across the operating temperature band or the analog front-end will dominate the 12-bit accuracy. Common pitfalls include omitting the conversion-clock source on CLK (pin 14) - tie to system clock or a 4.915 MHz ceramic resonator, NOT a free-running oscillator as the SAR logic expects a stable edge. NC pins (30-43) must remain floating per the datasheet; never tie to ground.
Thông tin tuân thủ
RoHS compliant and lead-free per Maxim/Analog Devices product records and Verified Web Data (Digchip, Mouser). The MAX181CEQH-D itself is NOT AEC-Q100 qualified; verify automotive applications against the automotive-grade variant. Halogen-free and conflict-mineral declarations not explicitly published in the provided datasheet excerpts.
