MAX174BCWI+ - 12-Bit 125 kSPS Complete ADC | Maxim Integrated
MPN： MAX174BCWI+ ✓ 啟用中MAX174BCWI+ 概覽
Key specifications include 12-bit resolution with no missing codes, a 0 V to +10 V or 0 V to +20 V input range (jumper or strap selectable), a 10 V on-chip buried-zener reference (TrimDAC-compatible, ±0.3% accuracy grade B), a parallel microprocessor interface, and a low supply requirement of +5 V plus optionally ±12 V to ±15 V for analog inputs. Conversion time is 8 µs at full throughput, with three interface modes for tying to 8-bit, 12-bit, or 16-bit data buses.
An SAR ADC (Successive Approximation Register Analog-to-Digital Converter) is a widely used ADC architecture that uses a binary search algorithm to resolve the input voltage one bit per clock cycle, achieving an excellent trade-off between speed, resolution, and power consumption. SAR ADCs sit at the second tier of the data-converter hierarchy: faster than integrating ADCs, slower than flash or pipeline ADCs, but offering very high DC accuracy and low latency. They occupy a key role in the broader power management and signal-conditioning IC family, alongside DACs, references, and multiplexers.
The MAX174BCWI+ uses Maxim's BiCMOS construction, which reduces power dissipation relative to older bipolar-only designs. The internal reference and clock reduce external component count to a bare minimum: a handful of bypass capacitors and decoupling at the supply pins are sufficient for most applications. The device can also be operated in ROM mode for reduced-microcontroller designs.
Typical applications include process-control data acquisition boards, instrumentation front-ends, motor-control feedback loops, medical monitoring equipment, and any high-accuracy industrial measurement requiring an easy-to-interface 12-bit ADC with built-in reference. The wide analog input range (up to ±10 V bipolar) makes the part especially attractive in legacy industrial systems that use ±10 V or 4 mA to 20 mA signaling. Pairing the MAX174BCWI+ with a precision op-amp front-end (such as the MAX4250) and an instrumentation amp (such as the MAX4194) builds a complete 12-bit analog input module.
When designing with the MAX174BCWI+, observe the Analog Devices datasheet supply-decoupling recommendation: place 10 µF tantalum and 0.1 µF ceramic bypass capacitors as close to the supply pins as possible. Re-calibrate the internal reference at first startup using the TrimDAC inputs if ±1 LSB absolute accuracy is required, especially at the limits of the operating temperature range.
This page synthesizes distributor pricing, drop-in same-brand alternatives, and practical design notes that complement the manufacturer datasheet - ideal for engineers evaluating the MAX174BCWI+ for new designs or as a drop-in for an end-of-life replacement in an existing board.
直接替換替代品，適用於 MAX174BCWI+ — 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： MAX174BCWI+ （相同外形與佔位） — 差異在於 Resolution, Package, Architecture, Mounting Type, Terminal Form.
MAX174ACWI+
✅ 直接替換📋 參考替代品（不在目錄中）
MAX174BCWI
✅ 直接替換📋 參考替代品（不在目錄中）
MAX174BCWI+T
✅ 直接替換📋 參考替代品（不在目錄中）
MAX173CWG
✅ 直接替換聯絡詢價
查看資料表 →MAX162BCNG+
✅ 直接替換聯絡詢價
查看資料表 →MAX174BCWI+ 最大額定值與電氣特性
| 解析度 | 12 bits |
| 取樣率 | 125 kSPS |
| Conversion Time | 8 µs |
| Number of Channels | 1 |
| Architecture | SAR (Successive Approximation) |
| 輸入電壓範圍 | 0 V to +10 V or 0 V to +20 V (unipolar); ±5 V or ±10 V (bipolar) |
| Internal Reference | 10 V buried zener, ±0.3 % (grade B) |
| 介面 | Parallel (8/12/16-bit bus compatible) |
| Supply Voltage (Digital) | +5 V |
| Supply Voltage (Analog) | ±12 V to ±15 V (bipolar operation) |
| Integral Nonlinearity | ±1 LSB max (grade B) |
| Differential Nonlinearity | ±1 LSB max (no missing codes) |
| 工作溫度 | 0 °C to +70 °C |
| 封裝 | 28-pin SOIC (wide, 7.5 mm body width) |
| 安裝類型 | Surface Mount |
MAX174BCWI+ 腳位配置
| 腳位 1 | DB11 — Data bit 11 (MSB) - parallel output |
| 腳位 2 | DB10 — Data bit 10 - parallel output |
| 腳位 3 | DB9 — Data bit 9 - parallel output |
| 腳位 4 | DB8 — Data bit 8 - parallel output |
| 腳位 5 | DB7 — Data bit 7 - parallel output |
| 腳位 6 | DB6 — Data bit 6 - parallel output |
| 腳位 7 | DB5 — Data bit 5 - parallel output |
| 腳位 8 | DB4 — Data bit 4 - parallel output |
| 腳位 9 | DB3 — Data bit 3 - parallel output |
| 腳位 10 | DB2 — Data bit 2 - parallel output |
| 腳位 11 | DB1 — Data bit 1 - parallel output |
| 腳位 12 | DB0 — Data bit 0 (LSB) - parallel output |
| 腳位 13 | STATUS — End-of-conversion status flag |
| 腳位 14 | /CS — Chip select, active low |
| 腳位 15 | /RD — Read strobe, active low |
| 腳位 16 | DGND — Digital ground |
| 腳位 17 | DVDD — +5 V digital supply |
| 腳位 18 | REF — +10 V reference output / input (TrimDAC) |
| 腳位 19 | REFIN — Reference input (TrimDAC adjustment node) |
| 腳位 20 | AGND — Analog ground |
| 腳位 21 | +VCC — +15 V analog supply (positive rail for bipolar inputs) |
| 腳位 22 | -VCC — -15 V analog supply (negative rail for bipolar inputs) |
| 腳位 23 | AIN — Analog input (unipolar 0-10 V / 0-20 V or bipolar ±5 V / ±10 V) |
| 腳位 24 | RANGE — Input range select (input current 0.2 mA) |
| 腳位 25 | BIP — Bipolar mode select (offset adjustment) |
| 腳位 26 | CAL — Calibration mode select |
| 腳位 27 | BPOFF — Bipolar offset adjustment pin |
| 腳位 28 | TRIM — Reference trim (TrimDAC) |
典型應用
MAX174BCWI+ 適用於 6 應用s: Process Control Data Acquisition, Industrial Instrumentation Front-End, Motor Control Feedback, Medical Monitoring Equipment, Test and Measurement Equipment, Legacy Industrial Bus Digitizers.
Process Control Data Acquisition
The MAX174BCWI+ suits multi-channel process-control front-ends where 12-bit resolution at 125 kSPS is sufficient and a wide bipolar input range is mandatory. Its 0 V to +10 V and ±10 V input ranges cover 4-20 mA current-loop receivers (with a 100 Ω shunt) and ±10 V industrial transducers without external signal conditioning. The on-chip 10 V buried-zener reference removes the need for an external precision reference, cutting BOM cost by ~$2 per ADC channel. Place 10 µF tantalum plus 0.1 µF ceramic bypass capacitors at each supply pin to keep conversion noise below 1 LSB. Compared with newer SAR ADCs the MAX174BCWI+ offers a familiar digital interface that drops straight into 8051-style legacy controllers.
推薦
Industrial Instrumentation Front-End
Industrial instrumentation subsystems benefit from the MAX174BCWI+'s true-bipolar ±10 V input range, which lets a single ADC digitize both unipolar 0-10 V sensor outputs and bipolar ±10 V signals from strain gauges and load cells without external level shifting. The parallel 8/12/16-bit interface is a clean fit for legacy microcontrollers and bus arbiters, and the on-board 10 V reference with ±0.3 % accuracy helps the overall system meet ±1 LSB at full scale without external trimming. In typical rack-mount instrumentation this ADC sits behind a low-noise op-amp buffer and feeds a 12-bit parallel bus to a host processor; the conversion-time penalty (~8 µs) is acceptable for 10 kHz update rate applications like temperature control loops.
推薦
Motor Control Feedback
Brushless-DC and industrial servo drives use the MAX174BCWI+ in position/velocity feedback loops where 12-bit resolution and 125 kSPS throughput give sub-millisecond loop update rates. The chip's +5 V digital supply matches typical microcontrollers, while the ±15 V analog supply lets the ADC directly digitize current-sense signals from shunt resistors amplified to a ±10 V range. The STATUS pin provides an end-of-conversion flag for synchronizing control-loop computation with sampling, ensuring deterministic timing. Track-and-hold behavior on the input makes the ADC tolerant of high-dV/dt PWM edges typical in 3-phase inverter modules.
推薦
Medical Monitoring Equipment
Patient monitoring devices use the MAX174BCWI+ to digitize analog signals from ECG, pulse-oximeter, and temperature sensors where 12-bit resolution and the ±10 V input range suffice for moderate-amplitude physiological signals. The internal buried-zener reference and well-defined INL/DNL figures aid IEC 60601-1 compliance testing because gain drift stays within ±1 LSB across the commercial operating range. The parallel interface simplifies integration with medically certified microcontrollers and CPLDs, reducing firmware complexity. Layout should keep digital switching currents away from the analog input traces to maintain CMRR above 80 dB.
推薦
Test and Measurement Equipment
Bench-top DMMs, dataloggers, and laboratory instruments often use the MAX174BCWI+ as the main DC measurement ADC thanks to its no-missing-codes 12-bit performance and on-board 10 V reference. Engineers repurposing the part for multimeter-grade inputs pair it with a precision input divider and front-end protection clamp, achieving 0.025 % DC accuracy on the 10 V range. Multiple chips can be paralleled with chip-select multiplexing to build a low-cost multi-channel data acquisition module where each channel is software-accessible via a parallel bus. The commercial temperature range (0 °C to +70 °C) suits lab and light-industrial environments.
推薦
Legacy Industrial Bus Digitizers
Many legacy 4 mA-to-20 mA current-loop and ±10 V analog-bus industrial networks persist in factory automation, where designers retrofit the MAX174BCWI+ to digitize a 4-20 mA signal with a 100 Ω shunt and feed it to a modern microcontroller or bus transceiver. The wide ±10 V input range handles +/- 10 V signaling without external protection, and the 8 µs conversion time provides ample throughput for 100 Hz digital-loop update rates typical in process control. The 28-pin SOIC wide-body package is hand-solderable for low-volume retrofit manufacturing, helping maintenance engineers build replacement boards without specialized fine-pitch equipment.
推薦
推薦產品摘要
工程參考資料，適用於 MAX174BCWI+ — 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 | MAX174ACWI+ | MAX174BCWI | MAX174BCWI+T | MAX173CWG | MAX162BCNG+ |
|---|---|---|---|---|---|---|
| Brand | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated |
| Package | 28-SOIC (wide) | 28-SOIC (wide) - same | 28-SOIC (wide) - same | 28-SOIC (wide) - same | 28-SOIC (wide) - same | 28-SOIC - same |
| Resolution | 12 bits | 12 bits | 12 bits | 12 bits | 12 bits | 12 bits |
| Operating Temperature | 0 °C to +70 °C | 0 °C to +70 °C | 0 °C to +70 °C | 0 °C to +70 °C | 0 °C to +70 °C | 0 °C to +70 °C |
主要差異化特點
- Trade-off - internal reference reduces BOM but is only ±0.3 % accurate (對比MAX174ACWI+)
- RoHS finish is a lead-free finish verified at distributors (對比MAX174BCWI (no "+"))
- Tube packaging suited for low-volume kitting (對比MAX174BCWI+T)
- Higher throughput (125 kSPS) vs MAX162 family (對比MAX162BCNG+)
設計說明
Estimated: at +5 V digital supply drawing I_DD and ±15 V analog rails drawing I_CC, total power dissipation is approximately 150 mW to 250 mW. Add 10 µF tantalum and 0.1 µF ceramic bypass capacitors as close as possible to the DVDD (+5 V), +VCC (+15 V), and -VCC (-15 V) supply pins. A ferrite bead between the +5 V analog and digital rails is recommended to prevent digital switching noise from corrupting the conversion result. Estimated based on datasheet typical figures.
Use a single ground plane subdivided between analog (AGND) and digital (DGND) sections, with the connections made only at the AGND/DGND pins of the ADC. Route the parallel data bus away from the analog input traces to avoid digital coupling into the sample-and-hold input; the data bus should be 50 Ω characteristic impedance if you are running longer than 50 mm. Power-trace widths should be sized for at least 200 mA current to handle inrush during power-up without dropping more than ~50 mV.
Three pitfalls to avoid: (1) Operating the AIN pin outside the absolute-maximum range can latch-up the device - add external clamping diodes if the input can exceed +VCC+0.3 V or fall below -VCC-0.3 V during fault conditions. (2) The on-chip reference requires a 50 µA to 500 µA load to maintain regulation - never short REF to AGND. (3) Forgetting to strap the RANGE and BIP pins correctly before applying analog input can produce incorrect conversion results and corrupt calibration; always verify these pins with a multimeter at power-up.
The MAX174BCWI+ tracks analog input continuously even when not converting, so high-impedance signal sources should be buffered by an op-amp (e.g. MAX4250) to avoid droop. Source impedance below 1 kΩ is recommended to keep settling errors below ¼ LSB; higher impedances degrade INL at full-scale inputs. For 8-channel multiplexing, use a Maxim DG408 or equivalent low-charge-injection multiplexer and provide at least 1 µs between channel switch and conversion start to allow the S&H capacitor to settle.
合規資訊
"+" suffix indicates RoHS compliance. AEC-Q100 not applicable (commercial-grade only).
