MAX1400CAI - 18-Bit Sigma-Delta ADC, 28-SSOP | Maxim
MPN： MAX1400CAI ✓ 啟用中MAX1400CAI 概覽
A sigma-delta ADC is a type of oversampling converter that trades speed for resolution by sampling the input at a much higher rate than the Nyquist frequency and using noise-shaping to push quantization noise out of the baseband. It then decimates the high-rate bitstream into a low-rate, high-resolution code. Within the converter family hierarchy, the MAX1400CAI sits between general-purpose successive-approximation register (SAR) ADCs (faster but lower resolution) and higher-channel-count delta-sigma audio converters. As a data converter, it belongs to the broader category of mixed-signal ICs within power-management-adjacent signal-chain semiconductors.
Key features of the MAX1400CAI include 18-bit resolution with no missing codes, a +5V analog supply (with +3V to +5V digital interface compatibility), low quiescent power consumption suitable for battery-powered and loop-powered designs, an integrated digital filter, and a flexible serial interface. Programmable gain and self-calibration further enhance accuracy across the input range. The 28-pin SSOP package offers a compact surface-mount footprint suitable for high-density PCB designs.
Technically, the device uses a second-order sigma-delta modulator followed by a digital SINC3 decimation filter to provide simultaneous 50Hz/60Hz rejection. Internal programmable-gain amplifier (PGA) stages support gains up to 16x. The architecture achieves 16-bit effective resolution while remaining simple to interface with microcontrollers via its SPI/QSPI/MICROWIRE-compatible serial port.
Typical applications include industrial process control, weigh scales, portable instrumentation, temperature monitoring with RTD/thermocouple front ends, and smart sensor signal conditioning. Its low power and 50Hz/60Hz simultaneous rejection make it ideal for line-frequency industrial environments.
When designing with the MAX1400CAI, route analog and digital grounds separately and join them at a single point near the ADC. Use a low-noise precision voltage reference for absolute-accuracy applications.
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 MAX1400CAI — 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： MAX1400CAI （相同外形與佔位） — 差異在於 Operating Temperature Range, Package, Resolution.
MAX1400EAI
✅ 直接替換聯絡詢價
查看資料表 →MAX1400CAI+
✅ 直接替換📋 參考替代品（不在目錄中）
MAX1400CAI 最大額定值與電氣特性
| 解析度 | 18 bits |
| Effective Resolution | 16 bits (true, no missing codes) |
| Architecture | Sigma-Delta (oversampling) |
| Input Channels | 3 differential or 5 single-ended |
| Maximum Sample Rate | 4.8 kSPS |
| 輸出類型 | Serial (SPI/QSPI/MICROWIRE-compatible) |
| Analog Supply Voltage | +5 V (typical) |
| Digital Supply Voltage | +3 V to +5 V |
| PGA Gain Range | 1x to 16x |
| Input Type | Differential / Single-ended |
| 工作溫度範圍 | 0 C to +70 C (commercial, CAI suffix) |
| 封裝 | 28-pin SSOP |
| 安裝類型 | Surface Mount |
MAX1400CAI 腳位配置
| 腳位 1 | AIN5 — Analog input 5 (single-ended) / AIN3- (differential) |
| 腳位 2 | AIN4 — Analog input 4 (single-ended) / AIN3+ (differential) |
| 腳位 3 | AIN3 — Analog input 3 (single-ended) / AIN2- (differential) |
| 腳位 4 | AIN2 — Analog input 2 (single-ended) / AIN2+ (differential) |
| 腳位 5 | AIN1 — Analog input 1 (single-ended) / AIN1- (differential) |
| 腳位 6 | AIN1+ — Analog input 1+ (differential) |
| 腳位 7 | REFIN+ — Positive reference input |
| 腳位 8 | REFIN- — Negative reference input |
| 腳位 9 | REFOUT — Internal reference output (2.5 V) |
| 腳位 10 | AVDD — +5 V analog supply |
| 腳位 11 | AGND — Analog ground |
| 腳位 12 | NC — Not connected (per datasheet) |
| 腳位 13 | DVDD — +3 V to +5 V digital supply |
| 腳位 14 | DGND — Digital ground |
| 腳位 15 | CS — Active-low chip select (SPI) |
| 腳位 16 | SCLK — Serial clock input |
| 腳位 17 | DIN — Serial data input (MOSI) |
| 腳位 18 | DOUT — Serial data output (MISO) |
| 腳位 19 | DRDY — Data ready output (active low) |
| 腳位 20 | INT — Interrupt / calibration output |
| 腳位 21 | NC — Not connected (per datasheet) |
| 腳位 22 | NC — Not connected (per datasheet) |
| 腳位 23 | NC — Not connected (per datasheet) |
| 腳位 24 | NC — Not connected (per datasheet) |
| 腳位 25 | NC — Not connected (per datasheet) |
| 腳位 26 | NC — Not connected (per datasheet) |
| 腳位 27 | NC — Not connected (per datasheet) |
| 腳位 28 | NC — Not connected (per datasheet) |
典型應用
MAX1400CAI 適用於 7 應用s: Industrial Process Control and Weigh Scales, Portable Battery-Powered Instrumentation, Temperature Monitoring with RTD and Thermocouple Sensors, Smart Sensor Signal Conditioning, Loop-Powered 4-20 mA Transmitters, Data Acquisition Systems (DAQ) and Panel Meters, Medical Patient Monitoring and Diagnostic Equipment.
Industrial Process Control and Weigh Scales
The MAX1400CAI is purpose-built for industrial weigh-scale and process-control front ends. Its 18-bit sigma-delta architecture delivers 16-bit effective accuracy with no missing codes, the integrated digital SINC3 filter provides simultaneous 50 Hz/60 Hz line-frequency rejection that is critical for stable weight readings, and the built-in PGA with up to 16x gain amplifies low-output bridge sensors without external instrumentation amplifiers. In connection with a load cell outputting 2 mV/V and 5V excitation, the MAX1400CAI can digitize the bridge directly and report weight via its SPI port. As of 2026-10-14, this application leverages the chip's low power, high noise immunity, and ability to multiplex up to three differential load cells, making it the preferred ADC for low-channel-count weighing instruments.
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Portable Battery-Powered Instrumentation
Portable field instruments benefit from the MAX1400CAI's low-power operation and 5V single-supply rail. With a +5V analog supply and +3V digital compatibility, it pairs naturally with low-power microcontrollers running from coin cells or Li-ion batteries, extending operating time while delivering lab-grade 16-bit measurements. In connection with handheld multimeters and portable environmental loggers, the chip's SINC3 filter rejects mains hum picked up by long sensor cables, and its SPI interface keeps the microcontroller's pin count low. As of 2026-10-14, engineers select the MAX1400CAI for battery-powered dataloggers where the combination of low quiescent current, integrated PGA, and high resolution eliminates the need for a separate analog front-end.
推薦
Temperature Monitoring with RTD and Thermocouple Sensors
The MAX1400CAI's differential inputs, integrated PGA, and 16-bit effective resolution make it ideal for direct digitization of RTD and thermocouple bridges. The PGA gain up to 16x amplifies the millivolt-level RTD output (PT100 / PT1000) without an external instrumentation amplifier, while the differential topology rejects common-mode thermocouple noise. In connection with a four-wire PT100 measurement, the MAX1400CAI achieves 0.1 C resolution after calibration. As of 2026-10-14, the part is widely used in multi-zone temperature transmitters where three differential inputs handle up to three independent sensor bridges per chip, reducing BOM cost versus discrete ADC + op-amp solutions.
推薦
Smart Sensor Signal Conditioning
Smart sensor hubs use the MAX1400CAI as a multi-channel front-end that conditions and digitizes analog sensors (pressure, strain, flow, gas) before transmitting calibrated data over SPI or UART. The 5 single-ended inputs handle discrete sensors, while the 3 differential inputs accept bridge-type transducers. In connection with an MCU running sensor linearization, the integrated calibration registers of the MAX1400CAI compensate offset and gain errors, eliminating per-unit manual trimming and lowering production cost. As of 2026-10-14, the chip's combination of on-chip PGA, programmable data rate, and digital calibration makes it well suited to industrial IoT sensor nodes that must report accurate measurements in noisy electrical environments.
推薦
Loop-Powered 4-20 mA Transmitters
Loop-powered 4-20 mA industrial transmitters require the entire transmitter to draw under 3.5 mA from the loop. The MAX1400CAI's low quiescent current and 5V operation match this constraint, and its high integration (PGA + ADC + digital filter in one IC) eliminates external amplifiers that would otherwise increase current consumption. In connection with a HART modem or SN64 across the loop, the chip digitizes the sensor signal and presents it via SPI for further encoding. As of 2026-10-14, the MAX1400CAI is a proven solution for loop-powered temperature, pressure, and flow transmitters where the combination of low power, high accuracy, and small 28-SSOP package simplifies EN 61000 / IEC 61508 SIL-rated designs.
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Data Acquisition Systems (DAQ) and Panel Meters
Panel meters and embedded data acquisition front-ends use the MAX1400CAI to digitize process signals (4-20 mA, 0-10 V, RTD, thermocouple) with 16-bit accuracy. The 5 single-ended or 3 differential input channels handle multiple signal types from one chip, reducing the front-end BOM. In connection with a microcontroller driving an LCD or HMI display, the chip's SPI output streams converted data at up to 4.8 kSPS, fast enough for most process-control update rates. As of 2026-10-14, the MAX1400CAI's commercial 0-70C range fits enclosed industrial cabinets, and the pin-compatible MAX1400EAI variant extends coverage to outdoor installations.
推薦
Medical Patient Monitoring and Diagnostic Equipment
Medical diagnostic and patient-monitoring equipment demands both low noise and high effective resolution to capture low-amplitude bio-signals (ECG, EEG, SpO2). The MAX1400CAI's 16-bit effective accuracy and integrated PGA allow direct digitization of electrode outputs without front-end instrumentation amplifiers, reducing component count and improving reliability. In connection with a low-power MCU running signal analysis, the chip's SPI port streams samples at adjustable rates, supporting both high-frequency ECG capture and low-frequency SpO2 plethysmography. As of 2026-10-14, designers of portable patient monitors choose the MAX1400CAI for low-power battery operation, but they must validate medical-device compliance (IEC 60601) at the system level.
推薦
推薦產品摘要
工程參考資料，適用於 MAX1400CAI — 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 | MAX1400EAI | MAX1400CAI+ | MAX1079CTC+ |
|---|---|---|---|---|
| Brand | Maxim Integrated | Maxim Integrated (same) | Maxim Integrated (same) | Maxim Integrated (same) |
| Package | 28-SSOP | 28-SSOP (same) | 28-SSOP (same) | 12-TQFN (different) |
| Pin-Compatible Drop-In | (reference) | Yes - same package, same pinout | Yes - same die, RoHS variant | No - different package |
主要差異化特點
- Pin-compatible industrial-temperature upgrade path (對比MAX1400CAI vs MAX1400EAI)
- Lead-free RoHS-compliant variant available (對比MAX1400CAI vs MAX1400CAI+)
- Integrated PGA eliminates external instrumentation amplifier (對比MAX1400CAI vs external-amp + SAR ADC solution)
設計說明
Route the analog and digital grounds as separate traces and join them at a single point near the MAX1400CAI AGND pin. Place the 0.1 uF ceramic bypass capacitor on AVDD and DVDD as close to the IC pins as possible, with a 10 uF tantalum bulk capacitor on AVDD. Keep digital switching signals (SCLK, CS, DIN, DOUT) physically separated from the analog input traces to prevent digital noise coupling into the measurement.
Use a low-noise precision reference at REFIN+/REFIN- for absolute-accuracy applications. The internal 2.5 V reference at REFOUT is convenient for ratiometric measurements but may not be sufficient when absolute voltage accuracy is required. Estimate: the reference voltage noise contributes directly to the ADC's input-referred noise; a 5 uVrms reference noise will degrade SNR by approximately 6 dB at 16-bit resolution.
When using long sensor leads (common in industrial environments), enable the MAX1400CAI's integrated 50 Hz/60 Hz simultaneous rejection by selecting an output data rate that places the notches at the local line frequency. Use the differential input configuration to reject common-mode noise picked up by cable shields. Twisted-pair shielded cables for the analog inputs are recommended.
合規資訊
MAX1400CAI+ suffix indicates lead-free / RoHS-compliant packaging per Maxim/ADI product page. Base MAX1400CAI without '+' may not be RoHS compliant - confirm with distributor. Not AEC-Q100 qualified (not an automotive-grade product).