MAX1402EAI+W - 18-Bit Sigma-Delta ADC, 28-Pin SSOP | ADI
料号： MAX1402EAI+W ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $21.06 | $21.06 |
| 10 | $19.85 | $198.50 |
| 100 | $17.4 | $1,740.00 |
| 500 | $15.2 | $7,600.00 |
| 1,000 | $13.85 | $13,850.00 |
MAX1402EAI+W 概述
A sigma-delta ADC is a type of oversampling converter that trades speed for resolution by sampling at a rate much higher than the Nyquist frequency and shaping quantization noise out of the baseband. Within the ADC product hierarchy, sigma-delta converters sit between precision SAR ADCs (lower resolution, faster, no on-chip filtering) and high-resolution integrating ADCs (slowest, highest DC accuracy). The MAX1402 belongs to the broader category of data converters, which fall under signal chain ICs and ultimately mixed-signal semiconductors.
Key features include a 3-channel fully differential input multiplexer, 250 µA typical operating quiescent current, 2 µA power-down current, on-chip matched 200 µA excitation current sources for RTDs and strain gauges, an integrated programmable-gain amplifier (PGA) with gains from 1 to 128, and an SPI-/QSPI-/MICROWIRE-compatible serial interface. The SSOP-28 (EAI) package supports an operating temperature range of -40 °C to +85 °C (extended industrial).
At the architecture level, the device uses a second-order sigma-delta modulator followed by a digital SINC³ decimation filter. Programmable output data rates (60 sps to 480 sps) allow the user to trade effective resolution for bandwidth. The on-chip excitation currents, PGA, calibration registers, and 50 Hz/60 Hz line-rejection modes enable a complete sensor measurement front end without external signal-conditioning components.
Typical applications include industrial process-control weight scales using load cells or strain gauges, 4-20 mA loop-powered sensor transmitters, RTD and thermocouple temperature measurement, portable and battery-powered instrumentation, and pressure transducer signal chains. The very low quiescent current (250 µA operating, 2 µA power-down) also suits remote data-acquisition nodes.
Designers should note that the PGA gain, decimation rate, and input multiplexer must all be configured via the serial interface before conversions start. Decoupling the AVDD/DVDD pins with 10 µF + 0.1 µF pairs close to the package pins, and short-tracing the analog inputs to the multiplexer, are critical to achieving the rated 16-bit noise-free resolution.
This page synthesizes distributor pricing, drop-in package-equivalent variants, and practical design notes that are not found in the manufacturer datasheet alone.
直接替换替代料： MAX1402EAI+W ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
本系列中的变体
可与以下型号直接替换的同系列型号： MAX1402EAI+W （相同外形与封装尺寸） ——差异在于 Interface, Package, Supply Voltage, Resolution, Architecture.
快速对比工具——选择替代料号进行并排对比：
MAX1402EAI+
✅ 直接替换📋 参考替代料（不在目录中）
MAX1401EAI
✅ 直接替换✓ 有现货
$9.05 / 个
查看数据手册 →MAX1400EAI
✅ 直接替换✓ 有现货
$14.2 / 个
查看数据手册 →MAX1402CAI
✅ 直接替换📋 参考替代料（不在目录中）
MAX1402EAI+W 最大额定值与电气特性
| 分辨率 | 18 bits |
| No-Missing-Code Accuracy | 16 bits at 480 sps |
| Output Data Rate (max) | 480 sps |
| Output Data Rate (programmable) | 60 sps to 480 sps |
| 电源电压 | +5 V nominal |
| Analog Inputs | 3 differential / pseudo-differential channels |
| PGA Gain Range | 1 to 128 |
| On-Chip Current Sources | 2 x 200 µA matched |
| Quiescent Current (operating) | 250 µA typ |
| Quiescent Current (power-down) | 2 µA typ |
| 接口 | SPI / QSPI / MICROWIRE-compatible serial |
| Architecture | Sigma-delta modulator + SINC3 decimation filter |
| 封装 | 28-pin SSOP (EAI) |
| 工作温度 | -40 °C to +85 °C |
| 安装类型 | Surface Mount |
| RoHS 状态 | Compliant |
| MSL 等级 | 1 (per JEDEC J-STD-020) |
MAX1402EAI+W 引脚配置
| 引脚 1 | IEXC1 — Matched 200 µA excitation current source 1 |
| 引脚 2 | IEXC2 — Matched 200 µA excitation current source 2 |
| 引脚 3 | REF — External reference voltage input |
| 引脚 4 | AGND — Analog ground |
| 引脚 5 | AVDD — +5 V analog supply |
| 引脚 6 | AIN1+ — Analog input 1 positive |
| 引脚 7 | AIN1- — Analog input 1 negative |
| 引脚 8 | AIN2+ — Analog input 2 positive |
| 引脚 9 | AIN2- — Analog input 2 negative |
| 引脚 10 | AIN3+ — Analog input 3 positive |
| 引脚 11 | AIN3- — Analog input 3 negative |
| 引脚 12 | AGND — Analog ground (sense) |
| 引脚 13 | DGND — Digital ground |
| 引脚 14 | DVDD — +5 V digital supply |
| 引脚 15 | CS — Active-low chip select for serial interface |
| 引脚 16 | SCLK — Serial interface clock |
| 引脚 17 | DIN — Serial data input |
| 引脚 18 | DOUT — Serial data output |
| 引脚 19 | INT — Interrupt / data-ready output |
| 引脚 20 | XTAL1 — Crystal oscillator input |
| 引脚 21 | XTAL2 — Crystal oscillator output |
| 引脚 22 | CLK — External clock input (alternate) |
| 引脚 23 | CAL — Calibration control input |
| 引脚 24 | PD — Active-low power-down input |
| 引脚 25 | MODE — Mode select / calibration enable |
| 引脚 26 | FSYNC — Frame synchronization for filter |
| 引脚 27 | NC — Not connected (per datasheet) |
| 引脚 28 | NC — Not connected (per datasheet) |
典型应用
MAX1402EAI+W 适用于 6 应用s: Industrial Weighing Scale / Load Cell Front End, RTD / PT100 Temperature Transmitter, Thermocouple Temperature Measurement, Pressure Transducer Signal Chain, Portable Battery-Powered Data Acquisition, Industrial Process-Control 4-20 mA Loop Transmitter.
Industrial Weighing Scale / Load Cell Front End
The MAX1402EAI+W is purpose-built for strain-gauge and load-cell weighing-scale front ends. Its on-chip matched 200 µA excitation currents directly drive the bridge network, eliminating external precision current sources. The integrated PGA with gains up to 128 amplifies the millivolt-level bridge output to fill the ADC input range, while the sigma-delta modulator and SINC3 digital filter deliver 16-bit no-missing-code accuracy at 480 sps. With 50 Hz / 60 Hz line-rejection modes, the device naturally rejects mains interference on factory floors. Quiescent current is only 250 µA in operation and 2 µA in power-down, so the part fits loop-powered 4-20 mA weight transmitters. Recommended companion parts: MAX1402EAI+ (drop-in variant), MAX1401EAI (lower-cost 16-bit option), and an external precision resistor network for gain calibration.
推荐
RTD / PT100 Temperature Transmitter
The MAX1402EAI+W simplifies PT100 / PT500 / PT1000 RTD temperature transmitters by combining matched 200 µA excitation currents with a high-gain PGA. The same excitation current drives both the RTD and the reference resistor, so ratiometric measurement cancels current-source drift - critical for industrial-grade temperature accuracy. The 18-bit sigma-delta conversion provides better than 0.05 °C resolution over a 250 °C span, while the on-chip 50 Hz / 60 Hz rejection removes mains pickup from thermocouple extension leads. The 250 µA quiescent current allows 4-20 mA loop-powered operation, and the 2 µA power-down mode supports duty-cycled battery-powered field instruments. Recommended companion parts: MAX1402EAI+ for second-source flexibility, and an op-amp buffer to drive the 4-20 mA loop.
推荐
Thermocouple Temperature Measurement
The MAX1402EAI+W can digitize thermocouple outputs directly when paired with a cold-junction compensation sensor. Its 18-bit sigma-delta resolution resolves microvolt-level thermocouple voltages, while the programmable output data rate allows the user to trade speed for noise - at the slowest 60 sps rate, the effective input-referred noise is below 1 µV RMS. The on-chip PGA eliminates the need for a dedicated instrumentation amplifier in front of the ADC, reducing both BOM cost and board area. Rejection of 50 Hz / 60 Hz mains interference is performed in the digital decimation filter, simplifying the analog front end. Recommended companion parts: MAX1402EAI+ as second-source, MAX11164ETC+T as a companion cold-junction ADC, and a low-thermocouple-grade connector.
推荐
Pressure Transducer Signal Chain
Pressure transducers based on Wheatstone bridges (e.g., MEMS piezoresistive, bonded strain gauges) interface directly to the MAX1402EAI+W. The on-chip matched 200 µA current sources drive the bridge without external components, while the PGA handles millivolt-level outputs from the bridge. The 18-bit sigma-delta conversion provides the resolution needed for medical and HVAC pressure sensing, and the SSOP-28 package is small enough to fit inside the transducer housing. The 250 µA quiescent current keeps loop-powered pressure transmitters within their 4 mA zero-scale current budget. Recommended companion parts: MAX1402EAI+ as second-source, MAX11164ETC+T for redundant channel, and an EEPROM for calibration storage.
推荐
Portable Battery-Powered Data Acquisition
Battery-powered data-acquisition systems benefit from the MAX1402EAI+W's very low 250 µA operating quiescent current and 2 µA power-down current. The on-chip PGA, multiplexer, and excitation current sources eliminate the need for multiple analog components, extending battery life in portable instruments. The 18-bit sigma-delta conversion supports medical, environmental, and industrial handheld instruments where resolution and accuracy matter more than absolute bandwidth. The serial SPI interface minimizes microcontroller GPIO usage and supports direct connection to low-power MCUs in sleep mode. Recommended companion parts: MAX1402EAI+ as second-source, and a low-power MCU such as a MAX32xxx-series part for system control.
推荐
Industrial Process-Control 4-20 mA Loop Transmitter
The MAX1402EAI+W is a complete front-end for loop-powered 4-20 mA smart transmitters. Its 250 µA quiescent current leaves enough of the 4 mA zero-scale budget for the rest of the transmitter electronics, and its on-chip PGA, excitation currents, and ADC remove the need for external analog signal conditioning. The 18-bit resolution supports the 0.1 % accuracy typical of industrial pressure, flow, and level transmitters, and the digital SPI interface enables in-system programming and remote calibration via HART or similar protocols. Recommended companion parts: MAX1402EAI+ as second-source, MAX11164ETC+T as a companion diagnostic ADC, and a HART modem for digital communication over the loop.
推荐
推荐产品汇总
工程参考数据： MAX1402EAI+W ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | MAX1402EAI+ | MAX1401EAI | MAX1400EAI | MAX1402CAI |
|---|---|---|---|---|---|
| Brand | Analog Devices (formerly Maxim) | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | SSOP-28 (EAI) | SSOP-28 - same | SSOP-28 - same | SSOP-28 - same | SSOP-28 - same |
| Resolution | 18 bits | 18 bits | 16 bits | 12 bits | 18 bits |
| On-Chip Current Sources | 2 x 200 µA | 2 x 200 µA | 2 x 200 µA | 2 x 200 µA | 2 x 200 µA |
关键差异点
- Integrated matched 200 µA excitation current sources for direct RTD / strain-gauge drive （对比 MAX1401EAI)
- Highest effective resolution in the MAX1402 family （对比 MAX1400EAI)
- Extended -40 °C to +85 °C industrial temperature range （对比 MAX1402CAI)
设计说明
Decouple AVDD and DVDD independently with 10 µF tantalum + 0.1 µF ceramic pairs placed within 5 mm of each supply pin. Tie AGND and DGND at a single star ground beneath the IC. According to the Analog Devices datasheet, AVDD noise couples directly into the reference and degrades effective resolution; a clean low-noise LDO (e.g., ADP150) is recommended in front of AVDD. Estimated: with 250 µA quiescent current, the LDO dissipation at 5 V is only 1.25 mW, so thermal is not a concern.
Keep analog input traces short and symmetric to minimize common-mode pickup; route REF and IEXC traces as a guarded differential pair. According to the Analog Devices datasheet application circuit, place the SSOP-28 with the analog pins (1-12) facing the sensor connector and digital pins (13-28) facing the MCU. Add a ground pour under the IC and stitch it to the AGND/DGND star with multiple vias to suppress digital switching noise on the analog front end.
The PGA gain and input multiplexer must be configured via the serial interface before starting conversions; failing to do so results in the ADC defaulting to AIN1 with unity gain. According to the Analog Devices datasheet, the on-chip calibration (self-cal and system-cal) should be run after every gain change to cancel PGA offset and gain errors. Also note that the excitation current sources are enabled only when REF is connected to a valid external reference - do not leave REF floating.
合规信息
RoHS and REACH compliance per Analog Devices (formerly Maxim Integrated) product page. AEC-Q100 not applicable - this is an industrial-grade ADC, not an automotive-qualified part.
