MAX121EWE+ - 14-Bit 308ksps ADC | Analog Devices
MPN： MAX121EWE+ ✓ 啟用中MAX121EWE+ 概覽
An ADC is a data-conversion IC that transforms an analog input voltage into a digital code for processing, measurement, or control. The MAX121 belongs to the successive-approximation ADC family, with the ADC category forming part of the broader data-conversion and signal-processing semiconductor hierarchy. Unlike flash and pipeline converters, this SAR architecture is appropriate for instrumentation where accuracy, cost, power consumption, and a compact serial interface are important design considerations.
Key features include 14-bit resolution, a maximum sampling rate of 308 ksps, and 78 dB SINAD. The integrated track-and-hold function simplifies front-end sampling, while the internal buried-zener reference reduces the need for an external precision reference. A low-noise reference and serial output are especially useful when measured data must be transferred directly to a digital signal processor or another serial master device.
Technically, the MAX121 uses a BiCMOS implementation combining analog sampling circuitry and digital control functions. Its serial-output architecture reduces the number of interconnects required for conversion data, allowing a compact 16-SOIC package. The manufacturer describes the device as operating with low power consumption and fast conversion speed, making it useful where acquisition speed must coexist with a limited board area and moderate system complexity.
Typical applications include industrial process measurement, sensor-interface digitizers, laboratory data-acquisition systems, DSP front ends, and embedded control systems. The 308 ksps rate supports high-speed sampling, while 14-bit resolution and 78 dB SINAD provide useful accuracy for monitoring analog quantities such as temperature, pressure, position, and voltage. Serial communications also reduce wiring requirements in multi-channel or distributed measurement equipment.
A critical design consideration is reference bypassing. According to the manufacturer datasheet, the reference output at VREF requires a 0.1 uF ceramic capacitor in parallel with a 22 uF or greater electrolytic capacitor to AGND, and the electrolytic capacitor ESR must be 100 mOhm or less. Input, reference, and digital-interface layouts should separate sensitive analog paths from switching and high-current return currents.
This page consolidates verified manufacturer and distributor information, package details, pricing, compatible family alternatives, and practical design guidance. It also distinguishes verified drop-in options from unspecified substitutes, helping engineers compare the MAX121EWE+ without relying on incomplete distributor listings or unverified cross-reference claims.
直接替換替代品，適用於 MAX121EWE+ — 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： MAX121EWE+ （相同外形與佔位） — 差異在於 Internal Reference, Package.
MAX121CWE+
✅ 直接替換聯絡詢價
查看資料表 →MAX121EWE
✅ 直接替換📋 參考替代品（不在目錄中）
MAX121CWE
✅ 直接替換📋 參考替代品（不在目錄中）
MAX121EWE+ 最大額定值與電氣特性
| 解析度 | 14 bit |
| 取樣率 | 308 ksps |
| Signal-to-Noise and Distortion | 78 dB SINAD |
| Architecture | Successive-approximation ADC (SAR) |
| Input Count | 1 input |
| Input Type | Single-ended |
| Output Interface | Serial output with DSP interface |
| Process Technology | BiCMOS |
| Sample-and-Hold | On-chip track-and-hold |
| Internal Reference | -5.00 V buried-zener reference |
| Reference Output | Available at the VREF pin |
| Reference Ceramic Bypass | 0.1 uF ceramic capacitor in parallel with a 22 uF or greater electrolytic capacitor |
| Reference Capacitor ESR Requirement | 100 mOhm or less |
| 封裝 | 16-SOIC, 0.295 inch / 7.50 mm width |
| 安裝類型 | Surface mount |
| Packaging | Tape & Reel |
MAX121EWE+ 16-soic, 0.295 inch / 7.50 mm width 腳位配置指南
MAX121EWE+（16-soic, 0.295 inch / 7.50 mm width 封裝）的腳位配置。 此類比元件具有輸入、輸出與電源腳位。偏移歸零、補償與致能腳位配置請參閱製造商資料表。適用於訊號調理與放大器電路。
無詳細腳位定義資料： MAX121EWE+.
請參閱 資料表 以查看完整腳位配置。
典型應用
MAX121EWE+ 適用於 6 應用s: Industrial Process Measurement, DSP Signal-Acquisition Front End, Sensor Signal Digitization, Laboratory Data Acquisition, Embedded Control Systems, Distributed Field Monitoring.
Industrial Process Measurement
The MAX121EWE+ fits industrial process-measurement systems that digitize pressure, temperature, level, or current sensor outputs while preserving 14-bit resolution and 78 dB SINAD. Its 308 ksps conversion rate permits faster acquisition than many general-purpose low-speed ADCs, allowing the controller to monitor multiple scaled sensor channels. The single-ended SAR input and on-chip track-and-hold simplify the analog front end, while the buried-zener reference reduces external reference complexity. Designers should still condition high-level industrial signals before the converter input and use the specified 0.1 uF ceramic plus 22 uF or greater electrolytic reference bypass network with ESR at or below 100 mOhm.
推薦
DSP Signal-Acquisition Front End
The MAX121EWE+ is appropriate for a DSP signal-acquisition front end requiring high sample throughput and compact serial connectivity. Its 308 ksps maximum rate supports rapid conversion, while 14-bit resolution and 78 dB SINAD supply useful information for waveform, vibration, or control analysis. The serial-output interface reduces the number of data lines required between the ADC and a DSP compared with a parallel converter. The design should use a short analog trace, a quiet AGND return, and the manufacturer-specified VREF bypass capacitors, while the host processor must support the converter's serial timing, clocking scheme, and signal levels.
推薦
Sensor Signal Digitization
The MAX121EWE+ can serve as the central ADC in a sensor digitization module for pressure, position, temperature, or low-level voltage sensing. Its 14-bit resolution provides 16,384 discrete codes, while the 78 dB SINAD specification defines the expected signal-to-noise and distortion performance for suitable excitation and input-conditioning circuits. The integrated track-and-hold and low-noise buried-zener reference help reduce external circuitry. For reliable results, the sensor amplifier must drive the input within the specified range, and the VREF network must be placed close to the converter with the required ceramic and low-ESR electrolytic capacitance.
推薦
Laboratory Data Acquisition
The MAX121EWE+ suits compact laboratory and test instrumentation where accurate, rapid conversion is required without a wide parallel data bus. Its 308 ksps throughput is useful for capturing repetitive or rapidly changing signals, and its 14-bit resolution and 78 dB SINAD can support measurements spanning a broad dynamic range. The serial interface eases connection to a controller, DSP, or communication transceiver. Layout quality remains essential: maintain a short analog path, connect the VREF bypass network directly to VREF and AGND, and isolate the converter from clock and power-converter return currents that could degrade conversion accuracy.
推薦
Embedded Control Systems
The MAX121EWE+ can serve as the analog measurement section of an embedded control system that evaluates sensor inputs and applies digital control decisions. A 308 ksps conversion rate allows the control loop to sample faster than many slow process-control inputs, while 14-bit resolution can reduce quantization error when scaling analog measurements. Its integrated track-and-hold and reference simplify implementation compared with a discrete converter and external reference arrangement. The controller should read the serial output according to the timing defined in the manufacturer datasheet, and the power and analog layout should prevent switching circuitry from coupling noise into the measurement path.
推薦
Distributed Field Monitoring
The MAX121EWE+ is suitable for distributed field-monitoring equipment that digitizes analog sensor values before transmission over a communications link. Its compact 16-SOIC package helps reduce board area, and the serial output limits wiring to the communications controller. The 14-bit resolution preserves measurement detail, while the 308 ksps rate supports higher-rate channels when needed. A communications transceiver such as RS-485 or CAN can carry the resulting digital data. Field designs should include input protection appropriate to the environment, isolated or protected communications where required, and strict separation between the analog input, reference bypass network, and high-energy interface circuits.
推薦
推薦產品摘要
工程參考資料，適用於 MAX121EWE+ — 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 | MAX121CWE+ | MAX121EWE | MAX121CWE |
|---|---|---|---|---|
| Package | 16-SOIC, 0.295 inch / 7.50 mm width | 16-SOIC | 16-SOIC | 16-SOIC |
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Resolution | 14 bit | 14 bit | 14 bit | 14 bit |
| ADC Architecture | Single-input SAR ADC | SAR ADC | SAR ADC | SAR ADC |
| Output Interface | Serial output with DSP interface | DSP interface | Serial output | Serial output |
| Track-and-Hold | On-chip | On-chip | On-chip | On-chip |
主要差異化特點
- The verified EWE+ configuration retains a 5 V reference (對比MAX121CWE+)
- Full verified core performance specification (對比MAX121EWE)
- Single-input 14-bit SAR conversion in a compact package (對比MAX121CWE)
設計說明
Place the VREF bypass network directly between VREF and AGND. The manufacturer datasheet specifies a 0.1 uF ceramic capacitor in parallel with a 22 uF or greater electrolytic capacitor, and the electrolytic part must have ESR of 100 mOhm or less. Keep both components close to their pins, minimize the loop area, and route the return directly to the quiet analog-ground reference rather than through digital or switching-current paths.
Treat the analog input, VREF, and AGND as a sensitive signal chain. Use a short input trace, avoid running it parallel to serial clock or power-converter traces, and keep high-current return paths away from the reference node. The integrated track-and-hold and buried-zener reference reduce component count, but they cannot compensate for poor grounding, reference decoupling, or input-trace coupling that injects conversion-dependent errors.
Do not treat the MAX121EWE+, MAX121CWE+, MAX121EWE, and MAX121CWE ordering codes as automatically interchangeable. The verified data identifies a 4.75 V reference for MAX121CWE+ versus a 5 V reference associated with MAX121EWE+, while the E and C suffix temperature details were not supplied. Download each complete manufacturer datasheet and verify pinout, temperature grade, supply limits, analog input range, and timing before substituting a part in production hardware.
合規資訊
The supplied web excerpts do not contain explicit RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals statements. AEC-Q100 is not applicable because this is an industrial/commercial data-conversion IC rather than an automotive-qualified device.
