ADS821U - 10-Bit 40-MSPS ADC | Texas Instruments | Signal Capture
MPN： ADS821U ✓ 啟用中ADS821U 概覽
An ADC is a data-acquisition IC that samples an analog voltage and converts it into a digital code for processing by a microcontroller, DSP, FPGA, or test system. The ADS821U belongs to the pipeline ADC family, with its resolution, conversion rate, input architecture, reference, and acquisition circuitry defining its role within a broader analog-to-digital conversion and signal-processing hierarchy.
The converter's principal features are 40 MSPS operation, 10-bit resolution, 58 dB SNR, and 9.3-bit ENOB. The no-missing-codes feature supports deterministic output behavior, while the internal track-and-hold circuit simplifies front-end design. The verified product information also identifies a 380 mW low-power figure and supports SOIC-28 and SSOP-28 family packaging, with ADS821U specifically supplied in the 28-pin SOIC package.
Technically, the ADS821U is designed for single-ended or differential input acquisition. An internal reference and internal track-and-hold function reduce the number of external support blocks required in a conventional measurement chain. However, signal bandwidth, input range, timing, reference behavior, and electrical limits must be confirmed from the manufacturer datasheet before finalizing analog front-end and clock design.
Typical uses include communications and signal-analysis equipment, industrial measurement systems, test and measurement instruments, and embedded control or processing platforms that need a 40-MSPS conversion rate. The 10-bit code width is appropriate where the required information bandwidth is greater than the precision demanded from every individual sample.
A key design consideration is that the ADC does not replace the surrounding analog system. Input scaling, source impedance, anti-alias filtering, clock jitter, grounding, decoupling, and digital-interface timing determine practical performance. Confirm the pinout and pin functions in the official datasheet before layout or replacement work.
This page combines verified manufacturer and distributor information with application guidance, practical design notes, and explicitly qualified replacement considerations. Unverified prices, complete pin functions, and unconfirmed cross-brand drop-in equivalents are not inferred.
直接替換替代品，適用於 ADS821U — 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。
ADS821U-1
✅ 直接替換📋 參考替代品（不在目錄中）
ADS821U 最大額定值與電氣特性
| Converter Type | Pipelined analog-to-digital converter |
| 解析度 | 10 bit |
| 取樣率 | 40 MSPS |
| Input Configuration | 1 input; single-ended or differential |
| Signal-to-Noise Ratio | 58 dB |
| Effective Number of Bits | 9.3 bit |
| Power Consumption | 380 mW |
| Internal Reference | Internal |
| Track-and-Hold | Internal |
| Missing Code Behavior | No missing codes |
| Input Voltage | 1.25 V |
| 封裝 | SOIC-28 (DW) |
| 腳位數 | 28 pin |
| 安裝類型 | Surface mount |
| 工作溫度 | -40 C to +85 C |
| Screening Level | Industrial |
| Architecture | Monolithic |
ADS821U soic-28 (dw) 腳位配置指南
ADS821U（soic-28 (dw) 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： ADS821U.
請參閱 資料表 以查看完整腳位配置。
典型應用
ADS821U 適用於 6 應用s: Communications Signal Capture, Test and Measurement Instrumentation, Industrial Measurement Systems, Waveform Data Acquisition, Embedded Control and Monitoring, Sensor Signal Digitization.
Communications Signal Capture
The ADS821U fits communications signal capture when the system needs 40-MSPS sampling and a 10-bit digital result. Its single-ended or differential input support lets the analog front end match the source, while the internal track-and-hold helps synchronize acquisition. The 58 dB SNR figure is the verified family-level metric; engineers should still verify bandwidth, input range, clocking, and output timing from the datasheet before setting the communications bandwidth.
推薦
Test and Measurement Instrumentation
ADS821U is appropriate for measurement front ends that sample waveforms at up to 40 MSPS and require a 10-bit code width. The internal reference and internal track-and-hold reduce support-circuit complexity, while the 28-pin SOIC package supports conventional surface-mount assembly. Use the converter when 9.3-bit ENOB and 58 dB SNR align with the instrument's dynamic-range requirement; for higher precision, select an ADC with a verified higher resolution instead.
推薦
Industrial Measurement Systems
The ADS821U can serve as the acquisition element in an industrial measurement system that needs real-time sampling of rapidly changing analog conditions. Its 40-MSPS throughput supports dense time-domain data, and the 10-bit resolution provides 1,024 digital code levels for digital transfer. The industrial screening level and -40 C to +85 C temperature specification are verified, but the system designer must still account for sensor excitation, isolation, grounding, and safety requirements.
推薦
Waveform Data Acquisition
ADS821U is well suited to waveform acquisition when the required record rate is no greater than 40 MSPS and 10-bit resolution is sufficient. The internal track-and-hold and reference support a compact acquisition chain, while the SOIC-28 package is practical for conventional PCB assembly. Designers should pair the ADC with anti-alias filtering, a low-jitter clock, adequate analog drive, and a digital processor that supports the converter's verified output interface.
推薦
Embedded Control and Monitoring
ADS821U can be used in embedded monitoring systems that need faster sampling than a general-purpose low-speed ADC. The 10-bit result can be transferred to a microcontroller or FPGA, while the single-ended or differential input selection supports different sensor-interface architectures. The design should validate acquisition timing, output coding, and supply sequencing against the datasheet, especially when the monitored signal bandwidth approaches the converter's sampling capability.
推薦
Sensor Signal Digitization
ADS821U is applicable when a sensor signal must be digitized rapidly enough to capture transients or waveform detail. Its 40-MSPS sampling rate and 10-bit resolution can be matched to medium-bandwidth sensor outputs, while the internal track-and-hold helps isolate the sampling instant. For sensor nodes, engineers must design input protection, biasing, filtering, and grounding around the actual sensor impedance; the verified 1.25 V input figure should not be treated as a complete front-end specification without datasheet context.
推薦
推薦產品摘要
工程參考資料，適用於 ADS821U — 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 | ADS821U-1 |
|---|---|---|
| Package | SOIC-28 (DW) | SOIC-28 (DW) |
| Brand | Texas Instruments | Texas Instruments |
主要差異化特點
- 40-MSPS conversion rate (對比ADS821U-1)
- 10-bit resolution with 9.3-bit ENOB (對比ADS821U-1)
- Integrated reference and track-and-hold (對比ADS821U-1)
設計說明
Keep the analog input path short and controlled. Place the ADC input pins and their associated input network according to the manufacturer layout guidance, use a low-impedance source where required, and minimize trace length between the driver, anti-alias filter, and ADC. A 40-MSPS converter can respond to high-frequency noise and timing errors even though its nominal output is only 10 bits.
Build the supply and decoupling network around the verified 380 mW device figure, while checking the datasheet for the exact operating supply and current conditions. Place required bypass capacitors close to the relevant supply pins, provide a low-impedance return path, and keep switching-converter noise away from sensitive analog traces. Estimated board power should include the ADC, reference, driver, interface, and support circuitry rather than the ADC value alone.
Do not treat a functional-equivalent ADC as a drop-in replacement without checking all 28 pins and the package drawing. Verify input range, reference behavior, clock polarity and timing, output coding, power sequencing, and thermal limits against the official datasheet. The supplied data identifies ADS821U as SOIC-28, but it does not provide the complete pin functions needed to certify an alternate part.
合規資訊
The supplied verified data identifies industrial screening but does not state RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals status. These fields remain unknown rather than inferred.
