ADS821 - 10-Bit 40MSPS ADC with Internal Reference | TI
MPN: ADS821 β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0 | $0.00 |
| 10 | $0 | $0.00 |
| 100 | $0 | $0.00 |
| 500 | $0 | $0.00 |
| 1,000 | $0 | $0.00 |
Drop-in alternatives for ADS821 β same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ADS826U
β Drop-Inπ Reference alternative (not in catalog)
ADS825U
β Drop-Inπ Reference alternative (not in catalog)
ADS824U
β Drop-Inπ Reference alternative (not in catalog)
ADS823U
β Drop-Inπ Reference alternative (not in catalog)
ADS822U
β Drop-Inπ Reference alternative (not in catalog)
ADS821 Maximum Ratings & Electrical Characteristics
| Resolution | 10-bit |
| Maximum Sampling Rate | 40 MHz |
| Architecture | Pipelined |
| Number of Inputs | 1 |
| Input Configuration | Differential or single-ended |
| Internal Track-and-Hold | Yes |
| Internal Reference | Yes |
| Power-Down Feature | Yes |
| Power Dissipation | 380 mW |
| Signal-to-Noise Ratio (SNR) | 58 dB |
| Effective Number of Bits (ENOB) | 9.3 bits |
| Supply Voltage | +5 V (single supply) |
| Package Options | SO-28 and SSOP-28 |
| Technology | Small-geometry CMOS |
| No Missing Codes | Yes |
| Digital Output | [DATA_NEEDED: digital output format] |
| Operating Temperature Range | [DATA_NEEDED: operating temperature range] |
| Input Full-Scale Range | [DATA_NEEDED: input full-scale range] |
| MSL Level | [DATA_NEEDED: MSL level] |
| RoHS Status | unknown |
ADS821 so-28 and ssop-28 Pin Configuration Guide
Complete pinout information for ADS821 (so-28 and ssop-28 package). This analog component features input, output, and power supply pins. Refer to the manufacturer datasheet for offset null, compensation, and enable pin configurations. Ideal for signal conditioning and amplifier circuits.
No detailed pinout data available for ADS821.
Refer to the datasheet for full pin configuration.
Safe Operating Area (SOA) & Thermal Characteristics
No official SOA curve available for this component. Always operate within absolute maximum ratings specified in the datasheet. Ensure adequate cooling and derate as needed.
Typical Applications
ADS821 is suitable for 6 applications: Medical Ultrasound Front-End, Video Digitizing and CCD Imaging, Digital Oscilloscope Front-End, Industrial Data Acquisition, Communication IF Sampling, Test and Measurement Instrumentation.
Medical Ultrasound Front-End
The ADS821's 40 MSPS sampling rate and 10-bit resolution are well matched to ultrasound echo digitization, where dynamic range and low power matter. The internal track-and-hold removes an external S/H, simplifying the front-end. Its 58 dB SNR preserves echo detail in multi-channel probes, and 380 mW power supports compact, high-channel-count systems. For best performance, drive the differential input with a low-noise high-speed op amp such as THS4031 and keep the gain path tightly routed. The internal reference reduces BOM count while maintaining stable conversion.
Recommended
Video Digitizing and CCD Imaging
The ADS821 digitizes analog video and CCD output signals at 40 MSPS with 10-bit accuracy, a good fit for high-resolution imaging paths. Differential input reduces common-mode noise, while internal reference and track-and-hold reduce peripheral circuitry. The 58 dB SNR supports 10-bit video extraction, and the 40 MHz rate captures fast line-rate pixel data. A clean +5V rail and a low-impedance pixel source are recommended to maintain ENOB. The power-down feature can be used between scan lines to reduce dissipation.
Recommended
Digital Oscilloscope Front-End
In DSO front-ends, the ADS821 provides 40 MSPS single-channel capture with 10-bit amplitude resolution, ideal for triggering and digitizing repetitive waveforms. The pipelined architecture supports continuous sampling, while differential input allows direct connection from an attenuator or probe buffer. The 58 dB SNR and 9.3 ENOB help maintain vertical accuracy. Place the converter close to the analog conditioning stage and route digital outputs away from the input. The low 380 mW power permits dense multi-channel instruments without heavy cooling.
Recommended
Industrial Data Acquisition
The ADS821 digitizes industrial sensor signals with 10-bit resolution at 40 MSPS, enabling high-speed waveform capture for motor drives, power monitoring, and vibration analysis. Its single +5V supply and internal reference ease system integration, while differential input improves noise immunity in electrically noisy industrial environments. A front-end anti-alias filter and a low-impedance driver are recommended. The power-down feature can idle the converter between bursts, reducing overall heat in modular I/O systems.
Recommended
Communication IF Sampling
The ADS821 can digitize intermediate-frequency signals up to tens of MHz with 10-bit resolution, suitable for narrowband communication receivers and software-defined radio front-ends. The 58 dB SNR and 40 MSPS sampling allow digital down-conversion without an analog mixer, simplifying receiver architecture. Differential input improves second-order distortion performance. Use a crystal-controlled sampling clock and keep digital feedback away from the analog input. The power-down mode helps conserve energy in burst-mode radio links.
Recommended
Test and Measurement Instrumentation
For general-purpose test instruments such as logic analyzers, spectrum analyzers, and data recorders, the ADS821 offers a compact 10-bit 40MSPS ADC with integrated reference and track-and-hold. The SO-28 and SSOP-28 packages fit dense PCB designs, and the single +5V supply simplifies power delivery. The 58 dB SNR supports meaningful 10-bit measurements, while the power-down pin enables fast acquisition bursts with reduced average dissipation. Careful ground-plane partitioning is essential to keep digital switching noise from coupling into the analog input.
Recommended
Recommended Products Summary
Engineering reference data for ADS821 β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ADS826U | ADS825U | ADS822U |
|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Package | SO-28 / SSOP-28 | SO-28 | SO-28 | SO-28 |
| Resolution | 10-bit | 10-bit | 10-bit | 10-bit |
| Maximum Sample Rate | 40 MHz | 60 MHz | 40 MHz | [DATA_NEEDED] |
| Input Configuration | Differential or single-ended | [DATA_NEEDED] | [DATA_NEEDED] | [DATA_NEEDED] |
| Internal Reference | Yes | [DATA_NEEDED] | [DATA_NEEDED] | [DATA_NEEDED] |
| Power Dissipation | 380 mW | [DATA_NEEDED] | [DATA_NEEDED] | [DATA_NEEDED] |
| SNR | 58 dB | [DATA_NEEDED] | [DATA_NEEDED] | [DATA_NEEDED] |
| Power-Down Feature | Yes | [DATA_NEEDED] | [DATA_NEEDED] | [DATA_NEEDED] |
| Supply Voltage | +5 V | [DATA_NEEDED] | [DATA_NEEDED] | [DATA_NEEDED] |
Key Differentiators
- Complete integrated converter with track-and-hold and reference (vs ADS826U)
- Optimized 40MSPS speed with low 380mW power (vs ADS822U)
- Differential or single-ended input flexibility (vs ADS825U)
Design Notes
Decouple all analog and digital supply pins with 0.1uF ceramic capacitors placed as close as possible to the pins, supplemented by 10uF bulk capacitors on the main +5V rail. Separate analog and digital ground planes and connect them at a single point to reduce digital switching noise coupling into the quantizer.
Provide a low-impedance input source for the ADS821 to ensure differential input settling within one 40 MSPS sample period. A high-speed op-amp driver such as THS4031 is recommended when the source impedance is high or when driving long PCB traces. Use series termination on digital outputs to reduce ringing.
Keep analog input traces short, balanced, and shielded with ground fill. Do not route high-speed digital output lines under the ADC or near the analog input pins. A solid uninterrupted ground plane directly under the SO-28/SSOP-28 package is essential for achieving the specified 58 dB SNR and 9.3 ENOB.
The internal reference is convenient, but bypass it with a low-ESR capacitor close to the REF pin as specified in the datasheet. If an external reference is used, ensure it is low-noise and properly filtered. Verify the power-down input polarity against the datasheet before implementing sleep-mode control.
Compliance Information
Compliance data was not included in the verified web data. Verify RoHS and REACH status from the TI product page before qualification.
