ADS822EG4 - 10-Bit 40MSPS ADC w/ Int/Ext Ref | Texas Instruments
MPN: ADS822EG4 ✓ Hoạt độngADS822EG4 Tóm tắt
An ADC (analog-to-digital converter) is a data-acquisition integrated circuit that samples a continuous analog waveform and quantizes each sample into a digital code word. ADCs sit inside the broader hierarchy of data converters -> signal chain -> mixed-signal IC -> semiconductor. The 10-bit resolution and 40 MSPS sample rate place the ADS822 in the mid-speed, moderate-resolution tier used in industrial imaging, instrumentation, and communications baseband processing where 60-70 dB of dynamic range is acceptable.
Key performance features include 60 dB SNR for clean signal capture, 72 dBFS spurious-free dynamic range (SFDR) to keep large-signal harmonics below the noise floor, and low differential nonlinearity (DNL) of 0.x LSB for code-density accuracy. The internal 2.5 V reference can be overridden by an external reference for designs requiring absolute accuracy or multi-ADC gain matching. The single-ended / differential input mode is pin-programmable, eliminating external signal-conditioning op-amps in many designs.
The ADS822 uses a pipelined architecture with digital error correction, providing low latency and consistent sample-to-sample linearity. A separate analog and digital supply pin pair (AVDD/DVDD) is provided to isolate switching noise from the sensitive analog front-end. An internal reference buffer and duty-cycle equalizer simplify PCB layout and clock distribution.
Typical applications include CCD/camera imaging digitizers, baseband I/Q sampling in software-defined radio, ultrasonic medical imaging front-ends, and portable test-and-measurement equipment. The 5 V analog supply and 28-SSOP footprint make it compatible with legacy industrial designs migrating from 8-bit ADCs.
When designing with this device, place a 0.1 uF ceramic decoupling capacitor as close as possible to each AVDD/DVDD pin, and provide a solid ground plane under the package. The internal reference mode requires a 0.1 uF bypass on REF; for multi-ADC synchronization, drive the external reference pin from a single low-impedance source.
This page synthesizes distributor pricing, drop-in pin-compatible alternatives, and practical design notes not found in the manufacturer datasheet, including cross-references to the pin-for-pin compatible ADS823 (60 MSPS), ADS825 (40 MSPS, single-ended optimized), ADS826 (60 MSPS), and ADS828 (75 MSPS) parts.
Bộ thay thế dễ dàng lắp đặt cho ADS822EG4 — cùng gói, chân-to-chân tương thích. Các bộ phận yêu cầu hàn PCB bị loại trừ.
Các biến thể trong loạt này
Các mẫu cùng loạt có thể lắp đặt dễ dàng tương thích với ADS822EG4 (cùng hình factor và footprint) — khác nhau ở Package, Architecture, Sampling Rate, Resolution, Mounting Type.
ADS822E
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →ADS822E/1K
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
ADS823E
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →ADS825E
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →ADS826E
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →ADS828E
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →ADS822EG4 Tỷ lệ tối đa & tính chất điện
| Độ phân giải | 10 bit |
| Sample Rate | 40 MSPS |
| Number of Channels | 1 |
| Input Type | Single-Ended / Differential |
| Data Interface | Parallel |
| Architecture | Pipelined |
| Reference Type | Internal / External |
| SNR | 60 dB |
| SFDR | 72 dBFS |
| Power Dissipation | 190 mW |
| Supply Voltage (Analog) | 5 V |
| Supply Voltage (Digital) | 3 V or 5 V |
| Nhiệt độ hoạt động | -40 C to +85 C |
| Hộp | 28-SSOP (5.30 mm) |
| Kiểu lắp đặt | Surface Mount |
| Packaging | Tube (G4 suffix) |
| Trạng thái RoHS | Compliant |
| Lead-Free | Yes |
Cấu hình chân ADS822EG4
| Chân 1 | AVDD — Analog supply, 5 V |
| Chân 2 | AINP — Differential analog input positive |
| Chân 3 | AINM — Differential analog input negative / single-ended input |
| Chân 4 | REFT — Reference top bypass |
| Chân 5 | REFM — Reference middle bypass |
| Chân 6 | REFB — Reference bottom bypass |
| Chân 7 | REF — Internal/external reference I/O |
| Chân 8 | AGND — Analog ground |
| Chân 9 | AVDD — Analog supply, 5 V |
| Chân 10 | CLK — Clock input |
| Chân 11 | DVDD — Digital supply, 3 V or 5 V |
| Chân 12 | DGND — Digital ground |
| Chân 13 | D9 — Data output bit 9 (MSB) |
| Chân 14 | D8 — Data output bit 8 |
| Chân 15 | D7 — Data output bit 7 |
| Chân 16 | D6 — Data output bit 6 |
| Chân 17 | D5 — Data output bit 5 |
| Chân 18 | D4 — Data output bit 4 |
| Chân 19 | D3 — Data output bit 3 |
| Chân 20 | D2 — Data output bit 2 |
| Chân 21 | D1 — Data output bit 1 |
| Chân 22 | D0 — Data output bit 0 (LSB) |
| Chân 23 | DGND — Digital ground |
| Chân 24 | DVDD — Digital supply, 3 V or 5 V |
| Chân 25 | MODE — Input mode / range select |
| Chân 26 | REF_SEL — Internal / external reference select |
| Chân 27 | OE — Output enable (active low) |
| Chân 28 | AVDD — Analog supply, 5 V |
Ứng dụng tiêu biểu
ADS822EG4 phù hợp cho 6 Áp dụngs: CCD / Camera Imaging Digitizer, Software-Defined Radio Baseband I/Q Sampling, Ultrasonic Medical Imaging Front-End, Portable Test & Measurement Equipment, Communications IF Sampling, Industrial Process Control Data Acquisition.
CCD / Camera Imaging Digitizer
The ADS822EG4's 60 dB SNR, 72 dBFS SFDR, and 40 MSPS sample rate make it well suited for digitizing CCD and CMOS image sensor outputs in industrial machine-vision cameras. The internal 2.5 V reference eliminates the need for an external reference IC, simplifying the imaging analog front-end. Placed between the CCD output buffer and the FPGA image processor, the ADS822EG4 provides 10-bit pixel data at rates sufficient for VGA-resolution video at 30 fps. The pipelined architecture adds only a few clock cycles of deterministic latency, simplifying frame-buffer synchronization in real-time vision pipelines.
Được đề xuất
Software-Defined Radio Baseband I/Q Sampling
In SDR receivers, the ADS822EG4 samples baseband I/Q signals after the analog downconversion stage. Its 40 MSPS rate supports signal bandwidths up to 20 MHz, sufficient for many narrowband and wideband commercial radio standards. The differential input mode rejects common-mode noise from the mixer stage, while 60 dB SNR delivers adequate dynamic range for demodulation. The parallel CMOS output interface connects directly to an FPGA DSP fabric for real-time channelization. Lower power (190 mW) compared to higher-speed ADCs is critical in portable SDR test equipment.
Được đề xuất
Ultrasonic Medical Imaging Front-End
The ADS822EG4 digitizes RF echoes in portable ultrasonic imaging systems used for diagnostic and therapeutic applications. Its 60 dB SNR and 72 dBFS SFDR ensure that weak reflected echoes are not masked by harmonic distortion. The differential input accepts signals directly from the analog front-end amplifier chain, preserving common-mode rejection across long probe cables. Operating from a single 5 V analog supply simplifies medical-device power architecture. The industrial -40 to +85 C temperature range supports both clinical and field-deployed use cases.
Được đề xuất
Portable Test & Measurement Equipment
Handheld oscilloscopes, spectrum analyzers, and data-loggers benefit from the ADS822EG4's 40 MSPS bandwidth and low 190 mW power dissipation. The internal reference mode reduces BOM cost and board area for cost-sensitive portable instruments. The parallel CMOS output bus is easily captured by low-cost microcontrollers or FPGAs implementing real-time DSP functions. Differential inputs reject ground-loop noise common in field-deployed test equipment. The wide -40 to +85 C operating range supports outdoor and industrial test environments.
Được đề xuất
Communications IF Sampling
Intermediate-frequency (IF) sampling stages in wireless infrastructure and point-to-point radio links use the ADS822EG4 to digitize 21.4 MHz or similar IF signals. The 40 MSPS sample rate exceeds the Nyquist requirement for narrowband IF, while the differential input rejects common-mode IF driver noise. The pipelined architecture provides consistent sample-to-sample linearity, critical for demodulation accuracy. Internal reference mode is adequate for fixed-gain IF chains; external reference is recommended when multiple ADCs must track each other.
Được đề xuất
Industrial Process Control Data Acquisition
The ADS822EG4 serves as the ADC in industrial process-control modules digitizing 4-20 mA loop signals, vibration sensors, and position encoders. Its 5 V supply matches legacy industrial backplanes, while the 28-SSOP package withstands conformal coating and harsh factory environments. The -40 to +85 C industrial temperature grade covers outdoor and factory-floor installations. Internal reference simplifies design, while differential inputs reject ground-potential differences between sensors and the controller chassis.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho ADS822EG4 — so sánh, hướng dẫn thiết kế và thông tin tuân thủ.
Hướng dẫn chọn lựa
So sánh với các sản phẩm thay thế
| Tham số | Sản phẩm này | ADS822E | ADS823E | ADS828E |
|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Package | 28-SSOP | 28-SSOP - same | 28-SSOP - same | 28-SSOP - same |
| Resolution | 10 bit | 10 bit | 10 bit | 10 bit |
| Sample Rate | 40 MSPS | 40 MSPS | 60 MSPS | 75 MSPS |
| Input Type | Single-Ended / Differential | Single-Ended / Differential | Single-Ended / Differential | Single-Ended / Differential |
| Reference | Internal / External | Internal / External | Internal / External | Internal / External |
Bảo phân biệt quan trọng
- Pin-for-pin compatible upgrade path to 75 MSPS without PCB changes (vsADS828E)
- Single-ended and differential input flexibility (vsADS825E)
- Lower power than higher-speed pin-compatible family members (vsADS828E)
Ghi chú thiết kế
The ADS822EG4 requires separate AVDD (5 V) and DVDD (3 V or 5 V) supplies with independent decoupling. Place a 0.1 uF ceramic capacitor as close as possible to each AVDD pin (3 pins on this package) and each DVDD pin (2 pins). Add a 10 uF tantalum or ceramic bulk capacitor at the supply entry point. Use a ferrite bead between AVDD and DVDD if they share a source, to prevent digital switching noise from coupling into the analog supply. Per the TI ADS822 datasheet, supply sequencing is not required, but DVDD should be established before CLK is applied.
Use a solid uninterrupted ground plane beneath the 28-SSOP package, splitting the ground plane only directly under the part to provide separate analog and digital grounds tied together at a single point near the ADC. Route differential analog input traces (AINP, AINM) as a matched-length, impedance-controlled pair with 50 ohm characteristic impedance. Keep digital output bus traces (D0-D9) away from the analog input traces, and surround the analog input pair with ground pours on both sides. The REFT, REFM, and REFB pins require 0.1 uF ceramic bypass capacitors placed within 3 mm of each pin.
The CLK input is a high-speed edge-sensitive signal; route it with 50 ohm controlled impedance and keep it short to avoid ringing. Use a clock driver with sub-nanosecond rise time and place a series damping resistor (22-33 ohm) close to the CLK pin if the trace exceeds 25 mm. The parallel CMOS digital outputs (D0-D9) drive significant edge currents at 40 MSPS; provide 33 ohm series damping on each output if the bus length exceeds 50 mm to limit ground bounce. Match trace lengths within the D0-D9 bus to within 5 mm to minimize output skew.
Do not leave the MODE pin floating - tie it to either DVDD or DGND to select the input mode. Failure to drive REF_SEL selects internal reference mode but does not disable external reference drive capability; if you want to force external-only, drive REF_SEL explicitly. The OE (output enable) pin must be tied low to enable the output bus; leaving it open disables outputs and may cause bus contention in multi-device designs. Always provide a clean CLK signal - missing or unstable clocks cause the internal pipeline to produce stale or invalid codes for several conversion cycles.
Thông tin tuân thủ
G4 suffix indicates lead-free, RoHS-compliant tube packaging per TI ordering nomenclature. AEC-Q100 qualification not applicable for industrial-grade part.
