ADS1286U/2K5G4 - 12-Bit 20kHz Micropower SAR ADC | TI
MPN: ADS1286U/2K5G4 ✓ Hoạt độngADS1286U/2K5G4 Tóm tắt
A successive-approximation ADC (often abbreviated SAR ADC) is a type of data-conversion IC that walks an internal capacitive DAC from MSB to LSB each conversion cycle, producing a low-latency, deterministic sample output with no pipeline delay. SAR ADCs are widely used when a system needs a clean single-shot sample with simple control, low standby current, and modest resolution - they sit between slower sigma-delta ADCs (which trade latency for higher resolution) and flash ADCs (which trade power for speed). Within a system, the SAR ADC is positioned just after analog signal conditioning and ahead of a digital controller that consumes the conversion result.
Key features include guaranteed no missing codes at 12 bits, 20 kHz maximum sampling rate, 250 µA typical supply current, an SPI/SSI-compatible serial interface, a single 5 V supply, and an industrial -40 °C to +85 °C operating temperature range. The 8-SOIC footprint and two-wire serial interface simplify board layout and reduce MCU pin overhead in space-constrained designs.
The architecture combines an input sample-and-hold with a charge-redistribution SAR core and a precision internal reference path, giving deterministic latency of one conversion cycle and the absence of pipeline or integration delay. Because the digital interface is a simple shift-register readout, the part is straightforward to drive from virtually any microcontroller with an SPI peripheral.
Typical applications include remote sensor data acquisition, isolated analog front ends, battery-powered instrumentation, industrial process-control transducers, and portable medical accessory boards. The DIP and SOIC footprints also support hand-soldered prototype or through-hole-style retrofit boards. When designing the analog front end, take care to bypass VDD with a 0.1 µF ceramic close to the pin and to keep the analog input traces short and guarded, since the 12-bit, 20 kSPS converter will expose any added noise or reference drift directly in the conversion result. This page consolidates distributor pricing, pin-compatible drop-in alternatives, and practical design guidance not found in the standalone manufacturer datasheet.
Bộ thay thế dễ dàng lắp đặt cho ADS1286U/2K5G4 — 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 ADS1286U/2K5G4 (cùng hình factor và footprint) — khác nhau ở Architecture, Missing Codes, Package, Resolution.
ADS1286U/2K5
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
ADS1286UAG4
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
ADS1286UL/2K5G4
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
ADS1286U
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →ADS7823E/2K5
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
ADS1286U/2K5G4 Tỷ lệ tối đa & tính chất điện
| Độ phân giải | 12 bit |
| Architecture | SAR (Successive Approximation) |
| Number of Inputs | 1 (single-ended or differential) |
| Sample Rate (max) | 20 kSPS |
| Analog Input Range | 0 V to 5.3 V |
| Supply Voltage (nominal) | 5 V |
| Supply Current (typ) | 250 uA |
| Data Interface | SPI / SSI compatible, 2- or 3-wire serial |
| Missing Codes | Guaranteed no missing codes |
| Input Type | Differential with sample-and-hold |
| Khoảng nhiệt độ hoạt động | -40 C to +85 C |
| Hộp | 8-SOIC (0.154", 3.90 mm width) |
| Kiểu lắp đặt | Surface Mount |
| Trạng thái RoHS | Compliant |
Cấu hình chân ADS1286U/2K5G4
| Chân 1 | VDD — Positive analog/digital supply (5 V nominal) |
| Chân 2 | IN+ — Non-inverting analog input (sample-and-hold positive) |
| Chân 3 | IN- — Inverting analog input (sample-and-hold negative) |
| Chân 4 | GND — Ground |
| Chân 5 | /CS — Chip select, active low, enables serial interface |
| Chân 6 | DOUT — Serial data output, conversion result, MSB first |
| Chân 7 | SCLK — Serial clock, clocks conversion result out |
| Chân 8 | GND — Ground / digital return |
Ứng dụng tiêu biểu
ADS1286U/2K5G4 phù hợp cho 6 Áp dụngs: Remote Sensor Data Acquisition, Isolated Analog Front Ends, Battery-Powered Instrumentation, Industrial Process-Control Transducers, Portable Medical Accessory Boards, Hand-Soldered Prototype / Retrofit Boards.
Remote Sensor Data Acquisition
The ADS1286U/2K5G4 fits remote sensor data acquisition because its 250 uA typical supply current and 5 V single-supply operation let it run from battery or 4-20 mA loop power for years, while the 12-bit, 20 kSPS throughput digitizes thermistor, RTD, and strain-gauge bridges at full bandwidth. According to the TI datasheet, the differential input and integrated sample-and-hold reject common-mode noise on long sensor cables, and the 2-wire SPI/SSI interface reduces the opto-isolator channel count in isolated front ends to just data + clock.
Được đề xuất
Isolated Analog Front Ends
In isolated analog front ends, the ADS1286U/2K5G4 minimizes the isolation barrier cost because its SPI/SSI-compatible 2-wire interface only needs an opto-isolator pair plus a third wire for /CS, instead of the four or five isolators required by parallel-output ADCs. The TI datasheet confirms 12-bit, 20 kSPS operation at 250 uA typical from a 5 V supply on the field side, and its industrial -40 C to +85 C range covers factory-floor and process-control environments. Place 0.1 uF ceramic bypass on VDD and a ferrite on the analog input to keep iso-side transients out of the conversion.
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Battery-Powered Instrumentation
Battery-powered instrumentation benefits from the ADS1286U/2K5G4 because the 250 uA typical supply current extends coin-cell and 9 V battery life into multi-year service, while the 20 kSPS max sample rate covers instrumentation audio and slow transducer transients. The TI datasheet specifies a single 5 V supply with no charge pump, so a small LDO with the part works as a complete power-and-conversion node, and the SOIC-8 form factor keeps the PCB area small inside hand-held enclosures.
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Industrial Process-Control Transducers
Industrial process-control transducers use the ADS1286U/2K5G4 for 4-20 mA loop-powered pressure, flow, and level sensors where the 250 uA current draw keeps total loop budget low. According to the TI datasheet, the differential input handles bridge-style sensor outputs directly, and the -40 C to +85 C industrial temperature range with guaranteed no missing codes gives the linearity headroom required for closed-loop control. Add an op-amp buffer on the analog input if the source impedance is above the datasheet's recommended maximum.
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Portable Medical Accessory Boards
Portable medical accessory boards - handheld pulse-oximeter cap boards, single-channel ECG front ends, and bedside sensor pods - fit the ADS1286U/2K5G4 because of its 12-bit/20 kSPS throughput and 250 uA micropower operation from a single 5 V rail. The TI datasheet confirms the SPI/SSI two-wire interface lets a low-cost MCU sample and stream over USB or Bluetooth, while the SOIC-8 footprint leaves room for analog guards on small multilayer boards in FDA-trackable low-leakage designs.
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Hand-Soldered Prototype / Retrofit Boards
The ADS1286 family is available in 8-SOIC and 8-PDIP, making the SOIC-8 ADS1286U/2K5G4 ideal for hand-soldered prototype or retrofit boards in university labs, repair shops, and small-batch refurbish lines. Per the TI datasheet, the 12-bit, 20 kSPS, 5 V single-supply ADC has a forgiving 0-5.3 V analog input range, and the SOIC land pattern is easy to hand-rework with a fine-tip iron and 0.5 mm solder braid for repair technicians.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho ADS1286U/2K5G4 — 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 | ADS1286U/2K5 | ADS1286UAG4 | ADS1286UL/2K5G4 | ADS7823E/2K5 |
|---|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Package | 8-SOIC (0.154", 3.90 mm) | 8-SOIC (0.154") - same | 8-SOIC (0.154") - same | 8-SOIC (0.154") - same | 8-VSSOP - smaller footprint, same pin count |
| Resolution | 12 bit | 12 bit | 12 bit | 12 bit | 12 bit |
| Serial Interface | SPI/SSI (2- or 3-wire) | SPI/SSI (2- or 3-wire) | SPI/SSI (2- or 3-wire) | SPI/SSI (2- or 3-wire) | SPI/SSI |
Bảo phân biệt quan trọng
- Industry-leading 250 uA micropower supply current at 12-bit/20 kSPS (vsADS7823E/2K5)
- Pin-compatible wide SOIC body for hand-soldering and rework (vsADS7823E/2K5)
- Full same-package drop-in compatibility with the ADS1286 family (vsADS1286PG4 / ADS1286PK (8-PDIP))
Ghi chú thiết kế
Estimated: at 5 V supply and 250 uA typical supply current from the TI datasheet, the steady-state power budget is roughly 1.25 mW. For battery-powered designs, an LDO with <100 uA quiescent current (e.g. one of TI's low-Iq families) is recommended so the regulator does not dominate the sleep-mode current. Place a 0.1 uF ceramic bypass close to VDD and a bulk 1-10 uF at the board input.
Keep analog input traces short and guarded on the SOIC side, with a ground ring or via fence around IN+ and IN-. Place the 0.1 uF VDD bypass within 3 mm of pin 1 (VDD) and run separate analog/digital ground returns back to a single-star point. According to the TI ADS1286 datasheet layout guidance, do not route the SCLK trace beneath or alongside the analog input traces or noise will couple into the sample-and-hold.
Do not drive /CS low before the supply has stabilized - the datasheet's no-missing-codes guarantee assumes power-up with /CS high. Drive /CS inactive between conversions when running continuous sampling to avoid bus contention. Also ensure the host's SCLK frequency is within the part's maximum serial-clock rating per the TI datasheet timing table - exceeding it can corrupt the conversion result on SOIC builds.
Thông tin tuân thủ
RoHS and lead-free per TI product data in verified web data; AEC-Q100 not applicable to non-automotive ADC; please confirm latest halogen-free and REACH attestation on the TI product page before placing volume orders.