ADS7817U/2K5G4 - 12-Bit 200kHz Differential Input MicroPower ADC | TI
N.º da peça: ADS7817U/2K5G4 ✓ Ativo| Qtd. | Preço unitário | Total |
|---|---|---|
| 1 | $7.45 | $7,45 |
| 10 | $6.62 | $66,20 |
| 100 | $5.41 | $541,00 |
| 500 | $4.83 | $2.415,00 |
| 1.000 | $4.21 | $4.210,00 |
| 2.500 | $3.78 | $9.450,00 |
ADS7817U/2K5G4 Visão geral
An SAR ADC is a successive-approximation-register analog-to-digital converter - a type of data converter that uses a binary search through an internal DAC to determine each digital code in N clock cycles. SAR ADCs sit under the broader hypernyms of data converter -> ADC -> precision converter -> integrated circuit, and are valued for their deterministic latency, single-shot accuracy, and zero-pipeline-delay behavior, which makes them the dominant architecture for multiplexed multi-channel data acquisition systems and motor-control feedback loops.
The ADS7817 family is specified for bipolar differential input ranges and a fully-differential sample-and-hold front end, with a programmable reference from 100 mV to 2.5 V that scales the input-referred LSB size between 49 uV and 1.22 mV. Its micro-power operating current and sub-3 uA power-down current suit battery-instrumentation, transducer bridges, and portable sensor signal chains where energy budget dominates the BOM.
The ADS7817 achieves 200 kHz throughput while consuming micro-power during conversion, then automatically powers down between conversions. Internal architecture includes a charge-redistribution capacitive DAC, a high-bandwidth differential input amplifier, and an SAR control core clocked from an external serial clock; the SPI-/QSPI-/MICROWIRE-compatible serial interface packs 12-bit results into a compact frame.
Typical applications include battery-powered instrumentation, industrial process control loops, portable medical monitors, sensor-signal digitization for strain gauges and thermocouples, and general-purpose data acquisition front-ends. The differential input is particularly attractive where common-mode noise from motor inverters or long sensor cables would saturate a single-ended ADC.
When designing with the ADS7817, place the reference decoupling capacitor close to the REF pin and keep the analog and digital grounds joined at a single point near the converter's GND pin to preserve differential-input linearity. Note that the /U SOIC-8 (D) and /E MSOP-8 packages share the same pinout but differ in thermal mass - choose /E only when board area is more critical than dissipation.
This page synthesizes distributor stock, parametric drop-in equivalents in the SOIC-8 footprint, and design considerations that the manufacturer datasheet alone does not aggregate, helping engineers evaluate ADS7817U/2K5G4 for both new designs and legacy replacements.
Alternativas drop-in para ADS7817U/2K5G4 — mesmo encapsulamento, compatível pino a pino. Peças de encapsulamento diferente que exigem retrabalho na PCB são excluídas.
Ferramenta de comparação rápida — selecione peças alternativas para comparação lado a lado:
ADS7817U/2K5
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
ADS7817E/2K5G4
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
ADS7816U/2K5G4
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
ADS7818U/2K5G4
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
ADS7822U/2K5G4
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
ADS7817U/2K5G4 Classificações máximas e características elétricas
| Resolução | 12 bits |
| Taxa de amostragem | 200 kHz |
| Architecture | SAR (Successive Approximation Register) |
| Input Channels | 1 differential input |
| Input Type | True differential, bipolar |
| Reference Voltage Range | 100 mV to 2.5 V (external) |
| Input-Referred LSB | 49 uV to 1.22 mV (Vref dependent) |
| Operating Current (active) | MicroPower (value not in retrieved snippets; see datasheet) |
| Power-Down Current | 3 uA maximum |
| Interface | Serial (SPI/QSPI/MICROWIRE compatible) |
| Encapsulamento | 8-SOIC (D) - /U suffix |
| Reel Quantity | 2,500 (per /2K5G4 suffix) |
| Lead Finish | Pb-free matte tin (RoHS) |
| Status RoHS | Compliant (G4 suffix) |
Configuração de pinos do ADS7817U/2K5G4
| Pino 1 | VIN+ — Non-inverting analog input |
| Pino 2 | GND — Analog and digital ground |
| Pino 3 | VIN- — Inverting analog input |
| Pino 4 | REF — External reference voltage input (100 mV to 2.5 V) |
| Pino 5 | DOUT/DRDY — Serial data output / data ready |
| Pino 6 | DCLOCK — Serial data clock input |
| Pino 7 | CS — Chip select (active low) |
| Pino 8 | VDD — Power supply input |
Aplicações típicas
ADS7817U/2K5G4 é adequado para 7 aplicaçãos: Battery-Powered Sensor Instrumentation, Industrial Process Control Loops, Portable Medical Monitoring, Strain-Gauge Bridge Digitization, Thermocouple and Thermopile Digitization, General Data Acquisition Front-Ends, Motor Control Feedback Loops.
Battery-Powered Sensor Instrumentation
The ADS7817U/2K5G4's 3 uA maximum power-down current and micro-power active consumption make it ideal for battery-powered sensor instrumentation that spends most of its life in standby between conversions. The differential input directly digitizes bridge-type sensors (strain gauges, load cells, MEMS accelerometers) without an external instrumentation amplifier for many ranges. According to TI datasheet guidance, the automatic power-down between conversions can extend battery life by 10x to 100x versus a continuously-converting ADC. The 200 kHz throughput is more than sufficient for typical sensor bandwidths (audio, vibration, temperature) and the SOIC-8 (D) package is hand-solderable for low-volume prototypes.
Recomendado
Industrial Process Control Loops
The ADS7817U/2K5G4's true differential input, 12-bit resolution, and 200 kHz sampling rate are well-matched to industrial process-control loops where 4-20 mA current loops and bridge transducers must be digitized with high common-mode rejection. The differential topology rejects the 50/60 Hz common-mode noise injected by long sensor cables in factory environments, and the SPI-compatible serial interface simplifies isolation with a digital isolator. The 8-SOIC (D) package is industrial-temperature-grade, and the automatic power-down between conversions reduces heat dissipation in enclosed control cabinets.
Recomendado
Portable Medical Monitoring
The ADS7817U/2K5G4 is widely used in portable medical monitoring designs such as blood-pressure cuffs, pulse oximeters, and body-temperature patches where battery life and small board area are critical. The micro-power operation and automatic power-down allow the ADC to be duty-cycled for measurement windows while the rest of the system is in deep sleep, preserving months of battery life from a single coin cell. The differential input handles ECG-style signals with substantial common-mode voltage, and the 12-bit resolution is adequate for vital-sign digitization.
Recomendado
Strain-Gauge Bridge Digitization
The ADS7817U/2K5G4's true differential input is the canonical topology for strain-gauge bridge digitization. A Wheatstone bridge produces a differential millivolt-level signal on top of a 2.5 V common-mode voltage; the ADS7817's differential input directly digitizes this signal without an intermediate instrumentation amplifier for many transducer sensitivities. Programmable reference voltage from 100 mV to 2.5 V allows the user to scale the bridge excitation to match the ADC's full-scale range, maximizing dynamic range. The 12-bit resolution gives approximately 1 part in 4000 of measurement granularity, suitable for weighing scales and load-cell applications.
Recomendado
Thermocouple and Thermopile Digitization
The ADS7817U/2K5G4 is widely deployed in thermocouple and thermopile temperature measurement systems. The differential input rejects 50/60 Hz pickup on long thermocouple leads, and the programmable reference voltage down to 100 mV allows direct digitization of low-amplitude thermoelectric voltages without pre-amplification. For higher-precision temperature measurement, average multiple conversions digitally to improve effective resolution. The micro-power operation makes the ADS7817 suitable for battery-powered hand-held thermocouple meters and field instruments.
Recomendado
General Data Acquisition Front-Ends
The ADS7817U/2K5G4 is a building block for general-purpose data-acquisition front-ends in PLCs, test-and-measurement instruments, and laboratory data loggers. The 200 kHz throughput handles audio-bandwidth and many industrial control bandwidths, the SPI-compatible serial interface minimizes pin count on connectorized data-acquisition modules, and the SOIC-8 (D) package is the de-facto standard for hand-prototypable ADC circuits. Pair multiple ADS7817 devices behind a multiplexer for multi-channel systems, or combine with a precision reference such as the TL431 for ratiometric measurements.
Recomendado
Motor Control Feedback Loops
The ADS7817U/2K5G4's deterministic SAR latency makes it appropriate for digitizing motor-control feedback signals where pipeline delay cannot be tolerated. The differential input handles current-sense amplifier outputs with high common-mode dv/dt from PWM switching, and the 200 kHz sampling rate accommodates the bandwidth of typical motor-control current loops. The micro-power operation allows the ADC to be powered from the same low-current rail that powers the analog front-end, simplifying power-tree design in compact motor-drive modules.
Recomendado
Resumo dos produtos recomendados
Dados de referência de engenharia para ADS7817U/2K5G4 — comparação, orientação de projeto e informações de conformidade.
Guia de seleção
Comparação com alternativas
| Parâmetro | Este produto | ADS7817U/2K5 | ADS7817E/2K5G4 | ADS7816U/2K5G4 | ADS7818U/2K5G4 | ADS7822U/2K5G4 |
|---|---|---|---|---|---|---|
| Package | 8-SOIC (D) | 8-SOIC (D) | MSOP-8 | 8-SOIC (D) | 8-SOIC (D) | 8-SOIC (D) |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Resolution | 12 bits | 12 bits | 12 bits | 12 bits | 12 bits | 12 bits |
| Sampling Rate | 200 kHz | 200 kHz | 200 kHz | 100 kHz | 200 kHz | 200 kHz |
| Input Type | True differential, bipolar | True differential, bipolar | True differential, bipolar | True differential, bipolar | Pseudo-differential | Pseudo-differential |
| Reference Voltage Range | 100 mV to 2.5 V | 100 mV to 2.5 V | 100 mV to 2.5 V | 100 mV to 2.5 V | 100 mV to 2.5 V | 50 mV to VDD |
| Interface | Serial SPI/QSPI/MICROWIRE | Serial SPI/QSPI/MICROWIRE | Serial SPI/QSPI/MICROWIRE | Serial SPI/QSPI/MICROWIRE | Serial SPI/QSPI/MICROWIRE | Serial SPI |
| Reel Quantity | 2,500 | 2,500 | 2,500 | 2,500 | 2,500 | 2,500 |
Principais diferenciais
- True differential bipolar input at micro-power consumption (vs ADS7822U/2K5G4)
- Higher sampling rate than ADS7816 (vs ADS7816U/2K5G4)
- Micro-power operation with 3 uA max power-down current (vs ADS7808UB/1K)
Notas de projeto
Place the reference decoupling capacitor (typically 10 uF ceramic in parallel with 0.1 uF) directly at the REF pin, with the trace to the reference source as short as possible to minimize noise injection into the ADC's reference node. Keep analog and digital ground planes joined at a single point near the converter's GND pin, and route the differential analog input traces symmetrically to preserve common-mode rejection. The CS, DCLOCK, and DOUT traces should be kept away from the analog input traces to avoid digital-to-analog crosstalk into the sample-and-hold.
For optimal differential-input linearity, drive the +IN and -IN inputs from low-impedance sources. Source impedances above 1 kOhm can degrade AC performance and increase distortion due to the dynamic input-current transients during the sample-and-hold acquisition phase. If high source impedances are unavoidable, add a wideband buffer amplifier (such as an OPA227 or OPA627) in front of the ADC. Keep the input common-mode voltage within the input common-mode specification, typically 0 V to VDD.
Do not exceed the absolute maximum analog input voltage on +IN or -IN - the ESD diodes clamp at approximately VDD+0.3 V and GND-0.3 V, and over-voltage stress can permanently damage the device. When the ADC is in power-down mode, the input pins draw negligible current, so external protection circuitry must handle transients during both active and power-down states. Add a small RC anti-aliasing filter (typically 100 ohms + 10 nF) at the input for applications with significant out-of-band noise.
Use a clean, well-decoupled power supply for VDD - a ferrite bead in series with a 10 uF + 0.1 uF capacitor network is recommended to filter switching-converter noise. The ADS7817's low operating current makes it tolerant of moderate supply noise, but high-frequency noise above 1 MHz can alias into the ADC's baseband through the sampling process. Tie the unused input (either +IN or -IN) to mid-scale or ground through a low-impedance path when used in single-ended fashion to maximize effective resolution.
The SOIC-8 (D) package has a thermal resistance theta_JA of approximately 150 C/W, which is adequate for the micro-power dissipation typical of the ADS7817. At full 200 kHz throughput, the package dissipates well under 100 mW, so no heatsink is required. For compact MSOP-8 (/E) variants in enclosed housings with limited airflow, ensure the ambient temperature stays within the datasheet's operating range. The Pb-free matte-tin lead finish is compatible with standard lead-free reflow profiles (peak 260 C, 20-40 s above 250 C).
Informações de conformidade
G4 suffix denotes Pb-free matte-tin lead finish and RoHS compliance. Halogen-free per TI documentation. AEC-Q100 not applicable - this is a general-purpose industrial/consumer ADC; for automotive applications consult TI's Q1-qualified equivalents.
