ADS8900B - 20-Bit 1-MSPS SAR ADC with Ref Buffer | TI
MPN: ADS8900B ✓ نشطADS8900B نظرة عامة
A SAR ADC converts an analog input to a digital output using a binary search algorithm with a capacitive DAC and precision comparator. SAR converters occupy a key position in the data acquisition signal chain, balancing speed, resolution, and power for microcontroller and DSP-based systems.
Key features include 1-MSPS sampling at 20-bit resolution, ±1 ppm integral nonlinearity (INL), and 104.5 dB SNR under typical conditions. The device supports unipolar, fully differential, and pseudo-differential analog inputs. The integrated reference buffer eliminates the need for a high-bandwidth external reference buffer, and the integrated LDO enables simplified power tree design. The SPI-compatible serial interface supports daisy-chain and multi-device configurations.
The ADS8900B uses a high-speed capacitive-DAC SAR architecture achieving excellent linearity and low noise. Typical power consumption is approximately 15 mW at 1 MSPS from a 3.3V analog supply and 1.8V digital supply, suiting space-constrained precision designs.
Typical applications include industrial automation and process control, power quality monitoring, medical instrumentation, and automated test equipment, where the ±1 ppm INL and 104.5 dB SNR directly improve measurement accuracy.
Design consideration: decouple analog and digital supplies thoroughly and evaluate the integrated LDO-generated reference versus a low-noise external reference such as the REF5030A for the highest-accuracy systems.
بدائل مباشرة لـ ADS8900B — نفس الحزمة، متوافق دبوس بدبوس. تُستثنى القطع ذات الحزم المختلفة التي تتطلب تعديل PCB.
الطرازات في هذه السلسلة
طرازات من نفس السلسلة متوافقة تمامًا مع ADS8900B (نفس عامل الشكل والبصمة) — يختلف في Architecture, Package, Resolution.
ADS8902B
✅ بديل مباشر📋 بديل مرجعي (غير موجود في الكتالوج)
ADS8904B
✅ بديل مباشر📋 بديل مرجعي (غير موجود في الكتالوج)
ADS8910B
✅ بديل مباشر📋 بديل مرجعي (غير موجود في الكتالوج)
ADS8920B
✅ بديل مباشر📋 بديل مرجعي (غير موجود في الكتالوج)
AD7980ARMZ
✅ بديل مباشر ⚠️ مواصفات غير مُتحقق منهاتواصل لمعرفة السعر
عرض ورقة البيانات ←ADS8900B الحدود القصوى والخصائص الكهربائية
| الدقة | 20 bit |
| معدل أخذ العينات | 1 MSPS |
| Number of Channels | 1 |
| Architecture | SAR (capacitive DAC) |
| INL | ±1 ppm (typical) |
| SNR | 104.5 dB (typical) |
| Analog Input Type | Unipolar, fully differential, pseudo-differential |
| Reference Buffer | Integrated |
| Integrated LDO | Yes |
| الواجهة | SPI-compatible serial, daisy-chain capable |
| Analog Supply | 3.3 V |
| Digital Supply | 1.8 V |
| Power Consumption | Approx. 15 mW at 1 MSPS (typical) |
| العلبة | VQFN-20 (RGE) |
| نوع التركيب | Surface Mount |
| حالة RoHS | Compliant |
تكوين أطراف ADS8900B
| دبوس 1 | REFM — Reference buffer output / reference decoupling [DATA_NEEDED: confirm per datasheet] |
| دبوس 2 | REFT — Reference decoupling [DATA_NEEDED: confirm per datasheet] |
| دبوس 3 | INP — Positive analog input |
| دبوس 4 | INN — Negative analog input |
| دبوس 5 | AVDD — 3.3V analog supply |
| دبوس 6 | GND — Ground |
| دبوس 7 | CAP — Integrated LDO output capacitor |
| دبوس 8 | DVDD — 1.8V digital supply |
| دبوس 9 | SCLK — Serial clock input |
| دبوس 10 | SDI — Serial data input |
| دبوس 11 | SDO — Serial data output |
| دبوس 12 | CS — Chip select |
| دبوس 13 | CONVST — Conversion start |
| دبوس 14 | BUSY — Conversion busy indicator |
| دبوس 15 | PD — Power down control |
التطبيقات النموذجية
ADS8900B مناسب لـ 6 التطبيقs: Industrial Automation and Process Control, Power Quality Monitoring, Medical Instrumentation, Automated Test Equipment (ATE), Data Acquisition (DAQ) Systems, Vibration and Acoustic Analysis.
Industrial Automation and Process Control
The ADS8900B's ±1 ppm INL and 104.5 dB SNR provide the measurement accuracy demanded by precision process-control loops and factory instrumentation. Sampling at 1 MSPS captures fast transients in sensor front ends for pressure, flow, and temperature bridges. Its SPI interface connects directly to TI C2000 or MSP430 MCUs, and the integrated reference buffer and LDO simplify the analog power tree in crowded industrial control boards.
موصى به
Power Quality Monitoring
In power quality analyzers and smart grid metering, the ADS8900B digitizes voltage and current channels with 20-bit resolution, resolving small harmonic components against large fundamental signals thanks to 104.5 dB SNR. The 1-MSPS rate supports transient capture per IEC-class monitoring, and its pseudo-differential input accommodates single-ended sensor outputs. Integrated reference buffering removes reference-buffer design risk in multichannel racks.
موصى به
Medical Instrumentation
Diagnostic and analytical medical instruments benefit from the ADS8900B's 20-bit resolution and ±1 ppm linearity, which preserve weak biosignal detail from photodiodes, pressure sensors, and chemical front ends. At 1 MSPS it supports both slow physiological waveforms and fast optical/ultrasonic bursts. The integrated LDO and reference buffer reduce component count, aiding compact handheld and benchtop medical designs with strict reliability needs.
موصى به
Automated Test Equipment (ATE)
ATE and bench instrumentation require converter accuracy that does not limit system error budgets; the ADS8900B's ±1 ppm INL ensures the digitizer contributes negligible linearity error at 20 bits. The 1-MSPS throughput accelerates multi-point DC parametric sweeps, and daisy-chain SPI simplifies multichannel synchronisation across board-level acquisition modules. Integrated reference buffering eases layout in dense test fixtures.
موصى به
Data Acquisition (DAQ) Systems
General-purpose precision DAQ modules use the ADS8900B as a core digitizer: its fully differential inputs reject common-mode noise from long cable runs, and 104.5 dB SNR preserves 20 effective bits of dynamic range. The SPI-compatible interface with daisy-chain mode lets several ADCs share one controller port, and the 3.3V/1.8V supply levels integrate cleanly with modern low-voltage logic and isolated interfaces.
موصى به
Vibration and Acoustic Analysis
Condition-monitoring systems digitize accelerometer and MEMS microphone outputs, where the ADS8900B's wide dynamic range (104.5 dB SNR) resolves early bearing-fault harmonics buried in noise. The 1-MSPS sampling covers ultrasonic frequency bands up to hundreds of kHz for spectral analysis. Pseudo-differential input supports single-ended IEPE-style front ends, and low 15 mW consumption benefits distributed sensor nodes.
موصى به
ملخص المنتجات الموصى بها
بيانات مرجعية هندسية لـ ADS8900B — المقارنة وإرشادات التصميم ومعلومات الامتثال.
دليل الاختيار
المقارنة مع البدائل
| المعامل | هذا المنتج | ADS8902B | ADS8904B | ADS8910B | AD7980 |
|---|---|---|---|---|---|
| Package | VQFN-20 (RGE) | VQFN-20 (RGE) - same | VQFN-20 (RGE) - same | VQFN-20 (RGE) - same | VQFN-20 (RGE) - verify pinout |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Analog Devices |
| Resolution | 20 bit | 20 bit | 20 bit | 18 bit | 18 bit |
| Integrated Reference Buffer | Yes | Yes | Yes | Yes (family feature) | No (external buffer needed) |
| Integrated LDO | Yes | Yes | Yes | Yes (family feature) | No |
أبرز الفروقات
- Full 20-bit resolution at 1 MSPS (مقابلADS8910B)
- Integrated reference buffer and LDO (مقابلAD7980)
- ±1 ppm INL linearity (مقابلADS8920B)
ملاحظات التصميم
Decouple the 3.3V analog supply and 1.8V digital supply independently with 100 nF ceramic capacitors placed within 2 mm of the respective VQFN-20 (RGE) supply pins, plus bulk 10 uF capacitance per rail. Keep the analog input pair (INP/INN) routed as a matched differential pair away from SCLK/SDO digital traces to prevent coupling into the 104.5 dB SNR signal path. Use a solid ground plane under the ADC and stitch to the exposed pad.
The integrated reference buffer removes the need for a fast external buffer, but reference decoupling capacitors on REFT/REFM must follow datasheet recommendations exactly - undersized reference capacitance degrades AC performance at 1 MSPS. For maximum accuracy systems, compare the integrated LDO reference path against a low-noise external reference such as the REF5030A. Do not omit the LDO output capacitor on the CAP pin.
Drive CONVST from a clean, jitter-free source: aperture jitter directly limits SNR at 20-bit resolution. Daisy-chain SPI operation across multiple ADS890xB devices is supported, but verify SCLK rise/fall times and add series termination on long SPI runs to limit reflections and digital ground bounce that can corrupt the analog return path.
معلومات الامتثال
RoHS compliant per TI product page. REACH and halogen-free status not confirmed in provided data.
