ADS8900B - 20-Bit 1-MSPS SAR ADC with Ref Buffer | TI
MPN: ADS8900B ✓ AktifADS8900B Ringkasan
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.
Alternatif penggantian untuk ADS8900B — paket yang sama, pin-pada-pin kompatibel. Bagian paket yang berbeda memerlukan kerja ulang PCB diabaikan.
Variasi di dalam seri ini
Model-series yang sama yang kompatibel dengan penggantian ADS8900B (sama faktor bentuk dan footprint) — berbeda di dalam Architecture, Package, Resolution.
ADS8902B
✅ Drop-In📋 Alternatif referensi (tidak dalam katalog)
ADS8904B
✅ Drop-In📋 Alternatif referensi (tidak dalam katalog)
ADS8910B
✅ Drop-In📋 Alternatif referensi (tidak dalam katalog)
ADS8920B
✅ Drop-In📋 Alternatif referensi (tidak dalam katalog)
AD7980ARMZ
✅ Drop-In ⚠️ Spesifikasi Tidak DisahkanKontak untuk harga
Lihat Datasheet →ADS8900B Rating Maksimal & Karakteristik Listrik
| Resolusi | 20 bit |
| Laju Pengambilan Sampel | 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 |
| Antarmuka | 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) |
| Paket | VQFN-20 (RGE) |
| Tipe Mounting | Surface Mount |
| Status RoHS | Compliant |
Konfigurasi Pin ADS8900B
| Pin produk 1 | REFM — Reference buffer output / reference decoupling [DATA_NEEDED: confirm per datasheet] |
| Pin produk 2 | REFT — Reference decoupling [DATA_NEEDED: confirm per datasheet] |
| Pin produk 3 | INP — Positive analog input |
| Pin produk 4 | INN — Negative analog input |
| Pin produk 5 | AVDD — 3.3V analog supply |
| Pin produk 6 | GND — Ground |
| Pin produk 7 | CAP — Integrated LDO output capacitor |
| Pin produk 8 | DVDD — 1.8V digital supply |
| Pin produk 9 | SCLK — Serial clock input |
| Pin produk 10 | SDI — Serial data input |
| Pin produk 11 | SDO — Serial data output |
| Pin produk 12 | CS — Chip select |
| Pin produk 13 | CONVST — Conversion start |
| Pin produk 14 | BUSY — Conversion busy indicator |
| Pin produk 15 | PD — Power down control |
Aplikasi Umum
ADS8900B cocok untuk 6 aplikasis: 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.
Direkomendasikan
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.
Direkomendasikan
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.
Direkomendasikan
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.
Direkomendasikan
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.
Direkomendasikan
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.
Direkomendasikan
Ringkasan Produk Direkomendasikan
Data referensi engineering untuk ADS8900B — pembandingan, panduan desain, dan informasi konformitas.
Panduan Pemilihan
Pembandingan dengan Alternatif
| Parameter Umum | Produk Ini | 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 |
Diferensiator Kunci
- Full 20-bit resolution at 1 MSPS (vsADS8910B)
- Integrated reference buffer and LDO (vsAD7980)
- ±1 ppm INL linearity (vsADS8920B)
Catatan Desain
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.
Informasi Konformitas
RoHS compliant per TI product page. REACH and halogen-free status not confirmed in provided data.
