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.
Pilihan pengganti yang segera untuk ADS8900B — sama paket, pin-pin kompatibel. Bahagian paket yang berbeza memerlukan kerja ulang PCB diasingkan.
Varietas dalam siri ini
Model serupa yang kompatibel dengan pengganti yang segera ADS8900B (sama faktor bentuk dan kaki) — berbeza dalam Architecture, Package, Resolution.
ADS8902B
✅ Masuk Drop-In📋 Alternatif rujukan (tidak dalam katalog)
ADS8904B
✅ Masuk Drop-In📋 Alternatif rujukan (tidak dalam katalog)
ADS8910B
✅ Masuk Drop-In📋 Alternatif rujukan (tidak dalam katalog)
ADS8920B
✅ Masuk Drop-In📋 Alternatif rujukan (tidak dalam katalog)
AD7980ARMZ
✅ Masuk Drop-In ⚠️ Spesifikasi Tidak DisahkanHubungi untuk harga
Lihat Datasheet →ADS8900B Penilaian maksimum & Ciri-ciri Elektrik
| Pemecahkatan | 20 bit |
| kadar sampling | 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 |
| Antaramuka | 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) |
| Kemasan | VQFN-20 (RGE) |
| Jenis Pemasangan | Surface Mount |
| Status RoHS | Compliant |
Konfigurasi Pin ADS8900B
| Pin 1 | REFM — Reference buffer output / reference decoupling [DATA_NEEDED: confirm per datasheet] |
| Pin 2 | REFT — Reference decoupling [DATA_NEEDED: confirm per datasheet] |
| Pin 3 | INP — Positive analog input |
| Pin 4 | INN — Negative analog input |
| Pin 5 | AVDD — 3.3V analog supply |
| Pin 6 | GND — Ground |
| Pin 7 | CAP — Integrated LDO output capacitor |
| Pin 8 | DVDD — 1.8V digital supply |
| Pin 9 | SCLK — Serial clock input |
| Pin 10 | SDI — Serial data input |
| Pin 11 | SDO — Serial data output |
| Pin 12 | CS — Chip select |
| Pin 13 | CONVST — Conversion start |
| Pin 14 | BUSY — Conversion busy indicator |
| Pin 15 | PD — Power down control |
Aplikasi Biasa
ADS8900B patut 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.
Disebarkan
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.
Disebarkan
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.
Disebarkan
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.
Disebarkan
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.
Disebarkan
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.
Disebarkan
Ringkasan Produk Disebarkan
Data referensi kejuruteraan untuk ADS8900B — perbandingan, panduan rancangan, dan maklumat kesediaan
Panduan Pilihan
Perbandingan dengan Gantian
| Parametr | 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 |
Penyeberangsung Jelas
- 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.
Maklumat Kesediaan
RoHS compliant per TI product page. REACH and halogen-free status not confirmed in provided data.
