ADS8481IRGZR - 18-Bit 1MSPS SAR ADC w/Ref | Texas Instruments
N.º de pieza: ADS8481IRGZR ✓ Activo| Cant. | Precio unitario | Total |
|---|---|---|
| 1 | $13.5 | $13,50 |
| 10 | $11.95 | $119,50 |
| 100 | $10.4 | $1.040,00 |
| 500 | $9.2 | $4.600,00 |
| 1.000 | $8.1 | $8.100,00 |
ADS8481IRGZR Descripción general
An SAR ADC is a sampling converter that uses a charge-redistribution capacitor array and a comparator to digitize an input voltage in N successive approximation steps - one per bit of resolution. SAR ADCs occupy the broad product hierarchy: ADC (analog-to-digital converter) -> data converter -> signal chain IC -> semiconductor. The ADS8481 sits in the precision, medium-speed, single-channel SAR niche favored where high resolution and deterministic latency are required - in contrast to delta-sigma ADCs that offer higher dynamic range at lower bandwidth. The ADS8481 family is also categorized as a micropower sampling data acquisition ADC, emphasizing its low power consumption relative to its 1 MSPS throughput.
Key features include 1 MSPS sampling rate, 18-bit NMC over temperature, internal 4.096-V low-drift reference, hardware-configurable output bus width, and an inherent sample-and-hold front end that accepts pseudo-differential unipolar input signals. The internal reference and reference buffer eliminate the need for an external reference IC, simplifying BOM and reducing board area in multichannel designs.
The architecture combines a precision input sample-and-hold, a charge-redistribution CDAC, an internal 4.096-V bandgap reference, and a digital interface engine that packs results into 18-bit, 16-bit, or 8-bit words to fit the host's bus width. Because SAR conversion is performed in a single conversion cycle of fixed duration, throughput latency is deterministic and well-suited to multiplexed or closed-loop control applications where timing predictability is critical.
Typical applications include industrial process control and data acquisition, multi-axis motor control with position feedback, test and measurement instrumentation, weigh scales and strain-gauge digitizers, and medical instrumentation signal chains. Choose this ADC when a 18-bit, 1 MSPS, single-channel SAR with an internal reference is required in a compact VQFN-48 footprint.
When designing with this device, ensure the input common-mode voltage is within the pseudo-differential input range and provide adequate decoupling on REFIN/REF and AVDD pins. The exposed thermal pad (EP) must be soldered to a continuous ground copper pour to keep junction temperature within safe limits.
This page synthesizes distributor stock, drop-in pin-compatible alternatives, and practical layout guidance for the 48-pin VQFN exposed-pad variant (RGZ suffix) of the ADS8481 family - complementary to the bare-die or QFP variants discussed in the broader product family datasheet.
Alternativas directas para ADS8481IRGZR — mismo encapsulado, compatible pin a pin. Se excluyen las piezas de otro encapsulado que requieren retrabajo de la PCB.
Variantes de esta serie
Modelos de la misma serie compatibles directamente con ADS8481IRGZR (mismo factor de forma y huella) — difiere en Package, Input Type, Data Interface, Operating Temperature, Analog Supply Voltage.
Herramienta de comparación rápida — seleccione piezas alternativas para compararlas lado a lado:
ADS8481IBRGZR
✅ Sustitución directa✓ En stock
$11.75 / unidad
Ver hoja de datos →ADS8481IRGZT
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
ADS8481IBRGZT
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
ADS8472IRGZR
✅ Sustitución directa✓ En stock
$8.5 / unidad
Ver hoja de datos →ADS8472IBRGZR
✅ Sustitución directa✓ En stock
$12.2 / unidad
Ver hoja de datos →ADS8481IRGZR Valores máximos y características eléctricas
| Resolución | 18 bits |
| Frecuencia de muestreo | 1 MSPS (max) |
| Architecture | SAR (Successive Approximation Register) |
| Number of Channels | 1 |
| Input Type | Pseudo-differential, unipolar, single-ended |
| Rango de tensión de entrada | 0 V to +4.096 V (with internal reference) |
| Internal Reference Voltage | 4.096 V |
| Data Interface | Parallel (18-bit / 16-bit / 8-bit bus modes) |
| No Missing Codes | 18-bit NMC over temperature |
| Offset Error | ±0.1 mV |
| Power Consumption | Micropower |
| Temperatura de funcionamiento | -40 C to +85 C |
| Encapsulado | 48-pin VQFN Exposed Pad (RGZ), Tape & Reel |
| Package Outline | VQFN EP 48-pin |
| Tipo de montaje | Surface Mount |
Configuración de pines de ADS8481IRGZR
| Pin 1 | AVDD — Analog supply voltage |
| Pin 2 | REFIO — Reference input/output |
| Pin 3 | REFM — Reference ground (negative) |
| Pin 4 | REFP — Reference positive bypass |
| Pin 5 | AINM — Analog negative input (pseudo-differential) |
| Pin 6 | AINP — Analog positive input (pseudo-differential) |
| Pin 7 | AGND — Analog ground |
| Pin 8 | REFCAP — Reference bypass capacitor |
| Pin 9 | RESET — Hardware reset input |
| Pin 10 | CONVST — Conversion start input |
| Pin 11 | RD — Read strobe / parallel output enable |
| Pin 12 | BYTE — Bus width select (18/16/8-bit) |
| Pin 13 | DC — Duty cycle / acquisition control |
| Pin 14 | CS — Chip select input |
| Pin 15 | BUSY — Conversion busy output |
| Pin 16 | NC — Not connected (per datasheet) |
| Pin 17 | EOC — End-of-conversion output |
| Pin 18 | DVDD — Digital supply voltage |
| Pin 19 | DGND — Digital ground |
| Pin 20 | DB0 — Parallel data bit 0 (LSB) |
| Pin 21 | DB1 — Parallel data bit 1 |
| Pin 22 | DB2 — Parallel data bit 2 |
| Pin 23 | DB3 — Parallel data bit 3 |
| Pin 24 | DB4 — Parallel data bit 4 |
| Pin 25 | DB5 — Parallel data bit 5 |
| Pin 26 | DB6 — Parallel data bit 6 |
| Pin 27 | DB7 — Parallel data bit 7 |
| Pin 28 | DB8 — Parallel data bit 8 |
| Pin 29 | DB9 — Parallel data bit 9 |
| Pin 30 | DB10 — Parallel data bit 10 |
| Pin 31 | DB11 — Parallel data bit 11 |
| Pin 32 | DB12 — Parallel data bit 12 |
| Pin 33 | DB13 — Parallel data bit 13 |
| Pin 34 | DB14 — Parallel data bit 14 |
| Pin 35 | DB15 — Parallel data bit 15 |
| Pin 36 | DB16 — Parallel data bit 16 |
| Pin 37 | DB17 — Parallel data bit 17 (MSB) |
| Pin 38 | TAG — Tag input for synchronization |
| Pin 39 | NC — Not connected (per datasheet) |
| Pin 40 | NC — Not connected (per datasheet) |
| Pin 41 | NC — Not connected (per datasheet) |
| Pin 42 | NC — Not connected (per datasheet) |
| Pin 43 | NC — Not connected (per datasheet) |
| Pin 44 | NC — Not connected (per datasheet) |
| Pin 45 | NC — Not connected (per datasheet) |
| Pin 46 | NC — Not connected (per datasheet) |
| Pin 47 | NC — Not connected (per datasheet) |
| Pin 48 | NC — Not connected (per datasheet) |
Aplicaciones típicas
ADS8481IRGZR es adecuado para 6 aplicacións: Industrial Process Control & Data Acquisition, Multi-Axis Motor Control with Position Feedback, Test & Measurement Instrumentation, Weigh Scales & Strain-Gauge Digitizers, Medical Instrumentation Signal Chains, Audio Signal Path Digitization & Metering.
Industrial Process Control & Data Acquisition
The ADS8481IRGZR's 18-bit NMC and pseudo-differential unipolar 0-4.096 V input map directly onto current-loop / 4-20 mA-sourced process signals after a resistor-sense stage. The 1 MSPS throughput digitizes multiplexed thermocouple, RTD, and load-cell transducer channels with deterministic latency, while the internal 4.096 V reference eliminates a BOM item and keeps gain error below the resolution step. Placed behind an input MUX and front-end op-amp, the converter produces one settled 18-bit conversion per CONVST pulse, simplifying galvanically-isolated multi-channel DAQ designs that must reject 50/60 Hz mains noise.
Recomendado
Multi-Axis Motor Control with Position Feedback
For servo and stepper drive systems, the ADS8481IRGZR digitizes encoder analog signals and current-sense shunts with 18-bit precision and deterministic SAR latency, enabling tight PI/DM-control loops. The 1 MSPS sample rate exceeds typical 8 kHz current-loop bandwidth by 125x, so loop controllers can oversample for dithered averaging without compromising throughput. The internal reference and exposed thermal pad keep the converter footprint inside the motor-drive PCB, while the parallel digital bus avoids SPI bit-banging in deterministic safety-rated firmware update paths.
Recomendado
Test & Measurement Instrumentation
Bench-top DMMs and bench-scale digitizers benefit from the ADS8481IRGZR's 18-bit NMC and low +/-0.1 mV offset error, achieving sub-1 LSB measurement uncertainty after calibration. The 1 MSPS throughput supports wideband sensor capture while the internal 4.096 V reference provides traceability for accurate voltage measurements. The parallel bus allows rapid data streaming to an FPGA-based DSP back-end for FFT, statistical, or post-processing of raw samples.
Recomendado
Weigh Scales & Strain-Gauge Digitizers
Load-cell digitizers exploit the ADS8481IRGZR's pseudo-differential 0-4.096 V range that matches the full-scale output of typical bridge sensors excited at 5 V with low common-mode bias. 18-bit NMC and low drift give 5+ digit stable weight readings, while the internal reference reduces warm-up drift and calibration recompute. Multiple channels can be time-multiplexed on a single converter to keep multi-axis force-plate systems compact.
Recomendado
Medical Instrumentation Signal Chains
Patient monitoring devices (ECG, pulse-ox front-ends, infusion pump flow-rate) leverage the ADS8481IRGZR's deterministic SAR latency to align conversion with the mains-line rejection cycle. The 18-bit resolution resolves the small dynamic range of physiological signals, and the internal reference reduces power and board area - critical for battery-powered portable instruments. The exposed thermal pad supports the strict thermal budget of wearable designs.
Recomendado
Audio Signal Path Digitization & Metering
Studio metering bridges, VU/peak program meters, and digital crossover systems use the ADS8481IRGZR to digitize audio-taper levels after a precision detector. With 18-bit precision across the 0-4.096 V audio-tapered range, the converter provides more than 100 dB dynamic range useful for digital trim controls. The internal reference simplifies power-rail design, while the 1 MSPS throughput is more than adequate for the bandwidth-limited audio path.
Recomendado
Resumen de productos recomendados
Datos de referencia de ingeniería para ADS8481IRGZR — comparación, orientación de diseño e información de cumplimiento.
Guía de selección
Comparación con alternativas
| Parámetro | Este producto | ADS8481IBRGZR | ADS8481IRGZT | ADS8472IRGZR | ADS8472IBRGZR |
|---|---|---|---|---|---|
| Package | 48-VQFN Exposed Pad (RGZ) | 48-VQFN Exposed Pad (RGZ) - same | 48-VQFN Exposed Pad (RGZ) - same | 48-VQFN Exposed Pad (RGZ) - same | 48-VQFN Exposed Pad (RGZ) - same |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Resolution | 18 bit | 18 bit | 18 bit | 16 bit | 16 bit |
| Sampling Rate | 1 MSPS | 1 MSPS | 1 MSPS | 1 MSPS | 1 MSPS |
| Internal Reference | 4.096 V | 4.096 V | 4.096 V | 4.096 V | 4.096 V |
| Input Type | Pseudo-differential, unipolar | Pseudo-differential, unipolar | Pseudo-differential, unipolar | Pseudo-differential, unipolar | Pseudo-differential, unipolar |
| Data Interface | Parallel (18/16/8-bit) | Parallel (18/16/8-bit) | Parallel (18/16/8-bit) | Parallel (18/16/8-bit) | Parallel (18/16/8-bit) |
| Performance Grade | Standard (I- grade) | Tight bin (IB- grade) | Standard | Standard (16-bit) | Tight bin (16-bit IB) |
| Operating Temperature | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C |
Diferenciadores clave
- Internal 4.096 V reference - no external REF IC required (frente a ADS8482IRGZR (true-differential, 16-bit variant))
- Higher resolution (18-bit) versus the 16-bit family (frente a ADS8472IRGZR)
- Tight B-grade bin available in the same package (frente a ADS8481IRGZR (standard grade))
Notas de diseño
Solder the exposed thermal pad (EP) of the VQFN-48 RGZ package to a continuous analog-ground copper pour directly underneath the IC. Place the REFCAP and AVDD decoupling 1 uF/100 nF pair within 2 mm of pins. Use a star-ground topology with AVDD, DVDD, and the analog input shield all returning to the EP pad - this reduces ground bounce during bus transitions and keeps reference noise from coupling into the CDAC charge balancing.
Route the parallel data bus (DB0-DB17), CONVST, RD, and BUSY signals away from analog traces - place a ground guard on both sides. For CONVST-driven modes, hold CONVST pulse width > 20 ns and keep ground impedance low for the digital return current. Use a slow-edge rate on CONVST if ringing is observed; SAR converters tolerate slower edges within their timing margins.
Do not leave the BYTE pin floating - the 18/16/8-bit bus-width mode is selected at power-up based on BYTE pin state; a floating pin will yield an unpredictable bus mode. Avoid using REFIO as an output when an external reference is being driven into the same node - either drive externally OR let REFIO be the buffered internal reference output, never both. Avoid layouts with AINM tied directly to ground before pin-strap; for true pseudo-differential performance, AINM should track the sensor reference, not PCB ground.
Información de cumplimiento
RoHS and lead-free compliant per TI product page. No AEC-Q100 variant for this part family.
