LTC2389HLX-18 - 18-Bit 2.5Msps SAR ADC 99.8dB SNR | Analog Devices
N.º de pieza: LTC2389HLX-18 ✓ Activo| Cant. | Precio unitario | Total |
|---|---|---|
| 1 | $67.5 | $67,50 |
| 10 | $62.1 | $621,00 |
| 100 | $56.8 | $5.680,00 |
| 500 | $52.78 | $26.390,00 |
| 1.000 | $50.25 | $50.250,00 |
LTC2389HLX-18 Descripción general
A SAR ADC (Successive Approximation Register Analog-to-Digital Converter) is a precision data converter that uses a binary-search algorithm and an internal capacitive DAC to resolve an analog input into a digital code. SAR ADCs combine high resolution with low latency and zero pipeline delay, occupying the tier between flash converters (fastest, lowest resolution) and sigma-delta ADCs (highest resolution, slowest). They are the workhorse of precision industrial instrumentation, medical imaging, and high-speed control loops.
Key features include pin-configurable analog input ranges — fully differential ±4.096 V, pseudo-differential unipolar 0 V to 4.096 V, and pseudo-differential bipolar ±2.048 V — allowing direct interface to multiple signal-chain formats without external level shifting. The device delivers 18-bit no-missing-codes performance, a wide common-mode range, and on-chip reference buffer that simplifies the analog front-end.
Internally, the LTC2389-18 uses a charge-redistribution capacitive DAC with a precision thin-film resistor network for laser-trimmed linearity, and an internal oscillator that eliminates the need for an external clock. The internal reference and reference buffer together minimize external component count while preserving 99.8 dB SNR across the full operating temperature range.
Typical applications include high-speed precision data acquisition systems, medical imaging front-ends, vibration and acoustic analysis, spectrum and FFT analysis, and process control loops. The wide input range makes it suitable for direct connection to bridge sensors, audio CODEC front-ends, and industrial 4–20 mA loop receivers after appropriate signal conditioning.
When designing with this device, keep analog and digital grounds separated and joined at a single star point under the IC. Place the 10 µF input decoupling capacitor and reference bypass capacitor as close as possible to the supply and REFIN pins to achieve the rated 99.8 dB SNR. Allow sufficient quiet settling time between conversions when operating near full throughput.
This page synthesizes distributor stock, cross-reference alternatives, and design notes not found in the bare datasheet, providing an engineer-ready summary tailored for high-precision SAR ADC selection and PCB bring-up.
Alternativas directas para LTC2389HLX-18 — 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 LTC2389HLX-18 (mismo factor de forma y huella) — difiere en RoHS Status, Package, Resolution, Internal Reference, Missing Codes.
Herramienta de comparación rápida — seleccione piezas alternativas para compararlas lado a lado:
LTC2389HLX-18#PBF
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
LTC2348HLX-18
✅ Sustitución directa✓ En stock
$58.1 / unidad
Ver hoja de datos →LTC2335HLX-16
✅ Sustitución directa✓ En stock
$15.4 / unidad
Ver hoja de datos →LTC2389HLX-18 Valores máximos y características eléctricas
| Resolución | 18 bits |
| Sample Rate | 2.5 Msps |
| Architecture | SAR (Successive Approximation Register) |
| Input Channels | 1 (single-ended/differential configurable) |
| Analog Input Range | ±4.096 V differential / 0–4.096 V unipolar / ±2.048 V bipolar pseudo-differential (pin-configurable) |
| SNR | 99.8 dB |
| Internal Reference Voltage | 4.096 V |
| Reference Temperature Coefficient | ±20 ppm/°C (maximum) |
| Initial Reference Accuracy | ±0.5% |
| Tensión de alimentación | 5 V (single supply) |
| Encapsulado | 48-LQFP (7x7 mm) |
| Internal Reference Buffer | Yes |
| No Missing Codes | 18 bits guaranteed |
| Estado RoHS | Compliant |
| Lead-Free (PBF) | Yes (per #PBF suffix) |
Configuración de pines de LTC2389HLX-18
| Pin 1 | GND — Ground |
| Pin 2 | REFIN — Reference input / internal reference output |
| Pin 3 | REFOUT — Internal reference output (4.096 V) |
| Pin 4 | IN+ — Positive analog input |
| Pin 5 | IN- — Negative analog input |
| Pin 6 | GND — Ground |
| Pin 7 | VDD |
Aplicaciones típicas
LTC2389HLX-18 es adecuado para 6 aplicacións: High-Speed Precision Data Acquisition, Medical Imaging Front-End, Spectrum and FFT Analysis, Process Control Loop Digitization, Vibration and Acoustic Analysis, Audio CODEC Front-End.
High-Speed Precision Data Acquisition
The LTC2389HLX-18 fits high-speed precision DAQ modules because its 2.5 Msps sample rate and 99.8 dB SNR deliver 18-bit dynamic range across a wide analog bandwidth. Placed after a low-noise driver such as the LT6203 and driven from a 5 V analog rail, the converter resolves microvolt-level transducer outputs into clean 18-bit codes. Compared with sigma-delta ADCs of equivalent noise floor, the LTC2389HLX-18 achieves settling in a single conversion cycle, eliminating pipeline delay in multiplexed systems.
Recomendado
Medical Imaging Front-End
Medical ultrasound and patient-monitoring front-ends benefit from the LTC2389HLX-18's 99.8 dB SNR and pin-configurable ±4.096 V differential input. The wide common-mode range accepts bipolar bioelectric signals directly, while the internal 4.096 V reference with ±20 ppm/°C drift keeps gain calibration stable across body-temperature variations. The 2.5 Msps throughput supports time-domain beamforming and high-sample-rate ECG acquisition with no missing codes at 18-bit resolution.
Recomendado
Spectrum and FFT Analysis
The LTC2389HLX-18 is well matched to wide-bandwidth spectrum analysis where 99.8 dB SNR enables spurious-free dynamic range across the full Nyquist band. With 2.5 Msps sampling, the converter captures up to 1.25 MHz of input bandwidth with anti-aliasing filter roll-off. The internal reference and buffer eliminate reference-noise spurs common in lower-performance SAR ADCs, yielding clean FFT bins for vibration, acoustic, and RF measurement setups.
Recomendado
Process Control Loop Digitization
Industrial process-control loops use the LTC2389HLX-18 to digitize 4–20 mA loop receivers and bridge sensor outputs with 18-bit precision. The pin-configurable pseudo-differential unipolar 0–4.096 V input range accepts current-loop voltage drops directly, while the internal reference removes drift concerns over industrial temperature ranges. With 2.5 Msps throughput, a single converter can scan multiple channels through an external mux without latency penalty.
Recomendado
Vibration and Acoustic Analysis
Vibration and acoustic measurement systems benefit from the LTC2389HLX-18's combination of 2.5 Msps sample rate and 99.8 dB SNR. The wide dynamic range captures both small accelerometer outputs and large transient shock events without compression, while the internal reference maintains gain stability across extended measurement campaigns. Single 5 V supply operation simplifies portable vibration analyzer designs.
Recomendado
Audio CODEC Front-End
High-end audio CODEC front-ends can use the LTC2389HLX-18 as a precision ADC path for professional recording and mastering. The 99.8 dB SNR exceeds 16-bit audio dynamic range, and the pin-configurable ±2.048 V bipolar pseudo-differential input accepts balanced line-level signals directly. The internal reference and reference buffer minimize low-frequency noise modulation that would otherwise compromise audiophile-grade recording chains.
Recomendado
Resumen de productos recomendados
Datos de referencia de ingeniería para LTC2389HLX-18 — comparación, orientación de diseño e información de cumplimiento.
Guía de selección
Comparación con alternativas
| Parámetro | Este producto | LTC2389HLX-18#PBF | LTC2348HLX-18 | LTC2335HLX-16 |
|---|---|---|---|---|
| Package | 48-LQFP (7x7 mm) | 48-LQFP (7x7 mm) - same | 48-LQFP (7x7 mm) - same | 48-LQFP (7x7 mm) - same |
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Resolution | 18 bits | 18 bits | 18 bits | 16 bits |
| Sample Rate | 2.5 Msps | 2.5 Msps | 200 ksps | 5 Msps |
| SNR | 99.8 dB | 99.8 dB | 95 dB | 93 dB |
| Input Channels | 1 | 1 | 8 | 1 |
| Input Range | ±4.096 V diff / 0–4.096 V unipolar / ±2.048 V bipolar (pin-config) | Same (pin-configurable) | ±10.24 V true bipolar / 0–10.24 V | ±4.096 V differential |
| Internal Reference | 4.096 V ±20 ppm/°C | 4.096 V ±20 ppm/°C | 4.096 V ±10 ppm/°C | 4.096 V ±20 ppm/°C |
| Supply Voltage | 5 V single | 5 V single | 5 V single | 5 V single |
| RoHS / Lead-Free | Compliant / Yes (#PBF) | Compliant / Yes | Compliant / Yes | Compliant / Yes |
Diferenciadores clave
- Industry-leading 99.8 dB SNR at 2.5 Msps in 48-LQFP (frente a LTC2348HLX-18)
- Higher resolution at similar sample rate vs LTC2335HLX-16 (frente a LTC2335HLX-16)
- Pin-configurable input range eliminates external signal conditioning (frente a LTC2373CUH-18)
Notas de diseño
Use a four-layer PCB with a dedicated analog ground plane under the LTC2389HLX-18. Place the 10 µF input supply decoupling capacitor and the reference bypass capacitor as close as possible to the VDD and REFIN pins. Keep analog input traces short and symmetric — for fully differential operation, route IN+ and IN- as a length-matched differential pair with 50 Ω characteristic impedance to preserve CMRR at high frequencies.
Estimated: At 2.5 Msps continuous sampling with a 5 V single supply, the LTC2389HLX-18 draws approximately 25–30 mA from VDD — a 0.1 Ω supply-rail impedance causes 2.5–3 mV of supply ripple, which couples into the reference and degrades SNR by 1–2 dB. Always place a ferrite bead between the analog supply rail and the ADC supply pin, and add a bulk 10 µF ceramic + 0.1 µF ceramic combination. Do not omit the reference bypass capacitor; the internal reference cannot achieve ±20 ppm/°C drift without proper bypassing.
Route the digital interface (SDO, SCK, CONV, BUSY) away from the analog input traces. The exposed pad on the LQFP must be soldered to the analog ground plane to provide both thermal dissipation and a low-inductance ground return. Keep digital output traces length-matched when interfacing an FPGA to avoid timing skew across the SPI-compatible bus. Add a small RC filter on the digital supply (OVDD) pin if the host FPGA generates significant switching noise.
Power the analog VDD rail from a low-noise LDO such as the LT3042 rather than directly from a switching regulator. The 99.8 dB SNR specification assumes a clean analog supply with sub-µV RMS ripple. Estimated: using a generic 50 µV-ripple switching regulator instead of a low-noise LDO can degrade SNR by 6–10 dB. Add a series ferrite and shunt ceramic at the LDO output if additional filtering is required.
Información de cumplimiento
RoHS and lead-free compliance achieved by ordering the #PBF suffix (LTC2389HLX-18#PBF). Original Linear Technology product line, now under Analog Devices. AEC-Q100 qualification not applicable for this industrial/consumer-grade part.
