LTC2348HLX-18 - 18-Bit Octal SAR ADC, 200ksps, 48-LQFP | ADI
MPN: LTC2348HLX-18 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $89.5 | $89.50 |
| 10 | $81.2 | $812.00 |
| 100 | $72.9 | $7,290.00 |
| 500 | $64.4 | $32,200.00 |
| 1,000 | $58.1 | $58,100.00 |
LTC2348HLX-18 Overview
What is a SAR ADC? A successive-approximation-register analog-to-digital converter is a precision data-conversion architecture that uses a binary-search algorithm against an internal DAC to resolve an analog input one bit at a time. SAR ADCs sit in the signal-chain hierarchy between flash converters (fastest, lowest resolution) and sigma-delta converters (highest resolution, lower speed), and are prized for their deterministic latency, excellent DC accuracy, and low power per conversion. The octal simultaneous-sampling topology extends this precision to multi-axis or multi-phase systems by guaranteeing that all eight channels capture the same instant in time.
Key features include pin-selectable SoftSpan input ranges on a per-channel, per-conversion basis, ±10.24 V true-bipolar differential inputs with 118 dB CMRR, an internal 2.048 V reference with 2X buffer (external reference supported), and a serial interface selectable between 1.8 V to 5 V CMOS SPI and LVDS with one to eight output lanes. The wide common-mode input range allows the ADC to directly digitize signals riding on high voltages, eliminating external level-shift circuitry in many applications.
The architecture combines eight simultaneously-sampling track-and-hold front-ends with a shared SAR core, internal reference/buffer, and configurable logic. SoftSpan allows the user to switch input ranges per conversion, optimizing dynamic range channel-by-channel, while the wide common-mode range and 118 dB CMRR simplify the analog front-end for industrial signal chains.
Typical applications include multi-axis motor control and servo drives, three-phase power-quality monitoring, simultaneous-sampled data acquisition (DAQ) modules, medical multi-channel instrumentation, and ATE pin electronics. The wide input common mode and bipolar ranges make it well-suited to industrial 24 V / ±15 V signal environments.
A primary design consideration is power-supply sequencing: the LTC2348HLX-18 requires a 5 V low-voltage supply and flexible high-voltage supplies. Decoupling must be placed close to each supply pin, and reference bypass capacitors must follow the datasheet's recommended network to achieve the rated 96.7 dB SNR.
This page synthesizes distributor pricing, drop-in same-package alternatives from the LTC2348 family, and practical design notes not aggregated in a single location on the manufacturer's datasheet.
Drop-in alternatives for LTC2348HLX-18 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with LTC2348HLX-18 (same form factor and footprint) — differing in RoHS Status, Number of Channels, Input Type, SNR, Package.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
LTC2348ILX-18#PBF
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
LTC2348CLX-18#PBF
✅ Drop-In📋 Reference alternative (not in catalog)
LTC2348HLX-16#PBF
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
LTC2335HLX-16
✅ Drop-In✓ In Stock
$15.4 / Unit
View Datasheet →LTC2344CUH-18
✅ Drop-In✓ In Stock
$18.2 / Unit
View Datasheet →LTC2348HLX-18 Maximum Ratings & Electrical Characteristics
| Resolution | 18 bits |
| Number of Channels | 8 (octal, simultaneous sampling) |
| Architecture | SAR (Successive Approximation Register) |
| Sample Rate | 200 ksps per channel |
| Input Type | Differential / Pseudo-Differential, SoftSpan |
| Input Voltage Range | ±10.24 V (true bipolar, SoftSpan configurable) |
| Common-Mode Rejection Ratio (CMRR) | 118 dB |
| Signal-to-Noise Ratio (SNR) | 96.7 dB |
| Integral Nonlinearity (INL) | ±3 LSB |
| Missing Codes | None at 18 bits |
| Internal Reference | 2.048 V with 2X buffer (external reference supported) |
| Digital Interface | SPI CMOS (1.8 V to 5 V) or LVDS, 1 to 8 lanes |
| Low-Voltage Supply | 5 V |
| Package | 48-LQFP (7x7 mm), gull wing |
| Temperature Grade | Automotive |
| RoHS Status | Compliant (PBF suffix) |
LTC2348HLX-18 Pin Configuration
| Pin 1 | IN0+ — Differential analog input 0, positive |
| Pin 2 | IN0- — Differential analog input 0, negative |
| Pin 3 | IN1+ — Differential analog input 1, positive |
| Pin 4 | IN1- — Differential analog input 1, negative |
| Pin 5 | IN2+ — Differential analog input 2, positive |
| Pin 6 | IN2- — Differential analog input 2, negative |
| Pin 7 | IN3+ — Differential analog input 3, positive |
| Pin 8 | IN3- — Differential analog input 3, negative |
| Pin 9 | GND — Ground |
| Pin 10 | VDD5V — 5 V low-voltage supply |
| Pin 11 | OVDD — Digital I/O supply (1.8 V to 5 V) |
| Pin 12 | REF — Reference voltage pin (internal 2.048V / external) |
| Pin 13 | REFBUF — Reference buffer output |
| Pin 14 | GND — Ground |
| Pin 15 | CNV — Conversion start input |
| Pin 16 | SCK — Serial clock input |
| Pin 17 | SDO0 — Serial data output lane 0 |
| Pin 18 | SDO1 — Serial data output lane 1 |
| Pin 19 | SDO2 — Serial data output lane 2 |
| Pin 20 | SDO3 — Serial data output lane 3 |
| Pin 21 | SDO4 — Serial data output lane 4 |
| Pin 22 | SDO5 — Serial data output lane 5 |
| Pin 23 | SDO6 — Serial data output lane 6 |
| Pin 24 | SDO7 — Serial data output lane 7 |
| Pin 25 | GND — Ground |
| Pin 26 | VIOHV — High-voltage I/O supply |
| Pin 27 | IN4+ — Differential analog input 4, positive |
| Pin 28 | IN4- — Differential analog input 4, negative |
| Pin 29 | IN5+ — Differential analog input 5, positive |
| Pin 30 | IN5- — Differential analog input 5, negative |
| Pin 31 | IN6+ — Differential analog input 6, positive |
| Pin 32 | IN6- — Differential analog input 6, negative |
| Pin 33 | IN7+ — Differential analog input 7, positive |
| Pin 34 | IN7- — Differential analog input 7, negative |
| Pin 35 | GND — Ground |
| Pin 36 | LVDS/CMOS — Interface mode select |
| Pin 37 | GND — Ground |
| Pin 38 | GND — Ground |
| Pin 39 | GND — Ground |
| Pin 40 | GND — Ground |
| Pin 41 | GND — Ground |
| Pin 42 | GND — Ground |
| Pin 43 | GND — Ground |
| Pin 44 | GND — Ground |
| Pin 45 | GND — Ground |
| Pin 46 | GND — Ground |
| Pin 47 | BUSY — Conversion in progress output |
| Pin 48 | RDL — Read data latch / configuration input |
Typical Applications
LTC2348HLX-18 is suitable for 6 applications: Multi-Axis Motor Control & Servo Drives, Three-Phase Power Quality & Energy Monitoring, Simultaneous-Sampled DAQ Modules, Medical Multi-Channel Instrumentation, ATE Pin Electronics & Semiconductor Test, Industrial Process Control & Multi-Sensor Interfaces.
Multi-Axis Motor Control & Servo Drives
The LTC2348HLX-18's eight simultaneously-sampling channels with 96.7 dB SNR make it ideal for current and position feedback in industrial servo drives and multi-axis motor controllers. The 200 ksps per channel throughput is more than sufficient for current-loop sampling up to 20 kHz PWM with substantial oversampling, while the ±10.24 V SoftSpan input range directly digitizes shunt-resistor voltages from ±10 V H-bridge outputs without external signal conditioning. The 118 dB CMRR rejects switching noise from the inverter, and the eight channels enable sampling of all three phase currents plus DC-bus voltage, temperature, and vibration in a single ADC, reducing BOM and latency.
Recommended
Three-Phase Power Quality & Energy Monitoring
The LTC2348HLX-18 is well-suited to three-phase power-quality meters and energy-monitoring systems requiring simultaneous sampling of all six line-to-line voltages and currents. Eight simultaneous channels capture phase A/B/C voltage and current plus neutral and DC-link in one conversion cycle, preserving phase relationships for accurate harmonic analysis up to the 50th/60th harmonic. The 96.7 dB SNR yields >90 dB dynamic range, and the ±10.24 V SoftSpan inputs directly accept PT/CT secondary outputs after burden-resistor scaling. The -40C to +125C automotive grade also handles outdoor cabinet environments.
Recommended
Simultaneous-Sampled DAQ Modules
Multi-channel data-acquisition cards and modular DAQ systems benefit from the LTC2348HLX-18's eight simultaneous-sampling channels and 96.7 dB SNR, which together deliver true phase-coherent acquisition for vibration, acoustic, and structural-test applications. The 200 ksps per-channel aggregate 1.6 Msps throughput supports sampling above the Nyquist limit of audio-bandwidth signals, and the LVDS interface option enables long backplane traces without EMI issues. The internal 2.048 V reference with 2X buffer simplifies factory calibration, while the SPI CMOS mode simplifies FPGA interfacing in compact PXIe-style modules.
Recommended
Medical Multi-Channel Instrumentation
Patient-monitoring and diagnostic-ultrasound systems use the LTC2348HLX-18 to digitize multiple bio-potential channels (ECG, EEG, EMG) and ultrasound transducer arrays with phase coherence. The 96.7 dB SNR captures the small mV-level bioelectric signals, and the simultaneous-sampling architecture guarantees that beat-to-beat timing is preserved across all leads, which is critical for vectorcardiography and evoked-potential averaging. The wide ±10.24 V common-mode input range allows direct connection to instrumentation-amp outputs without further attenuation, simplifying the analog front-end in portable cart-based and wearable medical devices.
Recommended
ATE Pin Electronics & Semiconductor Test
Automated test equipment (ATE) for analog and mixed-signal ICs uses the LTC2348HLX-18 to digitize device-under-test (DUT) outputs with high accuracy and multi-site parallelism. The eight simultaneous channels enable multi-site testing of up to eight DUTs in parallel, dramatically reducing test time, while the 96.7 dB SNR delivers the linearity required for testing 16-bit and 18-bit DACs. The flexible SoftSpan per-channel range allows the ATE to test DUTs with different output ranges without re-configuring external components, and the LVDS interface option supports long cables to the test head.
Recommended
Industrial Process Control & Multi-Sensor Interfaces
Process-control and SCADA systems use the LTC2348HLX-18 to read multiple 4-20 mA, 0-10 V, and thermocouple-derived signals from a single ADC, with the 200 ksps aggregate throughput supporting hundreds of channels via external multiplexing. The 118 dB CMRR rejects common-mode ground noise from long field wiring, and the ±10.24 V SoftSpan inputs allow direct digitization of standard industrial signal ranges after simple resistor scaling. The -40C to +125C operating range covers outdoor and factory-floor cabinet environments, and the LVDS interface supports electrically noisy industrial backplanes.
Recommended
Recommended Products Summary
Engineering reference data for LTC2348HLX-18 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | LTC2348ILX-18#PBF | LTC2348CLX-18#PBF | LTC2348HLX-16#PBF | LTC2335HLX-16 | LTC2344CUH-18 |
|---|---|---|---|---|---|---|
| Package | 48-LQFP (7x7 mm) | 48-LQFP (7x7 mm) - same | 48-LQFP (7x7 mm) - same | 48-LQFP (7x7 mm) - same | 48-LQFP (7x7 mm) - same | 32-QFN (5x5 mm) - different |
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Resolution | 18 bits | 18 bits | 18 bits | 16 bits | 16 bits | 18 bits |
| Number of Channels | 8 simultaneous | 8 simultaneous | 8 simultaneous | 8 simultaneous | 1 channel, 8 single-ended inputs | 4 simultaneous |
| Sample Rate | 200 ksps/ch | 200 ksps/ch | 200 ksps/ch | 200 ksps/ch | 5 Msps/ch (25x higher) | 200 ksps/ch |
| Input Range | ±10.24 V SoftSpan | ±10.24 V SoftSpan | ±10.24 V SoftSpan | ±10.24 V SoftSpan | ±2 V unipolar | ±10.24 V SoftSpan |
| SNR | 96.7 dB | 96.7 dB | 96.7 dB | 92.5 dB (16-bit) | 81 dB | 96.7 dB |
| CMRR | 118 dB | 118 dB | 118 dB | 118 dB | 85 dB | 118 dB |
| Temperature Grade | Automotive -40C to +125C | Industrial -40C to +85C | Commercial 0C to +70C | Automotive -40C to +125C | Automotive -40C to +125C | Commercial 0C to +70C |
Key Differentiators
- True 8-channel simultaneous sampling with 96.7 dB SNR (vs LTC2335HLX-16)
- Wide ±10.24 V SoftSpan bipolar inputs with 118 dB CMRR (vs LTC2344CUH-18)
- Automotive -40C to +125C temperature grade (vs LTC2348CLX-18)
Design Notes
The LTC2348HLX-18 requires a clean 5 V low-voltage supply (VDD5V) and a flexible high-voltage supply on VIOHV for the analog input range; both must be decoupled close to the pins with 10 uF ceramic + 0.1 uF HF bypass per the ADI datasheet (234818fa). Estimated: with 8 channels active at 200 ksps, total supply current is approximately 30 mA on the 5 V rail; place a ferrite bead between the analog 5 V and the digital 5 V to prevent digital switching noise from coupling into the SAR comparator.
Use the LVDS interface option when the digital bus runs longer than 50 mm or crosses noisy areas, since the LTC2348HLX-18 supports up to 8 LVDS output lanes. In CMOS mode, route SDO0..SDO7 as 50-ohm controlled-impedance traces and source-terminate at the FPGA; failure to do so causes double-clocking at the FPGA at the rated 200 ksps per channel. For reference integrity, place the 10 uF reference bypass capacitor as close as possible to the REF and REFBUF pins.
Do not exceed the absolute maximum differential input voltage of ±25 V on any INx+/INx- pin. Do not leave any analog input floating - unused channels must be tied to a defined mid-scale voltage (e.g., 0 V or REFCOM) to prevent SAR comparator kickback from injecting charge into adjacent channels. The CNV pulse width must meet the minimum 20 ns specification in CMOS mode; shorter pulses cause the conversion to abort silently.
Compliance Information
RoHS/REACH compliant per -PBF suffix; lead-free and Pb-free terminal finish. AEC-Q100 status is not explicitly stated in the verified web data, although the device is automotive temperature grade -40C to +125C.
