LTC2344CUH-18 - 18-Bit 400kSPS Quad SAR ADC | Analog Devices
MPN: LTC2344CUH-18 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $28.5 | $28.50 |
| 10 | $25.65 | $256.50 |
| 100 | $22.8 | $2,280.00 |
| 500 | $20.5 | $10,250.00 |
| 1,000 | $18.2 | $18,200.00 |
LTC2344CUH-18 Overview
A successive approximation register (SAR) ADC is a precision data converter architecture that resolves one bit per clock cycle using a binary-weighted capacitor DAC and a comparator, then digitizes the input through a successive approximation search. SAR ADCs are valued for low latency, deterministic behavior, no pipeline latency, and excellent DC accuracy. Within the converter family hierarchy, SAR ADCs sit below pipelined ADCs (higher speed, higher channel count) and delta-sigma ADCs (highest resolution, lowest bandwidth); the LTC2344 family targets the mid-bandwidth, multi-channel, high-precision industrial segment.
Key specifications include 18-bit resolution with no missing codes, 400 kSPS per channel simultaneous sampling rate, four differential SoftSpan inputs accepting true bipolar ±10.24 V or 0-5 V ranges, 100 dB SNR typical, and ±2 LSB INL maximum. The serial interface supports pin-selectable SPI CMOS (1.8 V to 5 V) or LVDS output, with one to four lanes selectable in CMOS mode to optimize bus width and throughput. The internal 2.048 V reference and buffer reduce external component count.
Typical applications include industrial process control and automation, multi-channel data acquisition systems, medical imaging front ends, instrumentation and test equipment, and high-speed multichannel precision monitoring. The 32-QFN package with exposed pad provides low thermal resistance suitable for continuous high-throughput conversion.
When designing, decouple AVDD/DVDD/OVDD with 1 µF and 0.1 µF ceramic capacitors placed as close to the pins as possible. Drive the CNV rising edge to start conversion; route the LVDS or CMOS data lines with controlled impedance and length-matching. The exposed pad must be soldered to a continuous ground plane for thermal dissipation and low-impedance return paths. This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the standalone manufacturer datasheet.
Drop-in alternatives for LTC2344CUH-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 LTC2344CUH-18 (same form factor and footprint) — differing in Input Type, Package, Digital Interface, Number of Channels, Internal Reference.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
LTC2344CUH-16
✅ Drop-In✓ In Stock
$18.95 / Unit
View Datasheet →LTC2341HUH-18
✅ Drop-In✓ In Stock
$24.95 / Unit
View Datasheet →LTC2344IUH-18
✅ Drop-In📋 Reference alternative (not in catalog)
LTC2344CUH-18#PBF
✅ Drop-In📋 Reference alternative (not in catalog)
LTC2344HUH-18
✅ Drop-In✓ In Stock
$33.6 / Unit
View Datasheet →LTC2344CUH-18 Maximum Ratings & Electrical Characteristics
| Resolution | 18 bits |
| Sampling Rate per Channel | 400 kSPS |
| Number of Channels | 4 (simultaneous sampling) |
| Architecture | SAR (Successive Approximation Register) |
| Input Type | Differential, wide common-mode range |
| Input Range (SoftSpan) | Bipolar ±10.24 V / unipolar 0-5 V (range dependent) |
| Supply Voltage | 5 V (single analog supply) |
| Digital I/O Supply | 1.8 V to 5 V (OVDD) |
| Internal Reference | 2.048 V (with internal buffer) |
| SNR | 100 dB typical |
| INL | ±2 LSB maximum |
| Serial Interface | SPI CMOS (1.8V-5V) / LVDS, pin-selectable, 1-4 lanes (CMOS) |
| Sample-and-Hold | Per-channel, true simultaneous acquisition |
| Operating Temperature Range | -40 to 125 C |
| Package | 32-QFN (5x5 mm) with exposed pad |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant (#PBF suffix) |
LTC2344CUH-18 Pin Configuration
| Pin 1 | AIN0+ — Differential analog input 0, positive |
| Pin 2 | AIN0- — Differential analog input 0, negative |
| Pin 3 | GND — Analog ground |
| Pin 4 | AIN1+ — Differential analog input 1, positive |
| Pin 5 | AIN1- — Differential analog input 1, negative |
| Pin 6 | GND — Analog ground |
| Pin 7 | AIN2+ — Differential analog input 2, positive |
| Pin 8 | AIN2- — Differential analog input 2, negative |
| Pin 9 | GND — Analog ground |
| Pin 10 | AIN3+ — Differential analog input 3, positive |
| Pin 11 | AIN3- — Differential analog input 3, negative |
| Pin 12 | GND — Analog ground |
| Pin 13 | REF — Reference bypass pin (internal 2.048 V reference) |
| Pin 14 | REFIN — External reference input (when internal reference is bypassed) |
| Pin 15 | COM — Common-mode voltage output for input common-mode bias |
| Pin 16 | GND — Analog ground |
| Pin 17 | AVDD — 5 V analog supply |
| Pin 18 | GND — Analog ground |
| Pin 19 | OVDD — Digital I/O supply (1.8 V to 5 V) |
| Pin 20 | GND — Digital ground |
| Pin 21 | SDO — Serial data output (CMOS mode) / LVDS data output |
| Pin 22 | SCK — Serial clock input |
| Pin 23 | CNV — Convert input (rising edge initiates conversion) |
| Pin 24 | BUSY — Busy output (high during conversion) |
| Pin 25 | CS — Chip select input |
| Pin 26 | LVDS/CMOS — Interface mode select (LVDS = high, CMOS = low) |
| Pin 27 | SDO2 — Serial data output lane 2 (CMOS multi-lane mode) |
| Pin 28 | SDO3 — Serial data output lane 3 (CMOS multi-lane mode) |
| Pin 29 | SDO4 — Serial data output lane 4 (CMOS multi-lane mode) |
| Pin 30 | GND — Digital ground |
| Pin 31 | DVDD — Digital core supply (decoupled from AVDD and OVDD) |
| Pin 32 | GND — Digital ground |
Typical Applications
LTC2344CUH-18 is suitable for 6 applications: Industrial Process Control and Automation, Multi-Channel Data Acquisition Systems, Medical Imaging and Patient Monitoring Front Ends, Test and Measurement Instrumentation, Power Line and Energy Monitoring, Vibration and Acoustic Monitoring.
Industrial Process Control and Automation
The LTC2344CUH-18 fits industrial process control because its four simultaneous-sampling 18-bit channels eliminate inter-channel skew when digitizing multi-phase sensor signals. With 400 kSPS per channel and 100 dB SNR, it captures fast transients on the factory bus. Powered from a single 5 V rail with integrated reference and buffer, it reduces BOM in 4-20 PLC modules. The 32-QFN exposed-pad package handles industrial -40 to 125 C operation with low EMI leakage. Use cases include multi-axis motor control feedback, vibration monitoring, and pressure/temperature bridge arrays. Companion MPNs include isolated gate drivers and the LT8709 buck converter.
Recommended
Multi-Channel Data Acquisition Systems
The LTC2344CUH-18 is purpose-built for multi-channel data acquisition cards needing simultaneous sampling and 18-bit DC accuracy at 400 kSPS per channel. Its differential SoftSpan inputs accept ±10.24 V bipolar signals directly from sensors or instrumentation amplifiers without level shifting. The pin-selectable CMOS or LVDS serial interface allows one to four output lanes, so designers trade off bus width against FPGA pin count. The internal reference eliminates an external reference IC, reducing PCB area. Companion MPNs include precision op-amps for input buffering and FPGAs for data aggregation.
Recommended
Medical Imaging and Patient Monitoring Front Ends
The LTC2344CUH-18 suits medical imaging front ends and patient monitoring where 18-bit resolution captures fine amplitude steps in ECG, EEG, ultrasound, and impedance signals. Four simultaneous channels align phase across lead sets, while 400 kSPS per channel captures wide-bandwidth ultrasound RF envelopes. The 100 dB SNR preserves dynamic range critical for diagnostic accuracy. Low digital I/O voltages (1.8 V to 5 V) interface with modern FPGAs and microcontrollers. The 32-QFN package fits compact patient-worn and bedside modules. Companion MPNs include low-noise op-amps for analog front ends.
Recommended
Test and Measurement Instrumentation
The LTC2344CUH-18 delivers 18-bit accuracy and 400 kSPS/channel throughput needed in benchtop and modular test instruments such as oscilloscope auxiliary channels, spectrum analyzer IF digitizers, and precision multimeter digitizing stages. Four channels support parallel measurements of stimulus and stimulus response with phase alignment. The SoftSpan bipolar input ranges accept ±10 V signals without external dividers, simplifying front-end signal conditioning. LVDS serial output maintains noise immunity in long-cable backplane designs. Companion MPNs include low-noise references and precision op-amps.
Recommended
Power Line and Energy Monitoring
The LTC2344CUH-18 fits three-phase power line monitoring and energy metering because four simultaneous 18-bit channels digitize three-phase voltage and current with phase alignment for accurate power calculations. Wide ±10.24 V common-mode inputs accept signals directly from current shunts or current transformers on 480 V AC lines. 400 kSPS per channel captures high-order harmonics up to 200 kHz. The integrated reference and buffer reduce BOM for cost-driven smart-meter designs. Companion MPNs include isolated ADCs and isolated gate drivers for high-voltage safety barriers.
Recommended
Vibration and Acoustic Monitoring
The LTC2344CUH-18 fits multi-axis vibration and acoustic monitoring systems in industrial predictive maintenance, audio test, and structural health monitoring. Four simultaneous channels capture vibration from accelerometers mounted in X/Y/Z plus a reference, preserving phase relationships critical for modal analysis. 400 kSPS per channel digitizes high-frequency vibration content up to 200 kHz. The 100 dB SNR preserves low-amplitude acoustic signatures against sensor noise floor. Companion MPNs include MEMS accelerometers, MEMS microphones, and low-noise op-amps for analog front ends.
Recommended
Recommended Products Summary
Engineering reference data for LTC2344CUH-18 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | LTC2344CUH-16 | LTC2341HUH-18 | LTC2344IUH-18 | LTC2344HUH-18 | LTC2344CUH-18#PBF |
|---|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | 32-QFN (5x5 mm) | 32-QFN (5x5 mm) - same | 32-QFN (5x5 mm) - same | 32-QFN (5x5 mm) - same | 32-QFN (5x5 mm) - same | 32-QFN (5x5 mm) - same |
| Resolution | 18 bits | 16 bits | 18 bits | 18 bits | 18 bits | 18 bits |
| Number of Channels | 4 (simultaneous) | 4 (simultaneous) | 1 | 4 (simultaneous) | 4 (simultaneous) | 4 (simultaneous) |
| Sampling Rate per Channel | 400 kSPS | 400 kSPS | 400 kSPS | 400 kSPS | 400 kSPS | 400 kSPS |
| Input Range | ±10.24 V bipolar / 0-5 V unipolar | ±10.24 V bipolar / 0-5 V unipolar | ±10.24 V bipolar / 0-5 V unipolar | ±10.24 V bipolar / 0-5 V unipolar | ±10.24 V bipolar / 0-5 V unipolar | ±10.24 V bipolar / 0-5 V unipolar |
| Operating Temperature Range | 0 to 70 C (commercial) | 0 to 70 C (commercial) | -40 to 125 C (extended) | -40 to 85 C (industrial) | -40 to 125 C (extended) | 0 to 70 C (commercial) |
| Internal Reference | 2.048 V with buffer | 2.048 V with buffer | 2.048 V with buffer | 2.048 V with buffer | 2.048 V with buffer | 2.048 V with buffer |
| RoHS / Lead-Free | No (#PBF suffix required for lead-free) | No (#PBF suffix required) | No (#PBF suffix required) | No (#PBF suffix required) | No (#PBF suffix required) | Yes (lead-free, RoHS compliant) |
Key Differentiators
- Highest resolution in the LTC2344 family (vs LTC2344CUH-16)
- True 4-channel simultaneous sampling (vs LTC2341HUH-18)
- Industrial temperature grade option (vs LTC2344IUH-18)
- Lead-free / RoHS-compliant variant (vs LTC2344CUH-18#PBF)
Design Notes
Decouple AVDD, DVDD, and OVDD separately with 1 µF and 0.1 µF ceramic capacitors placed as close to the IC pins as possible. According to the Analog Devices datasheet, AVDD (5 V) supplies the analog front-end and reference buffer, DVDD is the internal digital core, and OVDD (1.8 V to 5 V) sets the digital I/O voltage. Each supply domain needs its own ferrite bead or filter to prevent digital switching noise from coupling into the analog domain. Estimated: based on datasheet decoupling recommendations, a 4-layer PCB with dedicated analog and digital ground planes minimizes supply-induced errors to within 1 LSB at 18-bit resolution.
The 32-QFN package with exposed pad relies on the PCB ground plane for heat dissipation. According to the Analog Devices datasheet, the exposed pad must be soldered to a continuous ground plane with multiple thermal vias (typically 9-16 vias in a 3x3 array) to a bottom-layer heat sink. At 400 kSPS simultaneous sampling on all four channels, the device dissipates approximately 100 mW, well within the 32-QFN thermal envelope, but the thermal vias are still required for reliable solder wetting during reflow.
Route analog inputs as differential pairs from each AIN+/AIN- source, keeping them matched in length and away from digital signals. According to the Analog Devices datasheet, the COM pin provides the input common-mode voltage and should be bypassed to ground with 1 µF and 0.1 µF ceramic capacitors. Place the reference bypass capacitor (typically 10 µF ceramic or tantalum in parallel with 0.1 µF) directly at the REF pin. Use the CNC layout software to verify that all analog traces are routed on the top layer above a continuous ground plane.
When using LVDS serial output, route SDO+/- as a 100 Ω differential pair with controlled impedance and length matching within 100 mils. According to the Analog Devices datasheet, the LVDS mode provides the best noise immunity for high-speed serial data transfer. The CNV and SCK traces should be kept short and routed away from analog inputs to prevent digital coupling into the analog domain. Use series termination resistors (typically 33 Ω) on digital outputs driving long PCB traces to dampen reflections.
Do not leave any analog input floating - per the Analog Devices datasheet, unused channels should be tied to a defined DC voltage (such as COM or midscale) to prevent excessive current draw from the input ESD cells. Do not exceed the absolute maximum analog input voltage of ±15 V or current draws will damage the input protection structures. Do not toggle CNV while BUSY is high, as this can corrupt the conversion in progress. When switching between CMOS and LVDS modes, allow 1 µs settling time before initiating the next conversion.
Compliance Information
Lead-free RoHS compliance indicated by #PBF suffix per Analog Devices documentation. Not AEC-Q100 qualified - the LTC2344CUH-18 is a precision ADC intended for industrial, instrumentation, and medical applications rather than automotive safety-critical deployments.
