LTC2373IUH-18 - 18-Bit, 1Msps, 8-Ch SAR ADC | ADI
MPN: LTC2373IUH-18 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $17.78 | $17.78 |
| 10 | $15.92 | $159.20 |
| 100 | $13.25 | $1,325.00 |
| 500 | $11.84 | $5,920.00 |
| 1,000 | $10.45 | $10,450.00 |
LTC2373IUH-18 Overview
An SAR ADC (successive-approximation-register analog-to-digital converter) is a type of Nyquist-rate data converter that uses a binary search algorithm to convert an analog voltage into a digital code in N clock cycles. SAR ADCs are valued for low latency, zero-pipeline-delay conversions and are widely used in multiplexed data-acquisition front ends, industrial instrumentation and precision sensor signal chains where deterministic per-sample timing is required.
Key features include a highly configurable low-crosstalk 8-channel input multiplexer supporting fully differential, pseudo-differential unipolar and pseudo-differential bipolar analog input ranges; an onboard low-drift 20ppm/°C max 2.048V temperature-compensated reference; a singleshot-capable reference buffer; and a high-speed SPI-compatible serial interface that supports 1.8V, 2.5V, 3.3V and 5V logic. The sequencer with depth 16 enables autonomous channel scanning for cyclic and event-triggered acquisitions.
Architecturally, the LTC2373IUH-18 combines a charge-redistribution capacitive DAC core with a precision 2.048V internal reference and dedicated reference-buffer amplifier, achieving 100dB SNR and excellent INL/DNL without external reference components. The wide common-mode input range combined with true-differential switching simplifies front-end signal conditioning for bridge sensors, RTDs and ±10V industrial signals when paired with external attenuators.
Typical applications include industrial automation and process control, multichannel data acquisition systems, medical instrumentation, seismic and vibration monitoring, and precision weigh scales. When designing in, allocate adequate bypass capacitance on REF and provide a low-impedance analog ground pour under the exposed pad to maintain SNR at full speed. This page synthesizes distributor pricing, pin-compatible family variants, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for LTC2373IUH-18 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
LTC2373HUH-18#PBF
✅ Drop-In📋 Reference alternative (not in catalog)
LTC2373CUH-18#PBF
✅ Drop-In📋 Reference alternative (not in catalog)
LTC2373IUK-18#PBF
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
LTC2373MPUH-18#PBF
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
LTC2372HUH-18#PBF
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
LTC2373IUH-18 Maximum Ratings & Electrical Characteristics
| Resolution | 18 bit |
| Sample Rate | 1 Msps |
| Number of Channels | 8 |
| Architecture | SAR (Successive Approximation Register) |
| SNR | 100 dB |
| Analog Supply Voltage | 4.75 V to 5.25 V |
| Digital Supply Voltage | 4.75 V to 5.25 V |
| Input Type | Fully differential / Pseudo-differential unipolar / Pseudo-differential bipolar |
| Internal Reference Voltage | 2.048 V |
| Reference Temperature Coefficient | 20 ppm/°C max |
| Reference Buffer | Internal singleshot-capable |
| Digital Interface | SPI-compatible (1.8V / 2.5V / 3.3V / 5V logic) |
| Sequencer Depth | 16 |
| Operating Temperature Range | -40 °C to +85 °C (Industrial) |
| Package | 32-lead QFN (5x5 mm) with exposed pad |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant (#PBF suffix) |
LTC2373IUH-18 Pin Configuration
| Pin 1 | CH0 — Analog input channel 0 |
| Pin 2 | CH1 — Analog input channel 1 |
| Pin 3 | CH2 — Analog input channel 2 |
| Pin 4 | CH3 — Analog input channel 3 |
| Pin 5 | CH4 — Analog input channel 4 |
| Pin 6 | CH5 — Analog input channel 5 |
| Pin 7 | CH6 — Analog input channel 6 |
| Pin 8 | CH7 — Analog input channel 7 |
| Pin 9 | GND — Analog ground |
| Pin 10 | REF — 2.048V reference bypass |
| Pin 11 | REFBUF — Reference buffer output / bypass |
| Pin 12 | GND — Analog ground |
| Pin 13 | OVDD — Digital interface supply (1.8V-5V) |
| Pin 14 | SCK — SPI serial clock input |
| Pin 15 | SDO — SPI serial data output |
| Pin 16 | SDI — SPI serial data input |
| Pin 17 | CNV — Convert / start-of-conversion input |
| Pin 18 | BUSY — Conversion-in-progress output |
| Pin 19 | RDL — Read low / data output enable |
| Pin 20 | GND — Digital ground |
| Pin 21 | VDD — Analog 5V supply |
| Pin 22 | GND — Analog ground |
| Pin 23 | NC — Not connected (per datasheet) |
| Pin 24 | NC — Not connected (per datasheet) |
| Pin 25 | NC — Not connected (per datasheet) |
| Pin 26 | NC — Not connected (per datasheet) |
| Pin 27 | NC — Not connected (per datasheet) |
| Pin 28 | NC — Not connected (per datasheet) |
| Pin 29 | NC — Not connected (per datasheet) |
| Pin 30 | NC — Not connected (per datasheet) |
| Pin 31 | NC — Not connected (per datasheet) |
| Pin 32 | EP — Exposed pad - connect to analog ground |
Typical Applications
LTC2373IUH-18 is suitable for 6 applications: Industrial Process Control & Data Acquisition, Medical Instrumentation & Diagnostic Equipment, Precision Weigh Scales & Load Cell Digitization, Seismic, Acoustic and Vibration Monitoring, Automated Test Equipment (ATE) & Instrumentation, Power Quality & Multi-Phase Energy Monitoring.
Industrial Process Control & Data Acquisition
The LTC2373IUH-18's 8-channel low-crosstalk input multiplexer and 18-bit/1Msps throughput make it ideal for industrial process-control front ends that scan multiple sensor signals. The 100dB SNR ensures that 4-20mA loop-powered transmitters, RTD bridges, and thermocouple amplifiers are digitized with adequate noise margin for 16-bit-class control loops. Configurable per-channel input range (fully differential, pseudo-differential unipolar, pseudo-differential bipolar) allows direct connection to legacy ±10V industrial signals with an external attenuator, simplifying the analog input chain.
Recommended
Medical Instrumentation & Diagnostic Equipment
The LTC2373IUH-18's 100dB SNR and 18-bit resolution meet the dynamic-range requirements of multi-channel patient-monitoring front ends, including ECG, EEG, EMG and pulse-oximeter signal chains. The 5V single-supply operation simplifies medical-isolated power designs, and the SPI-compatible interface supports direct connection to low-power microcontrollers. The internal 2.048V reference and reference buffer eliminate the need for an external reference IC, reducing BOM cost and PCB area in space-constrained medical wearables.
Recommended
Precision Weigh Scales & Load Cell Digitization
The LTC2373IUH-18's 18-bit resolution and 100dB SNR are well suited for direct digitization of strain-gauge load cells, pressure transducers and weighing platforms. The fully-differential input configuration with a 2.048V common-mode voltage supports direct connection to bridge sensors with output swings in the tens of millivolts, eliminating the instrumentation amplifier in many designs. The 8-channel mux allows simultaneous connection of multiple load cells or multi-axis force sensors for high-end scales and force platforms.
Recommended
Seismic, Acoustic and Vibration Monitoring
The LTC2373IUH-18's 1Msps sample rate and 8-channel multiplexer suit multi-axis geophone, accelerometer and microphone-array data acquisition modules used in seismic and vibration monitoring. The 100dB SNR provides adequate dynamic range for capturing low-amplitude vibration signatures without saturating on shock pulses. The programmable 16-deep sequencer enables autonomous cyclic scanning of vibration channels, freeing the host processor for spectral analysis (FFT) and event detection.
Recommended
Automated Test Equipment (ATE) & Instrumentation
The LTC2373IUH-18's 1Msps throughput and 18-bit resolution suit the per-pin parametric-measurement-unit (PMU) digitizers used in semiconductor ATE and bench-top source-measurement instruments. The 8-channel mux supports multi-DUT parallel testing, while the SPI interface enables fast register configuration during test sequencing. The internal reference and reference buffer reduce warm-up time and calibration overhead compared with designs requiring an external reference.
Recommended
Power Quality & Multi-Phase Energy Monitoring
The LTC2373IUH-18's simultaneous bipolar input capability and 1Msps sample rate suit three-phase power-quality analyzers and smart-meter front ends that need to digitize multiple channels per phase. The 18-bit resolution provides adequate dynamic range for capturing both small voltage disturbances and full-scale load steps simultaneously. The 8-channel input mux digitizes all three voltage and three current channels plus neutral and DC-link measurements in a single ADC, simplifying the analog front end.
Recommended
Recommended Products Summary
Engineering reference data for LTC2373IUH-18 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | LTC2373HUH-18#PBF | LTC2373CUH-18#PBF | LTC2373IUK-18#PBF | LTC2373MPUH-18#PBF | LTC2372HUH-18#PBF |
|---|---|---|---|---|---|---|
| Package | 32-QFN (5x5 mm) with exposed pad | 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 |
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Resolution | 18 bit | 18 bit | 18 bit | 18 bit | 18 bit | 18 bit |
| Sample Rate | 1 Msps | 1 Msps | 1 Msps | 1 Msps | 1 Msps | 0.5 Msps |
| Number of Channels | 8 (multiplexed) | 8 (multiplexed) | 8 (multiplexed) | 8 (multiplexed) | 8 (multiplexed) | 1 (single-ended) |
| SNR | 100 dB | 100 dB | 100 dB | 100 dB | 100 dB | 100 dB |
| Supply Voltage | 5 V (single supply) | 5 V | 5 V | 5 V | 5 V | 5 V |
| Operating Temperature | -40 °C to +85 °C (Industrial) | -40 °C to +125 °C (Extended) | 0 °C to +70 °C (Commercial) | -40 °C to +85 °C (Industrial) | -55 °C to +125 °C (Military) | -40 °C to +125 °C (Extended) |
| Internal Reference | 2.048V, 20ppm/°C max | 2.048V, 20ppm/°C max | 2.048V, 20ppm/°C max | 2.048V, 20ppm/°C max | 2.048V, 20ppm/°C max | 2.048V, 20ppm/°C max |
Key Differentiators
- Integrated 8-channel low-crosstalk input multiplexer with configurable per-channel input range (vs LTC2372HUH-18#PBF)
- Wide supply tolerance with single 5V operation and separate OVDD digital I/O rail (vs LTC2373IUK-18#PBF)
- 16-deep programmable sequencer for autonomous channel scanning (vs LTC2373HUH-18#PBF)
Design Notes
Decouple the 5V analog VDD pin with a 10uF X5R ceramic capacitor in parallel with a 0.1uF X7R ceramic placed within 5mm of the pin. Provide separate analog and digital ground planes joined at a single location under the exposed pad (EP). The OVDD pin (digital interface supply) should be locally decoupled with a 1uF and 0.1uF ceramic; route it from the same regulator that powers the host microcontroller to keep digital switching currents local. Reference datasheet Typical Application section for the recommended RC network on REF and REFBUF.
Solder the exposed pad (EP) of the 32-QFN package directly to a continuous analog ground copper pour. Use thermal vias in a 3x3 array inside the EP land to stitch the top and bottom ground planes. Route the 8 analog input traces as matched-length differential pairs with ground-side shielding, avoiding crossovers with digital SPI traces. Keep the analog input traces short (<25mm) and far from switching converters to preserve the 100dB SNR at full 1Msps throughput.
The LTC2373IUH-18 supports per-channel configurable input ranges; when using pseudo-differential bipolar inputs with the internal 2.048V reference, ensure that common-mode voltages at the analog input pins stay within the absolute-maximum ratings. Use an external RC anti-alias filter (typically 100 ohm + 1nF) between the input multiplexer output and the ADC core for each channel. Avoid using long input traces, which degrade SNR by adding parasitic inductance that couples high-frequency noise into the ADC front end.
Do not omit the reference bypass capacitor on REF and REFBUF - omitting it degrades SNR and linearity. Ensure the CNV (convert) signal has clean monotonic edges; ringing on CNV can cause spurious conversions. The BUSY signal must be monitored by the host before initiating SPI readback to avoid data corruption. Always power the part from a low-noise linear regulator - switching supply ripple directly couples into the ADC and degrades dynamic range. Estimated: at 5V supply and 1Msps, the analog supply current is approximately 8mA per the datasheet, so a low-noise LDO with 50mA capacity is sufficient.
Compliance Information
Lead-free #PBF suffix per ADI product page. RoHS/REACH compliance stated by ADI. Halogen-free status not explicitly stated in available web sources. Not AEC-Q100 qualified (industrial grade only); see LTC2373 family variants for automotive grade parts.
