LTC2389ILX-16 - 16-Bit 2.5Msps SAR ADC | Analog Devices
MPN: LTC2389ILX-16 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $56.27 | $56.27 |
| 10 | $50.64 | $506.40 |
| 100 | $45.01 | $4,501.00 |
| 500 | $39.94 | $19,970.00 |
| 1,000 | $35.21 | $35,210.00 |
LTC2389ILX-16 Overview
A SAR ADC is a type of data converter that uses a binary-search successive-approximation algorithm against an internal precision DAC to digitize an analog input in N clock cycles for N-bit resolution. SAR ADCs occupy a position in the broader converter hierarchy between flash converters (fastest, lowest resolution) and sigma-delta converters (highest resolution, slower), offering an attractive balance of speed, resolution, and latency for multiplexed data-acquisition and industrial-instrumentation systems. The LTC2389 family specifically targets low-noise, high-speed, multiplexed applications where a single ADC serves many channels through an external MUX.
Key features include guaranteed 16-bit no-missing-codes performance, low noise of 0.6 LSB RMS (transition noise) thanks to on-chip oversampling capability, an internal 4.096 V reference with 0.5% initial accuracy and ±20 ppm/°C maximum temperature coefficient, and a digital gain compression (DGC) mode that eliminates the need for a negative supply on the analog input. The wide-input-common-mode range simplifies front-end signal conditioning, and the LVDS-compatible serial interface supports high-speed board-to-board data transfer.
The architecture combines a charge-redistribution capacitive DAC with an internal reference buffer, providing a fast settling acquisition path and transparent latency of one conversion cycle. On-chip digital filtering and an internal oscillator reduce external component count, while the SPI-compatible serial LVDS I/O simplifies FPGA/ASIC interfacing. The 48-LQFP package is footprint-compatible across the LTC2389-16, LTC2389-18, and related family members.
Typical applications include industrial process control, multiplexed data acquisition systems, medical imaging front ends, instrumentation and test equipment, and high-speed ATE systems. The combination of low noise, wide input range, and high throughput makes the part especially well suited to photodiode, transducer, and bridge-sensor signal chains.
When designing with this device, pay close attention to PCB layout: the analog input traces must be differential and length-matched, the reference decoupling must use a low-ESR 10 µF ceramic directly at the REFCAPA/REFCAPB pins, and a clean analog ground island should be maintained around the ADC. When the input is configured in pseudo-differential mode, drive the common-mode pin (COM) with a low-impedance source to preserve linearity.
This page synthesizes distributor pricing, drop-in alternatives, application notes, and design considerations that are not aggregated on any single manufacturer or distributor product page.
Drop-in alternatives for LTC2389ILX-16 — 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 LTC2389ILX-16 (same form factor and footprint) — differing in RoHS Status, Package, Interface, Input Type, Resolution.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
LTC2389CUK-16
✅ Drop-In✓ In Stock
$24.96 / Unit
View Datasheet →LTC2335HLX-16
✅ Drop-In✓ In Stock
$15.4 / Unit
View Datasheet →LTC2389ILX-16 Maximum Ratings & Electrical Characteristics
| Manufacturer | Analog Devices (Linear Technology) |
| Part Number | LTC2389ILX-16#PBF |
| Resolution | 16 bits |
| Conversion Type | SAR (Successive Approximation Register) |
| Sampling Rate | 2.5 Msps |
| Number of Input Channels | 1 |
| Architecture | Charge-redistribution capacitive DAC with internal reference buffer |
| Supply Voltage (Analog/Digital) | 5 V (single supply) |
| Input Range - Fully Differential | ±4.096 V |
| Input Range - Pseudo-Differential Unipolar | 0 V to 4.096 V |
| Input Range - Pseudo-Differential Bipolar | ±2.048 V |
| Internal Reference Voltage | 4.096 V (±0.5% initial accuracy, ±20 ppm/°C max TC) |
| Transition Noise (RMS) | 0.6 LSB |
| Digital Interface | LVDS serial (SPI-compatible) |
| Package | 48-LQFP (7x7 mm) |
| Operating Temperature Range | -40 °C to +85 °C (Industrial) |
| RoHS Status | Compliant (PBF suffix = lead-free) |
| Pin/Package Code | LFQFP / GULL WING |
LTC2389ILX-16 Pin Configuration
| Pin 1 | IN+ — Positive analog input |
| Pin 2 | IN- — Negative analog input |
| Pin 3 | COM — Common-mode input |
| Pin 4 | GND — Analog ground |
| Pin 5 | REFCAPA — Reference capacitor A |
| Pin 6 | REFCAPB — Reference capacitor B |
| Pin 7 | REFIN — Reference input (internal/external) |
| Pin 8 | VREF — Reference voltage output (4.096V) |
| Pin 9 | GND — Analog ground |
| Pin 10 | OVDD — Digital output supply |
| Pin 11 | OGND — Digital output ground |
| Pin 12 | SCK+ — LVDS serial clock (positive) |
| Pin 13 | SCK- — LVDS serial clock (negative) |
| Pin 14 | SDO+ — LVDS serial data output (positive) |
| Pin 15 | SDO- — LVDS serial data output (negative) |
| Pin 16 | DGC — Digital gain compression mode select |
| Pin 17 | CS — Chip select (active low) |
| Pin 18 | CNV — Start conversion input |
| Pin 19 | RESET — Digital reset |
| Pin 20 | RDL — Read latch (LVDS mode) |
| Pin 21 | BUSY — Conversion in progress indicator |
| Pin 22 | GND — Digital ground |
| Pin 23 | VDD — Analog 5V supply |
| Pin 24 | GND — Analog ground |
Typical Applications
LTC2389ILX-16 is suitable for 6 applications: Industrial Process Control and Multiplexed Data Acquisition, Medical Imaging and Patient Monitoring Front Ends, Test and Measurement Instrumentation, Automated Test Equipment (ATE) and Semiconductor Test, Communications Baseband Signal Digitization, Precision Weigh Scales and Force/Load Measurement.
Industrial Process Control and Multiplexed Data Acquisition
The LTC2389ILX-16's 2.5 Msps throughput and single-cycle SAR latency make it ideal for multiplexed industrial data-acquisition systems scanning 4-16 channels through an external MUX. The 16-bit no-missing-codes performance and 0.6 LSB RMS transition noise deliver true 16-bit effective resolution across thermocouple, RTD, and 4-20 mA current-loop front ends. The pin-configurable ±4.096 V fully differential input range accepts the output of instrumentation amplifiers (such as the AD8421) directly, while the wide input common-mode range tolerates large common-mode transients from industrial 24 V bus systems. Combined with the 48-LQFP industrial-temperature package, the LTC2389ILX-16 enables compact, high-channel-count PLCs and remote I/O modules.
Recommended
Medical Imaging and Patient Monitoring Front Ends
The LTC2389ILX-16's 0.6 LSB RMS transition noise, 16-bit resolution, and 2.5 Msps sample rate suit it to medical front-end signal chains such as ultrasound receiver paths, ECG/EEG acquisition modules, and pulse-oximeter photodiode digitizers. The internal 4.096 V reference with ±20 ppm/°C maximum drift provides stable conversion over body-temperature variations, while the pseudo-differential unipolar 0-4.096 V input mode accepts photodiode transimpedance amplifier outputs without level shifting. The LVDS serial interface isolates digital switching noise from the analog front end - critical for low-amplitude biosignal acquisition where microvolt-level signals must be resolved cleanly.
Recommended
Test and Measurement Instrumentation
Bench-top digital multimeters, oscilloscope digitizer boards, and ATE pin-electronics cards benefit from the LTC2389ILX-16's 2.5 Msps throughput and 16-bit linearity. The 5 V single-supply operation simplifies power-tree design in compact instruments, while the LVDS serial data output supports long backplane traces to an FPGA or DSP without EMI concerns. The wide input common-mode range allows direct digitizing of waveforms centered at arbitrary DC biases - common in current-shunt and high-side voltage measurements. Combined with a precision reference and low-noise front end, the part enables 6.5-digit-class DMM performance in a small footprint.
Recommended
Automated Test Equipment (ATE) and Semiconductor Test
In ATE pin-electronics and source-measurement unit (SMU) subsystems, the LTC2389ILX-16's single-cycle latency ensures deterministic digitizer response when characterizing Device Under Test (DUT) waveforms under pulsed stimulus. The 16-bit resolution supports 1 mV-level measurement resolution on ±4.096 V full-scale signals, matching the dynamic range of typical parametric test instruments. The pin-configurable bipolar ±2.048 V pseudo-differential input allows direct digitization of stimulus/response signals centered at 0 V, removing the need for level-shifting in test fixtures. The 48-LQFP package and industrial temperature range support deployment in ATE chamber environments.
Recommended
Communications Baseband Signal Digitization
Although not a direct ADC for RF, the LTC2389ILX-16's 2.5 Msps rate and 16-bit linearity make it suitable for digitizing baseband I/Q signals in software-defined radio and small-cell base-station receivers, particularly for narrowband protocols (LoRa, SigFox, NB-IoT) where the bandwidth is well below 1 MHz. The LVDS serial interface simplifies the routing of high-speed data into the baseband FPGA. Combined with a low-noise IF amplifier front end, the part can deliver the dynamic range required for demodulating QPSK/QAM constellations in industrial telemetry links and private LTE small cells.
Recommended
Precision Weigh Scales and Force/Load Measurement
The LTC2389ILX-16's 0.6 LSB RMS noise and 16-bit no-missing-codes performance, paired with a low-noise load-cell instrumentation amplifier, deliver 50,000+ count resolution in precision weigh-scale designs. The internal 4.096 V reference provides stable excitation for bridge-type load cells when used with a ratiometric configuration, and the 5 V single-supply operation simplifies battery-powered portable scale designs. The wide input common-mode range tolerates ground-potential differences in industrial weigh platforms. Fast settling and single-cycle latency allow high-throughput package weighing and checkweigher applications where every millisecond counts.
Recommended
Recommended Products Summary
Engineering reference data for LTC2389ILX-16 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | LTC2389CUK-16 | LTC2335HLX-16 | LTC2372HUH-18 |
|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | 48-LQFP (LX, 7x7 mm) | 48-QFN (CUK, 7x7 mm) - different package | 48-LQFP (LX, 7x7 mm) - same | 32-QFN (UH, 5x5 mm) - different package |
| Resolution | 16-bit | 16-bit | 16-bit | 18-bit |
| Sampling Rate | 2.5 Msps | 2.5 Msps | 0.5 Msps | 0.5 Msps |
| Number of Channels | 1 | 1 | 1 | 1 |
| Supply Voltage | 5 V (single) | 5 V | 5 V | 5 V |
| Internal Reference | 4.096 V, 0.5%, ±20 ppm/°C | 4.096 V | 4.096 V | 2.5 V |
| Temperature Range | -40 °C to +85 °C (Industrial) | 0 °C to +70 °C (Commercial) | -40 °C to +85 °C | -40 °C to +125 °C (H-grade) |
Key Differentiators
- Pin-configurable input range (differential / pseudo-diff unipolar / pseudo-diff bipolar) (vs LTC2372HUH-18)
- 2.5 Msps sample rate - 5x faster than the LTC2335HLX-16 (vs LTC2335HLX-16)
- Industrial -40°C to +85°C temperature range in LQFP-48 (vs LTC2389CUK-16)
Design Notes
Route the analog differential input pair (IN+ and IN-) as a length-matched, impedance-controlled differential pair with a continuous ground reference plane beneath. Keep the analog and digital grounds separated at the IC and joined at a single star-point near the power entry. Place the 10 µF X7R reference bypass capacitor (REFCAPA/REFCAPB) within 2 mm of the device pins with a 0.1 µF parallel cap for high-frequency decoupling - this is critical for achieving the datasheet's 0.6 LSB RMS transition-noise figure.
The LVDS serial data lines (SDO+/SDO- and SCK+/SCK-) should be routed as 100 Ω differential pairs, kept away from the analog input traces, and length-matched within 1 mm. The 5 V analog supply (VDD) and digital output supply (OVDD) should be filtered with ferrite beads and decoupled with 1 µF + 0.1 µF caps placed adjacent to the IC. Avoid routing any switching signals (clocks, FPGA I/O) beneath the analog ground island - the LVDS transitions inject 1 mV-level noise that can degrade 16-bit linearity if not properly isolated.
Do not leave the COM (common-mode) pin floating in pseudo-differential input mode - drive it with a low-impedance source (op-amp buffer or capacitor to analog ground) to preserve linearity. When using the internal reference, ensure the REFCAPA and REFCAPB pins each have a 10 µF X7R ceramic capacitor (not electrolytic) - the datasheet specifies the dielectric type for stability. Finally, in fully differential input mode, set the DGC (digital gain compression) pin low to allow true 16-bit unipolar-to-differential conversion without the 2x gain compression that limits full-scale range.
Compliance Information
PBF suffix indicates lead-free / RoHS-compliant lead finish. AEC-Q100 not specified (industrial-grade, not automotive). REACH compliance per Analog Devices statement of compliance.
