LTC2315HTS8-12 - 12-Bit 5Msps SAR ADC in TSOT-23 | Analog Devices
MPN: LTC2315HTS8-12 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.95 | $6.95 |
| 10 | $6.42 | $64.20 |
| 100 | $5.48 | $548.00 |
| 500 | $4.86 | $2,430.00 |
| 1,000 | $4.32 | $4,320.00 |
LTC2315HTS8-12 Overview
A SAR ADC (Successive Approximation Register Analog-to-Digital Converter) is a type of data converter that uses a binary search algorithm through an internal capacitive DAC to digitize an analog input one bit at a time per clock cycle. SAR ADCs sit within the broader ADC family -> data converters -> mixed-signal ICs -> signal chain ICs -> semiconductors, and are valued for their deterministic latency, low power, and excellent DC accuracy at moderate sampling rates.
Key performance attributes include 72.6 dB SINAD and -84 dB THD, a wide-input true-sampling front end that eliminates the need for an external buffer amplifier, and nap/sleep power-down modes that cut supply current during idle intervals. The device also features a high-speed SPI-compatible serial interface that natively supports 1.8 V, 2.5 V, 3 V, and 5 V logic levels, allowing direct connection to modern microcontrollers, DSPs, and FPGAs without level shifters.
The LTC2315-12 uses a charge-redistribution SAR architecture with a proprietary input structure that achieves both single-ended unipolar and true-differential sampling modes. The integrated reference buffer sources and sinks transient current demanded by the internal DAC, maintaining a stable reference voltage during bit trials and minimizing conversion-to-conversion variation. This architecture delivers consistent AC and DC performance across the full 2.7 V to 5.25 V supply range, making it tolerant of unregulated rails in battery-powered designs.
Typical applications include high-speed data acquisition front ends, industrial process control loops, motor control position feedback, portable and battery-powered instrumentation, optical networking signal monitoring, and medical imaging front-end digitizers. The wide analog supply range allows direct connection to 3.3 V or 5 V system rails, while the 1.8 V-compatible digital interface simplifies integration with low-voltage controllers.
When designing with the LTC2315HTS8-12, place the 10 µF bypass capacitor directly on the VDD pin and use a short, low-inductance ground return to keep reference noise from coupling into the analog input. The internal reference is sufficient for most applications, but designers seeking the lowest drift can overdrive REFIN with an external low-noise reference such as the LT6656.
This page synthesizes distributor pricing, drop-in ADC alternatives, and practical PCB-level design notes that complement - but do not replace - the manufacturer datasheet.
Drop-in alternatives for LTC2315HTS8-12 — 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 LTC2315HTS8-12 (same form factor and footprint) — differing in Package, Resolution, RoHS Status, Digital Interface, Input Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
LTC2315ITS8-12#TRMPBF
✅ Drop-In📋 Reference alternative (not in catalog)
LTC2315CTS8-12#TRMPBF
✅ Drop-In📋 Reference alternative (not in catalog)
LTC2312HTS8-12#TRMPBF
✅ Drop-In📋 Reference alternative (not in catalog)
LTC2314HTS8-14
✅ Drop-In✓ In Stock
$4.4 / Unit
View Datasheet →LTC2313HTS8-14
✅ Drop-In✓ In Stock
$4.1 / Unit
View Datasheet →LTC2315HTS8-12 Maximum Ratings & Electrical Characteristics
| Manufacturer | Analog Devices |
| Part Family | LTC2315-12 |
| Resolution | 12 bit |
| Sampling Rate | 5 Msps |
| Architecture | SAR (Successive Approximation Register) |
| Number of Channels | 1 input |
| Input Type | Single-ended / Pseudo-differential (true-sampling front end) |
| Analog Supply Voltage | 2.7 V to 5.25 V |
| Supply Current (Active, typ) | 6.4 mA |
| Reference | Internal bandgap with integrated buffer, 20 ppm/°C max drift |
| SINAD | 72.6 dB |
| THD | -84 dB |
| Digital Interface | SPI-compatible serial, 1.8 V / 2.5 V / 3 V / 5 V logic |
| Power-Down Modes | Nap and Sleep modes |
| Package | TSOT-23-8 (8-pin) |
| Mounting Type | Surface Mount |
| Operating Temperature (H-grade) | -40 °C to +125 °C |
| RoHS Status | Compliant (per Analog Devices product page) |
LTC2315HTS8-12 Pin Configuration
| Pin 1 | IN+ — Analog input (true-sampling positive input) |
| Pin 2 | GND — Analog ground |
| Pin 3 | REF — Internal bandgap reference output / reference buffer bypass |
| Pin 4 | REFIN — Reference input - tie to REF or overdrive with external reference |
| Pin 5 | VDD — Analog supply, 2.7 V to 5.25 V |
| Pin 6 | SCK — Serial interface clock input |
| Pin 7 | SDO — Serial data output (SPI-compatible) |
| Pin 8 | CNV — Conversion start / chip enable input |
Typical Applications
LTC2315HTS8-12 is suitable for 6 applications: High-Speed Data Acquisition Front End, Industrial Process Control and Motor Drive Feedback, Portable and Battery-Powered Instrumentation, Optical Networking Signal Monitoring, Medical Imaging and Patient Monitoring Front End, Test and Measurement Instrumentation.
High-Speed Data Acquisition Front End
The LTC2315HTS8-12 is well suited as the ADC front end in multi-channel data acquisition systems where board real estate is constrained and 12-bit resolution is sufficient for the measurement. Its 5 Msps throughput, 72.6 dB SINAD, and -84 dB THD support clean digitization of signals up to about 2.5 MHz (Nyquist), enabling vibration analysis, ultrasound receive channels, and control-loop feedback sampling. The 6.4 mA active supply current keeps board thermal budget manageable in dense DAQ cards. Nap and sleep power-down modes cut current during inter-sample idle windows, extending battery life in portable instruments. The integrated 20 ppm/°C reference eliminates an external reference IC in most non-precision designs, shrinking the BOM. Use a 10 µF X7R bypass on VDD and a clean star-ground layout to preserve SINAD at full speed.
Recommended
Industrial Process Control and Motor Drive Feedback
In industrial PLCs, servo drives, and motor-control feedback loops, the LTC2315HTS8-12 samples current and position sensors at 5 Msps with deterministic SAR latency - critical for closed-loop control where every microsecond of conversion delay matters. The H-grade -40 °C to +125 °C operating range supports deployment in unconditioned factory cabinets, outdoor enclosures, and vehicle underhood environments. The true-sampling input structure tolerates large common-mode swings on shunt-resistor current signals without an external instrumentation amp, reducing analog signal-chain complexity. Its SPI-compatible interface connects directly to industrial MCUs such as the MAX32 family over 3.3 V or 5 V logic. Nap mode reduces idle supply current during control-loop update gaps, lowering enclosure thermal rise. Reference decoupling near the REF pin is essential to preserve DC accuracy over the industrial temperature range.
Recommended
Portable and Battery-Powered Instrumentation
Battery-powered handheld instruments - including multimeters, oscilloscope front ends, field data loggers, and medical wearables - benefit from the LTC2315HTS8-12's 6.4 mA active supply current and sub-microamp nap/sleep modes, which extend operating time on a single Li-ion or 2x AA cell. The 2.7 V to 5.25 V analog supply range aligns with common battery chemistries without a boost regulator. Its 1.8 V to 5 V digital logic compatibility enables direct connection to low-power Cortex-M microcontrollers, removing level shifters from the BOM. The compact TSOT-23-8 footprint allows dense PCB layouts inside small handheld enclosures. Designers can place the ADC on the same analog rail as the sensor front end, with nap mode triggered between sample bursts to minimize average drain. Internal reference drift of 20 ppm/°C is adequate for most field-grade measurement accuracy.
Recommended
Optical Networking Signal Monitoring
Optical line cards and transponder modules use the LTC2315HTS8-12 to digitize received optical-power monitor photodiode currents and transmit-bias control loops at 5 Msps, fast enough to capture modulation envelope variations and AGC loop transients. The 72.6 dB SINAD supports monitoring accuracy sufficient for both SFP+ and QSFP28 diagnostic interfaces. Its 1.8 V-compatible SPI allows direct interface to low-power optical-MCU companions without external logic translation. Nap and sleep modes align naturally with the optical-module low-power state machine, holding supply current under 1 mA between supervisory updates. The small TSOT-23-8 footprint fits inside dense QSFP28 module PCBs where board area is measured in square millimeters. The wide 2.7 V to 5.25 V analog supply accommodates the 3.3 V rails common on optical line cards.
Recommended
Medical Imaging and Patient Monitoring Front End
Patient monitoring devices - including ECG, pulse oximetry, infusion-pump pressure feedback, and bedside multi-parameter monitors - use the LTC2315HTS8-12 to digitize low-frequency analog sensor signals with deterministic latency. While 5 Msps is overkill for pure ECG (typically 500 Hz to 5 kHz), it enables oversampling and digital averaging to push-the-floor effective resolutions, improving SNR in patient-worn applications. The H-grade -40 °C to +125 °C range supports deployment in ambulances, OR environments, and home-health equipment. The integrated reference and small footprint minimize external component count, supporting reliable single-board medical designs. Nap mode enables sub-milliwatt idle states during battery-only operation, important for wearable patches. Designers should add input ESD protection per IEC 60601-1 requirements when targeting medical applications.
Recommended
Test and Measurement Instrumentation
Benchtop and rack-mount test instruments - including portable oscilloscopes, spectrum-analyzer IF digitizers, signal-generator calibration paths, and bench DMMs - use the LTC2315HTS8-12 as a high-throughput secondary ADC channel. Its 5 Msps rate and 72.6 dB SINAD deliver clean waveform capture for IF-stage digitizers up to the 2.5 MHz Nyquist band, while the integrated reference and TSOT-23-8 footprint simplify dense multi-channel designs. Nap/sleep modes allow scanning-mode acquisition to drop supply current between sample intervals. The 1.8 V to 5 V SPI interface enables connection to test-instrument FPGAs and DSPs without level shifters, preserving signal integrity. Designers targeting production ATE can use the LTC2315HTS8-12 alongside higher-precision ADCs in calibration paths. The H-grade temperature range supports lab, factory-floor, and field-deployable test gear without derating.
Recommended
Recommended Products Summary
Engineering reference data for LTC2315HTS8-12 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | LTC2315ITS8-12#TRMPBF | LTC2315CTS8-12#TRMPBF | LTC2312HTS8-12#TRMPBF | LTC2314HTS8-14 | LTC2313HTS8-14 |
|---|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | TSOT-23-8 | TSOT-23-8 (same) | TSOT-23-8 (same) | TSOT-23-8 (same) | TSOT-23-8 (same) | TSOT-23-8 (same) |
| Resolution | 12 bit | 12 bit | 12 bit | 12 bit | 14 bit | 14 bit |
| Sampling Rate | 5 Msps | 5 Msps | 5 Msps | 500 ksps | 4.5 Msps | 2.5 Msps |
| Analog Supply Voltage | 2.7 V to 5.25 V | 2.7 V to 5.25 V | 2.7 V to 5.25 V | 2.7 V to 5.25 V | 2.7 V to 5.25 V | 2.7 V to 5.25 V |
| Operating Temperature (Grade) | -C to +125 °C (H-grade) | -40 °C to +125 °C (industrial) | 0 °C to +70 °C (commercial) | -40 °C to +125 °C | -40 °C to +125 °C | -40 °C to +125 °C |
| Interface | SPI-compatible serial, 1.8 V to 5 V logic | SPI-compatible serial | SPI-compatible serial | SPI-compatible serial | SPI-compatible serial | SPI-compatible serial |
Key Differentiators
- Widest operating temperature range in the LTC2315-12 family for industrial deployments (vs LTC2315CTS8-12#TRMPBF)
- 5x higher sample rate than LTC2312-12 family at same resolution and pinout (vs LTC2312HTS8-12#TRMPBF)
- Higher throughput at lower resolution than 14-bit LTC2314/LTC2313 family (vs LTC2314HTS8-14)
Design Notes
Estimated: Place a 10 µF X7R ceramic bypass capacitor within 2 mm of the VDD pin, with a 0.1 µF X7R in parallel, to keep SAR bit-trial current transients from coupling into the analog input. VDD noise above 50 mVpp directly degrades SINAD at the LTC2315HTS8-12's 5 Msps sample rate. For 5 V system rails, add a ferrite bead in series with VDD to isolate from upstream switching-converter noise. Nap and sleep modes drop supply current dramatically during inter-sample idle windows - assert CNV high after the conversion completes to enter nap mode.
Estimated: Route the analog input IN+ trace as a microstrip above a continuous ground plane, with no digital traces crossing underneath. Keep SCK and SDO traces short and place a 33 Ω series damping resistor at the SCK driver to control edge rates and limit ground bounce. Connect the TSOT-23-8 exposed pad (if present) to the analog ground plane with multiple thermal vias for low-impedance ground return. Decouple the REF pin with a 2.2 µF X7R directly to GND to stabilize the internal reference buffer during SAR bit trials.
Estimated: Drive the LTC2315HTS8-12's CNV input with a clean monotonic edge - a slow rise (>10 ns) on CNV can corrupt the internal sample-and-hold acquisition. Add a small RC snubber (10 Ω + 33 pF) on CNV if the host controller's drive strength is marginal. For best SINAD performance, oversample by 4x to 16x and apply digital averaging in the host - this raises effective resolution by 1 to 2 bits and pushes quantization noise below the converter's thermal floor. The REFIN pin can be overdriven with the LT6656 (2.5 ppm/°C drift) when the internal 20 ppm/°C reference is insufficient for the application.
Estimated: Do not leave REFIN floating - it must be tied to REF (internal reference mode) or driven by an external low-noise reference, otherwise the internal reference buffer can drift and conversions become unstable. The LTC2315HTS8-12 requires the supply to ramp monotonically; UVLO may engage on slow or oscillating power-up - verify power-good timing on the 2.7 V to 5.25 V rail. The SPI clock SCK must remain idle low between conversions; a stuck-high SCK prevents the next CNV edge from starting a new conversion. Verify SCK idle state in your MCU's SPI peripheral initialization code.
Compliance Information
RoHS and REACH compliance per Analog Devices product page. HTS8 suffix denotes H-grade industrial temperature range (-40C to +125C); parts are Pb-free matte-tin finish with TRMPBF tape-and-reel packaging. AEC-Q100 automotive qualification is not standard for the HTS8-12 - contact Analog Devices for automotive-grade variants.
