LTC2461IDD - 16-Bit I2C ADC, 12-DFN Package | Analog Devices
MPN: LTC2461IDD ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.95 | $5.95 |
| 10 | $5.36 | $53.60 |
| 100 | $4.76 | $476.00 |
| 500 | $4.27 | $2,135.00 |
| 1,000 | $3.78 | $3,780.00 |
LTC2461IDD Overview
A delta-sigma ADC (also written delta-sigma or sigma-delta) is a type of oversampling converter that uses noise shaping to push quantization noise out of the baseband, enabling high effective resolution at low bandwidths without expensive laser-trimmed analog components. It belongs to the broader hierarchy of ADC (analog-to-digital converter) -> data converter -> mixed-signal IC -> semiconductor. The LTC2461's delta-sigma architecture paired with an integrated reference makes it well suited for compact, low-noise measurement front-ends where PCB real estate and BOM count are critical.
Key features include 16-bit effective number of bits, 60 Hz output rate in 1x speed setting (up to 1.2 kHz in 2x), 1.25 V single-ended pseudo-differential input range, integrated 1.25 V reference with 2 ppm/°C typical drift, an I2C-compatible 2-wire serial interface with selectable addresses, internal oscillator, and automatic offset and full-scale calibration. The device continuously performs self-calibration, eliminating the need for external trimming while keeping total unadjusted error below a few LSb over temperature.
The LTC2461IDD implements a proprietary charge-balancing modulator clocked by its own internal RC oscillator, so no external clock source is required. The output word rate is configurable via the I2C OBR (Output Rate) bit, and conversion results are available as standard 16-bit I2C read transactions. The 12-lead DFN package exposes the exposed pad for thermal and ground integrity.
Typical uses include portable instrumentation, weigh scales, direct sensor digitisation for thermocouples and RTDs (with external front-end), battery-cell voltage monitoring in 3 V and 5 V systems, precision current sensing with a current-sense resistor, and consumer medical devices such as blood-pressure meters and glucose monitors. The integrated reference eliminates an extra IC in compact designs, and the I2C interface reduces microcontroller GPIO usage to two lines.
When designing with the LTC2461IDD, place the 0.1 µF VDD bypass capacitor as close to the VDD pin as possible, and tie the GND exposed pad to a low-impedance ground pour to minimise digital return currents. For best noise performance, average multiple conversions in firmware and avoid switching the I2C SCL line near the ADC's acquisition window.
This page combines distributor pricing, drop-in 12-DFN alternatives, comparison versus pinout-grade industry sources, and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for LTC2461IDD — 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 LTC2461IDD (same form factor and footprint) — differing in Interface, Package, Resolution, RoHS Status, Architecture.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
LTC2463IDD#PBF
✅ Drop-In📋 Reference alternative (not in catalog)
LTC2461IDD#PBF
✅ Drop-In📋 Reference alternative (not in catalog)
LTC2461CDD#PBF
✅ Drop-In📋 Reference alternative (not in catalog)
LTC2463CDD#PBF
✅ Drop-In📋 Reference alternative (not in catalog)
ADS1110A6IDBVR
✅ Drop-In✓ In Stock
$1.95 / Unit
View Datasheet →ADS1110A3IDBVRG4
✅ Drop-In✓ In Stock
$3.7 / Unit
View Datasheet →LTC2461IDD Maximum Ratings & Electrical Characteristics
| Resolution | 16 bit |
| Number of Channels | 1 Input |
| Architecture | Sigma-Delta |
| Input Configuration | Single-Ended (LTC2461); pseudo-differential |
| Input Voltage Range | 0 V to 1.25 V (single-ended, with VDD = 2.7V-5.5V) |
| Supply Voltage (VDD) | 2.7 V to 5.5 V |
| Integrated Reference Voltage | 1.25 V |
| Reference Drift | 10 ppm/°C (max), 2 ppm/°C (typ) |
| Reference Initial Accuracy | 0.1% (typ) |
| Output Data Rate | 60 Hz (1x), up to 1.2 kHz (2x) |
| Interface | I2C (2-wire, standard mode) |
| Package | 12-DFN (3 mm × 3 mm) with exposed pad |
| Operating Temperature Range | -40 °C to +85 °C (industrial, IDD suffix) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant (PBF suffix per datasheet) |
| Lead Finish | Lead-free (PBF suffix) |
LTC2461IDD Pin Configuration
| Pin 1 | GND — Ground reference (also exposed pad) |
| Pin 2 | ADR — I2C address select (tie high/low to select slave address) |
| Pin 3 | NC — Not connected (per datasheet) |
| Pin 4 | NC — Not connected (per datasheet) |
| Pin 5 | SDA — I2C serial data (open-drain, requires pull-up) |
| Pin 6 | SCL — I2C serial clock |
| Pin 7 | NC — Not connected (per datasheet) |
| Pin 8 | NC — Not connected (per datasheet) |
| Pin 9 | IN+ — Positive analog input (single-ended signal input on LTC2461) |
| Pin 10 | IN- — Negative analog input (tie to GND for single-ended LTC2461) |
| Pin 11 | REF — Reference voltage (1.25 V integrated; bypass with 0.1 µF) |
| Pin 12 | VDD — Positive supply voltage (2.7 V to 5.5 V) |
Typical Applications
LTC2461IDD is suitable for 6 applications: Portable Weigh Scale, Battery Cell Voltage Monitor, Industrial Temperature Sensor Digitisation, Consumer Medical Device Front-End, Precision Current Measurement, Sensor Calibration & Test Fixture.
Portable Weigh Scale
The LTC2461IDD's 16-bit effective resolution and integrated 1.25 V reference are well suited to bridge-based load-cell digitisation in portable scales. With a load cell typically delivering 0 to 1 mV/V at 1.25 V excitation, the 1.25 V internal reference can be used to excite the bridge directly, eliminating an external reference IC. The 60 Hz single-conversion output rate rejects 50/60 Hz line interference when averaging multiple conversions, and the I2C interface keeps the microcontroller pin count to two lines. The 12-DFN package fits inside small handheld enclosures, and the 2.7 V to 5.5 V supply works from a single Li-ion or two alkaline cells, supporting battery-powered weighing operations across retail, kitchen, and laboratory scale products.
Recommended
Battery Cell Voltage Monitor
The LTC2461IDD's 0 V to 1.25 V single-ended input maps directly to a divided-down Li-ion or LiFePO4 cell voltage, allowing direct digital readout of cell state. With 16-bit resolution, the LSB size at 1.25 V full-scale is roughly 19 µV, enabling millivolt-level state-of-charge tracking across a single cell. The 2.7 V to 5.5 V supply rail lets the same ADC run from a 3.3 V system rail or directly from a stack up to 5 V. The integrated reference removes an external voltage reference, shrinking the BOM in space-constrained BMS boards. The 60 Hz output rate is well-matched to battery-monitoring update intervals of typical refresh rates, and averaging multiple conversions in firmware further reduces noise without adding latency.
Recommended
Industrial Temperature Sensor Digitisation
The LTC2461IDD accepts a 0 V to 1.25 V single-ended input directly from an RTD or thermocouple front-end with appropriate excitation, ideal for industrial process-front-end temperature and pressure modules. The integrated 1.25 V reference provides a stable excitation voltage for RTD ratio-metric measurements, eliminating drift errors caused by external reference variation. The 16-bit resolution and sigma-delta modulator's inherent 50/60 Hz rejection give precise readings of slow-changing process variables in 4 mA to 20 mA loop replacement modules. I2C-style multimodule addressing supports multiple sensor nodes on the same bus. The -40 °C to +85 °C industrial temperature range covers most industrial indoor and protected-outdoor installations.
Recommended
Consumer Medical Device Front-End
The LTC2461IDD's integrated reference, single-rail 3.3 V supply, and 12-DFN package are well matched to compact medical front-ends such as blood-pressure meters, glucose monitors, and pulse oximeters. The 0 to 1.25 V input range directly digitises a current-sense resistor or a low-voltage bridge sensor without additional signal conditioning, simplifying front-end schematics. The 16-bit resolution is sufficient for blood-pressure cuff pressure measurements and glucose-meter current integration; averaging multiple 60 Hz conversions in firmware reduces effective noise to suit IEC 60601-1-2 medical EMC requirements. The I2C interface connects directly to low-power ARM Cortex-M0 medical MCUs, and the 12-DFN 3 mm × 3 mm package supports wearables used in slim patients.
Recommended
Precision Current Measurement
The LTC2461IDD is well suited to digitising a low-side current-sense resistor in industrial and bench-test instruments, where a 0 to 1.25 V input directly maps to a sense voltage across a low-ohm shunt. With 16-bit resolution, the converter resolves tens of microvolts of sense voltage, supporting microamp-level current measurements when paired with a low-offset amplifier. The integrated 1.25 V reference can be used as a bias for the sense amplifier, simplifying the analog front-end. The sigma-delta architecture rejects high-frequency switching noise from adjacent DC-DC converters, and the 60 Hz conversion rate matches the bandwidth of typical power-rail monitoring. The 12-DFN package supports dense current-sense layouts in multi-channel instruments.
Recommended
Sensor Calibration & Test Fixture
The LTC2461IDD's 16-bit sigma-delta architecture suits ATE and bench-test fixtures that need a stable, repeatable ADC with an integrated reference for verifying sensor linearity. The 1.25 V internal reference is factory-characterised to within 0.1%, giving a known accurate excitation for the device being tested. The 12-DFN footprint supports probe-friendly layouts, and the I2C interface simplifies integration with FPGA- or MCU-based test heads. The 1.2 kHz 2x output rate enables faster throughput in production test, while the 60 Hz 1x rate gives extra resolution for characterisation tests. The industrial -40 to +85 °C range supports test fixtures used in environmental chambers.
Recommended
Recommended Products Summary
Engineering reference data for LTC2461IDD — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | LTC2463IDD#PBF | LTC2461IDD#PBF | LTC2461CDD#PBF | LTC2463CDD#PBF | ADS1110A6IDBVR | ADS1110A3IDBVRG4 |
|---|---|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Texas Instruments | Texas Instruments |
| Package | 12-DFN (DD) 3x3 mm | 12-DFN (DD) 3x3 mm - same | 12-DFN (DD) 3x3 mm - same | 12-DFN (DD) 3x3 mm - same | 12-DFN (DD) 3x3 mm - same | 12-DFN equivalent footprint per Site MPN list | 12-DFN equivalent footprint per Site MPN list |
| Resolution | 16 bit | 16 bit | 16 bit | 16 bit | 16 bit | 16 bit | 16 bit |
| Input Configuration | Single-ended (0 V to 1.25 V) | Differential (±1.25 V) | Single-ended (0 V to 1.25 V) | Single-ended (0 V to 1.25 V) | Differential (±1.25 V) | Differential (with PGA) | Differential (with PGA) |
| Integrated Reference | 1.25 V, 10 ppm/°C max | 1.25 V, 10 ppm/°C max | 1.25 V, 10 ppm/°C max | 1.25 V, 10 ppm/°C max | 1.25 V, 10 ppm/°C max | Internal 2.048 V | Internal 2.048 V |
| Interface | I2C | I2C | I2C | I2C | I2C | I2C | I2C |
| Supply Voltage | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V |
| Temperature Grade | Industrial -40 °C to +85 °C | Industrial -40 °C to +85 °C | Industrial -40 °C to +85 °C | Commercial 0 °C to +70 °C | Commercial 0 °C to +70 °C | Industrial -40 °C to +85 °C | Industrial -40 °C to +85 °C |
| Output Data Rate (max) | — | 60 Hz (1x); 1.2 kHz (2x) | 60 Hz (1x); 1.2 kHz (2x) | 60 Hz (1x); 1.2 kHz (2x) | 60 Hz (1x); 1.2 kHz (2x) | 15 to 240 SPS (programmable) | 15 to 240 SPS (programmable) |
Key Differentiators
- Differential input sibling in same 12-DFN package (vs LTC2463IDD#PBF)
- Lead-free RoHS ordering code option (vs LTC2461IDD#PBF)
- Commercial-temperature-grade drop-in option (vs LTC2461CDD#PBF)
- Cross-brand 16-bit I2C ADC alternative (vs ADS1110A6IDBVR (Texas Instruments))
Design Notes
Place a 0.1 µF X7R ceramic bypass capacitor as close as possible to the VDD pin (pin 12) and a 0.1 µF capacitor on REF (pin 11) for the integrated 1.25 V reference. Add a 1 µF to 10 µF bulk capacitor near the supply entry point for transient suppression. The exposed pad must be soldered to a low-impedance ground pour to minimise ground bounce and serve as the primary thermal path.
Route the analog input traces (IN+, IN-) as a guarded differential pair, even for single-ended use on the LTC2461 - tie IN- to a clean ground plane near the ADC. Keep digital I2C traces (SCL, SDA) away from the analog input trace to avoid coupling switching transients into the input. Use a 4-layer PCB if the analog input impedance is high; a 2-layer board is fine for low-impedance sources.
Do not apply voltages outside 0 V to VDD on IN+ or IN-; the absolute maximum differential input voltage is VDD + 0.3 V. Avoid driving the SDA/SCL lines during the ADC's settling window (T_converge from datasheet) to prevent digital kickback into the conversion. When using ADR pin to select I2C address, do not leave it floating; tie it cleanly to VDD or GND.
For best 16-bit noise performance, average N consecutive conversions in firmware. The sigma-delta modulator's first-order noise-shaping attenuates 50/60 Hz line frequency when the conversion rate is set to 1x (60 Hz output). Add a 10 µF to 100 µF storage capacitor at the analog input if the source impedance is greater than 5 kΩ, to provide the kickback-free input charge.
The 12-DFN package has low thermal resistance (θJA around 40 °C/W per JEDEC EIA/JESD51 standards for a 4-layer board with thermal vias). The LTC2461's low supply current (~5 mA active, microamps in standby) and small package mean thermal management is not a primary design issue, but the GND pad must be soldered for the specified thermal and electrical performance.
Compliance Information
RoHS and REACH compliance status indicated by #PBF suffix per Analog Devices datasheet. AEC-Q100 automotive qualification is not applicable; for automotive ADC requirements, see the LTC2364 / LTC2366 / LTC2368 product family. Lead-free (PBF suffix) is the standard ordering code in 2026.
