Analog Devices Inc. LTC2480HDD#PBF

Overview

LTC2480HDD#PBF from Analog Devices (formerly Linear Technology) is a 16-bit plus sign no-latency delta-sigma ADC with patented Easy Drive input current cancellation. It supports programmable gain (1–256), simultaneous 50Hz/60Hz line rejection, rail-to-rail input range (0V to VCC), internal oscillator, and operates from 2.7V to 5.5V supply. It directly digitizes high-impedance sensors-e.g., strain gauges or load cells-with 2 ppm INL and ±1 µV offset error in industrial temperature range (–40°C to 125°C).

For engineers reviewing the LTC2480HDD#PBF datasheet, LTC2480HDD#PBF pinout, LTC2480HDD#PBF application, or LTC2480HDD#PBF equivalent, key selection criteria include differential input current cancellation for high-source-impedance interfaces, guaranteed no missing codes over full temperature range, integrated temperature sensor readout capability, and support for both internal and external clocking with configurable line-frequency rejection.

Technical Context

The LTC2480HDD#PBF implements a third-order delta-sigma modulator with automatic on-chip offset and full-scale calibration, eliminating latency in digital filter settling. Its Easy Drive architecture cancels differential input current dynamically, enabling accurate measurement from sources up to 100 kΩ without external buffering.

It features a 4-wire SPI-compatible serial interface with bidirectional SCK (internal/external clock mode), programmable gain via SDI command, and selectable conversion modes: normal speed (15 Hz max with internal oscillator) or 2× speed (30 Hz max). The H-grade variant guarantees all electrical specifications-including 2 ppm INL, ±40 ppm full-scale error, and 0.5 µV offset-over –40°C to 125°C.

Key Specifications

Pinout & Package

Package: 10-lead (3 mm × 3 mm) plastic DFN with exposed pad (Pin 11 = GND). RoHS-compliant, lead-free finish (PBF).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar delta-sigma ADC applications.

Compared with ADS124S08IPWR and MAX11206ETL+, the LTC2480HDD#PBF uniquely combines 16-bit precision with zero-differential-input-current operation, rail-to-rail input common mode, and H-grade temperature qualification-making it optimal for compact, high-reliability industrial sensor nodes where board space, power, and thermal robustness are critical.

Availability

LTC2480HDD#PBF is available at Aetrix Electronics and suitable for weight scales, industrial process controllers, and strain gauge transducer systems requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LTC2480HDD#PBF includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Analog Devices, Inc. (ADI) is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, formed through the acquisition of Linear Technology in 2017.

The LTC2480 belongs to ADI's precision delta-sigma ADC product line, designed specifically for high-accuracy, low-power sensor digitization in demanding industrial, test & measurement, and automotive applications where input impedance, temperature stability, and EMI immunity are critical.

FAQ

What is the maximum source impedance supported by the LTC2480HDD#PBF without accuracy degradation?

The LTC2480HDD#PBF supports source impedances up to 100 kΩ with no measurable degradation in DC accuracy due to its patented Easy Drive input current cancellation. This is confirmed by the +FS error vs RSOURCE plot (Figure TA04), which shows error remains within ±20 ppm up to 100 kΩ at 25°C. At –40°C and 125°C, performance is maintained per H-grade specifications, making it suitable for unbuffered strain gauge and thermistor interfaces.

Does the LTC2480HDD#PBF require an external crystal or oscillator?

No, the LTC2480HDD#PBF includes an on-chip trimmed oscillator that runs at 307.2 kHz when the fO pin is tied to GND. This eliminates the need for external crystals, ceramic resonators, or oscillators. An external clock may be applied to fO only if custom data rates or alternate line-frequency rejection profiles are required-otherwise, the internal oscillator provides fully autonomous operation.

How does the LTC2480HDD#PBF achieve simultaneous 50 Hz and 60 Hz line frequency rejection?

The LTC2480HDD#PBF achieves simultaneous 50 Hz/60 Hz rejection through a digitally configured notch filter implemented in its delta-sigma modulator's decimation stage. When enabled via SDI command, the internal digital filter places nulls at both 50 Hz and 60 Hz (±2%) with >87 dB rejection. This is distinct from sequential rejection modes and is verified in the Electrical Characteristics table under "Input Normal Mode Rejection, 50Hz/60Hz ±2%".

Can the LTC2480HDD#PBF measure its own die temperature?

Yes, the LTC2480HDD#PBF includes an on-chip PTAT (proportional-to-absolute-temperature) sensor that outputs 390–450 mV at 27°C. This voltage can be selected as the conversion input via SDI command (bit 7 = 1), allowing direct digitization of die temperature with the same 16-bit resolution and calibration as analog inputs. No external components are required.

What is the purpose of the exposed pad (Pin 11) on the LTC2480HDD#PBF DFN package?

The exposed pad (Pin 11) on the LTC2480HDD#PBF is electrically connected to GND and must be soldered to the PCB ground plane. It serves dual purposes: (1) thermal dissipation-reducing θJA from 120°C/W (MSOP) to 43°C/W (DFN); and (2) low-impedance grounding for analog, digital, and reference returns. Leaving it floating degrades noise performance and thermal reliability, especially in high-precision or high-temperature applications.