Analog Devices Inc. DC1012A-C

Overview

LTC2495 from Analog Devices (formerly Linear Technology) is a 16-bit, 16-channel (8 differential) delta-sigma ADC with integrated PGA, Easy Drive input technology, I²C interface, and on-chip temperature sensor. It delivers 2 ppm INL, 600 nV RMS noise, and programmable gain up to 256 - enabling direct digitization of rail-to-rail, high-impedance sensors in industrial data acquisition systems.

For engineers reviewing the LTC2495 datasheet, LTC2495 pinout, LTC2495 application, or LTC2495 equivalent, key selection criteria include its no-latency conversion architecture, simultaneous 50/60 Hz rejection mode, GND-to-VCC common-mode input range independent of reference, and integrated oscillator eliminating external timing components.

Technical Context

The LTC2495 employs a 3rd-order delta-sigma modulator with decimating FIR filter and auto-calibration per conversion cycle, ensuring zero-latency output and continuous offset/full-scale correction. Its Easy Drive sampling scheme cancels differential input current, enabling accurate measurements from sources up to multi-MΩ impedance without external buffering.

It supports dual-speed operation (1× and 2×), configurable 50 Hz / 60 Hz / simultaneous 50+60 Hz notch rejection, and flexible channel selection via I²C - with first-conversion validity after any channel change. The internal PTAT temperature sensor provides 0.5°C resolution and ±2°C absolute accuracy over –40°C to 85°C.

Key Specifications

Pinout & Package

38-lead (5 mm × 7 mm) plastic QFN package with exposed thermal pad (Pin 39 = GND). All seven ground pins (Pins 1, 4, 6, 31–34) must be soldered to PCB ground plane for proper operation and noise immunity.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar multichannel precision ADC applications.

Compared with ADS114S08B and AD7798, the LTC2495 uniquely combines I²C simplicity, zero-differential-input-current operation, simultaneous dual-frequency rejection, and integrated temperature sensing - making it optimal for compact, low-power, high-accuracy sensor hubs where layout area and calibration overhead are critical constraints.

Availability

LTC2495 is available at Aetrix Electronics and suitable for industrial process control, portable medical devices, and environmental data loggers requiring stable component supply, long-term calibration stability, and RoHS-compliant packaging.

Supply support for LTC2495 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 technologies, serving industrial, automotive, communications, and healthcare markets.

The LTC2495 belongs to ADI's precision delta-sigma ADC product line, designed specifically for low-power, high-accuracy sensor interface applications where ease of use, noise immunity, and minimal external components are paramount.

FAQ

What is the maximum input impedance the LTC2495 can directly digitize without external buffering?

The LTC2495 uses Easy Drive technology to eliminate dynamic input current errors, enabling direct digitization of sources with impedances up to several MΩ while maintaining full DC accuracy - verified at 10 MΩ source impedance in the datasheet's Typical Performance Characteristics (Figure G10, G11). This capability is intrinsic to the LTC2495's patented sampling architecture and applies across all gain settings and input configurations.

Does the LTC2495 require an external crystal or oscillator to operate?

No, the LTC2495 does not require an external crystal or oscillator. It includes a factory-trimmed internal oscillator running at 307.2 kHz (for 60 Hz rejection) - sufficient for all standard operating modes. The fO pin allows optional external clock injection only if custom data rates or alternate notch frequencies are needed; default operation is fully self-contained.

How does the LTC2495 achieve simultaneous 50 Hz and 60 Hz line-frequency rejection?

The LTC2495 achieves simultaneous 50/60 Hz rejection through a digitally reconfigurable FIR filter structure synchronized to an internal 280 kHz oscillator (as specified in Note 9). This creates dual-notch response centered precisely at both frequencies within a single conversion cycle - unlike sequential or software-based methods - delivering guaranteed >87 dB rejection without increasing latency or requiring multiple samples.

Can the LTC2495 measure its own die temperature, and what is the accuracy?

Yes, the LTC2495 integrates a high-accuracy PTAT temperature sensor with 0.5°C resolution and ±2°C absolute accuracy over –40°C to 85°C (LTC2495I grade). The sensor output is accessible via dedicated I²C register reads and is factory-calibrated - eliminating need for external temperature ICs in applications like thermocouple cold-junction compensation.

What is the significance of "no latency" in the LTC2495's conversion architecture?

"No latency" means the first conversion result after selecting a new input channel or changing configuration is fully settled and meets all AC/DC specifications - no dummy conversions or settling delays required. This is achieved via per-cycle auto-calibration and a deterministic digital filter that settles in one cycle, enabling deterministic real-time multiplexing in closed-loop control and fast-scan data acquisition systems.