Analog Devices Inc. LTC2500IDKD-32#PBF

Overview

LTC2500IDKD-32#PBF from Analog Devices (formerly Linear Technology) is a 32-bit oversampling successive approximation register (SAR) analog-to-digital converter with integrated configurable digital filter, designed for ultra-high-precision DC and low-frequency AC measurements. It delivers ±0.5 ppm INL (typ), 104 dB SNR at 1 Msps, and 148 dB dynamic range at 61 sps, operating from a single 2.5 V supply with VREF adjustable from 2.5 V to 5.1 V. It is used in seismic data acquisition systems requiring sub-microvolt resolution and long-term stability.

For engineers reviewing the LTC2500IDKD-32#PBF datasheet, LTC2500IDKD-32#PBF pinout, LTC2500IDKD-32#PBF application, or LTC2500IDKD-32#PBF equivalent, key selection criteria include guaranteed 32-bit no missing codes, dual-output architecture (filtered SDOA + no-latency SDOB), wide 0 V to VREF common-mode input range, SPI-compatible dual serial interfaces (SCKA/SDOA and SCKB/SDOB), and operation across –40°C to +85°C industrial temperature range.

Technical Context

The LTC2500IDKD-32#PBF implements a SAR ADC core followed by a programmable decimation filter (SINC1–SINC4, SSINC, flat passband) with down-sampling factors from 4 to 16384. Its dual-output architecture separates high-precision filtered data (32-bit, latency dependent on DF) from real-time composite data (24-bit differential + 7-bit common-mode + overrange bit, zero-cycle latency).

It supports synchronized multi-device operation via SYNC pin, features two independent SPI-compatible serial interfaces (SCKA/SDOA for filtered output, SCKB/SDOB for no-latency output), and uses separate analog (VDD) and digital I/O (OVDD) supplies - OVDD configurable from 1.71 V to 5.25 V to match host logic levels.

Key Specifications

Pinout & Package

Package: 24-lead 7 mm × 4 mm plastic DFN (DKD) with exposed thermal pad (Pin 25, GND). Requires soldering of exposed pad to PCB ground plane for thermal and electrical integrity.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-precision SAR ADC applications.

Compared with ADS1287IRHBT and AD7768-1ACPZ, the LTC2500IDKD-32#PBF uniquely delivers true 32-bit resolution with guaranteed no missing codes, dual-output concurrency, and field-programmable digital filtering - making it irreplaceable for applications demanding both real-time responsiveness and metrological-grade precision in a single device.

Availability

LTC2500IDKD-32#PBF is available at Aetrix Electronics and suitable for seismic monitoring systems, downhole energy logging tools, and high-accuracy metrology instruments requiring stable component supply across extended product lifecycles.

Supply support for LTC2500IDKD-32#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 LTC2500-32 product line was developed to address ultra-high-precision DC and low-frequency measurement needs in geophysical, scientific, and metrology applications - emphasizing noise floor, linearity, and temporal stability over speed.

FAQ

What is the guaranteed operating temperature range for the LTC2500IDKD-32#PBF?

The LTC2500IDKD-32#PBF is specified for industrial temperature operation from –40°C to +85°C. This rating is guaranteed across all electrical specifications including INL (±0.5 ppm typ), SNR (104 dB typ), and dynamic range (148 dB typ at 61 sps), making it suitable for downhole, outdoor, and factory-floor instrumentation where ambient extremes are expected. The part uses the "I" grade designation in its order code to denote this extended range.

How does the dual-output architecture of the LTC2500IDKD-32#PBF function in practice?

The LTC2500IDKD-32#PBF provides two independent digital outputs: SDOA carries the 32-bit digitally filtered, low-noise result (latency depends on down-sampling factor), while SDOB delivers a 32-bit no-latency composite code - comprising 24 bits of differential input, 7 bits of common-mode voltage, and 1 overrange detection bit - updated every conversion cycle. This allows real-time system control (e.g., overrange shutdown via SDOB) while simultaneously capturing high-fidelity data (via SDOA) for post-processing, without compromising either function.

Can the LTC2500IDKD-32#PBF operate with different reference voltages, and how does that affect performance?

Yes - the LTC2500IDKD-32#PBF accepts an external reference voltage (VREF) from 2.5 V to 5.1 V. Performance scales accordingly: higher VREF expands full-scale differential input range (±VREF) and improves SNR marginally (e.g., 104 dB at 5 V vs. ~102 dB at 2.5 V), while lower VREF reduces power in downstream signal chains. All DC specs (INL, offset, gain error) remain guaranteed across the range, and the wide 0 V to VREF common-mode input simplifies interface to unipolar or bipolar sensors regardless of VREF setting.

What is the purpose of the SYNC pin on the LTC2500IDKD-32#PBF, and how is it used?

The SYNC pin on the LTC2500IDKD-32#PBF is an edge-triggered input that resets and aligns the phase of the internal digital decimation filter across multiple devices. When asserted simultaneously to several LTC2500IDKD-32#PBF units, it ensures identical filter group delay and coherent sampling - essential for time-aligned multi-channel acquisition in seismic arrays or phased sensor systems. SYNC does not affect conversion timing or BUSY behavior; it operates independently of MCLK and only influences the digital filter state.

Is the LTC2500IDKD-32#PBF pin-compatible with other members of the LTC2500 family, such as the LTC2500CDKD-32#PBF?

Yes - the LTC2500IDKD-32#PBF shares identical pinout, package (24-lead 7 mm × 4 mm DFN), and electrical interface with the commercial-grade LTC2500CDKD-32#PBF. The only difference is the operating temperature range: "C" grade is 0°C to 70°C, while "I" grade (LTC2500IDKD-32#PBF) is –40°C to +85°C. All timing, digital interface behavior, filter configuration, and analog performance specifications are otherwise identical, enabling drop-in replacement in thermally demanding designs.