Analog Devices Inc. LTC2261IUJ-12#PBF

Overview

LTC2261IUJ-12#PBF from Analog Devices (acquired Linear Technology) is a 12-bit, 125Msps ultralow-power analog-to-digital converter with 70.8dB SNR, 85dB SFDR, and 0.17psRMS jitter. It operates from a single 1.8V supply, supports CMOS/DDR-CMOS/DDR-LVDS outputs, and targets high-frequency signal digitization in software-defined radios and portable medical imaging.

For engineers reviewing the LTC2261IUJ-12#PBF datasheet, LTC2261IUJ-12#PBF pinout, LTC2261IUJ-12#PBF application, or LTC2261IUJ-12#PBF equivalent, key selection criteria include its 800MHz full-power bandwidth, selectable 1–2VP-P input range, optional clock duty cycle stabilizer, serial SPI configuration interface, and –40°C to 85°C industrial temperature rating.

Technical Context

The LTC2261IUJ-12#PBF employs a 12-bit pipelined ADC core with integrated sample-and-hold, correction logic, and configurable digital output drivers. Its ENC+/ENC– differential clock interface accepts sine wave, PECL, LVDS, TTL, or CMOS inputs, and the optional duty cycle stabilizer enables full-speed operation across wide clock duty cycles.

It features dual reference options-internal 1.25V ±25ppm/°C VREF or external reference via SENSE pin-and supports three output modes: full-rate CMOS (12 single-ended D0–D11), DDR-CMOS (6 differential pairs), or DDR-LVDS (6 differential pairs with on-chip 100Ω termination). Pipeline latency is 5.0 cycles in full-rate mode and 5.5 cycles in DDR modes.

Key Specifications

Pinout & Package

40-pin (6mm × 6mm) plastic QFN package (UJ) with exposed thermal pad (Pin 41, GND). Requires soldering exposed pad to PCB ground plane for thermal and electrical performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD9226BSTZ-65 and LTC2264IUJ-12#PBF, the LTC2261IUJ-12#PBF offers superior jitter performance and flexible output interfaces for high-frequency undersampling, while the LTC2264IUJ-12#PBF adds integration density at the expense of per-channel configurability.

Availability

LTC2261IUJ-12#PBF is available at Aetrix Electronics and suitable for cellular infrastructure, software-defined radio development, and portable medical imaging systems requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LTC2261IUJ-12#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 technologies, serving industrial, automotive, communications, and healthcare markets.

The LTC2261IUJ-12#PBF belongs to ADI's high-speed ADC product line, designed specifically for demanding communications and instrumentation applications requiring exceptional dynamic range, low power, and flexible digital interfacing.

FAQ

What is the operating temperature range of the LTC2261IUJ-12#PBF?

The LTC2261IUJ-12#PBF is rated for operation from –40°C to +85°C, making it suitable for industrial and outdoor communications equipment. This extended temperature grade is confirmed in the Order Information table and Absolute Maximum Ratings section of the official datasheet, distinguishing it from the commercial-grade C-temp variant (0°C to 70°C).

Does the LTC2261IUJ-12#PBF support both internal and external voltage references?

Yes, the LTC2261IUJ-12#PBF supports both internal and external references via the SENSE pin (Pin 39). Connecting SENSE to VDD selects the internal 1.25V reference with ±1V input range; grounding it selects ±0.5V; applying 0.625–1.3V externally sets ±0.8×VSENSE range. Internal reference drift is ±25ppm/°C, verified in the Internal Reference Characteristics table.

What digital output formats does the LTC2261IUJ-12#PBF support?

The LTC2261IUJ-12#PBF supports three digital output formats: full-rate CMOS (12 single-ended outputs), double-data rate CMOS (6 multiplexed bit-pairs), and double-data rate LVDS (6 differential pairs with optional on-chip 100Ω termination). Output mode is selected via PAR/SER and SCK pins or SPI register writes, as detailed in the Pin Functions and Digital Inputs and Outputs sections.

How is the LTC2261IUJ-12#PBF configured for different sampling rates like 105Msps or 80Msps?

The LTC2261IUJ-12#PBF is specifically rated for 125Msps operation. The datasheet lists LTC2260-12 and LTC2259-12 as companion parts for 105Msps and 80Msps respectively - they share pinout and feature set but differ in AC performance and power consumption. The LTC2261IUJ-12#PBF itself is not characterized or guaranteed for sustained operation below 125Msps in production use.

Can the LTC2261IUJ-12#PBF be used with a single-ended clock input?

Yes, the LTC2261IUJ-12#PBF supports single-ended clock operation by tying ENC– (Pin 12) to ground and driving ENC+ (Pin 11) with a 1.8V square wave or sine wave. The datasheet specifies VIH = 1.2V and VIL = 0.6V for this mode, with input resistance of 30kΩ and capacitance of 3.5pF - all confirmed in the Digital Inputs and Outputs section under "Single-Ended Encode Mode".