Analog Devices Inc. LTC2269IUK#PBF

Overview

LTC2269IUK#PBF from Analog Devices (formerly Linear Technology) is a 16-bit, 20Msps low-noise analog-to-digital converter optimized for high-frequency, wide-dynamic-range signal digitization in communications systems. It delivers 84.1dB SNR, 99dB SFDR, ±1LSB typical INL, single 1.8V supply operation, and supports CMOS/DDR-CMOS/DDR-LVDS digital outputs - enabling high-fidelity data acquisition in SDR and portable medical imaging.

For engineers reviewing the LTC2269IUK#PBF datasheet, LTC2269IUK#PBF pinout, LTC2269IUK#PBF application, or LTC2269IUK#PBF equivalent, key selection criteria include its 200MHz full-power bandwidth, ±2.3LSB maximum INL over –40°C to +85°C, programmable input range (1VP-P to 2.1VP-P), SPI-configurable output modes, and 48-lead 7mm × 7mm QFN package with exposed thermal pad.

Technical Context

The LTC2269IUK#PBF employs a differential sample-and-hold front-end with 200MHz full-power bandwidth and 1.44LSB_RMS transition noise, supporting AC-coupled or DC-coupled analog inputs biased by the internal VCM (VDD/2) reference. Its clock interface accepts differential (LVDS/PECL) or single-ended (TTL/CMOS) ENC+/ENC– signals, with an optional duty cycle stabilizer ensuring performance across wide clock duty cycles.

Digital output flexibility includes full-rate CMOS (16 parallel lines), DDR-CMOS (8 lines), or DDR-LVDS (8 differential pairs), each configurable via SPI-controlled mode registers. Output supply OVDD is independently adjustable from 1.1V to 1.8V for CMOS modes, while LVDS mode operates at 1.7V–1.9V with programmable 1.75mA/3.5mA current and on-chip 100Ω termination.

Key Specifications

Pinout & Package

Package: 48-lead (7mm × 7mm) plastic QFN with exposed thermal pad (Pin 49 = GND, must be soldered to PCB ground plane).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 16-bit, 20Msps ADC applications.

Compared with AD9269BCPZ-20 and LTC2268IUK#PBF, the LTC2269IUK#PBF uniquely combines 20Msps speed, 99dB SFDR, integrated VCM generation, and single-supply LVDS operation - making it optimal for space-constrained, high-SFDR applications where clock robustness and power efficiency are critical.

Availability

LTC2269IUK#PBF is available at Aetrix Electronics and suitable for software defined radios, portable medical imaging systems, and multichannel data acquisition requiring stable component supply across extended temperature ranges.

Supply support for LTC2269IUK#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 LTC2269IUK#PBF belongs to ADI's high-speed precision ADC product line, designed specifically for demanding communications and instrumentation applications requiring exceptional dynamic range and low power in compact form factors.

FAQ

What is the operating temperature range for the LTC2269IUK#PBF?

The LTC2269IUK#PBF is rated for industrial temperature operation from –40°C to +85°C, as indicated by the "I" grade suffix in the part number. This range is validated across all specified electrical parameters including SNR, SFDR, INL, and power consumption, making it suitable for deployment in outdoor base stations, portable medical devices, and factory-floor data loggers without derating.

Does the LTC2269IUK#PBF support both differential and single-ended clock inputs?

Yes, the LTC2269IUK#PBF supports both configurations: ENC+ and ENC– can be driven differentially using LVDS, PECL, or other differential standards, or ENC– can be tied to GND for single-ended TTL/CMOS clock operation. The device automatically adapts its internal sampling edge detection accordingly, and the duty cycle stabilizer remains functional in either mode to maintain timing accuracy at 20Msps.

How is the input voltage range configured on the LTC2269IUK#PBF?

The LTC2269IUK#PBF input range is set via the SENSE pin: tying SENSE to VDD selects ±1.05V (2.1VP-P) range; grounding SENSE selects ±0.525V (1.05VP-P); applying 0.625V–1.3V to SENSE scales the range to ±0.84×VSENSE. This direct hardware configuration avoids SPI writes during power-up and ensures deterministic analog input scaling before first conversion.

Can the LTC2269IUK#PBF operate with only a 1.8V supply, or are additional voltages required?

The LTC2269IUK#PBF operates fully from a single 1.8V analog supply (VDD = 1.7V–1.9V). Digital outputs use a separate OVDD supply: 1.1V–1.8V for CMOS modes, 1.7V–1.9V for LVDS mode. No additional supplies (e.g., 3.3V or 5V) are required, simplifying power design and reducing bill-of-materials cost in battery-powered or space-constrained systems.

What is the purpose of the VCM pin on the LTC2269IUK#PBF, and how should it be used?

The VCM pin (Pin 1) provides a buffered, low-impedance common-mode bias voltage nominally equal to VDD/2. It must be used to bias the AIN+ and AIN– inputs at their optimal DC level - for example, with a 2.1VP-P range, inputs swing ±525mV around VCM. A 1μF ceramic capacitor must bypass VCM to ground to maintain stability and minimize noise coupling into the analog input path.