Analog Devices Inc. LTC2268IUJ-12#PBF

Overview

LTC2268IUJ-12#PBF from Analog Devices (formerly Linear Technology) is a 12-bit, dual-channel, simultaneous-sampling analog-to-digital converter optimized for high-frequency communications signal digitization. It delivers 70.6dB SNR, 88dB SFDR, and ultralow 0.15ps_RMS aperture jitter at 125Msps sampling rate, with full-power bandwidth of 800MHz and single 1.8V supply operation - enabling direct undersampling of IF signals in cellular base station receivers.

For engineers reviewing the LTC2268IUJ-12#PBF datasheet, LTC2268IUJ-12#PBF pinout, LTC2268IUJ-12#PBF application, or LTC2268IUJ-12#PBF equivalent, key selection criteria include guaranteed ±0.3LSB INL over –40°C to +85°C, serial LVDS 2-lane/1-lane output flexibility, differential or single-ended encode input support, and pin compatibility with LTC2267-12/LTC2266-12 family members.

Technical Context

The LTC2268IUJ-12#PBF integrates two independent 12-bit ADC cores with shared PLL-based clock conditioning and a digital serializer driving LVDS outputs. Its sample-and-hold circuit achieves 800MHz full-power bandwidth and 0.15ps_RMS jitter, enabling clean undersampling of RF/IF signals up to 140MHz while maintaining 70.6dB SNR at –1dBFS.

Digital interface flexibility includes SPI-configurable modes (via CS/SCK/SDI/SDO) and parallel programming (via PAR/SER, CS, SCK, SDI), supporting both 1-bit-per-channel (1-lane) and 2-bit-per-channel (2-lane) LVDS serialization. Internal clock duty cycle stabilizer ensures full-speed performance across wide input duty cycles without external correction.

Key Specifications

Pinout & Package

40-lead (6mm × 6mm) plastic QFN package with exposed pad (Pin 41 = 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 dual-channel, high-speed ADC applications.

Compared with AD9233BCPZ-125, LTC2268IUJ-12#PBF provides integrated dual-channel simultaneity and lower system-level jitter; compared with LTC2267IUJ-12#PBF, it delivers 20Msps higher throughput and 54mW higher power - justifying the trade-off in wideband IF sampling applications.

Availability

LTC2268IUJ-12#PBF is available at Aetrix Electronics and suitable for cellular infrastructure, software-defined radio, and portable medical imaging applications requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LTC2268IUJ-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 communications, industrial, automotive, and healthcare markets.

The LTC2268IUJ-12#PBF belongs to ADI's high-speed precision ADC product line, engineered specifically for wideband, low-jitter digitization in RF and communications infrastructure where signal fidelity and thermal robustness are non-negotiable.

FAQ

What is the operating temperature range for the LTC2268IUJ-12#PBF?

The LTC2268IUJ-12#PBF is specified for industrial temperature operation from –40°C to +85°C, as indicated by the "I" grade in the part number. This rating is validated across all key AC and DC specifications including SNR, SFDR, INL, and DNL - making it suitable for outdoor base station and ruggedized portable equipment deployments where ambient extremes are expected.

Does the LTC2268IUJ-12#PBF support single-ended analog inputs?

No - the LTC2268IUJ-12#PBF requires differential analog inputs on AIN1+/– and AIN2+/–. However, it does support single-ended encode clock inputs: ENC– may be tied to GND while ENC+ accepts TTL, CMOS, or 1.8V square wave signals. The analog input stage is fully differential and lacks internal termination or level-shifting for single-ended sources.

How many bits per clock cycle does the LTC2268IUJ-12#PBF output in 2-lane LVDS mode?

In 2-lane LVDS mode, the LTC2268IUJ-12#PBF outputs two bits per channel per clock edge - i.e., four total LVDS data bits (OUT1A, OUT1B, OUT2A, OUT2B) per DCO cycle. This corresponds to 16-bit serialization over eight DCO edges (two bits × two channels × four edges), delivering 125Msps × 2 = 250Mbps per lane.

Can the LTC2268IUJ-12#PBF use an external reference voltage?

Yes - the LTC2268IUJ-12#PBF supports external reference configuration via the SENSE pin. When SENSE is driven to a voltage between 0.625V and 1.3V, the device disables its internal 1.25V reference and scales the full-scale input range proportionally (e.g., 1.25V SENSE yields 2VP-P full scale). External reference mode maintains ±0.2% gain matching and ±3mV offset matching between channels.

What is the pipeline latency of the LTC2268IUJ-12#PBF, and why does it matter?

The LTC2268IUJ-12#PBF has a fixed pipeline latency of 6 clock cycles from analog input to valid LVDS data output. This deterministic delay is critical for closed-loop systems like digital predistortion (DPD) in power amplifiers, where precise timing alignment between feedback ADC samples and baseband transmit paths is required to maintain loop stability and linearization accuracy.