Analog Devices Inc. LTC2224IUK#PBF

Overview

LTC2224IUK#PBF from Analog Devices (formerly Linear Technology) is a 12-bit, 135Msps pipelined analog-to-digital converter optimized for high-frequency signal digitization in communications infrastructure. It delivers 67.3dB SNR at 140MHz input, 80dB SFDR up to 150MHz, and 775MHz full-power bandwidth with ultralow 0.15psRMS aperture jitter - enabling undersampling of IF signals in cable head-end and wireless baseband systems.

For engineers reviewing the LTC2224IUK#PBF datasheet, LTC2224IUK#PBF pinout, LTC2224IUK#PBF application, or LTC2224IUK#PBF equivalent, key selection criteria include its ±0.5V/±1V selectable input range, CMOS output swing (0.5V–3.6V), shutdown/nap modes, duty-cycle stabilizer, and guaranteed no-missing-codes performance across –40°C to +85°C.

Technical Context

The LTC2224IUK#PBF employs a five-stage CMOS pipelined ADC architecture with digital correction logic, achieving 5-cycle pipeline latency and maintaining ±0.4LSB INL (typ) and ±0.3LSB DNL (typ) over temperature. Its differential S/H front-end supports 1.6V common-mode bias via VCM pin and accepts PECL/LVDS/TTL/CMOS clock inputs.

Internal reference generation enables ±0.5V or ±1V differential input ranges via SENSE pin configuration, while separate OVDD supply allows independent output voltage scaling. The ENC+/ENC– differential encode interface ensures robust timing margin, and CLOCKOUT provides data-valid strobe synchronized to sampled data.

Key Specifications

Pinout & Package

48-pin 7mm × 7mm QFN package with exposed pad (Pin 49 = 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-speed ADC applications.

Compared with AD9230-125EBZ, LTC2224IUK#PBF offers higher sample rate and superior SFDR for wideband IF undersampling, while LTC2222IUK#PBF provides a lower-cost, lower-power option with identical footprint and register compatibility for bandwidth-constrained upgrades.

Availability

LTC2224IUK#PBF is available at Aetrix Electronics and suitable for cable head-end systems, wireless infrastructure equipment, and communications test instrumentation requiring stable component supply, extended temperature operation (–40°C to +85°C), and long-term obsolescence mitigation.

Supply support for LTC2224IUK#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 aerospace, communications, industrial, and medical markets.

The LTC2224IUK#PBF belongs to ADI's high-speed data converter product line, designed specifically for demanding communications infrastructure applications requiring wide dynamic range, low jitter, and robust thermal performance across industrial temperature ranges.

FAQ

What is the operating temperature range for the LTC2224IUK#PBF?

The LTC2224IUK#PBF is rated for industrial temperature operation from –40°C to +85°C, as confirmed by its "I" grade designation and absolute maximum ratings table. This makes it suitable for deployment in outdoor wireless base stations, cable head-end racks, and industrial test equipment where ambient temperatures exceed commercial-grade limits. The part maintains full AC and DC specifications across this range, including ±0.4LSB INL (typ) and 67.3dB SNR at 140MHz.

Does the LTC2224IUK#PBF support single-ended analog input?

Yes, the LTC2224IUK#PBF supports single-ended analog input: connect AIN+ to the signal source and AIN– to the 1.6V VCM pin. However, harmonic distortion and INL degrade relative to differential operation, while SNR and DNL remain unchanged. The datasheet specifies ±1LSB INL for single-ended mode versus ±0.4LSB for differential. For optimal performance in communications applications, differential drive is strongly recommended.

How does the CLOCKOUT signal function in the LTC2224IUK#PBF?

The CLOCKOUT pin on the LTC2224IUK#PBF provides a data-valid strobe synchronized to the sampled data outputs (D0–D11). Data is latched on the falling edge of CLOCKOUT, with typical ENC-to-CLOCKOUT delay of 1.3–2.1ns and skew vs. data of ±0.6ns. This deterministic timing relationship simplifies FPGA or ASIC capture logic design and eliminates setup/hold violations common in high-speed parallel interfaces.

Can the LTC2224IUK#PBF operate with an external reference?

Yes, the LTC2224IUK#PBF supports external reference operation. When an external reference voltage (0.5V–1V) is applied to the SENSE pin, the ADC automatically configures for ±V_SENSE differential input range. The internal 1.6V bandgap reference remains active to bias the VCM output and input common-mode circuitry. External reference use requires proper decoupling and noise isolation to maintain specified SNR and SFDR performance.

What are the power supply requirements for the LTC2224IUK#PBF?

The LTC2224IUK#PBF requires two supplies: VDD = 3.1V to 3.5V (typical 3.3V) for analog core and logic, and OVDD = 0.5V to 3.6V for CMOS output drivers. Analog supply current is 206mA (typ), resulting in 630mW total dissipation. OGND and GND must be connected together per datasheet Note 2; the exposed pad (Pin 49) must be soldered to PCB ground for thermal and electrical stability.