Analog Devices Inc. LTC2256CUJ-14#PBF

Overview

LTC2256CUJ-14#PBF from Analog Devices (formerly Linear Technology) is a 14-bit, 25Msps ultralow-power analog-to-digital converter optimized for high-dynamic-range signal digitization in communications and instrumentation. It delivers 73dB SNR, 88dB SFDR, and 0.17psRMS jitter at 1.8V supply, enabling undersampling of IF signals up to 140MHz in portable medical imaging and multi-channel data acquisition systems.

For engineers reviewing the LTC2256CUJ-14#PBF datasheet, LTC2256CUJ-14#PBF pinout, LTC2256CUJ-14#PBF application, or LTC2256CUJ-14#PBF equivalent, this page provides verified specifications, QFN-40 package layout, SPI-configurable output modes (CMOS/LVDS), and validated alternatives for RF front-end and SDR receiver designs.

Technical Context

The LTC2256CUJ-14#PBF implements a pipelined ADC architecture with integrated sample-and-hold (800MHz full-power bandwidth), on-chip reference (1.25V ±25ppm/°C), and configurable input range (1–2VP-P). Its digital interface supports full-rate CMOS, DDR CMOS, or DDR LVDS outputs with separate OVDD supply (1.2–1.9V) for level control.

It features serial SPI configuration, optional clock duty cycle stabilizer, data output randomizer, and low-power modes (Nap: 9mW; Sleep: 0.5mW). The ENC+/ENC– differential clock input accepts PECL, LVDS, TTL, or CMOS signals, with timing jitter tightly controlled to preserve SNR at high input frequencies.

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 ADS5272IPFP and LTC2257CUJ-14#PBF, the LTC2256CUJ-14#PBF offers optimal balance of ultra-low power (35mW), compact QFN-40 packaging, and multimode digital outputs - making it preferred for portable, thermally constrained, or FPGA-flexible designs where 25Msps suffices.

Availability

LTC2256CUJ-14#PBF is available at Aetrix Electronics and suitable for portable medical imaging, software defined radio receivers, and multi-channel data acquisition systems requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for LTC2256CUJ-14#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 acquired Linear Technology in 2017 and continues its legacy of high-performance signal conditioning ICs for demanding analog applications.

The LTC2256CUJ-14#PBF belongs to the LTC225x family of ultralow-power, high-SFDR ADCs designed specifically for communications infrastructure, portable instrumentation, and high-fidelity data acquisition where dynamic range and power efficiency are co-critical.

FAQ

What is the maximum analog input frequency supported by the LTC2256CUJ-14#PBF?

The LTC2256CUJ-14#PBF features an 800MHz full-power bandwidth, allowing accurate digitization of analog signals up to that frequency. At 70MHz input, it achieves 73dB SNR and 88dB SFDR; performance degrades gradually beyond 140MHz, but undersampling remains viable due to its low 0.17psRMS jitter. For Nyquist-limited use, the 25Msps sampling rate sets the practical baseband limit to 12.5MHz.

Does the LTC2256CUJ-14#PBF support external reference voltage?

Yes, the LTC2256CUJ-14#PBF supports external reference via the SENSE pin. Applying 0.625V–1.3V to SENSE selects an input range of ±0.8× that voltage. The device also provides internal 1.25V reference (±25ppm/°C drift) with VREF output pin. External reference mode disables the internal reference and requires proper decoupling of the SENSE pin.

How does the PAR/SER pin affect configuration of the LTC2256CUJ-14#PBF?

The PAR/SER pin determines the programming interface: grounded enables full SPI mode (CS/SCK/SDI/SDO control all functions), while tied to VDD enables parallel mode where CS controls clock duty cycle stabilizer, SCK selects output mode (CMOS vs LVDS), and SDI enters sleep mode. This dual-mode flexibility simplifies integration into both microcontroller- and FPGA-based systems.

What digital output formats does the LTC2256CUJ-14#PBF support?

The LTC2256CUJ-14#PBF supports three digital output formats: full-rate CMOS (14 single-ended outputs), double-data-rate CMOS (7 pairs, e.g., D0_1), and double-data-rate LVDS (7 differential pairs, e.g., D0_1+, D0_1–). Output voltage levels are set by OVDD (1.2–1.9V for CMOS; 1.7–1.9V for LVDS), and LVDS mode includes on-chip 100Ω termination.

Is the LTC2256CUJ-14#PBF pin-compatible with other members of the LTC225x family?

Yes, the LTC2256CUJ-14#PBF is pin-compatible with LTC2257CUJ-14#PBF and LTC2258CUJ-14#PBF in the same 40-pin QFN package. All share identical pinout, register map, and power sequencing - enabling drop-in upgrades to 40Msps or 65Msps without PCB redesign, provided thermal and layout margins accommodate higher power.