Analog Devices Inc. LTC2258CUJ-12#PBF

Overview

LTC2258CUJ-12#PBF from Analog Devices (formerly Linear Technology) is a 12-bit, 65 Msps ultralow-power analog-to-digital converter optimized for undersampling high-frequency IF signals in communications systems. It delivers 71.1 dB SNR, 88 dB SFDR, and 0.17 psRMS aperture jitter with single 1.8 V supply, CMOS/DDR CMOS/DDR LVDS output options, and 800 MHz full-power bandwidth - enabling direct digitization of cellular base station and software-defined radio front-ends.

For engineers reviewing the LTC2258CUJ-12#PBF datasheet, LTC2258CUJ-12#PBF pinout, LTC2258CUJ-12#PBF application, or LTC2258CUJ-12#PBF equivalent, key selection criteria include its 65 Msps sampling rate at 79 mW power, differential input support up to 2 V_P-P, SPI-configurable modes (randomizer, duty cycle stabilizer), and QFN-40 package compatibility with pin-compatible 14-bit variants.

Technical Context

The LTC2258CUJ-12#PBF employs a 12-bit pipelined ADC architecture with integrated sample-and-hold, correction logic, and configurable digital output drivers. Its 0.17 psRMS jitter enables high-fidelity undersampling of IF signals up to 140 MHz while maintaining 71.1 dB SNR at 65 Msps.

It supports three digital output configurations - full-rate CMOS, DDR CMOS, and DDR LVDS - each with independent OVDD supply (1.2–1.9 V for CMOS; 1.7–1.9 V for LVDS). The ENC+/ENC– differential clock interface accepts sine, PECL, LVDS, TTL, or CMOS inputs, and optional clock duty cycle stabilization ensures performance across wide duty-cycle ranges.

Key Specifications

Pinout & Package

Package: 40-lead (6 mm × 6 mm) plastic QFN (UJ), exposed pad (Pin 41) soldered to PCB ground for thermal and electrical integrity. Pin count and layout are identical across LTC2258/LTC2257/LTC2256 families.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD9230-65EBZ, LTC2258CUJ-12#PBF integrates more system-level functions (reference, SPI, stabilizer), reducing BOM count and layout complexity; compared with LTC2268IUJ-12#PBF, it trades extended temperature rating for lower cost and same electrical performance in commercial-grade applications.

Availability

LTC2258CUJ-12#PBF is available at Aetrix Electronics and suitable for cellular infrastructure, portable medical imaging, and multi-channel test equipment requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for LTC2258CUJ-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. (acquired Linear Technology in 2017) is a global leader in high-performance analog, mixed-signal, and DSP solutions for precision and high-speed applications.

The LTC2258CUJ-12#PBF belongs to Linear's high-speed ADC product line, designed specifically for demanding communications and instrumentation applications requiring ultralow jitter, wide bandwidth, and flexible digital interfacing.

FAQ

What is the maximum sampling rate supported by the LTC2258CUJ-12#PBF?

The LTC2258CUJ-12#PBF supports a maximum sampling rate of 65 Msps. This is specified under recommended operating conditions (VDD = OVDD = 1.8 V, sine wave input, differential ENC+/ENC– drive). At this rate, the device achieves 71.1 dB SNR and 88 dB SFDR with 79 mW total power dissipation. Lower rates (40 Msps and 25 Msps) are supported by pin-compatible LTC2257-12 and LTC2256-12 variants.

Does the LTC2258CUJ-12#PBF require an external reference voltage?

No, the LTC2258CUJ-12#PBF includes an internal reference with nominal 1.25 V output (VREF, Pin 38) and supports flexible input ranges via the SENSE pin (Pin 39). Connecting SENSE to VDD selects ±1 V range; to GND selects ±0.5 V; or applying 0.625–1.3 V externally sets ±0.8×V_SENSE. External reference is optional and only needed for highest accuracy or custom range requirements.

How does the duty cycle stabilizer function in the LTC2258CUJ-12#PBF?

The duty cycle stabilizer in the LTC2258CUJ-12#PBF corrects non-50% clock duty cycles on ENC+/ENC– inputs to maintain optimal sampling window symmetry. It is enabled by driving CS high in parallel programming mode and operates transparently during conversion. This feature allows use of low-cost crystal oscillators or FPGA-generated clocks with poor duty cycle control while preserving 71.1 dB SNR performance at 65 Msps.

What digital output interfaces does the LTC2258CUJ-12#PBF support?

The LTC2258CUJ-12#PBF supports three digital output modes: full-rate CMOS (12 bits/sample), double-data-rate CMOS (6 bits/edge), and double-data-rate LVDS (6 bits/edge with differential signaling). Output type is selected via PAR/SER and SCK pins in parallel mode or SPI register in serial mode. OVDD voltage must be set accordingly: 1.2–1.9 V for CMOS, 1.7–1.9 V for LVDS.

Is the LTC2258CUJ-12#PBF pin-compatible with other members of the LTC225x family?

Yes, the LTC2258CUJ-12#PBF is pin-compatible with the LTC2257-12, LTC2256-12, LTC2258-14, and LTC2257-14 variants - all housed in the same 40-lead 6 mm × 6 mm QFN (UJ) package. This allows drop-in substitution across speed grades (65/40/25 Msps) and resolution (12-/14-bit) without PCB redesign, provided thermal and power delivery margins accommodate the variant's specifications.