Analog Devices Inc. LTC1745CFW#PBF

Overview

LTC1745CFW#PBF from Analog Devices (formerly Linear Technology) is a 25 Msps, 12-bit pipelined analog-to-digital converter optimized for high-frequency, wide dynamic range signal digitization in communications and instrumentation systems. It delivers 72.5 dB SNR and 91 dB SFDR at 3.2 V input range, features ±1 V or ±1.6 V pin-selectable differential input, and operates from a single 5 V supply with 380 mW power dissipation.

For engineers reviewing the LTC1745CFW#PBF datasheet, LTC1745CFW#PBF pinout, LTC1745CFW#PBF application, or LTC1745CFW#PBF equivalent, key selection considerations include its 240 MHz full-power bandwidth, 0.3 psRMS aperture jitter, ±1 LSB INL max over temperature, flow-through TSSOP-48 layout compatibility, and dual-range reference flexibility via SENSE pin configuration.

Technical Context

The LTC1745CFW#PBF implements a four-stage CMOS pipelined ADC architecture with integrated sample-and-hold, internal 2.35 V bandgap reference, and programmable input range selection. Its differential ENC/ENC encode interface supports PECL, GTL, TTL, or sinusoidal drive, enabling low-jitter sampling critical for undersampling applications.

It employs direct capacitor sampling with 4 pF input capacitance in hold mode, achieves 5-cycle data latency, and provides separate OVDD (0.5–5 V) for digital output drivers-allowing seamless interfacing with low-voltage DSPs or FIFOs without level-shifting circuitry.

Key Specifications

Pinout & Package

The LTC1745CFW#PBF is housed in a 48-lead plastic TSSOP (FW package) with flow-through pinout optimized for controlled-impedance analog and digital routing. Thermal resistance θ_JA = 35°C/W; maximum junction temperature = 150°C.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD9226ASTZ and LTC2245IUP#PBF, the LTC1745CFW#PBF offers the optimal balance of 25 MSPS throughput, 72.5 dB SNR, integrated reference, and single-supply simplicity - making it preferred for cost-sensitive, space-constrained communications and instrumentation designs where 12-bit fidelity suffices.

Availability

LTC1745CFW#PBF is available at Aetrix Electronics and suitable for telecommunications base stations, medical ultrasound systems, and spectrum analyzers requiring stable component supply with guaranteed long-term availability and traceable sourcing.

Supply support for LTC1745CFW#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 digital signal processing semiconductors.

The LTC1745CFW#PBF belongs to Linear's high-speed precision ADC product line, designed specifically for demanding communications, instrumentation, and medical imaging applications requiring low jitter, high SFDR, and flexible input range configuration.

FAQ

What is the operating temperature range for the LTC1745CFW#PBF?

The LTC1745CFW#PBF is rated for commercial operation from 0°C to +70°C (C-grade). This is confirmed in the Absolute Maximum Ratings table, where "LTC1745C" denotes the commercial temperature version. The device uses thermal metrics including θ_JA = 35°C/W and T_JMAX = 150°C to ensure reliable performance within this ambient range under typical PCB copper pour conditions.

Does the LTC1745CFW#PBF require an external reference, or is it internally generated?

The LTC1745CFW#PBF includes an internal 2.35 V bandgap reference used for both the VCM output and internal ADC reference generation. No external reference is required for basic operation; however, the SENSE pin allows selection between ±1 V and ±1.6 V input ranges using only VDD or GND connection - eliminating external resistive dividers in most configurations.

How does the SENSE pin configure the input range on the LTC1745CFW#PBF?

On the LTC1745CFW#PBF, tying SENSE to GND selects ±1 V differential input range; tying SENSE to VDD selects ±1.6 V range. Voltages between 1 V and 1.6 V set proportional ranges (e.g., 1.25 V → ±1.25 V), enabling fine-grained dynamic range optimization without external components - a feature explicitly documented in the Pin Functions section.

Can the LTC1745CFW#PBF interface directly with a 1.8 V FPGA I/O bank?

Yes - the LTC1745CFW#PBF supports OVDD from 0.5 V to 5 V. Setting OVDD = 1.8 V configures D0–D11, CLKOUT, and OF outputs to drive 1.8 V logic levels directly, with VOH ≥ 1.7 V and VOL ≤ 0.1 V under load, as verified in the Digital Inputs and Outputs specifications table.

What is the data latency of the LTC1745CFW#PBF, and how is it synchronized?

The LTC1745CFW#PBF has a fixed 5-cycle data latency from ENC edge to valid D0–D11 output. This deterministic delay is synchronized to CLKOUT, whose rising edge aligns with stable data - allowing FPGA or ASIC capture logic to latch outputs without additional timing constraints or deskew circuitry.