Analog Devices Inc. LTC1750CFW#PBF

Overview

LTC1750CFW#PBF from Analog Devices (formerly Linear Technology) is a 14-bit, 80 Msps analog-to-digital converter optimized for direct IF sampling up to 500 MHz. It integrates a programmable gain amplifier (PGA) front end with ±1.125 V differential input range (PGA = 0) or ±0.675 V (PGA = 1), delivers 75.5 dB SNR and 90 dB SFDR at 5 MHz, operates from a single 5 V supply, and targets high-performance receiver chains in cellular base stations and spectrum analyzers.

For engineers reviewing the LTC1750CFW#PBF datasheet, LTC1750CFW#PBF pinout, LTC1750CFW#PBF application, or LTC1750CFW#PBF equivalent, key selection criteria include full-power bandwidth (500 MHz), aperture jitter (0.12 psRMS), INL (±0.75 LSB), differential input drive requirement, and TSSOP-48 flow-through layout compatibility.

Technical Context

The LTC1750CFW#PBF employs a CMOS pipelined architecture with four ADC stages and an integrated PGA, enabling five-cycle data latency and deterministic timing. Its sample-and-hold circuit features 500 MHz full-power bandwidth and ultralow jitter, supporting undersampling of RF/IF signals without SNR degradation.

Digital interface flexibility includes 5 V, 3 V, 2 V, and LVDS-compatible outputs; ENC/ENC inputs accept differential PECL/GTL or single-ended TTL/CMOS, and the separate OVDD rail (0.5 V to 5 V) allows direct interfacing with low-voltage DSPs or FIFOs while maintaining signal integrity.

Key Specifications

Pinout & Package

The LTC1750CFW#PBF is housed in a 48-pin TSSOP package with flow-through pinout optimized for high-speed PCB layout, minimizing trace length mismatch and crosstalk in differential analog and clock paths.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD9246BCPZ-80 and MAX1198ETJ+, the LTC1750CFW#PBF uniquely combines 500 MHz analog bandwidth, integrated PGA, and single 5 V supply - making it optimal for cost-sensitive, board-space-constrained IF receivers requiring adaptive input scaling without external gain stages.

Availability

LTC1750CFW#PBF is available at Aetrix Electronics and suitable for cellular infrastructure, test equipment, medical imaging, and defense electronics requiring stable component supply across extended production lifecycles.

Supply support for LTC1750CFW#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 maintains its high-performance signal chain portfolio, emphasizing precision, speed, and reliability for demanding analog applications.

The LTC1750CFW#PBF belongs to Linear's high-speed ADC family designed specifically for wideband communications and instrumentation - prioritizing IF sampling fidelity, low jitter, and flexible interface options over ultra-low power or integrated digital processing.

FAQ

What is the operating temperature range for the LTC1750CFW#PBF?

The LTC1750CFW#PBF is specified for the commercial temperature range of 0°C to +70°C. This rating is confirmed in the Absolute Maximum Ratings table and applies to all DC and dynamic performance specifications unless otherwise noted. The 'C' grade suffix explicitly denotes this temperature grade, distinguishing it from the industrial-grade LTC1750IFW (–40°C to +85°C).

Does the LTC1750CFW#PBF support both 2's complement and offset binary output formats?

Yes, the LTC1750CFW#PBF supports both output formats. The MSBINV pin (Pin 22) controls this behavior: logic low selects 2's complement, and logic high selects offset binary. This configuration is fully static and can be changed during operation without disrupting conversion timing or requiring device reset.

Can the LTC1750CFW#PBF be used with a single-ended encode clock?

Yes, the LTC1750CFW#PBF accepts single-ended encode signals. Drive ENC with the clock signal and tie ENC to ground through a 0.1 µF ceramic capacitor. The internal differential receiver remains functional, and timing parameters (t1, t2, t4) retain their specified values under this configuration per the datasheet's "ENC/ENC Input" section.

What is the purpose of the SENSE pin on the LTC1750CFW#PBF?

The SENSE pin (Pin 1) selects the internal reference voltage: grounded for 0.7 V, tied to VDD for 1.125 V, or biased between those values to set VREF directly. The ADC's full-scale input range is ±VREF divided by the PGA gain, so SENSE directly determines the effective analog input span (e.g., ±1.125 V at PGA = 0 with VDD-connected SENSE).

How does the PGA function affect the LTC1750CFW#PBF's noise performance?

Enabling PGA gain (PGA = high) reduces the full-scale input range, which increases quantization noise relative to signal - resulting in a measured SNR drop from 75.5 dB (PGA = 0) to 73.0 dB (PGA = 1) at 5 MHz. However, the PGA improves SNR for small-signal inputs by amplifying them above the ADC's inherent noise floor before digitization.