Analog Devices Inc. LTC1745CFW#TRPBF

Overview

LTC1745CFW#TRPBF from Analog Devices (formerly Linear Technology) is a 12-bit, 25 Msps 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 differential input selection, and operates from a single 5 V supply with 380 mW power dissipation.

For engineers reviewing the LTC1745CFW#TRPBF datasheet, LTC1745CFW#TRPBF pinout, LTC1745CFW#TRPBF application, or LTC1745CFW#TRPBF equivalent, key selection criteria include its 240 MHz full-power bandwidth, 0.3 psRMS aperture jitter, ±1 LSB INL max over temperature, flow-through TSSOP-48 pinout, and compatibility with 0.5–5 V digital output supplies for direct interfacing to low-voltage DSPs or FIFOs.

Technical Context

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

DC accuracy is maintained across temperature with ±0.4 LSB typical INL and ±0.2 LSB typical DNL, while dynamic performance is stabilized by dedicated REFHA/REFHB and REFLA/REFLB pins requiring precise external bypassing (0.1 µF + 4.7 µF). The 5-cycle data latency and CLKOUT-synchronized output timing support deterministic system-level synchronization.

Key Specifications

Pinout & Package

The LTC1745CFW#TRPBF is housed in a 48-lead plastic TSSOP (FW package) with flow-through pinout designed to minimize trace crossovers and simplify high-speed analog layout. Ground pins are distributed across multiple locations to reduce ground bounce and improve PSRR.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD9226BCPZ-65 and LTC2245IUP#PBF, the LTC1745CFW#TRPBF offers the best balance of 25 Msps throughput, 72.5 dB SNR, single 5 V supply simplicity, and flow-through layout - making it ideal for cost- and space-constrained communications front-ends where 12-bit resolution suffices.

Availability

LTC1745CFW#TRPBF is available at Aetrix Electronics and suitable for telecommunications base stations, medical ultrasound imaging systems, and spectrum analyzers requiring stable component supply and long-term production continuity.

Supply support for LTC1745CFW#TRPBF 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 semiconductors, serving industrial, automotive, communications, and healthcare markets.

The LTC1745CFW#TRPBF belongs to ADI's legacy Linear Technology high-speed ADC product line, engineered for demanding communications infrastructure and test equipment where low jitter, high SFDR, and robust DC accuracy are critical.

FAQ

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

The LTC1745CFW#TRPBF is specified for commercial-grade operation from 0°C to 70°C (C-grade). This range is validated per the Absolute Maximum Ratings table and applies to all dynamic and DC specifications unless otherwise noted. For extended temperature operation, the LTC1745IFW variant supports –40°C to +85°C.

Does the LTC1745CFW#TRPBF support single-ended encode input?

Yes, the LTC1745CFW#TRPBF supports single-ended encode: tie ENC to ground and drive ENC with a TTL/CMOS signal. The datasheet specifies ENC/ENC differential thresholds, but the internal comparator accepts single-ended logic with appropriate noise margin. Performance remains identical to differential mode when ENC is properly bypassed with 0.1 µF.

How is the input range selected on the LTC1745CFW#TRPBF?

The LTC1745CFW#TRPBF input range is selected via the SENSE pin: connect SENSE to GND for ±1 V differential range, or to VDD for ±1.6 V differential range. Intermediate voltages (1.0 V to 1.6 V) scale the full-scale range linearly - e.g., 1.1 V on SENSE yields ±2.2 V range - enabling custom gain matching without external amplifiers.

What is the purpose of the VCM pin on the LTC1745CFW#TRPBF?

The VCM pin on the LTC1745CFW#TRPBF provides a stable 2.35 V common-mode bias voltage used to set the DC level of differential analog inputs. It must be bypassed with ≥4.7 µF ceramic capacitance to ground. VCM can directly bias transformer center taps or op-amp driver circuits to ensure optimal S/H linearity and harmonic suppression.

Can the LTC1745CFW#TRPBF interface directly with a 1.8 V FPGA?

Yes, the LTC1745CFW#TRPBF can interface directly with a 1.8 V FPGA by setting OVDD = 1.8 V. Its digital outputs (D0–D11, CLKOUT, OF) are fully specified down to 0.5 V OVDD, and output voltage levels (VOH/VOL) meet 1.8 V logic thresholds. No level translators are needed, reducing BOM count and signal integrity risk.