LT6402CUD-20#TRPBF

Overview

The LT6402CUD-20#TRPBF is a low distortion, low noise differential amplifier and ADC driver designed for applications from DC to 300MHz. It features a fixed gain of 20dB (10V/V) and operates on a single 5V supply with typical current consumption of 30mA. The device includes both unfiltered outputs (+OUT, –OUT) and built-in filtered outputs (+OUTFILTERED, –OUTFILTERED) with a 75MHz -3dB bandwidth. Key electrical specifications include an input-referred noise voltage density of 1.9nV/√Hz at 20MHz, a noise figure of 12.4dB, and an output third-order intercept point (OIP3) of 51dBm at 20MHz. It is housed in a compact 16-lead 3mm × 3mm QFN package.

Feature Summary

• Integrated differential low-pass filter with 75MHz cutoff frequency available at dedicated filtered output pins
• Adjustable output common mode voltage via VOCM pin, eliminating need for output transformers or AC-coupling capacitors
• Low input-referred noise voltage density and high linearity suitable for driving high-speed 12-bit and 14-bit ADCs
• Supports both DC-coupled and AC-coupled operation with minimal external support circuitry requirements

Applications

• Differential ADC driver for imaging and communications systems
• IF sampling receivers and SAW filter interfacing/buffering
• Single-ended to differential conversion circuits
• General-purpose differential gain blocks in data acquisition systems

Procurement Notes

Verify the suffix #TRPBF indicates lead-free tape and reel packaging. Confirm the 'C' grade designation meets the required operating temperature range, as it is guaranteed for 0°C to 70°C performance but designed for -40°C to 85°C. Ensure the 16-lead QFN package footprint matches the PCB layout. Check that the specific lot date code aligns with project timelines. Validate that the source document confirms the part marking LCBC for this specific ordering option.

Selection Notes

Select this component when a fixed 20dB gain is required alongside integrated filtering to reduce external component count. The built-in 75MHz filter simplifies anti-aliasing design for ADC inputs. Choose the C-grade variant if the application environment remains within 0°C to 70°C; otherwise, consider the I-grade for full -40°C to 85°C specification guarantees. Ensure the 5V supply constraint fits the system power budget. Verify that the 30mA quiescent current is acceptable for thermal management in the chosen QFN package.

Part Context

The LT6402-20 belongs to Analog Devices' family of low-noise differential amplifiers optimized for direct ADC interfacing. Unlike general-purpose op-amps, this device integrates specific feedback networks and output stages tailored for high-speed signal conditioning. The -20 suffix denotes the fixed 20dB gain configuration, distinguishing it from other gain variants in the series. It serves as a bridge between analog front-end sensors and digital conversion stages in high-frequency communication and instrumentation systems.

Replacement Considerations

Publicly confirmed substitute part numbers are not provided in the datasheet. Designers should verify pin compatibility and electrical parameter overlaps before considering alternative differential amplifiers. Cross-reference the 16-lead QFN package dimensions and thermal characteristics with potential replacements to ensure mechanical fit.