LT6604CUFF-2.5#PBF

Overview

The LT6604CUFF-2.5#PBF is a dual-channel integrated circuit featuring very low noise differential amplifiers and 2.5MHz fourth-order lowpass filters with Chebyshev response characteristics. It operates on supply voltages ranging from 3V to 11V, drawing approximately 28mA per channel at 5V. The device provides a signal-to-noise ratio exceeding 86dB at unity gain with a 3V supply. Key electrical parameters include a common-mode rejection ratio of 63dB, input bias current of -35µA typical, and differential output swing up to 9.3VP-P at 5V. It is housed in a 34-lead 4mm x 7mm QFN package.

Feature Summary

• Integrates two matched fully differential amplifiers with fixed 2.5MHz lowpass filtering for simultaneous signal conditioning and anti-aliasing.
• Features resistor-programmable differential gain allowing flexible interface configurations with external input resistors.
• Provides adjustable output common mode voltage via dedicated pins to facilitate direct interfacing with analog-to-digital converters.
• Ensures high precision through guaranteed phase and gain matching between the two independent channels.

Applications

• Dual ADC driver and filter stage for wireless infrastructure baseband processing
• Single-ended to differential conversion for high-speed test and measurement equipment
• Common mode translation of differential signals in medical imaging systems

Procurement Notes

Verify the specific suffix 'CUFF' indicates the commercial temperature grade (0°C to 70°C) and plastic QFN packaging as distinct from industrial variants. Confirm lead-free finish compliance with RoHS standards prior to ordering. Ensure PCB layout accommodates the exposed pad connection to the negative supply for thermal management and electrical grounding.

Selection Notes

Select this component when a combined amplifier and sharp cutoff filter is required to minimize board space and component count. The fixed 2.5MHz cutoff suits applications where bandwidth limitation is static. Consider the 34-lead QFN package constraints for thermal dissipation and soldering requirements compared to larger packages if higher power handling is needed.

Part Context

This part belongs to the LT6604 family of dual differential amplifiers with integrated lowpass filters. Variants within the series offer different cutoff frequencies ranging from 2.5MHz to 20MHz. The CUFF designation specifically identifies the commercial grade version in the small form factor QFN package, distinguishing it from industrial temperature range options.

Replacement Considerations

LT6604IUFF-2.5#PBF offers identical electrical performance but is specified for an extended operating temperature range of –40°C to 85°C.

FAQ

How is the differential gain of the LT6604CUFF-2.5 configured?

The differential gain is set by two equal external input resistors (RIN). The DC gain is calculated as 1580Ω divided by RIN.

What is the function of the VMID pin?

The VMID pin sets the output common mode voltage for the first filter stage. It is internally biased at mid-supply but can be overridden by an external low-impedance source.