ADC Driver in a 3×3 mm QFN
The LTC6401CUD-20#PBF is a fixed-gain ADC driver from Analog Devices, designed to condition signals ahead of a high-speed data converter in a data-acquisition chain. The 16-WFQFN exposed-pad package (3×3 mm, 0.5 mm pitch) keeps the signal path short — critical for preserving linearity at the frequencies where this driver operates.
The LTC6401 family offers multiple fixed-gain versions. The -20 suffix indicates a specific gain setting; the LTC6401CUD-26#PBF is a sibling with a different gain value. Both share the same 16-QFN footprint and pinout, so swapping between them on the same PCB layout is straightforward — no board spin required. The I-grade variants (LTC6401IUD-26#PBF, LTC6401IUD-14#PBF) extend the temperature range. If your system already runs the commercial-temperature CUD-20, the pin-compatible IUD-26 or IUD-14 is a drop-in if the gain target shifts or the ambient envelope widens.