4.5-V to 18-V input, 3A/2A/2A output, Synchronous triple buck converter 40-VQFN -40 to 125
Texas Instruments
Texas Instruments - TPS65251-3RHAR
$2.19 - $4.29
Texas Instruments - TPS65251-3RHAT
$2.52 - $5.05
Texas Instruments - TPS65251-3 HAT