Aquantia Corp, a Milpitas, Calif. developer of physical-layer transceiver ICs, has secured $19.17 million of a $25 million second round of financing, according to a regulatory filing cited by PE Wire. Pinnacle Ventures was joined by return backers Lightspeed Venture Partners and Greylock Partners. The company raised its first round in 2005 with more than $12 million.