Sonoma County technology companies raised nearly $110 million in venture capital during the second quarter, as the sector continued its rebound from last year's slump.

U.S. startups had their best funding quarter since mid-2008, just before Wall Street's historic meltdown, said Jessica Canning of Dow Jones VentureSource, which tracks private equity deals.

"Venture capital had a strong quarter," she said. "Deal activity is once again near levels seen before the start of the recession."

Sonoma County tech startups raised just $60 million during the same period last year.

Green technology, information technology and biotech attracted most of the funding nationwide, according to VentureSource's survey.

Enphase Energy, a Petaluma startup that makes energy-efficient microinverters for solar power systems, was a top recipient last quarter. It raised $46 million, according to a filing with U.S. securities regulators.

"We're the fastest-growing inverter company in the world," Enphase CEO Paul Nahi said Wednesday. Enphase solar microinverters increase a system's energy output from 5 to 25 percent, the company said.

Since Enphase launched its product line in 2008, it has sold more than 300,000 microinverter systems. "We had 13 percent market share in the U.S. in the first quarter," Nahi said. "We're looking at record sales every quarter."

The startup's latest funding round included an investment from Kleiner Perkins, one of Silicon Valley's leading venture capital firms.

Earlier this month, Enphase unveiled a "smart" solar thermostat that allows users to manage their solar, heating and cooling systems on a single Web-based platform.

"The owner can see what's going on and program everything online," Nahi said.

Enphase has about 100 employees, mostly in Petaluma.

TriVascular, a Santa Rosa medical technology startup, was the other big recipient, raising $45 million in venture equity and another $15 million in debt financing last quarter.

TriVascular plans to launch its first product, a stent-graft system for repairing abdominal aortic aneurysms, in Europe later this year.

The investment round was led by Palo Alto's Pinnacle Ventures, with participation from four other equity funds.

TriVascular has about 260 employees at its headquarters near Charles M. Schulz-Sonoma County Airport and plans to add 100 more over the next year as it starts commercial production, marketing and sales.

Three other Sonoma County companies landed smaller equity deals last quarter.

Petaluma's Dilithium Networks, which helps telecommunications providers deliver mobile video, sold $1.5 million of a $4 million offering.

Dilithium provides hardware, software and services for mobile video applications, with about 120 network customers serving 1.5 billion subscribers in 60 countries.

In February, Dilithium launched Galaxy, a technology platform designed to make it faster and easier for service providers to offer mobile video.

Raydiance, a Petaluma startup that is developing short-pulse laser technology, sold $1.25 million of a $5 million offering. The company's ultra-fast laser platform has applications for the medical device, electronics, defense, bioscience and energy markets, the company said.

And Sapheon, an early-stage Santa Rosa company working on a minimally invasive procedure for removing varicose veins, raised $481,250.

Nationwide, venture funds pumped $7.7 billion into tech startups last quarter, up 26 percent from the same period a year ago, according to VentureSource.