(Reuters) - Nvidia Corp's NVDA.O high-flying stock fell 6 percent on Friday as second-quarter sales in its fast-growing data center and autonomous driving businesses failed to live up to Wall Street's lofty expectations.

A NVIDIA logo is shown at SIGGRAPH 2017 in Los Angeles, California, U.S. July 31, 2017. REUTERS/Mike Blake

Nvidia’s stock nearly tripled in the past year, making it susceptible to any signs of weakness in those businesses, particularly the data center unit.

“This stock can’t afford to have a data center pause,” Barclays analysts wrote in a note.

Nvidia's data center business, which counts Amazon.com Inc's AMZN.O Amazon Web Services and Microsoft Corp's MSFT.O Azure cloud business among its customers, more than doubled to $416 million but fell short of the average analyst estimate of $423.3 million, according to financial and data analytics firm FactSet.

“To trade at a 40-50x (earnings) multiple, Nvidia needs to have cleaner beats and show stronger growth in the segments core to its longer-term story, certainly data center,” Barclays analyst Blayne Curtis said.

Revenue from the autonomous driving business rose 19.3 percent to $142 million, also falling short of the average estimate of $146.2 million, according to FactSet.

While investors were spooked by weakness at the two businesses, Wall Street analysts remained largely bullish on the stock. At least eight brokerages lifted their price targets.

Of the 38 brokerages covering the stock, 21 rate it “buy” or higher, 12 “hold” and 5 “sell” or lower. Friday’s decline brings the stock below analysts’ median price target of $160.

Nvidia’s second-quarter earnings and revenue topped analysts’ average estimate, partly driven by demand for its chips used to process cryptocurrency transactions.

“We estimate roughly $200 million of the $250 million in revenue upside came from crypto-currency demand,” said Instinet LLC Equity Research analyst Romit Shah.

Bitcoin BTC=BTSP made cryptocurrencies popular in recent years, but newer technologies, including Ethereum, have sparked a wave of mining using high-end gaming graphics cards. Miners use computers to process cryptocurrency transactions, and they are rewarded with additional cryptocurrency.

“Cryptocurrency and blockchain is here to stay. The market need for it is going to grow. And over time, it will become quite large,” Chief Executive Jensen Huang said in a post-earnings call.