* Expects fourth-quarter revenue of $227 mln-$230 mln * Shares up 14 pct, after market (Adds details, analysts' comments) By Sruthi Ramakrishnan June 25 (Reuters) - Touchscreen chipmaker Synaptics Inc SYNA.O , which counts smartphone makers Samsung, Blackberry and HTC among its customers, raised its revenue outlook for the current quarter citing higher-than-expected sales from mobile products. Synaptics shares were up 14 percent in extended trading on Tuesday after closing at $35.87 on the Nasdaq. The company said it now expects net revenue of $227 million to $230 million for the three months ending June 30, up from its previous forecast of $190 million to $205 million. ID:nPnSF38252 A "good portion" of the raised outlook could be attributed to Samsung Electronics Co Ltd 005930.KS , Feltl & Co analyst Jeffrey Schreiner told Reuters. Synaptics had said in April that it won contracts from Samsung for its Galaxy S4 smartphone and Note 8 tablet. ID:nL3N0DCP68 "A lot of this could be due to continued builds for the S4, maybe build for the Note 3, the S4 Mini, which we believe they probably were in that as well, a few other designs. The S4 Active is another version," Schreiner said. Demand from other handset makers such as Sony Corp 6758.T , LG Electronics Inc 066570.KS and HTC Corp 2498.TW could also be helping Synaptics, he said. Stifel Nicolaus and Co analyst Kevin Cassidy said sales of phones such as those from HTC might be better than expected. Synaptics, whose chips are also used in BlackBerry's BB.TO BBRY.O Z10, will report fourth-quarter results on Aug. 1. (Editing by Joyjeet Das) ((sruthi.ramakrishnan@thomsonreuters.com)(Within U.S.+1 646 223 8780, outside U.S. +91 80 4135 5800)(Reuters Messaging: sruthi.ramakrishnan.thomsonreuters.com@reuters.net)) Keywords: SYNAPTICS OUTLOOK/