Broadcom Ltd. CEO Hock Tan is betting big on winning antitrust approval for his proposed $100 billion-plus takeover of Qualcomm Inc.

Qualcomm last week rejected Broadcom's sweetened bid of $82 a share on the grounds that it undervalued the company and fell short of necessary regulatory commitments.

Broadcom has insisted $82 is its best and final offer, but committed to a so-called ticking fee that would add about 30 cents a share to the cash portion of the proposal for every month the merger-approval process drags on beyond a year.

The chipmaker also agreed to pay Qualcomm a whopping $8 billion breakup fee should regulators block the deal.

Asked about the regulatory risk of such a mammoth semiconductor deal after years of consolidation in the industry, Tan told CNBC , "I'm kind of a frugal guy.

Of bigger concern is potential pushback from European Union or Chinese regulators about the impact on innovation and the combined company's ability to dominate too much of the overall market.

The closest is Qualcomm's $40 billion purchase of NXP Semiconductors NV, which has yet to receive full regulatory signoff after more than 15 months.