Note 4 - Balance Sheet Components - Other Current Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Prepaid wafer purchase	$ 6,217	$ 6,217
Other prepaid expense	3,172	2,742
Interest receivable	1,466	1,352
Value-added tax receivable	1,427	1,235
Assets for product returns	1,047
Other	645	1,216
Total	$ 13,974	$ 12,762

Product return assets that are expected to be received within one year or the normal operating cycle, if longer.

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Carrying amount as of the balance sheet date of current interest earned but not received. Also called accrued interest or accrued interest receivable. For classified balance sheets, represents the current amount receivable, that is amounts expected to be collected within one year or the normal operating cycle, if longer.

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Amount of current assets classified as other.

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Amount of other miscellaneous assets expected to be realized or consumed within one year or operating cycle, if longer.

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Amount of asset related to consideration paid in advance for other costs that provide economic benefits within a future period of one year or the normal operating cycle, if longer.

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Amount of consideration paid in advance for supplies that provide economic benefits within a future period of one year or the normal operating cycle, if longer.

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Carrying amount as of the balance sheet date of value added taxes due either from customers arising from sales on credit terms, or as previously overpaid to tax authorities. For classified balance sheets, represents the current amount receivable, that is amounts expected to be collected within one year or the normal operating cycle, if longer.

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