Note 3 - Concentrations

12 Months Ended

Dec. 31, 2019

Notes to Financial Statements

Concentration Risk Disclosure [Text Block]

3. Concentrations

Financial instruments that subject the Company to concentrations of credit risk consist primarily of cash, cash equivalents, investments in marketable securities and trade accounts receivable. The Company extends differing levels of credit to customers and does not require collateral deposits. As of December 31, 2019 and 2018, the Company has allowance for doubtful accounts of $1,152. As of December 31, 2019 and 2018, the Company has allowance for distributors’ price discounts of $656 and $1,634, respectively.

The following table summarizes the significant customers’ (including distributors) accounts receivable and revenue as a percentage of total accounts receivable and total revenue, respectively:

	December 31,
Accounts Receivable	2019			2018
Customer A		15	%		13	%
Customer B		13			13
Customer C		*			*
Customer D		19			*
Customer E		*			*

	Year Ended December 31,
Revenue	2019			2018			2017
Customer A		14	%		18	%		12	%
Customer B		*			*			12
Customer C		11			*			*
Customer D		*			*			*
Customer E		*			11			*

* Less than 10% of total receivable or total revenue

Customer A is a subcontractor of a direct customer that would be a “Customer F” above. In the aggregate, revenue to Customer A and Customer F as a percentage of total revenue was approximately 14%, 18% and 17% for the years ended December 31, 2019, 2018 and 2017, respectively. Customer B is a subcontractor of a direct customer that would be a “Customer G” above. In the aggregate, revenue to Customer B and Customer G as a percentage of total revenue was approximately 11%, 14% and 14% for the years ended December 31, 2019, 2018 and 2017, respectively. In addition, the Company sells directly and indirectly through subcontractors to what would be a “Customer H” above. The Company believes, in the aggregate, revenue to Customer H, including its subcontractors as a percentage of total revenue was approximately 11% and 11% for the years ended December 31, 2018 and 2017, respectively.  The Company believes, in the aggregate, revenue to Customer H, including its subcontractors was significant but less than 10% of the total revenue for the year ended December 31, 2019.  Customers C and D are subcontractors and Customer E is a distributor, all of whom sell to various end customers.