Note 1 - Basis of Presentation	9 Months Ended
Sep. 30, 2015
Disclosure Text Block [Abstract]
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]	1. BASIS OF PRESENTATION The accompanying unaudited condensed consolidated financial statements have been prepared by Monolithic Power Systems, Inc. (the “Company” or “MPS”) in accordance with the rules and regulations of the Securities and Exchange Commission (the “SEC”). Certain information and disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States (“GAAP”) have been condensed or omitted in accordance with these rules and regulations. The information in this report should be read in conjunction with the Company’s audited consolidated financial statements and notes thereto included in the Annual Report on Form 10-K for the year ended December 31, 2014, filed with the SEC on March 2, 2015. In the opinion of management, the accompanying unaudited condensed consolidated financial statements reflect all adjustments (consisting only of normal recurring adjustments) necessary to present fairly the Company’s financial position, results of operations and cash flows for the interim periods presented. The financial statements contained in this Form 10-Q are not necessarily indicative of the results that may be expected for the year ending December 31, 2015 or for any other future periods. Summary of Significant Accounting Policies There have been no changes to the Company’s significant accounting policies during the three and nine months ended September 30, 2015 as compared to the significant accounting policies described in the Company’s audited consolidated financial statements included in the Annual Report on Form 10-K for the year ended December 31, 2014. Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers, which outlines a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers. The standard’s core principle is that an entity will recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. In July 2015, the FASB approved a one-year deferral of the effective date. The standard will be effective for annual reporting periods beginning after December 15, 2017. Entities have the option of using either a full retrospective or a modified retrospective application in the adoption of this standard. The Company is evaluating the transition method and the impact of the adoption on its consolidated financial position, results of operations and cash flows. In July 2015, the FASB issued ASU No 2015-11, Inventory (Topic 330), Simplifying the Measurement of Inventory, which replaces the lower of cost or market test with a lower of cost or net realizable value test. The standard applies to inventories for which cost is determined by methods other than the last-in first-out and the retail inventory methods. The standard will be effective for annual reporting periods beginning after December 15, 2016. The Company is evaluating the impact of the adoption on its consolidated financial position, results of operations and cash flows.

Note 1 - Basis of Presentation

9 Months Ended

Sep. 30, 2015

Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]

1. BASIS OF PRESENTATION

The accompanying unaudited condensed consolidated financial statements have been prepared by Monolithic Power Systems, Inc. (the “Company” or “MPS”) in accordance with the rules and regulations of the Securities and Exchange Commission (the “SEC”). Certain information and disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States (“GAAP”) have been condensed or omitted in accordance with these rules and regulations. The information in this report should be read in conjunction with the Company’s audited consolidated financial statements and notes thereto included in the Annual Report on Form 10-K for the year ended December 31, 2014, filed with the SEC on March 2, 2015.

In the opinion of management, the accompanying unaudited condensed consolidated financial statements reflect all adjustments (consisting only of normal recurring adjustments) necessary to present fairly the Company’s financial position, results of operations and cash flows for the interim periods presented. The financial statements contained in this Form 10-Q are not necessarily indicative of the results that may be expected for the year ending December 31, 2015 or for any other future periods.

Summary of Significant Accounting Policies

There have been no changes to the Company’s significant accounting policies during the three and nine months ended September 30, 2015 as compared to the significant accounting policies described in the Company’s audited consolidated financial statements included in the Annual Report on Form 10-K for the year ended December 31, 2014.

Recent Accounting Pronouncements

In May 2014, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers, which outlines a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers. The standard’s core principle is that an entity will recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. In July 2015, the FASB approved a one-year deferral of the effective date. The standard will be effective for annual reporting periods beginning after December 15, 2017. Entities have the option of using either a full retrospective or a modified retrospective application in the adoption of this standard. The Company is evaluating the transition method and the impact of the adoption on its consolidated financial position, results of operations and cash flows.

In July 2015, the FASB issued ASU No 2015-11, Inventory (Topic 330), Simplifying the Measurement of Inventory, which replaces the lower of cost or market test with a lower of cost or net realizable value test. The standard applies to inventories for which cost is determined by methods other than the last-in first-out and the retail inventory methods. The standard will be effective for annual reporting periods beginning after December 15, 2016. The Company is evaluating the impact of the adoption on its consolidated financial position, results of operations and cash flows.