Note 4 - Balance Sheet Components - Property and Equipment (Details) - USD ($) $ in Thousands	Mar. 28, 2020	Dec. 28, 2019
Total property and equipment, net	$ 39,933	$ 39,230
UNITED STATES
Total property and equipment, net	31,593	32,313
CHINA
Total property and equipment, net	1,528	1,683
PHILIPPINES
Total property and equipment, net	2,705	2,683
TAIWAN, PROVINCE OF CHINA
Total property and equipment, net	3,556	1,885
JAPAN
Total property and equipment, net	234	283
Other [Member]
Total property and equipment, net	317	383
Non-US [Member]
Total property and equipment, net	$ 8,340	$ 6,917