Income Taxes - Tax Effect of Temporary Differences and Carryforwards that Give Rise to Significant Portions of the Net Deferred Tax Assets (Details) - USD ($) $ in Thousands	Jan. 02, 2021	Dec. 28, 2019
Tax effect of temporary differences and carryforwards that give rise to significant portions of the net deferred tax assets
Net operating losses	$ 11,769	$ 10,426
Research and development credits	3,273	3,175
Accruals and reserves	2,382	2,334
Deferred revenue	81	54
Property and equipment	307	316
Intangible assets	328	370
Stock compensation	658	657
Net deferred tax asset	18,798	17,332
Valuation allowance	(18,820)	(17,351)
Net deferred tax liabilities	$ (22)	$ (19)

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from deferred income.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from intangible assets including goodwill.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from in-process research and development costs expensed in connection with a business combination.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible operating loss carryforwards.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from property, plant, and equipment.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from reserves and accruals.

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Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.

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