Patent ID: 7498657
Filing Date: 2009-03-03
Classification: H01L

Abstract:
1. A band-gap voltage reference circuit, comprising: a substrate coupled to a first voltage level, comprising a first trench, a second trench, and a third trench; an isolation layer filling the first trench, the second trench, and the third trench; a first doped region formed adjacent to one side of the first trench and coupled to a second voltage level; a second doped region formed between another side of the first trench, and the second trench; a third doped region formed between the second trench and one side of the third trench; a fourth doped region formed adjacent to another side of the third trench; a fifth doped region formed under the first doped region; an amplifier comprising a first input terminal coupled to the second doped region, a second input terminal coupled to the third doped region, and an output terminal coupled to the fourth doped region; a first current source coupled between a third voltage level and the first input terminal; and a second current source coupled between the third voltage level and the second input terminal.