| 摘要 |
PURPOSE: A substrate biasing circuit is provided to use a gate type diode instead of an electric charge pump, an oscillator, and a level detector, for maintaining and setting a wanted substrate bias level. CONSTITUTION: A substrate biasing circuit(100) formed on a p-type material(110), contains a n-well(112) and a p-well(114) formed on the n-well. Also the circuit contains each detecting transistor(128) formed on many field oxide areas(116), a gate type diode(118), and the p-well. The gate diode contains a n+ diffusing area(120) formed on the p-well, and a reverse area(122) limited to the p-well between the oxide area and the diffusing area. The gate type diode also contains an oxide layer(124) formed on the reverse area and a diode gate(126) formed on the oxide layer. A transistor contains an n+ drain area formed on the p-well, an n+ source area formed on the p-well, and channel area(134) limited to the p-well between a drain and a source area(130,132) and also contains a gate oxide layer(136) and a detecting gate(140) formed on the gate oxide layer.
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