| 摘要 |
PURPOSE: A substrate bias pumping circuit is provided to improve the pumping efficiency by preventing the accumulation of negative charges during the pumping. CONSTITUTION: The device comprises: the first and the second transfer transistor(N21,N22) which are formed between a pumping node and an output node and perform the pumping operation in turn by a control signal; the first and the second precharge transistor(P25,P26) which are connected between the first and the second transfer transistor and a ground and are controlled by the third and the fourth control signal; and a prevention unit(30) to prevent negative charges from being accumulated in a gate node of the first precharge PMOS transistor. The prevention unit comprises: the third PMOS transistor(P32) which is connected between a ground and a gate of the first PMOS transistor and whose gate is connected to a gate node of the second precharge PMOS transistor, as a unit to prevent negative charges from being accumulated in the gate node of the first precharge PMOS transistor; and the fourth precharge PMOS transistor(P33) which is connected between a ground and a gate of the second PMOS transistor and whose gate is connected to a gate node of the first precharge PMOS transistor, as a unit to prevent negative charges from being accumulated in the gate node of the second precharge PMOS transistor.
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