| 摘要 |
PURPOSE: A power on reset circuit is provided to reduce the lay-out area and to reset a chip when a power supply voltage goes up. CONSTITUTION: A power on reset circuit includes a load unit(10), a pulse generation circuit (20), a delay circuit(30) and a combination circuit(40). The load unit receives a power supply voltage gradually rising and delays the rising of the power supply voltage. The pulse generation circuit outputs a pulse signal having a predetermined pulse width when an output voltage of the load unit goes up to a predetermined voltage level. The delay circuit delays the pulse signal. The combination circuit combines pulse signals output from the pulse generation circuit and the delay circuit and outputs a reset signal having a pulse width less than those of the pulse signals.
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