| 摘要 |
PURPOSE: A power-up signal generator is provided to perform a stable initialization by preventing an error that an initialization signal occurs when an external power-supply voltage is not reached to a sufficient voltage level. CONSTITUTION: A power-up signal generator(202) includes an external initialization signal generator and an internal initialization signal generator(246). In the external initialization signal generator, a first current mirror controlled by a bias voltage is connected to a first node. A first active load, a first inverter and a second inverter are connected in series between an external power-supply voltage and a ground terminal. The first inverter and the second inverter receive a power-supply via the first active load. A voltage of the first node and an output signal of the second inverter are input to the first inverter circuit. A second node, an output terminal of the first inverter is connected to an input terminal of the second inverter. An output signal of the first inverter circuit is produced as a power-up signal in the external initialization signal generator. In the internal initialization signal generator(246), a second active load, a third active load and a second current mirror are connected between the internal power-supply voltage and a ground terminal. A second current mirror is controlled by the second bias voltage. A third node to which the third active load and the second current mirror are connected, is connected to the second node.
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