Power-on reset circuit and electronic device using the same
AssigneesHONG FU JIN PRECISION INDUSTRY (ShenZhen) CO., LTD., Hon Hai Precision Industry Co., Ltd.
InventorsGuang-Ze Li, Chun-Te Wu
Life of this patent
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Abstract
A power-on reset circuit, connected to an external direct current (DC) power source, to receive DC power signals and generate a reset signal, includes a delay circuit, a combination circuit and a shaping circuit. The delay circuit comprises a plurality of delay units, to delay the received DC power signals and output a plurality of delayed DC power signals. The combination circuit is connected to the delay circuit, to combine the delayed DC power signals into a combination signal, and output the combination signal. The shaping circuit is connected to and turns the combination circuit on and off according to the combination signal and outputs the reset signal.
Claims14
A power-on reset circuit, connected to an external direct current (DC) power source, to receive DC power signals and generate a reset signal for at least one functional chip, the power-on reset circuit comprising:
- a delay circuit comprising a plurality of delay units, structured and arrange to delay the received DC power signals and output a plurality of delayed DC power signals, the plurality of delay units each comprising:
- a first delay unit to delay the received DC power signal and output a first delayed signal, the first delay unit comprising a first capacitor and a first resistor connected in series between the external DC power source and ground;
- and
- a second delay unit to delay the received DC power signal and output a second delayed signal, the second delay unit comprising a second resistor and a second capacitor connected in series between the external DC power source and ground;
- a combination circuit connected to the delay circuit, to combine the plurality of delayed DC power signals together to generate a combination signal;
- and
- a shaping circuit connected to the combination circuit, the shaping circuit operable to be turned on and off according to the combination signal, and operable to output the reset signal.
An electronic device, connected to an external DC power source, comprising:
- a chipset;
- and
- a power-on reset circuit, connected to the external DC power source, to receive DC power signals from the external DC power source and generate a reset signal to reset the chipset, comprising:
- a delay circuit comprising a plurality of delay units, to delay the received DC power signals and output a plurality of delayed DC power signals, the plurality of delay units each comprising:
- a first delay unit to delay the received DC power signal and output a first delayed signal, the first delay unit comprising a first capacitor and a first resistor connected in series between the external DC power source and ground;
- and
- a second delay unit to delay the received DC power signal and output a second delayed signal, the second delay unit comprising a second resistor and a second capacitor connected in series between the external DC power source and ground;
- a combination circuit connected to the delay circuit, to combine the delayed DC power signals into an operating signal, and output the combination signal;
- and
- a shaping circuit connected to the combination circuit, the shaping circuit operable to be turned on and off according to the combination signal, and operable to output the reset signal.
Dependencies are inferred from the claim text.