Denso Corporation

Hiroyuki Satake

Yuki Mikami

Yoshihiro Kizaki

Shinya Uemura

Takeshi Miki

A power supply device comprises: a first linear regulator, which receives a voltage from a direct-current power supply at all times and outputs a first voltage; a step-down switching regulator, which receives the voltage from the direct-current power supply through a path via a power supply switch and outputs an intermediate voltage, and a second linear regulator, which receives the intermediate voltage and outputs a second voltage. The power supply device outputs a higher one of the first voltage and the second voltage. The first linear regulator has a smaller current consumption and a higher minimum operating voltage than the second linear regulator. When the voltage supplied from the direct-current power supply is lower than or equal to a predetermined threshold value, the switching regulator drives a main switching component interposed in series with a voltage input-output path to turn on at all times. The second linear regulator executes an output operation of the second voltage during a full-on period, during which the main switching component is driven to turn on at all times.

Power supply device and electronic control unit for lowering a minimum operating voltage and suppressing a consumed current to be low

A switching power device includes: a main circuit having a switching element and a coil that adjusts a current flowing through the coil and outputs a voltage; an output voltage detection circuit that outputs a first voltage; an error amplification circuit that outputs an error signal in response to a difference between the first voltage of the output voltage detection circuit and a second voltage; an oscillation circuit that outputs an oscillation signal; a driving circuit that outputs the driving signal to the switching element in response to a comparison result by comparing the oscillation signal of the oscillation circuit and the error signal of the error amplification circuit; and a soft-start control unit that controls the second voltage in response to the first voltage of the output voltage detection circuit when the first voltage reaches a soft-start threshold voltage between a standard detection voltage and a start detection voltage.

Switching power device

Plurality of current mirror circuits CMto CMat which the same amount of current Iflows in the circuits. Transistors Qa/Qbare ON state when it is in the steady state. Transistors Qa/Qbturn ON and transistors Qb/Qaturn OFF when a voltage generation circuitapplies a voltage more than predetermined value Vto node N. Therefore node Nbecomes fixed voltage V. On the other hand, voltage generation circuitapplies a voltage less than predetermined value Vto node N, transistors Qb/Qaturn ON, and transistors Qa/Qbturn OFF. Accordingly, the node Nbecomes fixed voltage V

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Kariya, Japan

Hiroyuki Satake