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DC-DC converter and semiconductor device

  • US 9,412,762 B2
  • Filed: 07/29/2014
  • Issued: 08/09/2016
  • Est. Priority Date: 07/31/2013
  • Status: Active Grant
First Claim
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1. A semiconductor device comprising:

  • a control circuit comprising;

    a holding circuit comprising a first transistor; and

    an operational amplifier;

    a second transistor; and

    a first output terminal,wherein a first terminal of the first transistor is electrically connected to the operational amplifier,wherein an output terminal of the operational amplifier is electrically connected to a gate of the second transistor,wherein a first terminal of the second transistor is electrically connected to the first output terminal,wherein the first transistor comprises a first oxide semiconductor film comprising a channel formation region,wherein the second transistor comprises a second oxide semiconductor film comprising a channel formation region,wherein each of the first oxide semiconductor film and the second oxide semiconductor film comprises In, M, and Zn,wherein an atomic ratio of In to M in the second oxide semiconductor film is higher than an atomic ratio of In to M in the first oxide semiconductor film, andwherein M is at least one of Ga, Y, Zr, La, Ce, and Nd.

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