Mich. Comp. Laws § 450.1303

Sec. 303. (1) If the articles of incorporation provide, subject to restrictions in section 304, a corporation may issue shares convertible at the option of the holder or the corporation or upon the happening of a specified event into shares of any class, into shares of any series of any class, or into bonds. Shares may be converted into bonds only if the corporation could at the time of conversion have purchased, redeemed, or otherwise acquired the shares by issuing the bonds under the restrictions of section 345. Authorized shares, issued or unissued, may be made convertible as provided in this subsection within the period and upon terms and conditions authorized in the articles of incorporation. (2) Unless otherwise provided in the articles of incorporation, and subject to the restrictions of section 304, a corporation may issue its bonds convertible at the option of the holder into other bonds or into shares of the corporation within the period and upon terms and conditions as fixed by the board. (3) If there is shareholder approval for the issue of bonds or shares convertible into shares of the corporation, the approval may provide that the board is authorized by amendment of the articles of incorporation to increase the authorized shares of any class or series to the number that will be sufficient, when added to the previously authorized but unissued shares of the class or series, to satisfy the conversion privileges of any bonds or shares convertible into shares of the class or series.