(a) The board shall impose an ad valorem tax at a rate sufficient to create an interest and sinking fund to pay the principal of and interest on general obligation bonds issued by the district under Section 1113.201 as the bonds mature.
(b) The tax required by this section together with any maintenance and operation tax the district imposes may not in any year exceed:
(1) 50 cents on each $100 valuation of all taxable property in the district; or
(2) the maximum amount approved by the voters under Section 1113.253.