Edit in JSFiddle

Result
JavaScript
HTML

var app = angular.module("MiApp", []);

function MiPageController($scope) {
    $scope.deshabilitado = false;
}

<body ng-app="MiApp" ng-controller="MiPageController">
    <input type="checkbox" ng-model="deshabilitado">¿Deshabilitar?
    <br />
    Valor:<input type="text" ng-disabled="deshabilitado==true">
</body>