Passing character limit to text field

Question

I have a combo "Person Type" with options (1 - Physical | 2 - Legal) and I need to limit the default character size to be filled in the text field "CPF/CNPJ".

In fact, I need to validate the text field for when the person type "1 - Physics" is selected in the combo, the maxlength is the default for the CPF, and so for the same to the CNPJ.

The Form

            <div class="col-xs-12 col-sm-12 col-md-12 col-lg-2">
                <div class="form-group">
                    <label for="tipoPessoa">Tipo Pessoa:*</label> 
                      <select 
                        id="tipoPessoa"
                        name="tipoPessoa"
                        data-ng-required="true"
                        data-ng-model="vm.tipoPessoa"
                        class="form-control input-sm"
                        data-ng-options="opt as opt.tipoPessoa for opt in options">
                      </select>                     
                </div>
            </div>

            <div class="col-xs-12 col-sm-12 col-md-12 col-lg-3">
                <div class="form-group">
                    <label for="cpfcnpj">CPF/CNPJ:*</label> 
                    <input type="text"
                        id="cpfcnpj" 
                        name="cpfcnpj"
                        data-ng-required="true"
                        data-ng-model="vm.simulacao.cpfcnpj"
                        required="required"
                        class="form-control input-sm" />

                </div>
            </div>

            <div class="col-xs-12 col-sm-12 col-md-12 col-lg-3">
                <button type="button" class="btn btn-sm btn-primary"
                    data-ng-click="vm.limparSelecionados(); vm.pesquisar();"
                    data-ng-disabled="Form.$invalid" style="margin-top: 22px;"
                    data-aria-label="Right Align">
                    <i class="glyphicon glyphicon-search"></i> <span>Pesquisar</span>
                </button>
            </div>