HT66L2540A-16NSOP HT66L2540A-24SSOP HT66L2540A-28QFN HT66L2540A-28SSOP HT66L2550A-24SSOP HT66L2550A-28SSOP HT66L2550A-32QFN HT66V0031 HT66V004 HT66V0041