Pin Diagrams Figure . 14-Pin PDIP, SOIC, TSSOP Figure . 20-Pin PDIP, SOIC, SSOP Figure . 20-Pin QFN Note: It is recommended that the exposed bottom pad be connected to VSS; however, it must not be the only VSS connection to the device. Figure . 28-Pin SPDIP, SSOP Figure . 28-Pin VQFN Figure . 40-Pin PDIP Figure . 40-Pin QFN Figure . 44-Pin TQFP