MC74F181N
Rochester Electronics
LMX393AUA
LMX393HAKA+
74F521PC
74HCT688N,652
UPC393C-A
74HC688P-E
DM74ALS521WMX
DM74ALS521N
TLV2352IPWLE
DM74ALS521WM
74HC85FP-E
DM74ALS520N
HA17903PSD-E
74HCT688FPEL-E
MC74F85M
74FCT521ASCX
CD74FCT521DTM
74AC11521DW
HEF4585BP,652