Most Popular Timers or RTCs DS3234SN# DS3234S# DS3234SN#T& R DS3231SN# DS3234SN# DS3231S# PCF8563T/5, 518 DS1682S+ DS3234S#T& R DS3231SN#T& R DS1682S+T& R M41T81M6F DS3231MZ+ DS1307Z+ DS1338Z-33+ M41T11M6F DS3234SN#T& R DS1339U-33+T& R PCF8563T/F4, 118 MCP7940NT-I/SN M41T82RM6F PCF8563TS/4, 118 ISL12057IUZ DS1338Z-33+T& R MCP7940N-I/SN DS3231M+TRL DS1307Z+T& R M4T28-BR12SH1 DS1307ZN+T& R ISL12057IUZ-T