Part Numbering System Real Time Clocks RX-8581SA B : Base Model No./ Pkg Frequency Tolerance RX-4581NB RTC-9701JE RTC-4701JE RTC-4701NB RTC-4574JE RTC-4574SA RTC-4574NB RTC-4553 RTC-4543SA RTC-4543SB RX-4591CF RX-4702CF RTC-8564JE RTC-8564NB RX-8581SA RX-8581JE RX-8581NB RX-8564CF RX-8025SA RX-8025NB RTC-7301SF RTC-7301DG RTC-62421 RTC-62423 RTC-72421 RTC-72423 RX-4581NB RTC-9701JE RTC-4701JE RTC-4701NB RTC-4574JE RTC-4574SA RTC-4574NB RTC-4553 SON 22pin VSOJ 20pin VSOJ 20pin SON 22pin VSOJ 20pin SOP 14pin SON 22pin SOP 14pin SOP 14pin SOP 18pin SON 10pin SON 10pin VSOJ 20pin SON 22pin SOP 14pin VSOJ 20pin SON 22pin SON 10pin SOP 14pin SON 22pin SSOP 24pin DIP 18pin DIP 18pin SOP 24pin DIP 18pin SOP 24pin RTC-4543SA RTC-4543SB RX-4591CF RX-4702CF RTC-8564JE RTC-8564NB RX-8581SA RX-8581JE RX-8581NB RX-8564CF RX-8025SA RX-8025NB RTC-7301SF RTC-7301DG RTC-62421 RTC-62423 RTC-72421 RTC-72423 B=5+/-23ppm B=5+/-23ppm B=5+/-23ppm B=5+/-23ppm B=5+/-23ppm B=5+/-23ppm B=5+/-23ppm A=5+/-10ppm, AA=5+/-5ppm, B=5+/-20ppm A=5+/-12ppm, B=5+/-23ppm A=5+/-12ppm, B=5+/-23ppm B=5+/-23ppm B=5+/-23ppm B=5+/-23ppm B=5+/-23ppm B=5+/-23ppm B=5+/-23ppm B=5+/-23ppm B=5+/-23ppm AA=5+/-5ppm AA=5+/-5ppm B=5+/-23ppm B=5+/-23ppm A=+/-10ppm, B=+/-50 A=+/-20ppm, B=+/-50 A=+/-10ppm, B=+/-50 A=+/-20ppm, B=+/-50 0 Tape & Reel Qty SOP Package Type Only 0: 1000 pcs. per reel 3: 250 pcs. per reel DIP Package Type Only S: 25pcs/Stick 6/17/2003