Datasheet

ManualsBrandsNXP SEMICONDUCTORS ManualsIntegrated Circuits (ICs)Timer IC t- real time clock Clock/calendar HVSON 8

Product data sheet Rev. 6 — 17 September 2013 76 of 78

NXP Semiconductors

PCF8523

Real-Time Clock (RTC) and calendar

28. Figures

Fig 1. Block diagram of PCF8523 . . . . . . . . . . . . . . . . . .3

Fig 2. Pin configuration for SO8 (PCF8523T) . . . . . . . . .4

Fig 3. Pin configuration for HVSON8 (PCF8523TK) . . . .4

Fig 4. Pin configuration for TSSOP14 (PCF8523TS). . . .4

Fig 5. Pin configuration for PCF8523U . . . . . . . . . . . . . .5

Fig 6. Auto-incrementing of the registers. . . . . . . . . . . . .7

Fig 7. Software reset command. . . . . . . . . . . . . . . . . . .12

Fig 8. Interrupt block diagram . . . . . . . . . . . . . . . . . . . .14

Fig 9. Battery switch-over behavior in standard mode

and with bit BSIE set logic 1 (enabled) . . . . . . . .17

Fig 10. Battery switch-over behavior in direct switching

mode and with bit BSIE set logic 1 (enabled) . . .18

Fig 11. Battery low detection behavior with

bit BLIE set logic 1 (enabled). . . . . . . . . . . . . . . .19

Fig 12. OS flag. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21

Fig 13. Data flow diagram of the time function. . . . . . . . .23

Fig 14. Access time for read/write operations . . . . . . . . .23

Fig 15. Alarm function block diagram. . . . . . . . . . . . . . . .25

Fig 16. Alarm flag timing . . . . . . . . . . . . . . . . . . . . . . . . .26

Fig 17. AF timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27

Fig 18. Offset calibration calculation workflow. . . . . . . . .31

Fig 19. Watchdog activates an interrupt when timed out .36

Fig 20. General countdown timer behavior . . . . . . . . . . .37

Fig 21. General countdown timer behavior . . . . . . . . . . .38

Fig 22. Example for second interrupt when TAM = 1. . . .40

Fig 23. Example for second interrupt when TAM = 0. . . .40

Fig 24. Example of shortening the INT1

pulse

by clearing the SF flag . . . . . . . . . . . . . . . . . . . . .41

Fig 25. Example of shortening the INT1 pulse

by clearing the CTAF flag. . . . . . . . . . . . . . . . . . .42

Fig 26. STOP bit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43

Fig 27. STOP bit release timing. . . . . . . . . . . . . . . . . . . .43

Fig 28. Bit transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45

Fig 29. Definition of START and STOP conditions. . . . . .45

Fig 30. System configuration . . . . . . . . . . . . . . . . . . . . . .45

Fig 31. Acknowledgement on the I

C-bus . . . . . . . . . . . .46

Fig 32. Bus protocol for write mode . . . . . . . . . . . . . . . . .47

Fig 33. Bus protocol for read mode . . . . . . . . . . . . . . . . .47

Fig 34. Device diode protection diagram of PCF8523 . .47

Fig 35. I

C-bus timing diagram; rise and fall times

refer to 30 % and 70 % . . . . . . . . . . . . . . . . . . . .53

Fig 36. Supply voltage with respect to sampling and

comparing rate. . . . . . . . . . . . . . . . . . . . . . . . . . .53

Fig 37. RC network on pin V

. . . . . . . . . . . . . . . . . . . .54

Fig 38. Application diagram . . . . . . . . . . . . . . . . . . . . . . .55

Fig 39. Package outline SOT96-1 (SO8) of PCF8523T. .56

Fig 40. Package outline SOT909-1 (HVSON8)

of PCF8523TK. . . . . . . . . . . . . . . . . . . . . . . . . . .57

Fig 41. Package outline SOT402-1 (TSSOP14)

of PCF8523TS. . . . . . . . . . . . . . . . . . . . . . . . . . .58

Fig 42. Bare die outline of PCF8523U . . . . . . . . . . . . . . .59

Fig 43. Alignment mark . . . . . . . . . . . . . . . . . . . . . . . . . .60

Fig 44. Tape and reel details for PCF8523 . . . . . . . . . . .61

Fig 45. PCF8523U wafer information. . . . . . . . . . . . . . . .62

Fig 46. Film Frame Carrier (FFC) (for PCF8523U) . . . . .63

Fig 47. Temperature profiles for large and small

components. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

Fig 48. Footprint information for reflow soldering of

SOT96-1 (SO8) of PCF8523T. . . . . . . . . . . . . . . 66

Fig 49. Footprint information for reflow soldering of

SOT402-1 (TSSOP14) of PCF8523TS . . . . . . . . 67