LP3925 Datasheet, PDF (3/51 Pages) Texas Instruments – High Performance Power Management Unit for Handset Applications

COMPARATOR ELECTRICAL CHARACTERISTICS ....................................................................... 40
ADC ................................................................................................................................................. 40
A/D CONVERTER DATA AND CONTROL REGISTERS ................................................................... 40
BATTERY DISCHARGE CURRENT MEASUREMENT ..................................................................... 40
JUNCTION TEMPERATURE MEASUREMENT ............................................................................... 41
OTHER ITEM CURRENT VOLTAGE MEASUREMENT .................................................................... 41
ADC ELECTRICAL CHARACTERISTICS ....................................................................................... 41
Reference Output ............................................................................................................................... 42
REFERENCE BUFFER ELECTRICAL CHARACTERISTICS ............................................................. 42
UVLO Operation ................................................................................................................................. 42
Current Sinks ..................................................................................................................................... 42
Support Functions ............................................................................................................................... 43
REFERENCE ............................................................................................................................. 43
OSCILLATOR ............................................................................................................................. 43
THERMAL SHUTDOWN .............................................................................................................. 43
I²C-Compatible Serial Bus Interface ...................................................................................................... 44
INTERFACE BUS OVERVIEW ...................................................................................................... 44
DATA TRANSACTIONS ............................................................................................................... 44
START AND STOP ...................................................................................................................... 44
ACKNOWLEDGE CYCLE ............................................................................................................. 44
“ACKNOWLEDGE AFTER EVERY BYTE” RULE ............................................................................. 45
ADDRESSING TRANSFER FORMATS .......................................................................................... 45
CONTROL REGISTER WRITE CYCLE .......................................................................................... 45
CONTROL REGISTER READ CYCLE ........................................................................................... 45
REGISTER READ AND WRITE DETAIL ......................................................................................... 46
Physical Dimensions ........................................................................................................................... 48
List of Figures
FIGURE 1. Device Operating Modes ............................................................................................................ 12
FIGURE 2. Startup and Shutdown Sequences ................................................................................................ 13
FIGURE 3. Charging Cycle voltage and Current Plots ....................................................................................... 17
FIGURE 4. Charger Power Structure ............................................................................................................ 17
FIGURE 5. Charger Charging Cycle Operation Description ................................................................................. 18
FIGURE 6. Charger Internal Power Switch Operation Description When Charger is Off ............................................... 18
FIGURE 7. Charger Internal Power Switch Operation Description When Charger is On ............................................... 19
FIGURE 8. Charger Block Diagram .............................................................................................................. 20
FIGURE 9. Charger CC to CV Mode Transition Diagram .................................................................................... 20
FIGURE 10. Typical PWM Operation ............................................................................................................ 22
FIGURE 11. Typical ECO Operation ............................................................................................................ 22
FIGURE 12. Buck's Switches Controlling Diagram ........................................................................................... 23
FIGURE 13. Typical ECO Operation ............................................................................................................ 23
FIGURE 14. Typical Ripple in ECO Mode ...................................................................................................... 23
FIGURE 15. USB Transceiver Block Diagram ................................................................................................. 31
FIGURE 16. USB Transceiver Configured to 3-Pin Interface ............................................................................... 32
FIGURE 17. USB Transceiver Configured to 4-Pin Interface ............................................................................... 33
FIGURE 18. USB Transceiver Configured to 5-Pin Interface ............................................................................... 34
FIGURE 19. BBC IU Characteristics ............................................................................................................. 37
FIGURE 20. RTC Functional Block Diagram ................................................................................................... 38
FIGURE 21. SIM Interface Level Shifters ....................................................................................................... 40
FIGURE 22. LP3925 ADC Temperature Range ............................................................................................... 41
FIGURE 23. Typical REF_OUT BatteryTemperature MeasurementApplication Diagram .............................................. 42
FIGURE 24. Current Sinks PWM Control ....................................................................................................... 43
FIGURE 25. Bit Transfer ........................................................................................................................... 44
FIGURE 26. Start and Stop Conditions ......................................................................................................... 44
FIGURE 27. Bus Acknowledge Cycle ........................................................................................................... 44
FIGURE 28. Register Write Format .............................................................................................................. 46
FIGURE 29. Register Read Format .............................................................................................................. 46
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