MC13783VKR2 Datasheet, PDF (38/50 Pages) Freescale Semiconductor, Inc – Power Management and Audio Circuit

Functional Description
Table 23. Voltage and Current Settings
Parameter
Set Points
Regulated charge voltage at BP Programmable voltage setting of 3.80/4.05/4.15/4.20/4.25/4.30/4.375/4.50V.
Regulated charge current
through M1M2
Programmable current from 0 to 1600 mA in 14 steps, and fully on mode.
Internal trickle charge current Programmable current from 0 to 84mA in steps of 12mA.
4.4.1.2 Charger Operation
4.4.1.2.1 CEA-936-A
The CEA-936-A carkit specification allows a USB connection to be used not only as an USB interface but
also as a generic supply plus analog audio interface. The purpose is to standardize the carkit interface over
a USB connection. The USB VBUS line in this case is used to provide a supply within the USB voltage
limits and with at least 500 mA of current drive capability. However, this also opens the possibility to create
a range of USB compatible wall chargers, referred to as CEA-936-A charger in the remainder of this
chapter. The CEA-936-A standard also allows providing a supply from the phone to the accessory over the
VBUS line, just like in the USB on the go case.
4.4.1.2.2 Standalone Trickle Charging
The MC13783 has a standalone trickle charge mode of operation in order to ensure that a completely dis-
charged battery can be charged without the Microprocessor's control. Upon plugging a valid charger to
the phone, the trickle cycle is started. For battery voltages below 2.7 V, the trickle charge current level is
set at 70 mA. When the battery voltage increases above the threshold, the trickle charge level is increased
to 266 mA. When the battery voltage rises above the threshold sufficient for phone operation, a power up
sequence is automatically initiated. Even after the phone has powered up, the Standalone trickle charge
will remain on until software enables charging. If the battery voltage was already greater than the voltage
needed for phone operation when a charger is attached, the phone will power up immediately without
starting a trickle charge cycle. The trickle charge is terminated upon charge completion, time out, or by
software control.
For the single path charging configuration, standalone trickle charging is only available for the SE1 = LOW
condition. The charge level remains constant at the lower 70 mA threshold through all battery voltage
ranges—that is, there is no increased charge current at the 2.7 V threshold.
Standalone Trickle charging is not available for the SE1 = HIGH / Single Path charging case.
4.4.1.3 Coin Cell
The coin cell charger circuit will function as a current-limited voltage source, resulting in the CC/CV taper
characteristic typically used for rechargeable Lithium-Ion batteries. The output voltage is selectable. The
coin cell charger voltage is programmable in the ON state. In the User Off modes, or in the Off state, the
coincell charger will continue to charge to the predefined voltage setting but at a lower maximum current.
In practice, this means that if in Off state the coin cell is fully charged, the coin cell charger will only
MC13783 Technical Data, Rev. 3.5
38
Freescale Semiconductor