WM8350GEB/RV Wolfson Microelectronics, WM8350GEB/RV Datasheet - Page 161

• Manufacturer Part Number: WM8350GEB/RV
• Description: Audio CODECs Audio CODEC plus pwr management
• Manufacturer: Wolfson Microelectronics

Specifications of WM8350GEB/RV

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Production Data
w
The battery charger target voltage is set by the CHG_VSEL field, as defined in Table 104.
R12 (0Ch)
Power Mgmt
(5)
R168 (A8h)
Battery charger
control 1
R169 (A9h)
Battery charger
control 2
Note: CHG_ENA can be accessed through R9 or through R168. Reading from or writing to either
register location has the same effect.
Table 104 Battery Charger Control
17.7.3
Trickle charging is enabled by default when the Wall (LINE) or USB pins are selected as the power
source. It is autonomously initiated, supervised and terminated by the WM8350, without requiring any
intervention by the host processor.
By default, trickle charging is initiated when the battery voltage is below the battery charge voltage
CHG_VSEL by more than 100mV. Setting the CHG_FRC bit allows trickle charging to be initiated at
higher battery voltages.
The trickle charge current is set by the CHG_TRICKLE_SEL field, as described in Table 105.
A choke circuit is provided to enhance the trickle charge current control. This allows the charge
current to be modified according to temperature conditions or according to the USB current limit
restrictions.
If the WM8350 temperature is above 115°C and trickle charge temperature choking is enabled, then
charging is interrupted for at least 8 seconds and until the temperature has fallen below the
threshold. If trickle charge temperature choking is not enabled, then charging continues. (Note that
the device shutdown temperature is set at 140°C - this threshold cannot be disabled.) Trickle charge
temperature choking is controlled by the CHG_TRICKLE_TEMP_CHOKE register bit.
If the USB current limit cannot support the charge current demanded by CHG_TRICKLE_SEL and
USB current choking is enabled, then the charge current will be modified, where possible, in order to
continue charging. The trickle charge current cannot be controlled dynamically - the only possible
charge currents are 50mA or 100mA. Therefore, the only form of USB choking in trickle charge mode
is for a demanded current of 100mA to be reduced to 50mA. Trickle charge USB current choking is
controlled by the CHG_TRICKLE_USB_CHOKE register bit. The time constant for the charger’s
attempts to increase the current after USB choking can be controlled by CHG_RECOVERY_T.
ADDRESS
TRICKLE CHARGING
BIT
5:4
15
15
14
9
CHG_ENA
CHG_ACTIVE
CHG_PAUSE
CHG_VSEL
[1:0]
LABEL
DEFAULT
00
1
0
0
CHG_ENA bit selects battery charger
current control
0 = Set battery charger current to zero
1 = Enable battery charge control
Protected by security key.
Charger Status.
0 = Battery Charging is inactive
1 = Battery Charging is active
(Note CHG_ENA is just a request; the
WM8350 determines if the conditions are
satisfied for Battery Charging).
Charger pause:
0 = Don't pause the charger
1 = Pause charging
Battery charge voltage:
00 = 4.05V
01 = 4.1V
10 = 4.15V
11 = 4.2V
PD, February 2011, Rev 4.4
DESCRIPTION
WM8350
161