|
LP3941 Datasheet, PDF (21/34 Pages) Texas Instruments – Cellular Phone Power Management Unit | |||
|
◁ |
Note 13: Registers hâ0c, hâ0d, hâ2e and hâ09 bits 3 and 4 are read only (R/O).
Note 14: Register hâ0d stores the status of ON, RTC_ALARM, CHG_IN and HF_PWR inputs at the time of PMIC power on event. The bits indicate why the device
turned on, and are static after the power on incident.
ON = 1 means the ON-input was logic high at the moment of power-up-sequence start.
RTC_ALARM = 1 indicates that RTC_ALARM-input was logic high when the power-up-sequence started.
CHG_IN = 1 indicates that external battery charger initiated the power-up-sequence. This also implies that the battery is connected (BSNS = 0V) and that battery
voltage is over 3.0V, because otherwise the circuit will not power up.
HF_POWER = 1 indicates HF_PWR was logic high when the power-up-sequence started.
0 in any register bit position means that the corresponding signal did not initiate the power-up sequence.
Multiple bits can be â1â at the same time if they simultaneously initiated the power-up-sequence.
Note 15: Register hâ2e shows the current status of comparator outputs, ADC block, ON-, RTC_ALARM and HF_PWR-inputs. Bit 3 of the register indicates if a
valid external battery charger is connected to the LP3941 at the moment. Register hâ2e is dynamic and shows the current status of these variables at all times.
COMP1/2 OUT = 1 means the corresponding comparator input is > threshold (see comparator specification).
ON, RTC_ALARM, HF_PWR = 1 indicates corresponding input pins are logic high.
CHARGER_PRESENT means CHG_IN pin has valid voltage for charging. (See charger specification.)
Note 16: For description on the operation of ADC Overflow and ADC Data Ready bits please see ADC specifications.
Regulator Output Voltage Programming
The following table summarizes the supported output voltages for LP3941A. Default voltages after start-up sequence have been
highlighted in bold.
Data Code
4hâ²00
4hâ²01
4hâ²02
4hâ²03
4hâ²04
4hâ²05
4hâ²06
4hâ²07
4hâ²08
4hâ²09
4hâ²0a
4hâ²0b
4hâ²0c
4hâ²0d
4hâ²0e
4hâ²0f
VO1
(V)
1.5
1.6
1.7
1.8
1.9
2.0
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
3.0
VO2
(V)
1.5
1.6
1.7
1.8
1.9
2.0
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
3.0
VO3
(V)
2.5
2.6
2.7
2.8
2.9
3.0
3.1
3.2
VO4
(V)
1.5
1.6
1.7
1.8
1.9
2.0
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
3.0
VO5
(V)
2.5
2.6
2.7
2.8
2.9
3.0
3.1
3.2
VO6
(V)
2.5
2.6
2.7
2.8
2.9
3.0
3.1
3.2
VO7
(V)
2.5
2.6
2.7
2.8
2.9
3.0
3.1
3.2
VO8
(V)
2.5
2.6
2.7
2.8
2.9
3.0
3.1
3.2
VO9
(V)
1.5
1.6
1.7
1.8
1.9
2.0
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
3.0
VO10
(V)
1.5
1.6
1.7
1.8
1.9
2.0
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
3.0
VO11
(V)
1.8
1.9
2.0
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
3.0
3.1
3.2
3.3
Register Programming Examples
Example 1. Setting register hâ00 value to 8hâffâ will enable
LDOs 1â8.
Example 2. Setting register hâ01 to 8hâ8câ will set LDO9 output
to 2.3V and LDO1 output to 2.7V. These voltages will appear
at the LDO outputs if the corresponding LDOs have been en-
abled. Programming a voltage value to a LDO, which is off,
will affect the LDO output voltage after the LDO is enabled.
Enabling and programming the output voltage are separate
operations.
Example 3. Setting register hâ09 bit â0â to â1â will disable the
main battery charger. Note that all register bits have to be
programmed together. It is not possible to program individual
bits alone. Writing into read only or unused bit positions does
not affect those bits nor does it cause errors. Therefore to
disable the main charger and to retain other bits in their default
values on would write 8hâ03â
ADC and Charger Programming
The following tables show how to select the main battery
charger End-Of-Charge current limit, how to set the charger
current limit and select a particular input for ADC measure-
ment. Default values have been highlighted in bold.
SEL-1
0
1
1
EOC Current Selection Code
SEL-0
1
ISET (mA)
0.1C
0
0.15C
1
0.2C
www.ti.com
20
200945 Version 4 Revision 2 Print Date/Time: 2011/10/25 13:09:13
|
▷ |