SWCS045B
– SEPTEMBER 2010 – REVISED JUNE 2011
General-purpose conversions do not require a result granularity in time lower than the duration of the
all-channels conversion sequences. While requiring a general-purpose conversion, there is no need to specify
channels: all channels are converted. This request is active when a write access to the toggle bit SP1 in the
GPADC
register
occurs,
and
an
INT
interrupt
is
generated
after
the
conversion
sequence.
A
GPADC_START-initiated conversion (SRT) has a higher priority than the software-initiated conversions.
If a software request occurs while a GPADC_START-initiated sequence (SRT) is running, the software request is
placed on hold and the ongoing real-time sequence continues until it completes and the converted data is stored
in the real-time dedicated registers. An INT interrupt is then generated and sent to the processor. The digital
control executes the software request when the real-time sequence of conversions completes. An INT interrupt is
then generated.
Channels description
The different ADC channels are summarized in the following table.
CH
TYPE
POWER DOMAIN
SCALER
OPERATION
0
External
VRTC
No
Battery type, resistor value
1
External
VRTC
No
Battery temperature, NTC resistor value
2
External
Special
1.875/1.25 V
Audio accessory/general purpose
3
External
VANA
No
General purpose
Temperature measurement/general
4
External
VANA
No
purpose
5
External
VANA
No
General purpose
6
External
VANA
No
General purpose
7
Internal
5/1.25 V or 6.25/1.25 V
Main battery
8
Internal
6.25/1.25 V
Backup battery
9
Internal
11.25/1.25 V
External charger input
10
Internal
6.875/1.25 V
VBUS
11
Internal
1.875/1.25 V
VBUS charging current
12
Internal
No
Die temperature
13
Internal
No
Die temperature
14
Internal
6.875/1.25 V
USB ID line
15
Internal
6.25/1.25 V
Test network
16
Internal
4.75/1.25 V
Test network
NOTE
Channel 11 scalar (ICHG) is placed in the analog charger and always enabled.
Channel 11 operational amplifier and path switch is located in the analog GPADC and
controllable with the GPADC_SCALER_EN_CH11 register bit.
VANA must be on to avoid leakage on GP inputs 3, 4, 5, and 6.
It is currently not possible to measure GPADC_IN2 up to 1.25 V, without enabling the scalar first
(up to 1.875 V).
The following equation provides the relationship between TWL6030 IC die junction temperature and the GPADC
registers read data: Tj(°C) = (GPADC
10CODE–671) × 0.465 + 27
with the following parameters:
GPADC10CODE is the decimal code read from the GPADC register.
671 is the decimal code read from the GPADC register when the junction temperature is 27
°C.
0.465 is the linear temperature
– GPADC code coefficient.
Examples:
Tj(–40°C) = (525-671) × 0.465 + 27 = –40.89°C
Tj(+125°C) = (878-671) × 0.465 + 27 = 123.25°C
Copyright
2010–2011, Texas Instruments Incorporated
79