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20 TEMPERATURE SENSOR/REFERENCE VOLTAGE GENERATOR (TSRVR)
20.2.2 External Connections
Figure 20.2.2.1 shows connection diagrams between the TSRVR and external components.
S1C31
TSRVR
VREFAm
Ch.n
ADINmx
A/D
ADINm0
converter
Ch.m
ADINmy
(1) When an external device is not connected
Figure 20.2.2.1 Connections between TSRVR and External Components
20.3 Operations
TSRVR should be configured before starting measurements using the internal A/D converter.
20.3.1 Reference Voltage Setting
The TSRVR output voltage can be supplied to the internal A/D converter as the reference voltage VREFAm when
it is not supplied externally. The output voltage can be selected using the TSRVR_nVCTL.VREFAMD[1:0] bits.
Connect C
to the VREFAm pin when supplying the reference voltage from TSRVR. A/D conversion by the
VREFA
internal A/D converter should be started after the reference voltage stabilization time t
time when the output voltage is selected.
20.3.2 Temperature Sensor Setting
The temperature sensor output voltage can be directly measured using the internal A/D converter. The measure-
ment should be started after the temperature sensor output stabilization time t
TSRVR_nTCTL.TEMPEN bit to activate the temperature sensor.
From the temperature sensor output voltage, the measured temperature can be calculated by the equations shown
below.
(V
- V
TSEN
TREF
T
= — — — — — — — — — — — — — — + T
SEN
TEMP
DV
Where
T
:
Actual temperature [°C]
SEN
V
: Temperature sensor output voltage at temperature T
TSEN
T
:
Reference temperature for calibration [°C]
REF
V
: Temperature sensor output voltage at temperature T
TREF
: Temperature sensor output voltage temperature coefficient [mV/°C] (Refer to the "Electrical Char-
TEMP
DV
acteristics" chapter.)
Convert the digital values corresponding to the respective temperatures, that are obtained by the internal A/D con-
verter, into voltage values and assign them to V
ADD
V
= — — — — — × V
(TSEN, TREF)
4,096
Where
ADD:
A/D conversion result at temperature T
V
: A/D converter reference voltage [V]
REFA
For details of the internal A/D converter, refer to the "12-bit A/D Converter" chapter.
20-2
2.0 V or 2.5 V
C
VREFA
) × 1,000
REF
and V
TSEN
REFA
Seiko Epson Corporation
S1C31
TSRVR
VREFAm
Ch.n
ADINmx
A/D
ADINm0
converter
Ch.m
ADINmy
(2) When an external device is connected
TEMP
(Eq. 20.1)
[V]
SEN
[V]
REF
.
TREF
(Eq. 20.2)
or T
(decimal)
SEN
REF
2.0 V or 2.5 V
C
VREFA
V
CC
Sensor output
Sensor
device
has elapsed from the
VREFA
has elapsed from writing 1 to the
S1C31D41 TECHNICAL MANUAL
(Rev. 1.1)
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