TC1796
System Units (Vol. 1 of 2)
System Control Unit
User’s Manual
5-48
V2.0, 2007-07
SCU, V2.0
5.7
Die Temperature Sensor
The TC1796 provides an on-chip Die Temperature Sensor (DTS). The output voltage of
the DTS can be measured using analog input AIN31 of the ADC1 module. For measuring
the DTS output voltage, the following conditions must be met:
•
The DTS circuitry has to be enabled by setting SCU_CON.DTSON = 1. After
enabling the DTS, a settling time of about 10
µ
s has to be respected before starting
a DTS measurement.
•
Bit ADC1_CHCON15.EMUX[0] has to be set to 1 for channel 15 of ADC1.
•
The analog input AIN31 of ADC1 has to be requested for conversion (corresponding
GRPS = 1). With this request, the reference voltages of the DTS (
V
AREF_DTS
,
V
ANGD_DTS
) and the sensor output signal (
V
DTS
) are connected to ADC1 for AD
conversion.
Figure 5-10 Die Temperature Sensor Selection
The die temperature can be determined according to the equation:
(5.2)
The DTS operates with an accuracy of
±
10
°
C.
MCA05621
M
U
X
ADC1
AIN31
V
SSM
&
Die
Temp.
Sensor
DTS
EMUX
ADC1_CHCON15
DTSON
SCU_CON
= X1
B
0
1
= 1
M
U
X
V
AREF1
0
1
M
U
X
V
AGND1
0
1
V
AREF
V
AGND
Analog
channel 31
requested for
conversion
Enable
V
DTS
V
AREF_DTS
V
AGND_DTS
temp_ao[V] = 1.0 V + (die tempe 40
°
C) / 190