DA6505.005
11 June 2018
TEMPERATURE SENSOR CONFRIGURATION REGISTER (FB/7BHEX
)
Temperature
sensor
configuration
register
measured. To avoid signal clipping GAINT=1,
SGNGAINT=1 and OFST%= -28% settings must be
used in external diode temperature measurement.
(FB/7BHEX) is for configuring temperature sensing.
See table 7.
The TSENSOR bit selects between sensor bridge
resistance temperature sensing and external
temperature sensing diode.
Note that to select trim data from registers there
must be also set TRIM=01 or 10 in the Trim and
test register (FA/7AHEX). After power up the
default setting is TRIM=00 which selects all trim
data from EEPROM.
When using the sensor bridge resistance based
temperature sensing (TSENSOR=0) it is necessary
to trim sensor bridge resistance setting by the
RSENSOR bits. There are sixteen sensor bridge
resistance trim values available ranging from 1.89kΩ
to 9.86kΩ. These correspond to internal trim resistor
R3 values ranging typically from 10.1kΩ down to
2.14kΩ and which are used to balance the formed
temperature sensing bridge circuit. For more details
see chapter SENSOR BRIDGE RESISTANCE
TEMPERATURE SENSING .
The Sensor bridge resistance selection configuration
value need to be stored into Sensor bridge
resistance selection data EEPROM address
(BB/3BHEX) since by default (TRIM=00) the trimming
value is read from the EEPROM before every
temperature measurement.
See also chapters AFE AND ADC INPUT SIGNAL
RANGE DEFINITIONS, AFE GAIN AND ADC
OFFSET
TEMPERATURE
SELECTIONS,
DIODE
EXTERNAL
TEMPERATURE
When using the external temperature sensing diode
(TSENSOR=1) the external temperature diode is
connected between VDDS pin (diode anode) and TD
SENSING and SENSOR BRIDGE RESISTANCE
TEMPERATURE SENSING which describe
pin
(diode
cathode).
During
temperature
temperature sensing signals and how the GAIN and
OFS settings define the sensor input signal range.
measurement the MAS6505 sinks a constant 10 µA
bias current from the temperature sensing diode and
the temperature dependent diode forward voltage is
Table 7. Temperature sensor configuration register (FB/7BHEX) description
Bit
Bit Name
Description
Value
Function
Number
7-5
4
-
-
X
0
1
-
TSENSOR
Temperature sensor selection
Sensor bridge resistance temperature sensing
External temperature sensing diode
R3=10110 Ω (Rsensor=1890 Ω)
R3=9890 Ω (Rsensor=2110 Ω)
R3=9644 Ω (Rsensor=2356 Ω)
R3=9370 Ω (Rsensor=2630 Ω)
R3=9064 Ω (Rsensor=2936 Ω)
R3=8722 Ω (Rsensor=3278 Ω)
R3=8340 Ω (Rsensor=3660 Ω)
R3=7914 Ω (Rsensor=4086 Ω)
R3=7438 Ω (Rsensor=4562 Ω)
R3=6907 Ω (Rsensor=5093 Ω)
R3=6314 Ω (Rsensor=5686 Ω)
R3=5652 Ω (Rsensor=6348 Ω)
R3=4912 Ω (Rsensor=7088 Ω)
R3=4087 Ω (Rsensor=7913 Ω)
R3=3166 Ω (Rsensor=8834 Ω)
R3=2137 Ω (Rsensor=9863 Ω)
3-0
RSENSOR
Sensor bridge resistance trim
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1110
1111
X = Don’t care
22 (44)
MAS [ MICRO ANALOG SYSTEMS ]
