DA6505.005
11 June 2018
TEMPERATURE GAIN TRIM REGISTER (FD/7DHEX
)
Temperature gain trim register (FD/7DHEX) is for
configuring analog front end (AFE) gain (GAINT)
setting for the temperature measurement. There are
32 selectable gain options from 1x (0dB) to 55.8x
(34.9dB). The gain setting 1x bypasses the AFE and
connects the input signal directly to the ADC input.
See table 9.
default setting is TRIM=00 which selects all trim
data from EEPROM.
The Temperature gain trim value needs to be stored
into Temperature gain trim data EEPROM address
(BD/3DHEX) since by default (TRIM=00) the trimming
value is read from the EEPROM before every
temperature measurement.
The polarity of temperature measurement gain is
selected by additional sign bit (SGNGAINT).
See also chapters AFE AND ADC INPUT SIGNAL
RANGE DEFINITIONS and AFE GAIN AND ADC
OFFSET SELECTIONS which describes how the
GAIN and OFS settings define the sensor input
signal range and how to choose optimal values.
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
Table 9. Temperature gain trim register (FD/7DHEX) description
Bit
Bit Name
Description
Value Function
Number
7-6
-
-
X
-
5
SGNGAINT Temperature Measurement Gain Sign
GAINT Temperature Measurement Gain
0
1
Positive
Negative
4-0
00000 1x (0dB), ISRT=1400mVpp
00001 4.7x (13.4dB), ISRT=298mVpp
00010 5.1x (14.2dB), ISRT=275mVpp
00011 5.6x (15dB), ISRT=250mVpp
00100 6x (15.6dB), ISRT=233mVpp
00101 6.5x (16.3dB), ISRT=215mVpp
00110 7.1x (17dB), ISRT=197mVpp
00111 7.7x (17.7dB), ISRT=182mVpp
01000 8.4x (18.5dB), ISRT=167mVpp
01001 9.1x (19.2dB), ISRT=154mVpp
01010 9.9x (19.9dB), ISRT=141mVpp
01011 10.7x (20.6dB), ISRT=131mVpp
01100 11.6x (21.3dB), ISRT=121mVpp
01101 12.6x (22dB), ISRT=111mVpp
01110 13.8x (22.8dB), ISRT=101mVpp
01111 14.9x (23.5dB), ISRT=94mVpp
10000 16.2x (24.2dB), ISRT=86.4mVpp
10001 17.6x (24.9dB), ISRT=79.5mVpp
10010 19.1x (25.6dB), ISRT=73.3mVpp
10011 20.7x (26.3dB), ISRT=67.6mVpp
10100 22.5x (27dB), ISRT=62.2mVpp
10101 24.5x (27.8dB), ISRT=57.1mVpp
10110 26.6x (28.5dB), ISRT=52.6mVpp
10111 28.8x (29.2dB), ISRT=48.6mVpp
11000 31.3x (29.9dB), ISRT=44.7mVpp
11001 34x (30.6dB), ISRT=41.2mVpp
11010 36.9x (31.3dB), ISRT=37.9mVpp
11011 40.1x (32.1dB), ISRT=34.9mVpp
11100 43.5x (32.8dB), ISRT=32.2mVpp
11101 47.3x (33.5dB), ISRT=29.6mVpp
11110 51.3x (34.2dB), ISRT=27.3mVpp
11111 55.8x (34.9dB), ISRT=25.1mVpp
X = Don’t care
Note: Corresponding temperature measurement input signal range at sensor input is ISRT=ISRADC/GAINT=1400mVpp/GAINT at
VDDS=1.68V
24 (44)
MAS [ MICRO ANALOG SYSTEMS ]
