Datasheet

300 1.008
=300 ( )ADJUST
eff
N
n
-
g
1.008 300
=
(300 )
eff
ADJUST
n
N
-
g
2
2 1
1
ln( )
BE BE
nkT I
V V
q I
- =
TMP411-Q1
www.ti.com SBOS527F –DECEMBER 2010–REVISED NOVEMBER 2013
N-FACTOR CORRECTION REGISTER
The n-correction value must be stored in twos-
complement format, yielding an effective data range
The TMP411-Q1 allows for a different n-factor value
from −128 to 127, as shown in Table 9. The n-
to be used for converting remote-channel
correction value may be written to and read from
measurements to temperature. The remote channel
pointer address 18h. The register power-on-reset
uses sequential current excitation to extract a
value is 00h, thus having no effect unless written to.
differential V
BE
voltage measurement to determine
the temperature of the remote transistor. Equation 1
Table 9. N-Factor Range
relates this voltage and temperature.
N
ADJUST
N
BINARY HEX DECIMAL
(1)
0111 1111 7F 127 1.747977
0000 1010 0A 10 1.042759
The value n in Equation 1 is a characteristic of the
particular transistor used for the remote channel. The
0000 1000 08 8 1.035616
default value for the TMP411-Q1 is n = 1.008. The
0000 0110 06 6 1.028571
value in the N-Factor Correction Register may be
0000 0100 04 4 1.021622
used to adjust the effective n-factor according to
0000 0010 02 2 1.014765
Equation 2 and Equation 3.
0000 0001 01 1 1.011371
0000 0000 00 0 1.008
(2)
1111 1111 FF −1 1.004651
1111 1110 FE −2 1.001325
1111 1100 FC −4 0.994737
(3)
1111 1010 FA −6 0.988235
1111 1000 F8 −8 0.981818
1111 0110 F6 −10 0.975484
1000 0000 80 −128 0.706542
MINIMUM AND MAXIMUM REGISTERS
The TMP411-Q1 stores the minimum and maximum temperature measured since power on, chip reset, or
minimum and maximum register reset for both the local and remote channels. The Local Temperature Minimum
Register may be read by reading the high byte from pointer address 30h and the low byte from pointer address
31h. The Local Temperature Minimum Register may also be read by using a two-byte read command from
pointer address 30h. The Local Temperature Minimum Register is reset at power on, by executing the chip-reset
command, or by writing any value to any of pointer addresses 30h through 37h. The reset value for these
registers is FFh/F0h.
The Local Temperature Maximum Register may be read by reading the high byte from pointer address 32h and
the low byte from pointer address 33h. The Local Temperature Maximum Register may also be read by using a
two-byte read command from pointer address 32h. The Local Temperature Maximum Register is reset at power
on by executing the chip reset command, or by writing any value to any of pointer addresses 30h through 37h.
The reset value for these registers is 00h/00h.
The Remote Temperature Minimum Register may be read by reading the high byte from pointer address 34h and
the low byte from pointer address 35h. The Remote Temperature Minimum Register may also be read by using a
two-byte read command from pointer address 34h. The Remote Temperature Minimum Register is reset at
power on by executing the chip reset command, or by writing any value to any of pointer addresses 30h through
37h. The reset value for these registers is FFh/F0h.
The Remote Temperature Maximum Register may be read by reading the high byte from pointer address 36h
and the low byte from pointer address 37h. The Remote Temperature Maximum Register may also be read by
using a two-byte read command from pointer address 36h. The Remote Temperature Maximum Register is reset
at power on by executing the chip reset command, or by writing any value to any of pointer addresses 30h
through 37h. The reset value for these registers is 00h/00h.
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