Datasheet
BETA COMPENSATION CONFIGURATION
TMP441
TMP442
SBOS425A – DECEMBER 2008 – REVISED MARCH 2009 ..............................................................................................................................................
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continue to be GND collector-connected in this mode,
REGISTER but no beta compensation is applied. When the beta
compensation configuration is set to '0111' or the
If the Beta Compensation Configuration Register is
sensor is diode-connected (base shorted to collector),
set to '1xxx' (beta compensation enabled) for a given
the η -factor used by the TMP441/42 is 1.008. When
channel at the beginning of each temperature
the beta compensation configuration is set to '1xxx'
conversion, the TMP441/42 automatically detects if
(beta compensation enabled) and the sensor is GND
the sensor is diode-connected or GND
collector-connected (PNP collector to ground), the
collector-connected, selects the proper beta range,
η -factor used by the TMP441/42 is 1.000. Table 8
and measures the sensor temperature appropriately.
shows the read values for the selected beta ranges
and the appropriate η -Factor used for each
If the Beta Compensation Configuration Register is
conversion.
set to '0111' (beta compensation disabled) for a given
channel, the automatic detection is bypassed and the
temperature is measured assuming a
diode-connected sensor. A PNP transistor may
Table 7. Conversion Rate Register
CONVERSION RATE REGISTER (Read/Write = 0Bh, POR = 07h)
AVERAGE I
Q
(TYP) ( µ A),
V
S
= 5.5V
R7 R6 R5 R4 R3 R2 R1 R0 CONVERSIONS/SEC TMP441 TMP442
0 0 0 0 0 0 0 0 0.0625 30 35
0 0 0 0 0 0 0 1 0.125 35 44
0 0 0 0 0 0 1 0 0.25 45 62
0 0 0 0 0 0 1 1 0.5 65 99
0 0 0 0 0 1 0 0 1 103 162
0 0 0 0 0 1 0 1 2 181 272
0 0 0 0 0 1 1 0 4 332 437
0 0 0 0 0 1 1 1 8
(1)
634 652
(1) Conversion rate depends on which channels are enabled.
Table 8. Beta Compensation Configuration Register
BCx3-BCx0 BETA RANGE DESCRIPTION N TIME
1000 Automatically selected range 0 (0.10 < beta < 0.18) 1.000 126ms
1001 Automatically selected range 1 (0.16 < beta < 0.26) 1.000 126ms
1010 Automatically selected range 2 (0.24 < beta < 0.43) 1.000 126ms
1011 Automatically selected range 3 (0.35 < beta < 0.78) 1.000 126ms
1100 Automatically selected range 4 (0.64 < beta < 1.8) 1.000 126ms
1101 Automatically selected range 5 (1.4 < beta < 9.0) 1.000 126ms
1110 Automatically selected range 6 (6.7 < beta < 40.0) 1.000 126ms
1111 Automatically selected range 7 (beta > 27.0) 1.000 126ms
1111 Automatically detected diode connected sensor 1.008 93ms
0000 Manually selected range 0 (0.10 < beta < 0.5) 1.000 93ms
0001 Manually selected range 1 (0.13 < beta < 1.0) 1.000 93ms
0010 Manually selected range 2 (0.18 < beta < 2.0) 1.000 93ms
0011 Manually selected range 3 (0.3 < beta < 25) 1.000 93ms
0100 Manually selected range 4 (0.5 < beta < 50) 1.000 93ms
0101 Manually selected range 5 (1.1 < beta < 100) 1.000 93ms
0110 Manually selected range 6 (2.4 < beta < 150) 1.000 93ms
0111 Manually disabled beta correction 1.008 93ms
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