TMP451

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SBOS686 – JUNE 2013

Configuration Register

configuration register sets the temperature range, the ALERT/THERM modes, and controls the shutdown mode.

The configuration register is set by writing to pointer address 09h, and read by reading from pointer address 03h.

Table 5 summarizes the bits of configuration register.

Table 5. Configuration Register Bit Descriptions

CONFIGURATION REGISTER (READ = 03h, WRITE = 09h, POR = 00h)

BIT NUMBER

NAME

FUNCTION

POWER-ON RESET VALUE

0 = ALERT Enabled

7

MASK1

0

1 = ALERT Masked

0 = Run

6

SD

0

1 = Shut down

0 = ALERT

5

ALERT/THERM2

0

1 = THERM2

4:3

Reserved

—

0

0 = 0°C to +127°C

2

RANGE

0

1 = –64°C to +191°C

1:0

Reserved

—

0

MASK1 (bit 7) of the configuration register masks the ALERT output. If MASK1 is '0' (default), the ALERT output

is enabled. If MASK1 is set to '1', the ALERT output is disabled. This configuration applies only if the value of

ALERT/THERM2 (bit 5) is '0' (that is, pin 6 is configured as the ALERT output). If pin 6 is configured as the

THERM2 output, the value of the MASK1 bit has no effect.

The shutdown bit (SD, bit 6) enables or disables the temperature-measurement circuitry. If SD = '0' (default), the

TMP451 converts continuously at the rate set in the conversion rate register. When SD is set to '1', the TMP451

stops converting when the current conversion sequence is complete and enters a shutdown mode. When SD is

set to '0' again, the TMP451 resumes continuous conversions. When SD = '1', a single conversion can be started

by writing to the one-shot start register. See the One-Shot Conversion section for more information.

ALERT/THERM2 (bit 5) sets the configuration of pin 6. If the ALERT/THERM2 bit is '0' (default), then pin 6 is

configured as the ALERT output; if it is set to '1', then pin 6 is configured as the THERM2 output.

The temperature range is set by configuring RANGE (bit 2) of the configuration register. Setting this bit low

(default) configures the TMP451 for the standard measurement range (0°C to +127°C); temperature conversions

are stored in the standard binary format. Setting bit 2 high configures the TMP451 for the extended measurement

range (–64°C to +191°C); temperature conversions are stored in the extended binary format (see Table 1).

The remaining bits of the configuration register are reserved and must always be set to '0'. The power-on reset

value for this register is 00h.

Copyright © 2013, Texas Instruments Incorporated

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