TC72(2011) Ver la hoja de datos (PDF) - Microchip Technology
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TC72 Datasheet PDF : 28 Pages
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TC72
5.0 INTERNAL REGISTER
STRUCTURE
TC72 registers are listed below.
TABLE 5-1: REGISTERS FOR TC72
Register
Read Write Bit Bit Bit Bit Bit Bit Bit Bit
Address Address 7 6 5
4
321
0
Control
LSB Temperature
MSB Temperature
Manufacturer ID
00hex
01hex
02hex
03hex
80hex
N/A
N/A
N/A
0 0 0 One-Shot 0 1 0 Shutdown
(OS)
(SHDN)
T1 T0 0
0
000
0
T9 T8 T7
T6
T5 T4 T3
T2
0 10
1
010
0
Value on
POR/BOR
05hex
00hex
00hex
54hex
5.1 Control Register
The Control register is both a read and a write register
that is used to select either the Shutdown, Continuous
or One-Shot Conversion operating mode. The Temper-
ature Conversion mode selection logic is shown in
Table 5-2. The Shutdown (SHDN) bit is stored in bit 0
of the Control register. If SHDN is equal to ‘1’, TC72 will
go into power-saving Shutdown mode. If SHDN is
equal to ‘0’, TC72 will perform a temperature
conversion approximately every 150 ms.
At power-up, the SHDN bit is set to ‘1’. Thus, TC72 is
in Shutdown operating mode at startup. Continuous
Temperature Conversion mode is selected by writing a
‘0’ to the SHDN bit of the Control register.
Shutdown mode can be used to minimize the power
consumption of TC72 when active temperature
monitoring is not required. The Shutdown mode
disables the temperature conversion circuitry;
however, the serial I/O communication port remains
active. A temperature conversion will be initialized by a
Write operation to the Control register to select either
the Continuous Temperature Conversion or the One-
Shot operating mode. The temperature data will be
available in the MSB and LSB Temperature registers
approximately 150 ms after the Control register Write
operation.
One-Shot mode is selected by writing a ‘1’ into bit 4 of
the Control register. The One-Shot mode performs a
single temperature measurement and returns to the
power-saving Shutdown mode. After completion of the
temperature conversion, the One-Shot bit (OS) is reset
to ‘0’ (i.e. “OFF”). The user must set the One-Shot bit
to ‘1’ to initiate another temperature conversion.
Bits 1, 3, 5, 6 and 7 of the Control register are not used
by TC72. Bit 2 is set to a logic ‘1’. Any write operation
to these bit locations will have no affect on the
operation of TC72.
5.2 Temperature Register
The Temperature register is a read-only register and
contains a 10-bit two’s complement representation of
the temperature measurement. Bit 0 through Bit 5 of
the LSB Temperature register are always set to a logic
‘0’.
At Power-On Reset (POR) or a Brown-Out Reset
(BOR) low voltage occurrence, the temperature regis-
ter is reset to all zeroes, which corresponds to a tem-
perature value of 0°C. A VDD power supply less than
1.6V is considered a reset event and will reset the
Temperature register to the power-up state.
5.3 Manufacturer ID Register
The Manufacturer Identification (ID) register is a read-
only register used to identify the temperature sensor as
a Microchip component.
TABLE 5-2: CONTROL REGISTER TEMPERATURE CONVERSION MODE SELECTION
Operational Mode
One-Shot (OS) Bit 4
Shutdown (SHDN) Bit 0
Continuous Temperature Conversion
0
0
Shutdown
0
1
Continuous Temperature Conversion
1
0
(One-Shot Command is ignored if SHDN = ‘0’)
One-Shot
1
1
© 2011 Microchip Technology Inc.
DS21743B-page 15
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