Datasheet

TMP105
0.1 Fm
V+
GND
A2
B2
C1
ALERT
(Output)
C2
A0
B1
A1
SCL
SDA
To
Two-Wire
Controller
I/O
Control
Interface
SCL
SDA
Temperature
Register
Configuration
Register
T
LOW
Register
T
HIGH
Register
Pointer
Register
TMP105
www.ti.com SLLS648D –FEBRUARY 2005– REVISED SEPTEMBER 2011
APPLICATIONS INFORMATION
The TMP105 is a digital temperature sensor that is optimal for thermal management and thermal protection
applications. The TMP105 is Two-Wire and SMBus interface-compatible, and is specified over a temperature
range of –40°C to +125°C.
The TMP105 requires no external components for operation except for pull-up resistors on SCL, SDA, and
ALERT, although a 0.1μF bypass capacitor is recommended, as shown in Figure 1. SCL, SDA and ALERT can
be tied to a 1.8V supply or V+ through pull-up resistors. A0 should be tied to V+ or GND.
Note: SCL, SDA, and ALERT pins require pull-up resistors.
Figure 1. Typical Connections of the TMP105
The sensing device of the TMP105 is the chip itself. Thermal paths run through the package leads. The lower
thermal resistance of metal causes the leads to provide the primary thermal path.
To maintain accuracy in applications requiring air or surface temperature measurement, care should be taken to
isolate the package and leads from ambient air temperature.
POINTER REGISTER
Figure 2 shows the internal register structure of the TMP105. The 8-bit Pointer Register of the devices is used to
address a given data register. The Pointer Register uses the two LSBs to identify which of the data registers
should respond to a read or write command. Table 1 identifies the bits of the Pointer Register byte. Table 2
describes the pointer address of the registers available in the TMP105. Power-up reset value of P1/P0 is 00.
Figure 2. Internal Register Structure of the TMP105
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