TMP05 Analog Devices, TMP05 Datasheet - Page 18

• Manufacturer Part Number: TMP05
• Description: 0.5C Accurate PWM Temperature Sensor in 5-Lead SC-70
• Manufacturer: Analog Devices

TMP05/TMP06
TEMPERATURE MONITORING
The TMP05/TMP06 are ideal for monitoring the thermal
environment within electronic equipment. For example, the
surface-mounted package accurately reflects the exact thermal
conditions that affect nearby integrated circuits.
The TMP05/TMP06 measure and convert the temperature at
the surface of their own semiconductor chip. When the TMP05/
TMP06 are used to measure the temperature of a nearby heat
source, the thermal impedance between the heat source and the
TMP05/TMP06 must be considered. Often, a thermocouple or
other temperature sensor is used to measure the temperature of
the source, while the TMP05/TMP06 temperature is monitored
by measuring T
mined, the temperature of the heat source can be inferred from
the TMP05/TMP06 output.
One example of using the TMP05/TMP06’s unique properties is
in monitoring a high power dissipation microprocessor. The
TMP05/TMP06 part, in a surface-mounted package, is mounted
directly beneath the microprocessor’s pin grid array (PGA)
package. In a typical application, the TMP05/TMP06’s output is
connected to an ASIC, where the pulse width is measured. The
TMP05/TMP06 pulse output provides a significant advantage in
this application, because it produces a linear temperature output
while needing only one I/O pin and without requiring an ADC.
H
and T
L
. Once the thermal impedance is deter-
0.1 µ F
0.1 µ F
V
V
DD
DD
TMP05 (U2)
TMP05 (U1)
V
GND
V
GND
DD
DD
CONV/IN
CONV/IN
FUNC
FUNC
OUT
OUT
V
V
DD
Figure 33. Typical Daisy-Chain Application Circuit
DD
T
0
T
H
(U1)
Rev. 0 | Page 18 of 28
T
T
L
0
T
(U1)
H
(U1)
START
PULSE
T
TIME
H
T
L
TIME
(U2)
(U1)
START
PULSE
T
DAISY-CHAIN APPLICATION
This section provides an example of how to connect two
TMP05s in daisy-chain mode to a standard 8052 microcon-
troller core. The ADuC812 is the microcontroller used in the
following example and has the 8052 as its core processing
engine. Figure 32 shows how to interface to the 8052 core
device. TMP05 Program Code Example 1 shows how to
communicate from the ADuC812 to the two daisy-chained
TMP05s. This code can also be used with the ADuC831 or any
microprocessor running on an 8052 core.
Figure 32 is a diagram of the input waveform into the ADuC812
from the TMP05 daisy chain, and it shows how the code’s
variables are assigned. It should be referenced when reading
TMP05 Program Code Example 1. Application notes are
available on the Analog Devices Web site showing the TMP05
working with other types of microcontrollers.
Figure 33 shows how the three devices are hardwired together.
Figure 34 to Figure 36 are flow charts for this program.
L
(U2)
TIMER T0
STARTS
START
PULSE
TEMP_HIGH0
Figure 32. Reference Diagram for Software Variables
TEMPSEGMENT = 1
INTO
in TMP05 Program Code Example 1
P3.7
P3.2/INTO
ADuC812
TEMP_LOW0
TEMPSEGMENT = 2 TEMPSEGMENT = 3
TEMP_HIGH1
INTO
TEMP_HIGH2
TEMP_LOW1
INTO