TC72-2.8MMF datasheet(17/28 Pages) MICROCHIP

17 / 28 page

DS21743B-page 17

TC72

6.0

APPLICATIONS INFORMATION

The TC72 does not require any additional components

in order to measure temperature; however, it is

recommended that a decoupling capacitor of 0.1mF to

1mF be provided between the VDD and GND pins.

Although the current consumption of the TC72 is

modest (250 mA, typical), the TC72 contains an on

chip data acquisition with internal digital switching

circuitry. Thus, it is considered good design practice to

use an external decoupling capacitor with the sensor. A

high frequency ceramic capacitor should be used and

be located as close as possible to the IC power pins in

order to provide effective noise protection to the TC72.

The TC72 measures temperature by monitoring the

voltage of a diode located on the IC die. The IC pins of

the TC72 provide a low impedance thermal path

between the die and the PCB, allowing the TC72 to

effectively monitor the temperature of the PCB board.

The thermal path between the ambient air is not as

efficient because the plastic IC housing package

functions as a thermal insulator. Thus, the ambient air

temperature (assuming that a large temperature

gradient exists between the air and PCB) has only a

small effect on the temperature measured by the TC72.

Note that the exposed metal center pad on the bottom

of the DFN package is connected to the silicon

substrate. The center pad should be connected to

either the PCB ground plane or treated as a “No

Connect” pin. The mechanical dimensions of the center

pad

are

given

Section 7.0

“Packaging

Information” of this data sheet.

A potential for self-heating errors can exist if the TC72

SPI communication lines are heavily loaded. Typically,

the self-heating error is negligible because of the

relatively small current consumption of the TC72. A

temperature accuracy error of approximately +0.5°C

will result from self-heating if the SPI communication

pins sink/source the maximum current specified for the

TC72. Thus, to maximize temperature accuracy, the

output loading of the SPI signals should be minimized.

FIGURE 6-1:

Typical Application.

I/O

SCK

SDI

SCK

SDO

TC72

0.1µF

VDD

GND

VDD

PICmicro®

MCU

SDO

SDI

TC72-2.8MMF датащи(PDF) 17 Page - Microchip Technology

TC72-2.8MMF датащи(HTML) 17 Page - Microchip Technology

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28

датащи скачать

ссылки URL