National LM95235 User Manual
Revision A
April 14, 2006
LM95235 Evaluation Board User’s Guide
LM95235 Evaluation Board User’s Guide
© Copyright 2006 National Semiconductor Corporation 1 www.national.com
LM95235 Evaluation Board User’s Guide
Table of Contents
Table of Contents 2
References 3
1.0 Introduction 4
2.0 Quick Start 5
3.0 Functional Description 7
4.0 Software Installation and Operation 8
5.0 Electrical and Mechanical Specifications 9
5.1 Electrical Specifications 9
5.2 Electrical Schematic 9
5.3 Evaluation Board Layout 10
5.4 Bill of Materials 11
5.5 Mechanical Specifications 11
© Copyright 2006 National Semiconductor Corporation 2 www.national.com
LM95235 Evaluation Board User’s Guide
References
1. “LM95235 Precision Remote Diode Temperature Sensor With SMBus Interface and
TruTherm™ Technology” datasheet.
The latest copy of the LM95235 datasheet can be obtained by going to the National
Semiconductor website
www.national.com, by searching on “LM95235”, and then downloading
the LM95235.pdf file.
2. SensorEval Version 1.1.0a or later, Evaluation Board CD containing:
a. The SensorEval.exe executable program used to run the LM95235 Evaluation
Board.
b. A softcopy of this User’s Guide
c. A readme.txt file with useful information about the program.
d. A softcopy of the SensorEval Software manual.
© Copyright 2006 National Semiconductor Corporation 3 www.national.com
1.0 Introduction
The LM95235 Evaluation Board is used together
with the National Semiconductor SensorEval
software (provided in the kit), and with a USB cable
(not provided in the kit), and with an external
personal computer (PC). Power to the LM95235
Evaluation Board is provided by the +5 VDC line of
the USB connection. No external power supply or
signal sources are required for operation of the
LM95235 evaluation board.
Before connecting the PC to the LM95235
evaluation board through the USB cable, the PC is
first turned on and allowed to go through its boot-up
procedure. The user installs and initiates the
SensorEval software. See Section 4.0 for details.
After the SensorEval software is running, the user
can connect the USB cable first to the computer and
then to the LM95235 Evaluation Board.
The PC should be able to recognize the board and
the user simply selects the LM95235 Eval Board
radio button.
The block diagram below describes the LM95235
Evaluation Board itself. The USB input provides the
+5.0 VDC power to the board, which is regulated
down to 3.3 VDC to power the IC’s. The EEPROM
is programmed at the factory with a unique ID code
for this particular board. When the USB cable is
plugged in, the PC interrogates the USB devices and
can identify this device as the LM95235 Evaluation
Board.
The microcontroller on the board provides the serial
SMBus clock (SMBCLK), provides the SMBus data
(SMBDAT) signal, and relays the information from
the LM95235 to the PC via the USB lines.
The block in the lower right of the Block Diagram
shows the signals that are available to probe by the
user for the LM95235 device on the board.
1.1 Block Diagram
USB
Input
GND
Voltage
Regulator
Circuit
+5.0 VDC
+3.3 VDC
USB D+
USB D-
Microcontroller
Circuitry
U2
LM95235
SMBCLK
SMBDAT
EEPROM
Circuit
GND
VDD
SMBCLK
SMBDAT
T_Crit
OS/A0
GND
© Copyright 2006 National Semiconductor Corporation 4 www.national.com
GND
2.0 Quick Start
1. Install the CD into the CD drive of the computer
and install the SensorEval software (see Section
4.0).
2. Hookup the USB cable between the PC or
notebook computer and the LM95235EVAL
board as shown in Quick Start Diagram (See
Section 2.1).
3. Run the SensorEval software clicking the icon
on the desktop. The first screen after the
installation will look like this:
Select the LM95235 Evaluation Board.
Click OK.
5. The next screen will look like this:
If not, select “Another Device”. The next screen
should look like this:
Make sure that “4C” is selected in the upper left
Select LM95235 and click on Open button.
4. The next screen (first screen after the first run of
the program) will look like this:
© Copyright 2006 National Semiconductor Corporation 5 www.national.com
box labeled “I2C Addr”. Select “All Regs” in the
“Read Cont” box to read all of the registers,
including the temperature registers continuously.
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