National LM95235 User Manual

Revision A

April 14, 2006

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.

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

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:

box labeled “I2C Addr”. Select “All Regs” in the “Read Cont” box to read all of the registers, including the temperature registers continuously.

6. The Screen should look like this:

Local (on-chip) and remote temperatures should read continuously. The user can experiment with the different settings of Address BF.

7. If the user clicks the 06-FF tab the next screen

will look like this:

. The user can also select the 3904 diode or the

processor thermal diode called “90 nm”.

The user can experiment with the Mask settings. Also the user can change the conversion rate. The next screen shows the possibilities for the Conversion Rate.

8. If the user clicks on the Start Plot button a graph box will appear and will graph the temperature. An example is shown below

9. If the user selects the Start Log button the following screen will appear. The user then enters the filename that he chooses to log the data into.

2.1 Quick Start Diagram

Important! NO EXTERNAL POWER SUPPLY OR SIGNAL INPUTS ARE RE QUIRED!

Computer

with

SensorEval

software

loaded

USB Cable to

Computer

National Semiconductor

LM95235 Evaluation Board Rev. 1

LM95235

N/C

TCRIT#

N/C

OS/A0

SCL

SDA

+3.3

JP2

3.0 Functional Description

The LM95235 Evaluation Board, along with the SensorEval Software, provides the system designer with a convenient way to learn about the operation of the LM95235 Temperature Sensor chip. The user simply has to install the SensorEval software on his PC, run it, connect the USB cable from the PC to the Evaluation Board, and the user can read the temperatures. It’s that simple! The user doesn’t have to provide any power or external signals to the evaluation board.

3.1 LM95235 Evaluation Board Connection Table

Connector Label Pin

Number

J1 N/A

1

USB Cable Input. Connect the USB cable to this jack after the SensorEval software has been loaded on the PC. V

. The +3.3 VDC voltage supplied by the on-board

DD

voltage regulator to the LM95235 V

connect an external power supply to this pin!

Power to the LM95235 Evaluation Board is taken from the USB 5-Volt line. This +5 VDC is the input to the on-board LM2950 low dropout voltage regulator, which regulates the output voltage to +3.3 VDC. This output voltage powers the LM95235, the on-board microcontroller, and the EEPROM chip where the board ID information is stored.

The microcontroller provides the SMBus Clock (SMBCLK) signal and the SMBus Data (SMBDAT) signal to the LM95235 chip. This communication between the LM95235 and the PC USB data lines is controlled by the microcontroller. For all of the details of this communication protocol see the latest LM95235 datasheet, available at www.national.com.

Description

input pin. Do not

DD

Output header provides

user with signals for test

purposes only.

Do not apply any

external power or

signals to any of the

pins on these headers!

Connection to

temperature diodes

Do not apply any

external power or

signals to any of the

pins on these headers!

JP2

J4

2 SMBDAT. Data signal for the SMBus.

3 SMBCLK. Clock signal for SMBus.

OS#/A0. When this pin is pulled low it enables the

4

5 No Connection.

6

7 No Connection.

3, 4 Connect for D+ connection

1, 2 Connect for D- connection

Overtemperature Shutdown (OS) feature. When this pin is pulled high it is the Address pin function.

T_Crit#. This is the signal that goes low when the Set Temperature is exceeded.

4.0 Software Installation and Operation

4.1 Installation

The CD provided in the LM95235 Evaluation Board Kit contains the SensorEval software used to make the LM95235 Evaluation Board operate with the user’s PC. It is assumed that the user will be using a PC with a Pentium® III or higher processor and Microsoft Windows® XP/2000/98/ME operating system.

The software is installed as follows:

1. Insert the SensorEval CD into the CD drive of the

PC. See details in the readme.txt file.

2. The software manual, provided on the CD, may be

useful to the user during this process.

3. Follow all of the Installation instructions in the

windows as the SensorEval software is installing.

4. The installation process will put an icon on the PC

desktop so that the SensorEval program will run when the icon is double-clicked.

4.2 Operation

Follow the following procedure for operation the LM95235 Evaluation Board using the SensorEval software:

1. Run the SensorEval program by either double-

clicking on the icon on the desktop or by selecting Start, Program Files, National Semiconductor, SensorEval.

2. Plug in the USB cable on both the PC and the

LM95235 Evaluation Board.

Follow the register setup steps given in section 2.0 Quick Start of this User’s Guide. Make sure that you are following the given procedure for the specific evaluation board you are working with.

Refer to the electrical schematic, layout and connector diagrams for proper connections to external remote thermal diodes.

7

5

.0 Electrical and Mechanical Specifications

5.1 Electrical Specifications

Power Requirements

The Board uses the +5.0 VDC and GND lines from the USB connection.

This +5.0 VDC voltage is regulated down to +3.3 VDC for board power.

* NO EXTERNAL POWER SUPPLY INPUTS ARE REQUIRED *

5.2 Electrical Schematic

+ 3.3 VDC

Use a 0.1 uF capacitor for each Vcc pin of U2 and Reserved_6 pin.

L1

1 uH

J3

USB-B

VBUS

D-

D+

GND SHELL_1 SHELL_2

U4

AT24C02-10SI-2.7

1

A0

2

A1

3

A2

4

Vss

C14

2.2uF

1 2

3 4

5 6

R12 1M

Vcc

WP SCL SDA

U1

LP2950CDT-3.3/TO252

IN1OUT

GND

C15

0.1uF

8 7 6 5

3

C16

2.2uF

R7 22

R9 22

R11 1.5K

+ 3.3 VDC

R13

1.5K

0.1uF

1.5K

C1

0.1uFC20.1uFC30.1uFC40.1uFC50.1uF

+ 3.3 VDC

C9

27

40

29

20

Vcc3

Vcc4

PB0/T2

RESERVED_619RESERVED_7

CY7C64603-52NC

WAKEUP#

Gnd221AGnd

Gnd113Gnd3

4

8

26

33pF

32

31

33

34

30

PB4/INT4

PB1/T2EX

PB3/TXD1

PB2/RXD1

PB5/INT5#

U2

Gnd439Gnd547Gnd6

RDY2/AOE

XCLK38RESERVED_422RESERVED_5

9

16

52

42

R3 100k

C17

1

14

C18

0.1uF

C20

R14

0.1uF

5

Vcc1

Vcc2

AVcc

28

RESET#

24

USBD-

25

USBD+

18

DISCON#

10

PA4/FWR#

11

PA5/FRD#

12

CLKOUT

SCL

2

SCL

SDA

3

SDA

Y1

12 MHz

R4

1M

6

XIN

PB6/INT6

PB7/T2OUT

CTL2/AOUTFLAG

CTL0/AINFLAG

PC0/RxD0

PC1/TxD0

PC2/INT0#

PC3/INT1#

PC6/WR#

PC7/RD#

RESERVED_3

RESERVED_215XCLKSEL

RESERVED_1

17

23

PC4/T0 PC5/T1

0.1uF

7

C6

C10 33pF

MMBT3904/SOT

XOUT

35 36 37 41 43 44

TCRIT

45

OS/A0

46 48

49 50 51

+5.0 ± 0.1 V, 100 mA max.

C11

2.2uF

Q1

J4

HEADER 2x2

Shunt to select the PCB temperature diode.

+ 3.3 VDC

R1 0

C12

C13

0.1uF

100 pF

LM95235

U3

1

VDD

C19 100 pF

2

D+

3

D-

4

TCRIT#

34 12

SMBCLK SMBDAT

OS/A0

8 7

OS/A0

6 5

GND

R2

R15

1.5K

SCL SDA SDA

OS/A0

TCRIT

+3.3 VDC

SCL

TP1

GND

TP2

GND

TP3

GND

JP2

1 3 2 4 5 6 7

HEADER 1X

TP4

GND

SCL SDA

Schematic of the LM95235 Evaluation Board

5.3 Evaluation Board Layout

Figure 5.3 Layout diagram of the LM95235 Evaluation Board

(Note: socket and socket area not stuffed.)

5.4 Bill of Materials for LM95235 Evaluation Board

Item Qty Reference Part PCB Footprint

1 11 C1,C2,C3,C4,C5,C6, Capacitor, SMD, ceramic, 0.1uF sm/c_0805

C12,C15,C17,C20 2 2 C9, C10 Capacitor, SMD, ceramic, 33 pF sm/c_0805 3 3 C11,C14,C16 Capacitor, SMD, ceramic, 2.2 uF sm/ct_3216_12 4 2 C13,C19 Capacitor, SMD, ceramic, 100 pF sm/c_0805 5 1 J3 Connector, USB-B tm/usb_typeb 6 1 J4 HEADER 2x2 blkcon.100/vh/tm1sqs/w.100/4 7 1 L1 8 1 Q1 Transistor, SMD, MMBT3904/SOT sm/mmbt3904a 9 1 R1 Resistor, SMD, 0 Ohms sm/r_0805

10 2 R4,R12 Resistor, SMD, 1M sm/r_0805 11 2 R7,R9 Resistor, SMD, 22 Ohms sm/r_0805 12 5 R2,R11,R13,R14,R15 Resistor, SMD, 1.5K sm/r_0805 13 1 R3 Resistor, SMD, 100k Ohms sm/r_0805 14 1 U1 IC, National LP2950CDT-3.3/TO252 to252ab/dpak 15 1 U2 IC, Cypress CY7C64613-52NC sm/PQFP-52 16 1 U4 IC, EPROM, Atmel AT24C02-10SI-2.7 sog.050/8/wg.244/l.200 17 1 U3 LM95235CIMM sm/msop-8 18 1 Y1 Crystal, 12 MHz, Pletronics

Filter, 1uH, Stewart MI1206K900R-00

2S1200G140

sm/l_1206

tm/hc-49

5.4 Mechanical Specifications

5.4.1 Operating Mechanical and Environmental Specifications

Minimum Typical Maximum

Temperature

5.4.2 Evaluation Board Basic Dimensions

0°C 25°C 70°C

2.45 in/6.22 cm

3.25 in/8.76 cm

5.4.3 Electrostatic Discharge (ESD) Precautions

The user shall use ESD precautions as specified in National Semiconductor ESD control document (SC)CSI-3-038 available through www.national.com

.

BY USING THIS PRODUCT, YOU ARE AGREEING TO BE BOUND BY THE TERMS AND CONDITIONS OF NATIONAL SEMICONDUCTOR'S END USER LICENSE AGREEMENT. DO NOT USE THIS PRODUCT UNTIL YOU HAVE READ AND AGREED TO THE TERMS AND CONDITIONS OF THAT AGREEMEN T. IF YOU DO NOT AGREE WITH THEM, CONTACT THE VENDOR WITHIN TEN (10) DAYS OF RECEIPT FOR INSTRUCTIONS ON RETURN OF THE UNUSED PRODUCT FOR A REFUND OF THE PURCHASE PRICE PAID, IF ANY.

The LM95235 Evaluation Boards are intended for product evaluation purposes only and are not intended for resale to end consumers, are not authorized for such use and are not designed for compliance with European EMC Directive 89/336/EEC, or for compliance with any other electromagnetic compatibility requirements.

National Semiconductor Corporation does not assume any responsibility for use of any circuitry or software supplied or described. No circuit patent licenses are implied.

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2. A critical component is any component in a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system,

or to affect its safety or effectiveness. with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user.

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National LM95235 User Manual

LM95235 Evaluation Board User’s Guide

Table of Contents

LM95235 Evaluation Board User’s Guide

References

1.0 Introduction

2.0 Quick Start

3.1 LM95235 Evaluation Board Connection Table

4.0 Software Installation and Operation

4.1 Installation

BANNED SUBSTANCE COMPLIANCE