National Semiconductor LM64 User manual

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LM64 Evaluation Board User’s Guide
Copyright 2003 National Semiconductor Corporation

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Table of Contents
1.0 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3, 4
2.0 Getting Started . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.1 Required Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.2 Optional Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.3 Test Setup – Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.4 Test Setup - Hardware. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.5 Test Setup – System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.0 Connection Details. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4.0 Schematic of LM64 Evaluation Board . . . . . . . . . . . . . . . . . . . . . . . . . . 8, 9
5.0 Bill of Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

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1.0 Introduction
The LM64EVAL kit includes the following items:
1. The LM64 Evaluation Board
2. The SensorEval Software CD, including
a. the readme.txt file (read this first)
b. the installation setup file,
c. the SensorEval Software manual, and
d. this manual.
3. Jumpers to use for testing the GPD or GPIO pins if desired.
The LM64 Evaluation Board, as shown in Figure 1 (without the socket lid for clarity), is a complete
PCBA (printed circuit board assembly). The board has a USB connector, a voltage regulator circuit, a
microcontroller, an EEPROM, and a LM64 Remote Diode Temperature Sensor with Integrated Fan
Control. A schematic and bill of materials is included in this User’s Guide. Figure 1 shows the location
of pin1 for proper orientation of the LM64 in the socket.
Figure 1. The LM64 Evaluation Board with Open Socket showing pin numbering convention.
The LM64EVAL kit includes the SensorEval software, which is provided by National Semiconductor to
communicate with the LM64 Evaluation Board by way of the USB cable (not provided) from the
controlling computer. The SensorEval software is used to control the writing and reading of the digital
registers in the LM64 for doing the initial register setup, reading the local and remote temperatures,
establishing certain temperature limit setpoints, and setting up fan control and tachometer monitoring
registers.
Pin 1
Pin 7

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1.0 Introduction (Continued)
For the installation procedure for the SensorEval software see the readme.txt file on the SensorEval
software CD. For detailed use of the LM64 software used with the LM64 Evaluation Board, please
refer to the SensorEval software user’s guide on the CD. The LM64 datasheet is available at
www.national.com.
2.0 Getting Started
2.1 Required Equipment
In order to use the LM64 Evaluation Board you will need to have the following required pieces of
equipment:
1. A computer with at least a Pentium III processor, running MicrosoftWindows 98/2000/XP
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operating system, with 20 MB of free disk space, and at least one USB port
2. A standard USB cable (3 foot length should be sufficient) for connecting the computer to the
LM64 Evaluation Board.
3. If you plan to test with a 3-terminal fan you must have:
a. A 3-terminal DC brushless fan rated at less than 0.40 Amp. Note that provisions are
made on the board for either a standard processor fan connector or holes for soldering
wires on the board.
b. A Power Supply capable of delivering the fan rated voltage (+12 VDC or +5 VDC) at
twice the rated fan current. A pair of wires from the power supply to a female header
connector to connect with J2, Fan Power input, is suggested.
If it is desired to run the software only, without the LM64 Evaluation board, omit items 2 and 3 and
proceed to paragraph 2.3.
2.2 Optional Equipment
Optional pieces of equipment are as follows:
1. Remote Diode with wired connector to connect to a female 2-pin header, 0.1 in centers
2. Test equipment such as a digital voltmeter or oscilloscope.
2.3 Test Setup - Software
First, see the readme.txt file on the SensorEval CD for the latest installation instructions. Follow the
installation procedures to load the software on the computer and, if desired, to verify the operation of
the LM64 Evaluation Board.
The SensorEval icon will be on the desktop window after the software installation.
If it is desired to run the software without the LM64 Evaluation Board please proceed to the Software
User’s Guide on the SensorEval CD.
For use with the LM64 Evaluation Board disconnect the USB cable from the board and proceed to the
next section for the hardware setup.
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Microsoft, Windows, and XPare registered trademarks of Microsoft Corporation.

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2.0 Getting Started (continued)
2.4Test Setup – Hardware
Figure 2 below shows an example of a typical LM64 Evaluation Board test setup for driving fans,
attaching remote diodes, and monitoring the system.
Figure 2. Test Setup using the LM64 Evaluation Board
For the first time user, no jumpers are required on headers JP1, JP2, or JP3 for operation of the basic
temperature measuring and fan control functions. Details about these headers, and connections to
them, will be discussed later in this User Guide.
Hardware Test Setup Procedure
1. Before connecting the power supply to the LM64 Evaluation Board, turn it on and set the
output voltage to the voltage rating of the fan (+5 or +12 VDC). Turn the power supply off.
2. Connect the power supply to the LM64 Evaluation Board jack J2 as shown in Figure 2. Make
sure that the positive terminal is connected to V+ and the negative terminal is connected to the
GND of J2.
3. Plug in the fan as shown in Figure 2. This pinout is standard for PC processor fans.
4. The LM64 Evaluation Board comes with jumpers installed on J4, which connects the on-board
MMBT3904 diode-connected transistor to the input of the LM64 chip.
5. Connect the USB cable from the computer’s USB port to the LM64 Evaluation Board
6. Turn on the fan power supply.
7. Start the SensorEval software.
LM64
Fan Power
National Semiconductor
LM64 Evaluation Board
Tach
V+
V-
GND
A0
SDA
SCL
ALERT#
TCRIT
VDC
USB
V+
GND
Q1
J4
J2
J3
JP3
+12 VDC or +5 VDC
Fan Power Supply
No jumpers required.
May be used to test GPD’s and GPIO’s
No Jumpers
Required
Black Lead
Computer
USB
Port
Connection
GPD5
GPD4
GPD3
GPD2
GPD1
JP1
GPIO5
GPIO4
GPIO3
GPIO2
GPIO1
JP2
D+
D-
Test
Socket