MAXIM MAX6651EVSYS

19-1980; Rev 0; 3/01
MAX6651 Evaluation System
Features
♦ Proven PC Board Layout
♦ Convenient On-Board Test Points
♦ Fully Assembled and Tested
Ordering Information
MAX6651 EV Kit Files
EV KIT FILES
DESCRIPTION
PART
TEMP. RANGE
INTERFACE
TYPE
Application program
MAX6651EVKIT
0°C to +70°C
User supplied
Required parallel port driver
MAX6651EVSYS
0°C to +70°C
Windows software
INSTALL.EXE
Installs the EV kit files on your computer
MAX6651.EXE
LPTCON.VXD
Component List
MAX6651EVSYS SYSTEM COMPONENT LIST
PART
QTY
MAX6651EVKIT
1
MAX6651 EV kit
1
PC parallel port to SMBus
interface
MAXSMBUS
DESCRIPTION
MAX6651EVKIT COMPONENT LIST
DESIGNATION
QTY
C1
1
DESCRIPTION
10µF, 25V radial leaded
electrolytic capacitor
C2
0
Open
C3
1
0.1µF ceramic capacitor (1206)
MAX6651EVKIT COMPONENT LIST
DESIGNATION
QTY
DESCRIPTION
Q1
1
TO-220 logic-level N-channel FET
International Rectifier IRFZ24N
(Rdson < 0.1Ω at 5Vgs, 30Vbdss)
Q1
1
Heatsink, thermalloy 6028
Q1
1
No. 4 nut
Q1
1
4-40 x 1/4in machine screw
R1
1
10kΩ ±1% resistor (1206)
R2
1
100kΩ ±1% resistor (1206)
560Ω ±5% resistor (1206)
R3
1
R4–R8
5
49.9kΩ ±1% resistors (1206)
U1
1
MAX6651EEE
None
1
PC board, MAX6651 EV kit
LED1
1
Light-emitting diode
P1
1
2 x 10 right-angle socket
SamTec SSW-110-02-S-D-RA
RP1
1
SIP resistor network, 10kΩ, 6 pins,
common
None
1
3 1/2in software disk, MAX6651
EV kit
J1–J5, J7–J12
11
2-pin headers
None
1
J1, J5, J8–J12
7
Shunts
MAX6651 EV kit data sheet
(includes MAXSMBUS manual)
SMBus is a trademark of Intel Corp.
Windows is a registered trademark of Microsoft Corp.
________________________________________________________________ Maxim Integrated Products
1
For price, delivery, and to place orders, please contact Maxim Distribution at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
Evaluates: MAX6651
General Description
The MAX6651 evaluation kit (EV kit) is an assembled
and tested circuit board that demonstrates the
MAX6651 intelligent fan controller IC. Windows® 95/98
software provides a handy user interface to exercise the
MAX6651’s features. Order the MAX6651EVSYS for
complete evaluation of the MAX6651, including a Maxim
SMBus Interface Board (MAXSMBUS). Order the
MAX6651EVKIT if you already have an SMBus interface.
Evaluates: MAX6651
MAX6651 Evaluation System
Recommended Equipment
Description of Software
Before you begin, you will need the following equipment:
• Maxim MAX6651EVKIT and MAXSMBUS interface
board
The main window shows the register values of the
MAX6651. Register bit fields are presented as dropdown combo boxes. The 1/Speed and Tach0-3 register
values are also translated into the corresponding fan
(RPMs).
• A 12VDC power supply
• A computer running Windows 95/98
• A spare parallel port
• A 25-pin I/O extension cable
Quick Start
1) With the power off, connect the 12VDC power supply
of the MAXSMBUS board between POS9 and
GND.
2) Also connect the 12VDC supply to the MAX6651 EV
kit at the pads labeled FAN SUPPLY (±). (The
MAX6651’s +5V supply comes from the
MAXSMBUS board.)
3) Connect the boards together.
4) Connect the 25-pin I/O extension cable from the
computer’s parallel port to the MAXSMBUS board.
The EV kit software uses a loopback connection
to confirm that the correct port has been selected.
5) Ensure that the jumper settings are in the default
position (Table 1).
6) Connect a 12V tachometer-output fan to the FAN0+,
FAN0-, and FAN0T terminals. Additional fans may
be connected at FAN1+/FAN1-, FAN2+/FAN2-, and
FAN3+/FAN3-. Optional tachometer inputs FAN1T,
FAN2T, and FAN3T may be used to monitor the
auxiliary fans’ speed.
7) Install the MAX6651 EV kit software on your computer by running the INSTALL.EXE program on the
floppy disk. The program files are copied and icons
are created for them in the Windows Start menu.
8) Turn on the power supply. The fan will turn on at full
speed.
9) Start the MAX6651 program by opening its icon in
the Start menu.
Detailed Description
of Hardware
U1, the MAX6651, is an intelligent fan controller. MOSFET Q1 regulates the fan voltage (measured by the FB
input). In closed-loop mode, adjusting the fan voltage
set point regulates the main fan’s tachometer output.
PC Board Layout Tips
For best results, keep the Q1 gate drive trace as short
as possible.
See Figure 1, which shows the MAX6651 EV kit
schematic, and refer to the MAX6651 data sheet.
Troubleshooting
Problem: Cannot find MAX6651 parallel port connection.
Ensure that the I/O extension cable is connected to a
parallel port, and not to a SCSI or other type of port.
Verify that the supplied LPTCON.VXD is in the same
directory as MAX6651.EXE. If a local printer driver is
installed, temporarily disable it. The software will not work
if the program icon is dragged onto the Windows desktop; instead, install the software into a subdirectory, such
as C:\MAX6651. The software can also be run directly
from its floppy disk, as long as both MAX6651.EXE and
LPTCON.VXD are in the same directory.
10) In the Config register, drop down the full-on combo
box and choose closed-loop mode.
11) In the 1/Speed register, type in the value “100.”
Adjust this value up or down to choose the target
fan speed. Increasing the 1/Speed value makes the
closed-loop set point a slower fan speed.
12) Observe measured fan speed in the Tach0
tachometer display.
2
_______________________________________________________________________________________
MAX6651 Evaluation System
Evaluates: MAX6651
Table 1. Jumper Functions
JUMPER
POSITION
J1
*Open
See Table 2.
J2
*Open
See Table 2.
J3
*Open
See Table 2.
J4
*Closed
See Table 2.
*Closed
Connect on-board LED to GPIO0 output.
J5
Open
J7
Disconnect on-board LED from GPIO0 output.
Closed
Connect GPIO0 to GPIO1.
*Open
GPIO0 is not connected to GPIO1.
*Closed
J8
Fan 3 tachometer connects to FAN3T directly.
Open
Fan 3 tachometer connects to FAN3T through 49.9kΩ resistor R8.
*Closed
J9
Fan 2 tachometer connects to FAN2T directly.
Open
Fan 2 tachometer connects to FAN2T through 49.9kΩ resistor R7.
*Closed
J10
Fan 1 tachometer connects to FAN1T directly.
Open
Fan 1 tachometer connects to FAN1T through 49.9kΩ resistor R6.
*Closed
J11
Fan 0 tachometer connects to FAN0T directly.
Open
Fan 0 tachometer connects to FAN0T through 49.9kΩ resistor R5.
*Closed
J12
FUNCTION
FB feedback input connects to Q1 drain directly.
Open
FB feedback input connects to Q1 drain through 49.9kΩ resistor R4.
*Default configuration
Table 2. Address Selection Jumpers
J1
J2
J3
J4
ADDRESS
Closed
Open
Open
Open
1001 011R
Open
Closed
Open
Open
0011 111R
Open
Open
Closed
Open
1001 000R
*Open
*Open
*Open
*Closed
0011 011R
*Default configuration
_______________________________________________________________________________________
3
4
P1-20
P1-18
P1-16
P1-19
P1-15
P1-17
P1-11
P1-13
P1-14
P1-12
P1-7
P1-9
P1-1
P1-3
P1-5
P1-10
P1-8
P1-6
P1-2
P1-4
VCC
GPIO 4
GPIO 3
GPIO 2
GPIO 1
SCL
SDA
VCC
GPIO 0
J7
LED1
R3
560Ω
J5
VCC
GPIO4
GPIO3
GPIO2
GPIO1
GPIO0
VCC
J2
R1
10kΩ
1%
J1
5 SDA
6 SCL
7
12
11
9
10
C3
0.1µF
J3
ADD
8
R2
100kΩ
1%
J4
1
16
2
FB 15
TACH0
TACH1
GND OUT
4
13
MAX6651
U1
TACH2
14
VCC
3
TACH3
VCC
Q1
R4
49.9kΩ
1%
J12
R6
49.9kΩ
1%
J10
R8
49.9kΩ
1%
J8
C1
10µF
25V
C2
OPEN
R5
49.9kΩ
1%
J11
R7
49.9kΩ
1%
J9
RP1
10kΩ ✕ 5
FAN_SUPPLY-
FAN_SUPPLY+
FAN0-
FAN0T
FAN0+
FAN1-
FAN1T
FAN1+
FAN2-
FAN2T
FAN2+
FAN3-
FAN3T
FAN3+
Evaluates: MAX6651
MAX6651 Evaluation System
Figure 1. MAX6651 EV Kit Schematic
_______________________________________________________________________________________
MAX6651 Evaluation Kit
Figure 3. MAX6651 EV Kit PC Board Layout—Component Side
Figure 4. MAX6651 EV Kit PC Board Layout—Solder Side
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
5 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2001 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
Evaluates: MAX6651
Figure 2. MAX6651 EV Kit Component Placement Guide—
Component Side