19-3724; Rev 1; 10/05
MAX6698 Evaluation Kit/Evaluation System
General Description
The MAX6698 evaluation kit (EV kit) and evaluation sys-
tem is an assembled and tested PC board with a
mounted MAX6698. The EV kit allows full evaluation of
the MAX6698 seven-channel temperature sensor. The
MAX6698 monitors its own die temperature, the junction
temperatures of three external diode-connected transis-
tors, and the temperatures of three thermistors. It con-
verts the temperature to 8-bit (or 11-bit for remote chan-
nel 1) 2-wire serial data that can be accessed over a 2-
wire serial bus. Refer to the MAX6698 data sheet for
additional information.
The MAX6698 EV kit includes external diode-connected
transistors and thermistors soldered to the board, which
can be removed. The board can then be connected
through a twisted pair to remote diodes and thermistors
close to your system.
The MAX6698 evaluation system consists of a Maxim
command module (CMOD232) and a MAX6698 EV kit.
The CMOD232 board connects to a computer’s RS-232
serial port to provide a computer controlled
SMBus™/I
2
C bus. Windows
®
95/98/2000/XP-compati-
ble software provides a user-friendly interface to exer-
cise the features of the MAX6698. The program is menu
driven and offers a graphic interface with control but-
tons and status display.
Order the MAX6698EVCMOD2 for complete PC-based
evaluation of the MAX6698. Order the MAX6698EVKIT if
you already have a CMOD232 SMBus interface.
Features
♦
Three Thermal Diode Inputs and Three Thermistor
Inputs
♦
Local Temperature Sensor
♦
Programmable Temperature Alarms
♦
SMBus/I
2
C Compatible
♦
Easy-to-Use Menu-Driven Software
♦
Fully Assembled and Tested
♦
Includes Windows 95/98/2000/XP-Compatible
Software and Demo PC Board
Evaluate: MAX6698
Ordering Information
PART
MAX6698EVKIT
MAX6698EVCMOD2
TEMP
RANGE
0°C to +70°C
0°C to +70°C
SMBus
INTERFACE TYPE
Not included
CMOD232
Note:
The MAX6698 EV kit software is provided with the
MAX6698EVKIT. However, the CMOD232 board is required to
interface the EV kit to the computer when using the software.
MAX6698EVKIT Component List
DESIGNATION
QTY
DESCRIPTION
0.1µF ±10%, 16V X7R ceramic
capacitor (0603)
Murata GRM188R71C104KA01
TDK C1608X7R1C104K
2200pF ±10%, 50V X7R ceramic
capacitors (0603)
Murata GRM188R71H222K
TDK C1608X7R1H222K
100pF ±50V, C0G, 0603 ceramic
capacitors
Murata GRM1885C1H101J
TDK C1608CH1H101J
2 x 10 right-angle female
receptacle
Not installed
2N3906-type pnp transistors,
SOT23
Central Semiconductor CMPT3906
Diodes Incorporated MMBT3906
Vishay Semiconductors MMBT3906
10kΩ ±5% resistors (0603)
Not installed, resistors (0603)
MAX6698EVCMOD2
(MAX6698 EV System)
Component List
DESIGNATION
MAX6698EVKIT
CMOD232
AC adapter
QTY
1
1
1
DESCRIPTION
MAX6698 evaluation kit
SMBus/I
2
C interface board
9VDC at 200mA
(powers the CMOD232 board)
C1
1
C2, C3, C4
3
C5, C6, C7
3
J1
JU1–JU7
1
0
Q1, Q2, Q3
3
SMBus is a trademark of Intel Corp.
Windows is a registered trademark of Microsoft Corp.
R1, R2, R4
R3, R5
3
0
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
MAX6698 Evaluation Kit/Evaluation System
Evaluate: MAX6698
MAX6698EVKIT Component List
(continued)
DESIGNATION
REXT1, REXT2,
REXT3
RTHER1,
RTHER2,
RTHER3
U1
—
QTY
3
DESCRIPTION
1.60kΩ ±1% resistors (0805)
10kΩ ±1% through-hole, 0.095in
diameter thermistors
BetaTHERM Sensors 10K3A1C
MAX6698EE99 (16-pin QSOP)
MAX6698 EV kit PC board
4) Install the software by running the INSTALL.EXE pro-
gram. The install program copies the files and cre-
ates icons for them in the Windows 95/98/2000/XP
Start menu. (To remove the software at any time,
click on the UNINSTALL icon.)
5) Connect the 9V adapter to the CMOD232 board.
6) Connect the +3.3V supply to the pads labeled VIN
and GND on the MAX6698 EV kit.
7) Turn on the power supply.
8) Start the MAX6698 program by opening its icon in
the Start menu.
9) Wait until the program automatically detects the
address of the MAX6698 and displays the user-inter-
face panel (Figure 1).
3
1
1
Quick Start
Recommended Equipment
Before you begin, the following equipment is needed.
Do not turn on the power until all connections are
made:
• One computer running Windows 95, 98, 2000, or XP
• One RS-232 serial port (this is a 9-pin socket on the
back of the computer)
• One standard 9-pin, straight-through, male-to-
female cable to connect the computer’s serial port to
the Maxim CMOD232 board
• One 3.3V, 100mA DC power supply
Detailed Description
User-Interface Panel
The user interface is easy to operate; use the mouse, or
press the Tab and arrow keys to navigate. The check-
boxes, edit fields, and radio buttons correspond to bits
in the MAX6698 registers. Clicking on them generates
the correct SMBus command and updates the registers.
Note:
Words in boldface are user-selectable features in
the software.
Temperature
The MAX6698 monitors its own die temperature, the
junction temperatures of three external diode-connect-
ed transistors, and the temperatures of three thermis-
tors. The temperature measurements are capable of
either 8-bit (or 11-bit for remote channel 1) resolution;
8-bit resolution results in temperature resolution of
1°C/LSB and 11-bit resolution results in temperature
resolution of 0.125°C/LSB. Enable 11-bit resolution by
selecting the
Extended Resolution
checkbox.
Read the temperatures by clicking on the
Read Temp
buttons. The temperature is shown to the right of the
buttons.
Procedures
1) Carefully connect the boards by aligning the 20-pin
connector of the MAX6698 EV kit with the 20-pin
header of the CMOD232 board. Gently press them
together.
2) Disable the pullup resistors on the CMOD232 board
by moving switch SW1 to the OFF position.
3) Connect a cable from the computer’s serial port to
the CMOD232 board. Use a straight-through, 9-pin,
male-to-female cable.
Component Suppliers
S
UPPLIER
B
etaTHERM
C
entral Semiconductor
D
iodes Incorporated
M
urata
T
DK
V
ishay Semiconductors
P
HONE
5
08-842-0516
6
31-435-1110
8
05-446-4800
7
70-436-1300
8
47-803-6100
402-564-3131
F
AX
5
08-842-0748
6
31-435-1824
8
05-446-4850
7
70-436-3030
8
47-390-4405
402-563-6296
W
EBSITE
w
ww.betatherm.com
w
ww.centralsemi.com
w
ww.diodes.com
w
ww.murata.com
w
ww.component.tdk.com
w
ww.vishay.com
Note:
Indicate you are using the MAX6698 when contacting these manufacturers.
2
_______________________________________________________________________________________
MAX6698 Evaluation Kit/Evaluation System
External Diodes
The MAX6698 remote temperature sensor is optimized
for use with a diode-connected transistor whose ideality
factor is equal to 1.008. Transistors with different ideali-
ty factors produce different remote temperature read-
ings. Some typical discrete transistors may produce
readings that vary up to 3°C from the correct value.
Refer to the Maxim website (maxim-ic.com) Application
Note:
Compensating for Ideality Factor and Series
Resistance Differences Between Thermal Sense Diodes
for additional information.
register and asserts the OVERT output pin.
Note:
OVERT limit only applies to remote channel 1, thermis-
tor 1, thermistor 2, and thermistor 3.
Read the limits by clicking on the
Read
buttons. The
value is shown to the right of the button. Change the
limits by entering the value into the appropriate edit
field and clicking on the
Write
button. Note that OVERT
has 4°C of hysteresis. The temperature must decrease
4°C below the value set in the OVERT limit register to
deassert the OVERT output.
Evaluate: MAX6698
Thermistors
The MAX6698 reads up to three external thermistors.
Each thermistor is combined with an external resistor to
form a voltage-divider that is connected to a reference
voltage (V
REF
). Thermistor readings are voltage values
and are directly related to temperature. However,
because thermistors are very nonlinear, these values
are not calibrated to temperature in degrees C. Refer to
the MAX6698 data sheet for more information.
Configurations 1, 2, and 3
The configuration 1 register controls the STOP bit, the
power-on-reset (POR ) bit, the SMB timeout disabled
bit, the remote 1 fast conversion bit, and the resistance
cancellation bit. Configuration 2 enables or disables the
ALERT interrupt. Configuration 3 enables or disables
the OVERT outputs.
Figure 2 shows the checkboxes for the configuration 1
register. Each checkbox corresponds to a bit in the
register. Tables 1, 2, and 3 describe the function for
each checkbox in configurations 1, 2, and 3.
Read the register by clicking on the
Read
button.
Change the register by selecting or deselecting the
desired functions and clicking on the
Write
button.
ALERT and OVERT Temperature Limits
The MAX6698 has ALERT and OVERT (overtempera-
ture) limit registers. Temperature exceeding the ALERT
limit register generates an alert interrupt. Exceeding the
OVERT limit sets the overtemperature bit in the status
Table 1. Configuration 1 Register Checkboxes
BIT
7
NAME
STOP
STATE
Checked
Unchecked*
Checked
Unchecked*
5
SMB Timeout
Disabled
Remote 1 Fast
Conversion
Resistance
Cancellation
Reserved
Reserved
Reserved
Checked
Unchecked*
4
3
2
1
0
Checked
Unchecked*
Checked
Unchecked*
—
—
—
DESCRIPTION
Places the MAX6698 in software standby mode.
Places the MAX6698 in operational mode.
Resets all registers to their default values including the configuration 1
register. After selecting the POR checkbox, the checkbox returns to the
unchecked state.
Normal operation.
Disables the SMBus timeout, as well as alert response, thus providing true
I
2
C compatibility.
Enables the SMBus timeout.
Enables more frequent conversions on remote channel 1.
Disables fast conversion.
The MAX6698 cancels series resistance in the remote channel 1 diode.
Disables resistance cancellation.
Not used.
Not used.
Not used.
6
POR
*POR
state.
_______________________________________________________________________________________
3
MAX6698 Evaluation Kit/Evaluation System
Evaluate: MAX6698
Table 2. Configuration 2 Register Checkboxes
BIT
7
6
5
4
3
2
1
0
NAME
Reserved
Mask Local ALERT
Mask Thermistor 3 ALERT
Mask Thermistor 2 ALERT
Mask Thermistor 1 ALERT
Mask Remote-Diode 3
ALERT
Mask Remote-Diode 2
ALERT
Mask Remote-Diode 1
ALERT
STATE
—
Checked
Unchecked*
Checked
Unchecked*
Checked
Unchecked*
Checked
Unchecked*
Checked
Unchecked*
Checked
Unchecked*
Checked
Unchecked*
Not used.
Disables the local ALERT interrupt.
Enables the local ALERT interrupt.
Disables the thermistor 3 ALERT interrupt.
Enables the thermistor 3 ALERT interrupt.
Disables the thermistor 2 ALERT interrupt.
Enables the thermistor 2 ALERT interrupt.
Disables the thermistor 1 ALERT interrupt.
Enables the thermistor 1 ALERT interrupt.
Disables the remote-diode 3 ALERT interrupt.
Enables the remote-diode 3 ALERT interrupt.
Disables the remote-diode 2 ALERT interrupt.
Enables the remote-diode 2 ALERT interrupt.
Disables the remote-diode 1 ALERT interrupt.
Enables the remote-diode 1 ALERT interrupt.
DESCRIPTION
*POR
state.
Table 3. Configuration 3 Register Checkboxes
BIT
7
6
5
4
3
2
1
0
NAME
Reserved
Reserved
Mask Thermistor 3
Overtemp
Mask Thermistor 2
Overtemp
Mask Thermistor 1
Overtemp
Reserved
Reserved
Mask Remote-Diode 1
Overtemp
STATE
—
—
Checked
Unchecked*
Checked
Unchecked*
Checked
Unchecked*
—
—
Checked
Unchecked*
DESCRIPTION
Not used.
Not used.
Prevents OVERT from being asserted by a thermistor 3 fault.
Allows OVERT to be asserted by a thermistor 3 fault.
Prevents OVERT from being asserted by a thermistor 2 fault.
Allows OVERT to be asserted by a thermistor 1 fault.
Prevents OVERT from being asserted by a thermistor 1 fault.
Allows OVERT to be asserted by a thermistor 1 fault.
Not used.
Not used.
Prevents OVERT from being asserted by a remote-diode 1 fault.
Allows OVERT to be asserted by a remote-diode 1 fault.
*POR
state.
4
_______________________________________________________________________________________
MAX6698 Evaluation Kit/Evaluation System
Status 1, 2, and 3
The status 1, 2, and 3 boxes display the critical and
fault conditions that occur. Each line corresponds to a
bit in the registers. See Tables 4, 5, and 6 for a list of
the status conditions.
Read the status by clicking on the
Read Status
button.
Evaluate: MAX6698
Table 4. Status 1 Register
BIT
7
6
5
4
3
2
1
0
NAME
Reserved
Local ALERT
Thermistor 3 ALERT
Thermistor 2 ALERT
Thermistor 1 ALERT
Remote-Diode 3 ALERT
Remote-Diode 2 ALERT
Remote-Diode 1 ALERT
Not used.
The temperature of the MAX6698 is above the value set in the local ALERT limit
register.
The voltage of thermistor 3 is above the value set in the thermistor 3 ALERT limit
register.
The voltage of thermistor 2 is above the value set in the thermistor 2 ALERT limit
register.
The voltage of thermistor 1 is above the value set in the thermistor 1 ALERT limit
register.
The temperature of remote-diode 3 is above the value set in the remote-diode 3
ALERT limit register.
The temperature of remote-diode 2 is above the value set in the remote-diode 2
ALERT limit register.
The temperature of remote-diode 1 is above the value set in the remote-diode 1
ALERT limit register.
DESCRIPTION
Table 5. Status 2 Register
BIT
7
6
5
4
3
2
1
0
NAME
Reserved
Reserved
Thermistor 3 Overtemp
Thermistor 2 Overtemp
Thermistor 1 Overtemp
Reserved
Reserved
Remote-Diode 1
Overtemp
Not used.
Not used.
The voltage of thermistor 3 is above the value set in the thermistor 3 overtemperature
limit register.
The voltage of thermistor 2 is above the value set in the thermistor 2 overtemperature
limit register.
The voltage of thermistor 1 is above the value set in the thermistor 1 overtemperature
limit register.
Not used.
Not used.
The temperature of remote-diode 1 is above the value set in the remote-diode 1
overtemperature limit register.
DESCRIPTION
_______________________________________________________________________________________
5
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