MAXIM MAX31850EVKIT

MAX31850/MAX31851 Evaluation Kit
General Description
The MAX31850/MAX31851 evaluation kit (EV kit) provides the hardware and software graphical user interface
(GUI) necessary to evaluate the MAX31850/MAX31851
cold-junction compensated, 1-Wire® thermocouple-todigital converter.
The EV kit comes with a MAX31850KATB+ soldered to
the PCB. This is the K-type thermocouple ver­sion of the
device. Other thermocouple types can be evaluated by
procuring the desired thermocouple, ther­mocouple socket, and corresponding MAX31850 or MAX31851. Contact
the factory for free samples of the devices to match your
desired thermocouple type. See the Evaluating Other
Thermocouple Types section for part numbers and addi­
tional information regarding other thermocouple types.
EV Kit Contents
●● Assembled Circuit Board Including MAX31850K
●● Micro-USB Cable
●● K-Type Thermocouple
MAX31850/MAX31851 EV Kit Board
1-Wire is a registered trademark of Maxim Integrated
Products, Inc.
Windows and Windows XP are registered trademarks and
registered service marks of Microsoft Corporation.
19-6752; Rev 0; 7/13
Evaluates:
MAX31850/MAX31851
Features
●● Includes Everything Needed to Evaluate a
MAX31850K with a K-Type Thermocouple
●● EV Kit Hardware is USB Powered (USB Cable
Included)
●● Windows XP®- and Windows® 7-Compatible
Operating System Software
●● USB HID Interface
●● Second Channel Allows Easy Evaluation of Other
Thermocouple Types
●● Fully Assembled and Tested on Proven PCB Layout
●● RoHS Compliant
MA31850/MAX31851 EV Kit Files
FILE
DESCRIPTION
MAX31850_51EVKitSetup.EXE
Application Program
Note: The .EXE is downloaded as a .ZIP file.
Ordering Information appears at end of data sheet.
MAX31850/MAX31851 Evaluation Kit
Evaluates:
MAX31850/MAX31851
Component List
DESIGNATION QTY
DESCRIPTION
DESIGNATION QTY
DESCRIPTION
C1, C5, C203,
C214
4
0.01µF ceramic capacitors (0805)
TH1
1
K-type thermocouple socket
Omega PCC-SMP-K-5-ROHS
C2, C3, C6,
C7, C215
0
Do not populate, ceramic capacitors
(0805)
TH2
0
Do not populate, thermocouple socket
C4, C8, C212
3
0.1µF ceramic capacitors (0805)
TP1
1
White test point
C201, C202,
C204
TP2, TP3
2
Black test points
3
10µF ceramic capacitors (0805)
TP6
1
Red test point
C211
1
1.0µF ceramic capacitor (0805)
C213
1
0.22µF ceramic capacitor (0805)
U1
1
Thermocouple-to-digital converter
(10 TDFN-EP*)
Maxim MAX31850KATB+
D20, D21
2
Red/green dual LEDs
D22
1
Schottky diode
U3
0
Do not populate, MAX31850/
MAX31851
J20
1
5-pin female Micro-USB connector
U2, U4
2
J21
0
Do not populate, 2-pin header
TVS diode arrays (3 SOT)
NUP2105LT1G
JP1–JP12
12
3-pin (1 x 3) headers, 2.54mm pitch
U20
1
Microcontroller (28 SO)
Microchip PIC18LF2550-I/SO
L1–L4
4
470Ω ferrite beads (0603)
BLM18PG471SN1D
U21
1
M200
1
30V, 1.2A pMOS (3 SC70)
50mA to 600mA current-limit switch
(6 SOT23)
Maxim MAX4995AAUT+
R201, R202,
R214, R218
4
0Ω ±1% resistors (0805)
U22
1
500mA LDO regulator
Maxim MAX8902BATA+
R203, R205
1
560Ω ±1% resistors (0805)
R204
1
100kΩ ±1% resistor (0805)
X1
1
48MHz, 3.3V oscillator (SMD)
AVX KC3225A48.0000C30E00
R206
1
45.3kΩ ±1% resistor (0805)
—
1
Micro-USB cable
R207
1
10kΩ ±1% resistor (0805)
—
1
R210, R217
2
4.7kΩ ±1% resistors (0805)
K-type thermocouple
Omega 5SRTC-GG-K-24-36-ROHS
R211, R212
2
330Ω ±1% resistors (0805)
—
12
Jumpers/shunts
R213
1
2.2kΩ ±1% resistor (0805)
—
1
PCB: MAX31850/51 EV Kit
*EP = Exposed pad.
Component Suppliers
SUPPLIER
PHONE
WEBSITE
AVX North America
864-967-2150
www.avx.com
Omega Engineering, Inc
888-826-6342
www.omega.com
Note: Indicate that you are using the MAX31850/MAX31851 when contacting these component suppliers.
www.maximintegrated.com
Maxim Integrated │ 2
MAX31850/MAX31851 Evaluation Kit
Quick Start
Required Equipment
●● MAX31850/MAX31851 EV kit hardware
●● Windows XP or Windows 7 PC with a spare USB
port
●● USB Port
●● Micro-USB cable (included)
●● K-type thermocouple (included)
Note: In the following sections, software-related items are
identified by bolding. Text in bold refers to items directly
from the EV kit software. Text in bold and under­lined
refers to items from the Windows operating system.
Procedure
Follow the steps below to get started measuring
tem­
perature using the device interfaced to a K-type
thermocouple.
1) Connect the included K-type thermocouple to TH1
(thermocouple socket) of the EV kit hardware. One
terminal of the thermocouple is wider than the other,
ensuring proper polarity.
2) Ensure that jumpers/shunts are installed on JP1­­
–
JP6. JP1 and JP2 should both be either positioned
on the left for parasitic power mode or positioned on
the right to be externally powered. JP3–JP6 jumpers
can be in either position depending on the desired
location address.
3) Set the EV kit hardware on a nonconductive surface
to ensure that nothing on the PCB gets shorted
togeth­er.
4) Prior to starting the GUI, connect the EV kit hardware to a PC using the supplied Micro-USB cable,
or equiva­lent. The power LED (D20) should be green
and the com LED (D21) should be red and slowly
flash orange.
5) Windows should automatically begin installing the
necessary device driver. The USB interface of the
EV kit hardware is configured as an HID device and
therefore does not require a unique/custom device
driver. Once the driver installation is complete, a
Windows message appears near the System Icon
menu indicating that the hardware is ready to use.
Do not attempt to run the GUI prior to this message.
If you do, you must close the application and restart
it once the driver installation is complete. On some
versions of Windows, Administrator privileges may be
required to install the USB device.
www.maximintegrated.com
Evaluates:
MAX31850/MAX31851
6) Once the device driver installation is complete,
visit www.maximintegrated.com/evkitsoftware to
download the latest version of the EV kit software,
titled MAX31850_51EVKitSetup.ZIP. Save the EV kit
software to a temporary folder.
7) Unzip the .ZIP file and double click the .EXE file to run
the installer. A message box stating The publisher
could not be verified. Are you sure you want to
run this software? may appear. If so, click Yes.
8) Follow the instructions on the installer and once complete, click Finish. The default location of the GUI is
in the program files directory.
9) When the GUI appears, the status bar should display
EV kit hardware Connected in the bottom right
hand corner. The com LED (D21) on the EV kit board
should turn green.
Detailed Description of Software
Software Startup
If the MAX31850/MAX31851 EV kit is connected when
the software is opened, the software first initializes the
hardware to communicate. Then the software searches
for all ROM codes on the bus and lists them in the ROM
Code drop-down lists. If a ROM code is found with the
correct family code (3Bh), the software reads all data from
the device. If the software is started without the hardware
connected, the initialization sequence above is executed
once the EV kit is connected.
Read Data Tab
When the Read Data tab sheet (Figure 1) is selected, a
temperature conversion is performed and the scratchpad
and power-supply mode are read from the device. The
Read Power Mode button executes the Match ROM
(55h) and Read Power Supply (B4h) command and
displays the data in the Power Supply Mode edit field.
The Read Temperature button executes the Match ROM
(55h), Convert T (44h), and Read Scratchpad (BEh)
commands. This reads the Thermocouple Temp, Cold
Junction Temp, Fault Status, and Location Address,
and then the Linearized Temp is calculated. If the
Power Supply Mode is parasite, then a strong pullup
is enabled while the device converts temperature. If a
fault is detected, then the color indicator turns red and
the status bar displays FAULT!. Both buttons match the
ROM code selected in the ROM Code drop-down list. The
Thermocouple Type drop-down list is used to calculate
the linearized temperature and should be changed to
match the hardware thermocouple type. Table 1 lists all
Maxim Integrated │ 3
MAX31850/MAX31851 Evaluation Kit
Evaluates:
MAX31850/MAX31851
Figure 1. MAX31850/MAX31851 EV Kit GUI (Read Data Tab)
possible settings. The temperature can also be polled by
pressing the Start Polling button in the upper right-hand
corner. This executes the same commands as the Read
Temperature button. The polling rate can be selected
using the Polling menu bar option. To stop polling, press
the Stop Polling button.
Table 1. Sensitivity of Thermocouples
TYPE
SENSITIVITY (μV/ºC)
K*
41.276
J
57.953
N
36.256
R
10.506
S
9.587
T
52.18
E
76.373
*Default setting.
www.maximintegrated.com
Maxim Integrated │ 4
MAX31850/MAX31851 Evaluation Kit
Temperature Graph Tab
The Temperature Graph tab sheet (Figure 2) displays
a line graph of the polled temperatures. Data points are
plotted when the Start Polling button is pressed. To show/
hide a series in the graph, check/uncheck the checkboxes
Evaluates:
MAX31850/MAX31851
on the bottom. The graph can save up to 500,000 data
points per series. To save the data to a CSV file, press the
Save Data button. The graph can be cleared by pressing
the Clear Graph button.
Figure 2. MAX31850/MAX31851 EV Kit GUI (Temperature Graph Tab)
www.maximintegrated.com
Maxim Integrated │ 5
MAX31850/MAX31851 Evaluation Kit
1-Wire Commands Tab
The 1-Wire Commands tab sheet (Figure 3) contains
buttons for all the 1-Wire commands and displays the
data in HEX format. All the ROM command buttons first
issue a reset and detect a presence before sending their
command. The device can also be reset using the Reset
Device option in the Device menu. The Search ROM
(F0h) button searches for all the ROM codes on the bus
and places them in the ROM Codes Found drop-down
list. This same search can be performed using the Search
for ROMs option in the Device menu. When a ROM
code is selected from the drop-down list, the ROM Code
table is automatically populated with this selection. The
Match ROM (55h) button matches the ROM selected in
the drop-down list. The Read ROM (33h) button reads
Evaluates:
MAX31850/MAX31851
the ROM on the 1-Wire bus and displays it in the ROM
Code table. The Skip ROM (CCh) sends the skip ROM
command. The Read ROM (33h) and Skip ROM (CCh)
buttons should be used if only one device is on the bus.
The MAX31850/51 Commands should only be pressed
after a ROM command is complete. To perform a temperature conversion, press the Convert T (44h) button.
If the device is configured in parasite power mode (00h),
then the Enable Strong Pull Up checkbox should be
checked before the Convert T (44h) button is pressed.
The Read Scratchpad (BEh) button reads the scratchpad and displays the 9 bytes in the Scratchpad table.
The Read Power Supply (B4h) button reads the powersupply mode and displays the byte in the Power Supply
Mode edit field.
Figure 3. MAX31850/MAX31851 EV Kit GUI (1-Wire Commands Tab)
www.maximintegrated.com
Maxim Integrated │ 6
MAX31850/MAX31851 Evaluation Kit
Evaluates:
MAX31850/MAX31851
Detailed Description of Hardware
The MAX31850/MAX31851 EV kit hardware provides
everything needed to evaluate a K-type thermocouple. In
addition to a thermocouple and MAX31850, the hardware
includes a USB interface that is used to communicate
with the PC-based software. An added feature is that the
hard­ware is USB powered, meaning that no power supplies are needed.
Thermocouple Channels
The EV kit hardware features two thermocouple
channels. The top channel comes preconfigured with
a MAX31850KATB+, K-type thermocouple, and thermocouple socket. A sec­
ond channel is provided to
make it easy to evaluate other thermocouple types. The
bottom channel is almost fully populated, missing only the
desired MAX31850 or MAX31851 version, correspond­ing
thermocouple, and thermocouple socket. The following
section describes how to modify the hardware in order to
evaluate other thermocouple types.
Evaluating Other Thermocouple Types
To use the bottom channel, see Table 2 for the part numbers of the three items required for the desired thermocouple type.
Once the three items have been procured, power down
the EV kit by disconnecting the Micro-USB cable. Carefully
solder the Maxim device to the footprint labeled U3 and
the thermocouple socket to the footprint labeled TH2.
Finally, connect the thermocouple to the socket.
Reconnect the USB cable to the EV kit and then run the
software. In the Device menu on the GUI, select the
Search for ROMs option. Two devices should be found
and shown in the ROM Codes drop-down list. Select the
correct Thermocouple Type in the table and the device
is ready to be evaluated.
User-Supplied 1-Wire interface
To communicate with the devices with a user-supplied
1-Wire interface, first disconnect the USB and remove
resistor R218 to disconnect the on-board interface.
Connect the off-board 1-Wire interface to the GND, DQ,
and 3.3V test points for the externally powered mode. If
parasite-power mode is configured on JP1 and JP2, only
the GND and DQ test points need to be connected to the
user-supplied interface.
Power Configuration
To power the device externally with 3.3V, move both jumpers
on JP1 and JP2 to the 3.3V position on the right. For parasite power, move JP1 and JP2 to the GND and DQ position
on the left. See Table 3 for the jumper descriptions.
Table 2. Items for Other Thermocouple Types
TYPE
PART
THERMOCOUPLE*
SOCKET*
K
MAX31850KATB+
5SRTC-GG-K-24-36
PCC-SMP-K-5
J
MAX31850JATB+
5SRTC-GG-J-24-36
PCC-SMP-J-5
N
MAX31850NATB+
NMQIN-010E-6 (unverified)
PCC-SMP-N-5
T
MAX31850TATB+
5SRTC-GG-T-24-36
PCC-SMP-T-5
E
MAX31850EATB+
5SRTC-GG-E-24-36
PCC-SMP-E-5
S
MAX31851SATB+
—
—
R
MAX31851RATB+
—
—
*Thermocouple and socket part numbers are Omega part numbers. Contact Omega for RoHS part numbers.
www.maximintegrated.com
Maxim Integrated │ 7
MAX31850/MAX31851 Evaluation Kit
Evaluates:
MAX31850/MAX31851
Table 3. Description of Jumpers (JP1–JP6)
JUMPER
JUMPER POSITION
JP1
JP2
JP3
JP4
JP5
JP6
DESCRIPTION
3.3V
Connects the VDD pin of the device to 3.3V for external power mode
GND
Connects the VDD pin of the device to GND for parasite power mode
3.3V
Connects the AD pin’s high reference to 3.3V for external power mode
DQ
Connects the AD pin’s high reference to DQ for parasite power mode
High
Connects AD3 to a high reference
Low
Connects AD3 to GND
High
Connects AD2 to a high reference
Low
Connects AD2 to GND
High
Connects AD1 to a high reference
Low
Connects AD1 to GND
High
Connects AD0 to a high reference
Low
Connects AD0 to GND
Troubleshooting
The EV kit should work on the first try directly out of the box. In the rare occasion that a problem is suspected, see Table 4
to help troubleshoot the issue.
Table 4. Troubleshooting
SYMPTOM
CHECK
SOLUTION
Is the power LED (D20)
red?
If yes, then the electronic fuse is in a fault state. Inspect for electrical
shorts on the PCB and make sure that the PCB is not sitting on a
conductive surface.
Does the com LED
(D21) turn green when
the GUI is running?
If not, then exit the GUI and try running it again. If the com LED still
does not turn green, then exit the GUI and try connecting the USB cable
to a different USB port on the PC. Wait for a Windows message that
states the hardware is ready to use. Run the GUI again.
Are any of the LEDs
illuminated?
If not, then the PCB may not be getting power from the USB. Try a different USB cable or a different USB port.
The data temperature and
power-supply data is incorrect
JP1 (VDD pin)
The VDD pin cannot be left unconnected. Populate a jumper to the
right (3.3V) position for external power or to the left (GND) position for
parasite power.
GUI says “No ROM Codes
found”
R218
Make sure R218 is populated. This connects the DQ pin to the USB to
1-Wire interface.
GUI says hardware not found
www.maximintegrated.com
Maxim Integrated │ 8
www.maximintegrated.com
D
C
B
A
1
2
1
DNP
TH2
1
2
Channel 2
PCC-SMP-K-100
TH1
Channel 1
1
1
1
1
1
BLM18PG471
L4
GND
BLM18PG471
L3
BLM18PG471
L2
GND
BLM18PG471
L1
U2
1
2
U4
1
2
GND
NUP2105LT1G
2
3
2
GND
GND
NUP2105LT1G
2
3
2
GND
C7
DNP
C3
DNP
2
2
C8
0.1uF
C5
0.01uF
C6
DNP
GND
C4
0.1uF
C1
0.01uF
C2
DNP
GND
3.3V
1
2
3
CON3
CON3
3.3V
1
2
3
JP7
DNP
GND
TT+
VDD
DQ
U3
JP8
CON3
CON3
10
9
8
7
6
1
2
3
1
2
3
DNC
AD3
AD2
AD1
AD0
3.3V JP2
DQ
10
9
8
7
6
JP1
GND
DQ
1
2
3
4
5
3.3V
DNC
AD3
AD2
AD1
AD0
MAX31850/51
GND
TT+
VDD
DQ
U1
TP1
DQ
1
2
3
4
5
GND
3
GND
GND
3
AD0
1
2
3
AD1
JP12
1
2
3
JP11
AD2
1
2
3
JP10
AD3
1
2
3
JP9
AD0
1
2
3
AD1
JP6
1
2
3
JP5
AD2
1
2
3
JP4
AD3
1
2
3
JP3
TP3
TP2
GND
GND
GND
4
4
D
C
B
A
MAX31850/MAX31851 Evaluation Kit
Evaluates:
MAX31850/MAX31851
Figure 4a. MAX31850/MAX31851 EV Kit Schematic (Sheet 1 of 2)
Maxim Integrated │ 9
D
C
B
2
1
VCC
1
GND
48MHz
C215
DNP
3 CLK
3.3V
4
GND
GND OUT
INH
X1
J21
2
1
DNP
R210
4.7k
COM
C214
0.01uF
0
GND
R211
330
D21A
R214
Red
3.3V
Green
FLAG OUT
IN
GND
ON
SETI
U21
2
1
2
3
C213
0.22uF
VPP 1
HB 2
COM3
4
5
6
7
8
OSC1 9
10
11
12
13
14
3.3V
D22
GND
10uF
C202
5V
Green
2
DS3900_PIC
MCLR
P8,1W_PU
P3,HB
P7,1W_DQ
COM_LED,BOOT
P5
P1
USB_DET
P2
VPO
RCV
VMO
P6,CS
P10,SCK,SCL
GND
P11,SDI,SDA
OSC1
VDD
OSC2
GND
P4
P9,SDO
UOE
ENUM
PS,VAR
D+,VP
VUSB
D-,VM
U20
MAX4995AAUT+
R204
C201
100k
10uF
6
5
4
R212
R213
330
2.2k
D21B
560
Red
J20
D20A
1 VBUS
Vbus
R201 D2 0
DR202 D+
3 0
D+
4
I.D.
5
GND
USB_MICRO-B
R203
1
www.maximintegrated.com
2
A
1
28
27
26
25
24
23
22
21
20
19
18
17
16 D+
15 D-
R205
560
D20B
3
0
R218
8
7
6
5
DQ
C211
1.0uF
MAX8902BATA+
IN
OUT
GND BYP
EN
FB
GS
POK
U22
M200 R217
PMOS 4.7k
3.3V
1
2
3
4
3
GND
3.3V
R207
10k
R206
45.3k
C212
0.1uF
MAXIM_Logo
MAXIM
Logo
0.01uF
C203
3.3V
C204
10uF
3.3V
TP6
4
4
D
C
B
A
MAX31850/MAX31851 Evaluation Kit
Evaluates:
MAX31850/MAX31851
Figure 4b. MAX31850/MAX31851 EV Kit Schematic (Sheet 2 of 2)
Maxim Integrated │ 10
MAX31850/MAX31851 Evaluation Kit
Evaluates:
MAX31850/MAX31851
Figure 5. MAX31850/MAX31851 EV Kit PCB Layout—Top Layer
Figure 6. MAX31850/MAX31851 EV Kit PCB Layout—Bottom Layer
www.maximintegrated.com
Maxim Integrated │ 11
MAX31850/MAX31851 Evaluation Kit
Evaluates:
MAX31850/MAX31851
Ordering Information
PART
MAX31850EVKIT#
TYPE
EV Kit
#Denotes an RoHS-compliant device that may include
lead(Pb), which is exempt under the RoHS requirements.
www.maximintegrated.com
Maxim Integrated │ 12
MAX31850/MAX31851 Evaluation Kit
Evaluates:
MAX31850/MAX31851
Revision History
REVISION
NUMBER
REVISION
DATE
0
7/13
DESCRIPTION
Initial release
PAGES
CHANGED
—
Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses
are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits)
shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.
Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc.
© 2013 Maxim Integrated Products, Inc. │ 13