19-1440; Rev 2; 5/07
MAX1402 Evaluation Kit/Evaluation System
General Description
Features
The MAX1402 evaluation system (EV system) is a com-
plete, multichannel data-acquisition system consisting of
a MAX1402 evaluation kit (EV kit), Maxim 68HC16 micro-
controller (µC) module, and USBT0232. The MAX1402 is
a low-power, multichannel, serial-output analog to digital
♦ Easy to Configure
♦ Collects Up to 8192 Samples at Full Speed
♦ Complete Evaluation System
♦ Proven PCB Layout
®
converter (ADC). Windows 98/2000/XP-compatible soft-
♦ Fully Assembled and Tested
ware provides a handy user interface to exercise the
MAX1402’s features. Source code in C++ and 68HC11
assembly language is provided for the low-level portion of
the software.
♦ EV Kit Software Supports Windows 98/2000/XP
with RS-232/COM Port
♦ EV Kit Software Supports Windows 2000/XP with
Order the EV system for comprehensive evaluation of
the MAX1402 using a personal computer. Order only
the EV kit if the 68HC16 µC module has already been
purchased with a previous Maxim EV system, or for
custom use in other µC-based systems.
USB Port
Ordering Information
PART
TYPE RANGE
0°C to +70°C
0°C to +70°C
INTERFACE TYPE
User supplied
The MAX1402 EV kit and EV system can also be used
to evaluate the MAX1400. Simply order a free sample of
the MAX1400CAI along with the MAX1402 EV kit.
MAX1402EVKIT
MAX1402EVC16
Windows software
Note: The MAX1402 software can only be used with the com-
plete evaluation system (MAX1402EVC16), which includes the
68HC16MODULE-DIP, USBTO232, and the MAX1402EVKIT.
MAX1402 Stand-Alone EV Kit
The MAX1402 EV kit provides a proven printed-circuit
board (PCB) layout to facilitate evaluation of the
MAX1402 with user-supplied software and hardware. It
must be interfaced to appropriate timing signals for
proper operation. Refer to the MAX1402 IC data sheet
for timing requirements. See Table 2, Jumper Functions.
MAX1402 EV Kit
PART
QTY
DESCRIPTION
100pF ceramic capacitors (1206)
TDK C3216C0G2J101K
C3–C8
6
MAX1402 EV System
The MAX1402 EV system operates from a user-supplied
+8V to +12VDC power supply.
0.1µF ceramic capacitors (1206)
Murata GRM319R71H104K
TDK C3216X7R1H104K
C9, C10, C11
3
Component Lists
MAX1402 EV System
C12, C13
C15
2
1
Not installed, capacitors
2.2µF, 25V X7R ceramic capacitor
TDK C3216X7R1E225K
PART
QTY
DESCRIPTION
MAX1402 EV kit
J1
J2
1
1
0
6
2
2
1
2 x 20 right-angle socket
Female SMA connector
Not installed
MAX1402EVKIT
68HC16MODULE-DIP
1
1
68HC16 µC module
JU1–JU8
R1–R6
R7, R8
R9, R10
U1
USB-to-COM port adapter
board
100Ω 5% resistors (1206)
10Ω 5% resistors (1206)
Not installed, resistors
MAX1402CAI (28-pin SSOP)
USBTO232+
1
+Denotes lead-free and RoHS-compliant.
MAX6025AEUR (SOT23)
2.500V voltage reference
(200ppm/°C max)
U2
1
2.4576MHz ceramic resonator
Murata CSTCC2M45G53-R0
Y1
—
1
1
Windows is a registered trademark of Microsoft Corp.
PCB: MAX1402 Evaluation Kit+
________________________________________________________________ Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
MAX1402 Evaluation Kit/Evaluation System
switch, along the top-edge of the µC module.
Observe the polarity marked on the board.
underlined refers to items from the Windows
98/2000/XP operating system.
5) Connect the USBTO232 board to the 68HC16MODULE-
DIP module if you have not done so already.
Connections and Setup
software) to download the latest version of the EV
kit software. Save the EV kit software to a temporary
folder and uncompress the file (if it is a .zip file).
6) The MAX1402 EV kit software should have already
been downloaded and installed in the USBTO232
Quick Start.
2) Install the MAX1402 EV kit software on your com-
puter by running the INSTALL.EXE program. The
program files are copied and icons are created for
them in the Windows Start | Programs menu.
FILE
DESCRIPTION
INSTALL.EXE
UNINST.INI
Installs the EV kit files on your computer.
Database for uninstall program.
3) Make sure your 68HC16MODULE-DIP module has
the Rev. 2.0 ROM. The software will not function with
the Rev. 1.0 ROM.
Removes the EV kit files from your
computer. This file is automatically copied
to C:\WINDOWS during installation.
UNMAXIM.EXE
4) Carefully connect the boards by aligning the 40-pin
header of the MAX1402 EV kit with the 40-pin con-
nector of the 68HC16MODULE-DIP module. Gently
press them together. The two boards should be
flush against one another.
7) Start the MAX1402 program by opening its icon in
the Start | Programs menu.
8) Turn on power supply and slide SW1 to the ON
position on the 68HC16MODULE-DIP module.
Press the OK button to automatically connect and
download the KIT1402.C16 file to the module.
5) Connect the DC power source to the µC module at
terminal block J2, located next to the ON/OFF
switch, along the top-edge of the µC module.
Observe the polarity marked on the board.
9) When the software successfully establishes com-
munication with the EV kit board, you will see a con-
figuration tool and some other windows. Verify that
the CLKIN and reference voltage settings are cor-
rect. Close or minimize this dialog box.
6) Connect a cable from the computer’s serial port to
the µC module. If using a 9-pin serial port, use a
straight-through, 9-pin female-to-male cable. If the
only available serial port uses a 25-pin connector, a
standard 25-pin-to-9-pin adapter will be required.
The EV kit software checks the modem status lines
(CTS, DSR, and DCD) to confirm that the correct
port has been selected.
10) Apply input signals to the inputs labeled
AIN1–AIN5, at the bottom-edge of the MAX1402 EV
kit board. AIN6 is analog common. Observe the
readout on the screen.
Recommended Equipment (RS-232-to-COM
Port/PC Connection Option)
FILE
DESCRIPTION
INSTALL.EXE
UNINST.INI
Installs the EV kit files on your computer.
Database for uninstall program.
Before beginning, the following equipment is needed:
• MAX1402 EV system:
MAX1402 EV kit
Removes the EV kit files from your
computer. This file is automatically copied
to C:\WINDOWS during installation.
UNMAXIM.EXE
68HC16MODULE-DIP
• A DC power supply that generates +8VDC to
7) Start the MAX1402 program by opening its icon in
+12VDC at 30–50mA
the Start | Programs menu.
• A user-supplied Windows 98/2000/XP computer with
an available serial communications port, preferably a
9-pin plug
8) Turn the power on and slide SW1 to the ON posi-
tion. Select the correct serial port and press the OK
button. The program will automatically download
KIT1402.C16 to the module.
• A serial cable to connect the computer’s serial port to
the 68HC16MODULE-DIP
9) When the software successfully establishes com-
munication with the EV kit board, you will see a con-
figuration tool and some other windows. Verify that
the CLKIN and reference voltage settings are cor-
rect. Close or minimize this dialog box.
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
_______________________________________________________________________________________
3
MAX1402 Evaluation Kit/Evaluation System
10) Apply input signals to the inputs labeled
AIN1–AIN5, at the bottom-edge of the MAX1402 EV
kit board. AIN6 is analog common. Observe the
readout on the screen.
The MAX1400/MAX1402 automatically triggers its mea-
surements, unless the FSYNC control bit is set. The
evaluation kit software communicates with the
MAX1400/MAX1402 at intervals determined by the
Update Every combo box. To halt this automatic update,
uncheck the Update Every checkbox or change the
Update Every to a value between 100ms and 60000ms.
Upgrading the 68HC16 Module
The MAX1402 EV kit requires Rev. 2.0 of the Maxim
68HC16 Module ROM. Check the label on device U3
on the module; if its label says Rev. 1.0, contact the
factory for a replacement.
Normally, the microcontroller collects new data as soon
as it becomes available, by using the INT pin to trigger
an interrupt service routine. If the INT pin is not used as
an interrupt, then the MAX1400 must not be operated in
free-running mode. Check or uncheck the Use INT
Interrupt checkbox to configure the evaluation kit soft-
ware.
To install the new ROM, use the following procedure.
Use antistatic handling precautions. To reduce the risk
of ESD damage, gather all required materials and per-
form the installation at one sitting:
1) Slide the ON/OFF switch to the OFF position.
Configuration Tool
The Configuration Tool controls parameters that apply
to the entire EV kit. Like the other windows, the
Configuration Tool can be activated from the Show
menu of the main menu bar. The CLK control should
match the external ceramic resonator or crystal that
sets the master clock frequency. The VREF Reference
Voltage control tells the software what the reference
voltage is. This is used to convert the raw A/D output
codes into the corresponding input voltage to speed
user evaluation. The Data Rate control determines how
often the MAX1402 performs a measurement. Some
data rates provide 16-bit, noise-free resolution when
used with the SINC3 filter (discussed below). The Filter
Sync control can be used to inhibit the MAX1402 from
performing its self-timed measurements. The Buffer
Inputs checkbox enables the internal input buffers. The
Burnout Test Currents checkbox enables two small
(0.1µA) current sources to provide an input stimulus.
When used with a transducer, these current sources
can be used to verify that the transducer has not failed
open or short circuit.
2) Using a flat-blade screwdriver, gently pry U3, the
REV 1.0 ROM, out of its socket.
3) Remove the REV 2.0 ROM from its antistatic pack-
aging.
4) Align the REV 2.0 ROM in the U3 socket pins.
Observe correct polarity (the notch at the top of the
ROM). Verify that the pins are lined up with the
socket, and gently press the ROM into place.
Proceed to the regular Quick Start instructions.
Detailed Description
_________________________of Software
The MAX1402 digitizes up to seven inputs. The various
program functions are grouped into windows, which are
accessible from the Show menu on the main menu bar.
Main Display
The main display shows the calculated input voltage
and raw A/D output code for each active channel.
Although there are nine input channels, only certain
configurations are allowed.
At the bottom of the window, there are input voltage
range selection buttons. These buttons configure all
input channels for the same input voltage range.
Although the MAX1400/MAX1402 can be operated with
three different input ranges at the same time, the evalu-
ation kit software only supports a single range for all
channels.
Select any single channel or one of the scanning
sequences from the Inputs menu. AIN 1-6 designates
an analog input between the AIN1 pin and the AIN6 pin.
CALOFF designates the signal between the CALOFF+
and CALOFF- pins. CALGAIN designates the signal
between the CALGAIN+ and CALGAIN- pins.
The EV kit software assumes that CALOFF+ and
CALOFF- are grounded so that CALOFF measures zero
volts. Similarly, the software assumes that CALGAIN+ is
connected to REFIN+ and CALGAIN- is connected to
REFIN- so that CALGAIN measures the reference volt-
age. These two points calibrate the code-to-voltage
translation function performed in the software.
The digital filter on the MAX1402 can be configured for
SINC3 or SINC1 operation, which affects the filter cutoff
frequency. (SINC' means SIN(X) ÷ X, and SINC3 means
(SIN(X) ÷ X)3.) The SINC3 filter is required for 16-bit accu-
racy. The SINC1 filter provides faster settling time with less
accuracy. Alternatively, the raw modulator output can be
driven out the DOUT pin; however, the EV kit software
cannot read data from the MAX1402 in this mode.
4
_______________________________________________________________________________________
MAX1402 Evaluation Kit/Evaluation System
or unchecking its box. (The START bit and the zero bits
in the special function register (SFR) cannot be modi-
fied). The Read All Registers button causes the soft-
ware to read all of the MAX1400/MAX1402’s registers.
(Not functional when the MDOUT or FULLPD bit is set.)
Refer to Table 4, Guide to Register Bit Functions.
Calibration Tool
The MAX1402 EV kit software can average the mea-
surements from the calibration channels and use the
measured values to correct the voltage displays. The
calibration algorithm assumes that the CALOFF inputs
are externally connected together, and that the
CALGAIN inputs are externally connected to the refer-
ence voltage (VREF). View the calibration tool by
selecting it from the Show menu.
Communications Register (COMMS)
Setting the FSYNC control bit inhibits the MAX1400/
MAX1402 from performing its self-timed measurements.
If FSYNC = 1 when it is time to perform a measurement,
the MAX1400/MAX1402 simply skips that measure-
ment. Thus, power line frequency rejection is not affect-
ed by the FSYNC bit.
The software automatically disables calibration if either
of the calibration channels reports a code of 0 or
262143. This is to prevent erroneous calibration when
using a transfer function that does not include both 0V
and VREF.
Setting the STDBY bit places the part in low-power
standby mode. The serial interface and the CLK oscilla-
tor continue to operate. The part can be restored to
normal operation by clearing the STDBY bit.
When Use CALOFF and CALGAIN for Calibration is
checked, the software averages the raw A/D codes for
the CALOFF and CALGAIN channels. The average is
calculated as a weighted sum of the new data and the
old average value. The Slower/Faster slide bar controls
the weight of the new data vs. the weight of the old
average.
Special Function Register (SFR)
Setting the MDOUT bit causes the raw modulator output
to be driven out the DOUT pin; however, the EV kit soft-
ware cannot read data from the MAX1402 in this mode.
The EV kit software assumes that all three transfer func-
tion registers are set to the same value.
Setting the FULLPD bit in the SFR register places the
part in full power-down mode. The master oscillator
does not run. To restore normal operation, click on the
Reset menu item in the main display. This causes the
68HC16 software to pulse the MAX1402 RESET pin.
This calibration affects only the displayed voltage, not
the raw code numbers. The average CALOFF and
CALGAIN code values are used as the endpoints of a
linear interpolation, with CALOFF measuring zero volts
and CALGAIN measuring VREF.
Transfer Function Registers (TF1, TF2, TF3)
The three Transfer Function registers (TF1, TF2, TF3)
control how input voltage is mapped to code values. The
transfer function registers control a programmable-gain
amplifier (PGA) and an offset correction DAC.
The linear interpolation formula is as follows:
VREF ⋅(Code−CALOFFcode)
Voltage =
(CALGAINcode−CALOFFcode) ⋅PGAgain
If U/B = 1, the transfer function maps unipolar voltages
between 0V and VREF. If U/B = 0, then the transfer
function maps bipolar voltages between -VREF and
+VREF. Next, the PGA increases the code-per-volt pro-
cessing gain, reducing the full-scale voltage range by a
factor of 1, 2, 4, 8, 16, 32, 64, or 128. Finally, the offset
correction DAC offsets the voltage range by up to 7/6
of the full-scale voltage range.
Sampling Tool
To sample data at full speed, select Sample from the
main display menu, make your selections, and click on
the Begin Sampling button. Sampling rate is controlled
by the Configuration tool. Sample size is restricted to a
power of two. Sample Size controls the number of sam-
ples collected on each selected channel. After the
samples have been collected, the data is automatically
uploaded to the host and is graphed. Once displayed,
the data may be saved to a file.
Input pins AIN1 and AIN2 are controlled by TF1. Input
pins AIN3 and AIN4 are controlled by TF2. Input pin
AIN5 is controlled by TF3. Input pin AIN6 is the analog
common.
While the Sampling tool is open, the other windows are
locked out. Close the Sampling tool by clicking the
Close icon in the upper corner.
When SCAN = 1, the CALOFF and CALGAIN channels
are controlled by TF3. When SCAN = 0, the CALOFF
and CALGAIN channels are controlled by one of the
transfer function registers, as selected by the A1 and
A0 bits.
Register Display Tool
This tool displays all of the internal registers of the
MAX1400/MAX1402. Modify any bit value by checking
_______________________________________________________________________________________
5
MAX1402 Evaluation Kit/Evaluation System
For simplicity, the EV kit software assumes that all three
transfer functions are configured alike.
MAX1402, except that the function of pins 5, 6, 7, and 8
is changed. Instead of the OUT1/OUT2 outputs and
DS0/DS1 inputs, these pins are used to provide access
to the analog signal between the multiplexer and the
A/D converter. Tables 2 and 3 list the jumper functions
and default settings. Refer to the MAX1400 data sheet
for detailed information.
Detailed Description
________________________of Hardware
U1, the MAX1402, is a multichannel, high-resolution
A/D converter (refer to the MAX1402 data sheet). U2,
the MAX6025, is a 2.5V reference (refer to the
MAX6025 data sheet). Y1 contains a ceramic resonator
and its load capacitors. R1–R6 together with C3–C8
form anti-aliasing input filters. R8 and C11 filter the digi-
tal power supply. The analog supply comes through fil-
ter R7/C10.
Measuring Supply Current
Supply current can be estimated by measuring the volt-
age across a series resistor. On the EV kit board, the
MAX1402 draws all of its analog and digital power
through R8, which is 10Ω. In addition, all analog supply
current flows through R7, which is also 10Ω.
Input Filtering
The EV kit has an RC filter on each input with a time
constant of approximately 0.01µs = 10ns (R = 100Ω,
C = 100pF). When scanning between channels, the RC
filter’s settling time may increase the acquisition time
required for full accuracy.
Troubleshooting
Problem: unacceptable amounts of noise in the signal.
Collect a sample of 1024 measurements at a 60Hz data
rate. Observe whether the problem is caused by 60Hz
noise.
Any AC-powered equipment connected to the analog
signal ground can inject noise. Try replacing AC-pow-
ered DVMs with battery-powered DVMs.
Evaluating the MAX1400
The MAX1400 can be evaluated by shorting across
jumpers JU6 and JU7. The MAX1400 is exactly like the
6
_______________________________________________________________________________________
MAX1402 Evaluation Kit/Evaluation System
Table 2. Jumper Functions
JUMPER
JU1
STATE
Closed*
Open
FUNCTION
Use CalGain inputs for gain calibration (CALGAIN+ = REFIN+)
Use CalGain inputs as general purpose signal inputs
Use CalGain inputs for gain calibration (CALGAIN- = REFIN-)
Use CalGain inputs as general purpose signal inputs
Use CalOff inputs for offset calibration (CALOFF+ = GND)
Use CalOff inputs as general purpose signal inputs
Use CalOff inputs for offset calibration (CALOFF- = GND)
Use CalOff inputs as general purpose signal inputs
Use on-board reference U2 (REFIN- = GND)
JU1
JU2
Closed*
Open
JU2
JU3
Closed*
Open
JU3
JU4
Closed*
Open
JU4
JU5
Closed*
Open
JU5
REFIN+ and REFIN- must be driven by an external reference
Connects pin 5 to pin 7
JU6
JU6
JU7
JU7
Closed
Open
MAX1402: pin 5 = digital input DS1, pin 7 = current source
MAX1400: normal operation
Disconnects pin 5 from pin 7
MAX1402: pin 5 = digital input DS1, pin 7 = current source
MAX1400: insert filter between mux and A/D
Connects pin 6 to pin 8
MAX1402: pin 6 = digital input DS0, pin 8 = current source
MAX1400: normal operation
Closed
Open
Disconnects pin 6 from pin 8
MAX1402: pin 6 = digital input DS0, pin 8 = current source
MAX1400: insert filter between mux and A/D
JU8
JU8
Closed*
Open
Use on-board reference U2 (REFIN+ = 2.5V)
REFIN+ and REFIN- must be driven by an external reference
*Default trace on top layer of PCB.
Table 3. Default Jumper Settings
JUMPER
JU1
STATE
Closed*
Closed*
Closed*
Closed*
Closed*
FUNCTION
Use CalGain inputs for gain calibration (CALGAIN+ = REFIN+)
Use CalGain inputs for gain calibration (CALGAIN- = REFIN-)
Use CalOff inputs for offset calibration (CALOFF+ = GND)
Use CalOff inputs for offset calibration (CALOFF- = GND)
Use on-board reference U2 (REFIN- = GND)
JU2
JU3
JU4
JU5
Disconnects pin 5 from pin 7
JU6
Open
MAX1402: pin 5 = digital input DS1, pin 7 = current source
MAX1400: insert filter between mux and A/D
Disconnects pin 6 from pin 8
JU7
JU8
Open
MAX1402: pin 6 = digital input DS0, pin 8 = current source
MAX1400: insert filter between mux and A/D
Closed*
Use on-board reference U2 (REFIN+ = 2.5V)
*Default trace on top layer of PCB.
_______________________________________________________________________________________
7
MAX1402 Evaluation Kit/Evaluation System
Table 4. Guide to Register Bit Functions
REGISTER
BIT NAME
0/DRDY
RS2–RS0
R/W
DESCRIPTION
Start bit is zero; DIN pin must be 1 when idle
COMMS
Register select for subsequent operation
Selects subsequent read or write operation
Causes software reset when set to 1
Activates standby power-down mode when set to 1
Inhibits the A/D converter when set to 1
Selects the active channel
RESET
STDBY
FSYNC
A1
GS1
A0
Selects the active channel
MF1
Selects the data output rate
MF0
Selects the data output rate
CLK
Selects the CLKIN frequency
FS1
Select the data output rate
FS0
Select the data output rate
1
3
FAST
SCAN
M1
Selects SINC filter instead of SINC
GS2
Enables the scanning sequences
Enables the CalGain channel
Enables the CalOff channel
Enables the input buffers
M0
BUFF
DIFF
Selects differential input pairs
BOUT
IOUT
X2CLK
MDOUT
FULLPD
Enables the transducer burn-out test currents
Enables the OUT1 and OUT2 current sources (MAX1402 only)
Selects the CLKIN frequency
SFR
TF1, 2, 3
DATA
Changes the DOUT and INT pins to provide raw modulator output
Activates full power-down mode. Use hardware reset to restore normal operation.
All other bits in SFR must be zero
G2–G0
U/B
Select the PGA Gain
Selects unipolar or bipolar coding
D3–D0
D17–D0
DS1
Select the offset correction DAC code; D3 = sign, D2–D0 = magnitude
Raw code value
Value of the DS1 input pin (MAX1402 only)
Value of the DS0 input pin (MAX1402 only)
Channel identification tag
DS0
CID2–CID0
8
_______________________________________________________________________________________
MAX1402 Evaluation Kit/Evaluation System
Figure 1. MAX1402 EV Kit Schematic
_______________________________________________________________________________________
9
MAX1402 Evaluation Kit/Evaluation System
Figure 2. MAX1402 EV Kit Component Placement Guide—Component Side
10 ______________________________________________________________________________________
MAX1402 Evaluation Kit/Evaluation System
Figure 3. MAX1402 EV Kit PCB Layout—Component Side
______________________________________________________________________________________ 11
MAX1402 Evaluation Kit/Evaluation System
Figure 4. MAX1402 EV Kit PCB Layout—Solder Side
Revision History
Pages changed at Rev 2: Title change—all pages, 1,
2, 3, 4, 10, 11
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.
12 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2007 Maxim Integrated Products
is a registered trademark of Maxim Integrated Products, Inc.
|