_______________General Description
The MAX197 evaluation system (EV system) is a com-
plete, low-cost, 8-channel data-acquisition system con-
sisting of a MAX197 evaluation kit (EV kit) and a Maxim
80C32 or 68HC16 microcontroller (µC) module. IBM
PC compatible software provides a handy user inter-
face to demonstrate the MAX197's many features.
Source code is provided.
The MAX197 EV kit requires a single +5V supply and
includes optional input buffer amplifiers that operate
with ±15V supplies.
The MAX197 EV kit and EV system evaluate both the
MAX197 and the MAX199. To evaluate the MAX199,
order a sample of the MAX199 along with the MAX197
EV kit.
____________________________Features
o
Proven PC Board Layout
o
Complete Evaluation System
o
Convenient Test Points Provided On-Board
o
Data Logging Software
o
Source Code Provided
o
Fully Assembled and Tested
o
User-Selected Microcontroller Module 80C32
or 68HC16
Evaluates: MAX197/MAX199
MAX197 Evaluation Kit
________________________________________________________________
Maxim Integrated Products
1
Call toll free 1-800-998-8800 for free samples or literature.
19-0398; Rev 1; 7/95
PART
TEMP. RANGE
BOARD TYPE
MAX197EVKIT-DIP
0°C to +70°C
Through-Hole
68HC16 Module
MAX197 EV Kit
______________Ordering Information
____________
MAX197 EVC16 System
___________________Component List
____________
MAX197 EVC32 System
____________________Component List
_____________________________________________________MAX197 EVC16 System
MAX197EVC16-DIP
0°C to +70°C
Through-Hole
MAX197EVC32-DIP
0°C to +70°C
Through-Hole
QTY
DESCRIPTION
1
MAX197 Evaluation Kit (MAX197EVKIT-DIP)
1
68HC16 µC Module (68HC16MODULE-DIP)
QTY
DESCRIPTION
1
MAX197 Evaluation Kit (MAX197EVKIT-DIP)
1
80C32 µC Module (80C32MODULE-DIP)
Evaluates: MAX197/MAX199
MAX197 Evaluation Kit
2
_______________________________________________________________________________________
_______MAX197 Stand-Alone EV Kit
The MAX197 EV kit provides a proven PC board layout
to facilitate evaluation of the MAX197. It must be inter-
faced to appropriate timing signals for proper opera-
tion. Refer to the MAX197 data sheet for timing require-
ments.
___MAX197 EV System Quick Start
1) Copy the files from the distribution disk to your hard
disk or to blank floppy disks. The MAX197 EV kit
software should be in its own directory. The neces-
sary files are in the root directory of the distribution
disk, and the source code is in the SOURCE sub-
directory. The SOURCE subdirectory is not
required to operate the EV kit.
2) Carefully connect the boards together by aligning
the 40-pin header of the MAX197 EV kit with the 40-
pin connector of the µC module. Gently press them
together. The two boards should be flush against
each other.
3) Connect a +15V/-15V DC power supply to the
OPAMP V+ / OPAMP V- inputs of the MAX197 EV
kit. Connect the power supply's COMMON terminal
to the kit's AGND pad.
4) Connect a 9V to 15V DC power source to the µC
module. The terminal block is located next to the
on/off switch, in the upper right corner of the µC
module. Observe the polarity marked on the board.
The same +15V supply that powers OPAMP V+ can
be used to power the µC module.
5) 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, DCD) to confirm that the correct port
has been selected.
6) Start the MAX197 software on the IBM PC by setting
the current directory to match the directory that
contains the Maxim programs, and then type the
program name, "MAX197". Do not turn off or dis-
connect the µC module while the program is run-
ning; if you do, you will have to restart the program.
7) The program will ask which µC module is being
used and to which port it is connected. Press the
space bar until the correct port is highlighted, and
press C until the correct µC module is highlighted.
Press ENTER when both are correct. The MAX197
program will be in terminal emulation mode.
8) Turn on the power for the µC module. The µC mod-
ule will display its logon banner and test its RAM.
9) Download and run the RAM resident program on
the µC module by pressing ALT+L (i.e., hold down
the ALT key as you strike the L key). The program
prompts you for the file name. Press the ENTER
key to download and run the file.
10) Press ALT+C to switch to the Control Panel screen
after the RAM resident program has been success-
fully downloaded.
11) Apply input signals to the CH0CH7 inputs at the
right edge of the MAX197 EV kit board. Observe
the readout on the screen. Table 1 lists the com-
mands available from the control-panel screen.
12) Before turning off power to the MAX197 EV kit, exit
the program by pressing ALT+X.
___MAX197 EV Kit Component List
3-pin header
2-pin header
8-pin headers
DESIGNATION
0.1µF ceramic capacitors
Open
100pF ceramic capacitor
MXL1014CN quad op amps
2
U3, U4
MAX874CPA 4.096V reference
1
U2
MAX197BCNI
1
U1
Open
0
R1, R2, R3
Open
0
JU3, JU4
1
JU2
1
JU1
2
J15, J16
2 x 20 header
1
J11
1
C11
10µF tantalum capacitors
3
C10, C14, C18
0
C2C7, C9,
C12, C13
5
C1, C8, C15,
C16, C17
DESCRIPTION
QTY
Evaluates: MAX197/MAX199
MAX197 Evaluation Kit
_______________________________________________________________________________________
3
__Detailed Description of Software
Reading the MAX197
The EV kit reads the MAX197 using the algorithm
shown in source code Listings 1a and 1b.
When power is first applied, the MAX197 is in external
clock mode. However, the initialization software recon-
figures the MAX197 to internal clock mode.
The EV kit software demonstrates the MAX197's many
modes of operation. When writing your own application-
specific software, one of the following simplified algo-
rithms (shown in bold type) should be implemented.
These algorithms show the options available using the
power-down and acquisition mode control bits. Except
where otherwise specified, ACQMOD = 0.
When using an external reference, a power-up delay is
not necessary. When using the MAX197's internal ref-
erence, allow time for the REF capacitor to charge at
power-up and when exiting full power-down mode. For
a complete description of all control bits, refer to the
MAX197 data sheet.
Internal acquisition mode, standby power-down
between conversions:
1) Begin conversion by writing PD1 = 1, PD0 = 0. This
powers up the MAX197, causing it to perform a
conversion, then go into standby mode after con-
version completes.
2) After the INT pin goes low, read the result from the
MAX197.
Internal acquisition mode, full power-down between
conversions:
1) Power up the MAX197 by writing PD1 = 1, PD0 = 0
(standby).
2) Execute a power-up delay, to allow the reference
capacitor time to recharge.
3) Begin conversion by writing PD1 = 1, PD0 = 1 (full
power-down).
4) After the INT pin goes low, read the result from the
MAX197.
Internal acquisition mode, SHDN pin low between
conversions:
1) Power up the MAX197 by setting the SHDN pin
high.
2) Execute a power-up delay to allow the reference
capacitor time to recharge.
3) Begin conversion by writing PD1 = 1, PD0 = 0
(standby).
4) After the INT pin goes low, read the 16-bit result
from the MAX197.
5) Power down the MAX197 by setting the SHDN pin
low.
External acquisition mode, standby power-down
between conversions:
1) Begin acquisition time by writing PD1 = 1, PD0 = 0
(standby), ACQMOD = 1.
2) Execute the acquisition time delay.
3) Begin conversion by writing PD1 = 1, PD0 = 0
(standby), ACQMOD = 0.
4) After the INT pin goes low, read the result from the
MAX197.
External acquisition mode, full power-down
between conversions:
1) Power up the MAX197 by writing PD1 = 1, PD0 = 0
(standby).
2) Execute a power-up delay, to allow the reference
capacitor time to recharge.
3) Begin acquisition time by writing PD1 = 1, PD0 = 0
(standby), ACQMOD = 1.
4) Execute the acquisition time delay.
5) Begin conversion by writing PD1 = 1, PD0 = 1 (full
power-down), ACQMOD = 0.
6) After the INT pin goes low, read the result from the
MAX197.
External acquisition mode, SHDN pin low between
conversions:
1) Power up the MAX197 by setting the SHDN pin
high.
2) Execute a power-up delay, to allow the reference
capacitor time to recharge.
3) Begin acquisition time by writing PD1 = 1, PD0 = 0
(standby), ACQMOD = 1.
4) Execute the acquisition time delay.
5) Begin conversion by writing PD1 = 1, PD0 = 0
(standby), ACQMOD = 0.
6) After the INT pin goes low, read the result from the
MAX197.
7) Power down the MAX197 by setting the SHDN pin
low.
Evaluates: MAX197/MAX199
MAX197 Evaluation Kit
4
_______________________________________________________________________________________
Listing 1a. Using the 68HC16 to Read the MAX197
Evaluates: MAX197/MAX199
MAX197 Evaluation Kit
_______________________________________________________________________________________
5
Listing 1b. Using the 80C32 to Read the MAX197
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