19-1738; Rev 0; 6/00
MAX1284 Evaluation System
General Description
The MAX1284 evaluation system (EV system) is a com-
plete data-acquisition system consisting of a MAX1284
evaluation kit (EV kit) and a Maxim 68HC16MODULE-
DIP microcontroller (µC) module. The MAX1284 is a
high-speed, 12-bit data acquisition system. Windows
95/98
®
software provides a handy user interface to
exercise the MAX1284’s features.
Order the complete EV system (MAX1284EVC16) for
comprehensive evaluation of the MAX1284 using a PC.
You can order the EV kit (MAX1284EVKIT) if the
68HC16MODULE-DIP module has already been pur-
chased with a previous Maxim EV system, or for custom
use in other µC-based systems.
o
Proven PC Board Layout
o
Convenient On-Board Test Points
o
Data-Logging Software
o
Fully Assembled and Tested
Features
Evaluates: MAX1284
Ordering Information
PART
MAX1284EVKIT
MAX1284EVC16
TEMP. RANGE
0°C to +70°C
0°C to +70°C
INTERFACE TYPE
User supplied
Windows software
EV System Component List
PART
MAX1284EVKIT
68HC16MODULE-DIP
QTY
1
1
DESCRIPTION
MAX1284 EV kit
68HC16
µC
module
Note:
The MAX1284 software is designed for use with the com-
plete MAX1284EVC16 EV system (includes 68HC16MODULE-
DIP module together with MAX1284EVKIT). If the MAX1284 eval-
uation software will not be used, the MAX1284EVKIT board can
be purchased by itself, without the µC.
EV Kit Component List
DESIGNATION QTY
C1
C2, C3
C4
C5
J1
JU1
JU2
R1
TP1
U1
None
None
None
None
1
2
1
1
1
1
1
1
1
1
1
1
1
1
DESCRIPTION
0.01µF ceramic capacitor
0.1µF ceramic capacitors
4.7µF tantalum capacitor
10µF, 10V tantalum capacitor
2x20 right-angle socket
2-pin header
3-pin header
1kΩ
±5%
resistor
6-pin header
MAX1284BCSA
MAX1284 EV kit PC board
3-1/2in software disk,
MAX1284 EV kit
MAX1284 EV kit data sheet
MAX1284 data sheet
FILE
INSTALL.EXE
MAX1284.EXE
KIT1284.C16
EV Kit Component List
DESCRIPTION
Installs the EV kit files on your computer
Application program
Software loaded into 68HC16
µC
Recommended Equipment
Before you begin, you will need the following equip-
ment:
• Maxim MAX1284EVC16 (contains MAX1284EVKIT
board and 68HC16MODULE-DIP)
• A small DC power supply, such as a 12VDC 0.25A
plug-in transformer or a 9V battery
• An IBM PC-compatible computer running Windows
95/98
• A spare serial communications port, preferably a
9-pin plug
• A serial cable to connect the computer’s serial port to
the 68HC16MODULE-DIP
Windows 95/98 is a registered trademark of Microsoft Corp.
________________________________________________________________
Maxim Integrated Products
1
For free samples and the latest literature, visit www.maxim-ic.com or phone 1-800-998-8800.
For small orders, phone 1-800-835-8769.
MAX1284 Evaluation System
Evaluates: MAX1284
Quick Start
1) Carefully connect the boards by aligning the 40-pin
header of the MAX1284 EV kit with the 40-pin con-
nector of the 68HC16MODULE-DIP module, both
boards component-side up. Gently press them
together. The two boards should be flush against
one another.
2) Ensure that JU1 is open and JU2 is in the 1-2 posi-
tion.
3) Connect a +7VDC to +20VDC power source to the
µC module at the terminal block located next to the
on/off switch, along the top edge of the µC module.
Observe the polarity marked on the board.
4) 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.
5) Install the MAX1284 EV kit software on your com-
puter 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.
6) Start the MAX1284 program by opening its icon in
the Start menu.
7) The program will prompt you to connect the µC
module and turn its power on. Slide SW1 to the ON
position. Select the correct serial port and press
OK. The program will automatically download
KIT1284.C16 to the module.
8) Apply an input signal between AIN and GND.
Observe the readout on the screen.
Software Description
The evaluation software’s main window controls the
serial-clock speed and sample rate. It displays the volt-
age and output code as well as some statistics of the
input signal. A separate graph window shows the data
changing in real time. The update rate is limited to
about 10 samples per second, due to COM port band-
width limitations.
Statistics
The
Minimum
and
Maximum
fields show the highest
and lowest readings acquired. The
Average
field
shows a running mean based on the equation
a
i
= (k)(x
i
) + (1 - k)(a
i - 1
). The
Clear
button resets the
statistics. To remove offset errors, first apply 0V to the
active input channel, clear statistics, acquire some
samples, and then check
Tare.
This average offset
voltage will now be subtracted from all subsequent
measurements.
Sampling
Choose the desired sampling rate (QSPI™ Clock),
sampling size (Sample! menu item), and press Begin
Sampling! (in Sample! pop-up window). Sample size is
restricted to a power of 2 to permit FFT processing
once the data is saved to a file. After the samples have
been collected, the data is automatically uploaded to
the host and graphed. Once displayed, the data can
be saved optionally to a file.
Saving Graphs to Disk
Data in the real-time graph and in sampled data graphs
may be saved to a file. Only the raw output codes are
saved, but voltages may be inferred, based on the ref-
erence voltage and the maximum code value.
Evaluating Shutdown
The evaluation software configures the 68HC16’s QSPI
submodule to continuously read data from the
MAX1284 into the 68HC16. The sample rate is con-
trolled by the QSPI clock. To evaluate power-saving
modes, these automatic updates must be stopped.
First, set the QSPI clock control to
STOP.
This reconfig-
ures the 68HC16’s QSPI submodule to stop driving the
serial clock. Second, in the evaluation software’s main
window, uncheck the “Read Every...msec” checkbox. If
evaluating the hardware shutdown, move jumper JU2
to the 2-3 position.
Detailed Description
MAX1284 Stand-Alone EV Kit
The MAX1284EVKIT provides a proven PC board layout
to evaluate the MAX1284. It must be interfaced to
appropriate timing signals for proper operation.
Connect +5V to VDD, and connect the ground return to
GND (Figure 1). Refer to the MAX1284 data sheet for
timing requirements.
MAX1284 EV System
The MAX1284EVC16 EV system operates from a user-
supplied +7VDC to +20VDC power supply. Windows
95/98 software running on an IBM PC interfaces to the
EV system board through the computer’s serial commu-
nications port. See the
Quick Start
section for setup
and operating instructions.
2
Reference Voltage
The evaluation software assumes a 2.5V reference volt-
age, unless otherwise specified. Refer to the MAX1284
data sheet for more information. To override this value,
type the new reference voltage into the
Vref
edit box
and press the
Set Vref
button.
QSPI is a trademark of Motorola, Inc.
_______________________________________________________________________________________
MAX1284 Evaluation System
Evaluates: MAX1284
GND
J1-1
J1-2
J1-3
J1-4
VDD
VDD
C2
0.1µF
JU1
SHDN
3
6
J1-33
J1-34
J1-35
J1-37
J1-38
CS
DOUT
DOUT
SCLK
CS
C3
0.1µF
C4
4.7µF
VREF
(2.5V NOMINAL)
8
7
SHDN
DOUT
SCLK
CS
V
DD
1
2
4
5
C1
0.01µF
R1
1k
AIN
3 JU2
2
1
GND
C5
10µF
J1-7
J1-8
J1-28
J1-30
SCLK
UPSHDN
U1
MAX1284
AIN
REF
GND
TP1-1
TP1-2
TP1-3
TP1-4
TP1-5
TP1-6
GND
VDD
SCLK
CS
DOUT
SHDN
J1-25
J1-26
J1-27
J1-29
J1-31
J1-32
J1-36
J1-19
J1-20
J1-21
J1-22
J1-23
J1-24
J1-40
J1-13
J1-14
J1-15
J1-16
J1-17
J1-18
J1-39
J1-5
J1-6
J1-9
J1-10
J1-11
J1-12
Figure 1. MAX1284 EV Kit Schematic Diagram
Detailed Hardware
Description
The MAX1284, U1, is a high-speed, 12-bit data-acqui-
sition system. Resistor R1 (1kΩ) and capacitor C1
(0.01µF) form a single-pole, low-pass anti-aliasing filter
with a nominal 10µs time constant and a corner fre-
quency of approximately 16kHz. C3 and C4 bypass the
analog-to-digital converter’s (ADC’s) voltage reference.
When plugged into the 68HC16MODULE, the V
DD
cir-
cuit is powered by +5V (Figure 1; refer to the MAX1284
data sheet).
Problem:
Measurements are erratic, unstable; poor
accuracy.
Check the reference voltage using a DVM. Use an oscil-
loscope to check for noise. When probing for noise,
keep the oscilloscope ground return lead as short as
possible, preferably less than 1/2in (10mm).
Table 1. Jumper JU1 Functions
JUMPER
POSITION
Closed
JU1
Open*
1-2*
JU2
2-3
Shutdown
FUNCTION
SHDN
driven by
µC;
JU2 must be
open
SHDN
set by JU2
Operate
Troubleshooting
Problem:
No output measurement. System seems to
report zero voltage or fails to make a measurement.
Check the V
DD
supply voltage. Check the reference volt-
age using a DVM. Use an oscilloscope to verify that the
conversion-start signal is being strobed. Verify that
SHDN
is being driven high.
*Default
configuration
_______________________________________________________________________________________
3
MAX1284 Evaluation System
Evaluates: MAX1284
1.0"
Figure 2. MAX1284 EV Kit Component Placement Guide—
Component Side
1.0"
1.0"
Figure 3. MAX1284 EV Kit PC Board Layout—Component Side
Figure 4. MAX1284 EV Kit PC Board Layout—Solder Side
4
_______________________________________________________________________________________
19-1322; Rev 0; 12/97
68HC16 Module
_____________________________________________68HC16 Module Component List
DESIGNATION
C1, C2, C3
C4, C5
C6, C7
C8
C9
C10–C14
D1
J1
J2
J3
J4
JU1
JU2
JU3
JU4
JU5
L1
L2
LED1
R1
QTY
3
2
2
1
0
5
1
1
1
1
0
0
0
0
0
0
0
0
1
1
DESCRIPTION
1µF ceramic capacitors
22µF, 25V radial-lead electrolytic
capacitors
22pF capacitors
0.01µF capacitor
Reference designator, not used
0.1µF capacitors
1N4001 diode
40-pin right-angle male connector
2-circuit terminal block
Right-angle printed circuit board
mount, DB9 female socket
Open
Open
Reference designator, not used
Open
Open
Open
Open
Open
Light-emitting diode
10MΩ, 5% resistor
DESIGNATION
R2
R3, R4
R5
R6
SW1
SW2
U1
U2
U3
U4
U5
U6
U7
Y1
None
None
None
None
None
QTY
1
2
1
1
1
1
1
1
1
1
1
1
1
1
4
1
1
1
1
DESCRIPTION
330kΩ, 5% resistor
10kΩ, 5% resistors
470Ω, 5% resistor
10kΩ SIP resistor
Slide switch
Momentary pushbutton switch
68HC16 µC
MC68HC16Z1CFC16 (132-pin
plastic quad flat pack)
Maxim MAX233CPP
27C256 EPROM containing
monitor program
7805 regulator, TO-220 size
62256 (32K x 8) static RAM
74HCT245 bidirectional buffer
Maxim MAX707CPA
32.768kHz watch crystal
Rubber feet
28-pin socket for U3
20-pin socket for U6
3" x 5" printed circuit board
Heatsink for U4, thermalloy # 6078
68HC16 Module
68HC16 Module
________________General Description
The 68HC16 module is an assembled and tested print-
ed-circuit board intended for use with Maxim’s high-
speed serial-interface evaluation kits (EV kits). The
module uses an inexpensive 8-bit implementation of
Motorola’s MC68HC16Z1 microcontroller (µC) to collect
data samples at high speed using the QSPI™ interface.
It requires an IBM-compatible personal computer and
an external DC power supply, typically 12V DC or as
specified in EV kit manual.
Maxim’s 68HC16 module is provided to allow customers
to evaluate selected Maxim products. It is not intended
to be used as a microprocessor development platform,
and such use is not supported by Maxim.
68HC16 Module
________________Detailed Description
Power Input Connector J2
The 68HC16 module draws its power from a user-sup-
plied power source connected to terminal block J2. Be
sure to note the positive and negative markings on the
board. A three-terminal 5V regulator allows input voltages
between 8V and an absolute maximum of 20V. The
68HC16 module typically requires 200mA of input current.
68HC16 Microcontroller
U1 is Motorola’s 68HC16Z1 µC. Contact Motorola for µC
information, development, and support. Maxim EV kits use
the high-speed queued serial peripheral interface (QSPI)
and the internal chip-select generation.
A MAX707 on the module monitors the 5V logic supply,
generates the power-on reset, and produces a reset
pulse whenever the reset button is pressed.
QSPI is a trademark of Motorola Corp.
________________________________________________________________ Maxim Integrated Products
1
For free samples and the latest literature, visit www.maxim-ic.com or phone 1-800-998-8800.
For small orders, phone 1-800-835-8769.
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