General Description
The MAX115 evaluation system (EV system) is a com-
plete, eight channel data-acquisition system consisting
of a MAX115 evaluation kit (EV kit) and a Maxim
68HC16MOD-16WIDE microcontroller (µC) module. The
MAX115 is a high speed, multichannel, 12-bit data
acquisition system with simultaneous track/holds.
Windows 3.1/Windows 95 software provides a handy
user interface to exercise the MAX115’s features.
Order the complete EV System (MAX115EVB16) for
comprehensive evaluation of the MAX115 using a per-
sonal computer. Order the EV kit (MAX115EVKIT) if the
68HC16MOD-16WIDE Module has already been pur-
chased with a previous Maxim EV system or for custom
use in other µC-based systems.
Features
♦Proven PC Board Layout
♦Complete Evaluation System Samples to 40ksps
♦Convenient Test Points Provided On-Board
♦Data-Logging Software with FFT Capability
♦Fully Assembled and Tested
Evaluates: MAX115/MAX116
MAX115 Evaluation Kit
19-2404; Rev 0; 6/01
Ordering Information
PART TEMP. RANGE INTERFACE TYPE
MAX115EVKIT 0°C to +70°C User-Supplied
MAX115EVB16 0°C to +70°C Windows Software
MAX116EVKIT 0°C to +70°C User-Supplied
MAX116EVB16 0°C to +70°C Windows Software
PART QTY DESCRIPTION
MAX115EVKIT 1 MAX115 Evaluation Kit
68HC16 MOD-
16WIDE 168HC16 µC Module with 16-bit
parallel interface
PART QTY DESCRIPTION
MAX116EVKIT 1 MAX116 Evaluation Kit
68HC16 MOD-
16WIDE 168HC16 µC Module with 16-bit
parallel interface
MAX116EVB16 System Component List
MAX115EVB16 System Component List
DESIGNATION QTY DESCRIPTION
C1, C2, C4, C5,
C6, C9, C10 70.1µF ceramic 1206 chip
capacitors
C3, C8 2 10µF, 25V tantalum capacitors
C7 1 4.7µF, 6.3V tantalum capacitor
C11 1 100pF ceramic 1206 chip
P1, P2 2 2 x 20 right angle sockets
R1, R6 2 100Ω ±1% 1206 chip resistors
R2, R3, R4, R5 4 10kΩ ±5% 1206 chip resistors
R7, R8 1 10Ω ±5% 1206 chip resistors
U1 1 Maxim MAX115CAX or
MAX116CAX
U2 1 78L05 voltage regulator
U3 1 74HCT244
U4 1 79L05 negative voltage regulator
U5 1 16MHz clock oscillator module
NONE 1 PC board
NONE 1 Software disk, “MAX115
Evaluation Kit”
MAX115EVKIT/MAX116EVKIT Parts List
INSTALL.EXE Installs the EV kit files on your computer
MAX115.EXE Application program
MAX115.HLP Help file
KIT125.B16 Software loaded into 68HC16
MAX115.INI Program settings
UNINST.EXE Removes the EV kit files from your computer
MAX115 EV Kit File List
________________________________________________________________ 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.
Evaluates: MAX115/MAX116
MAX115 Evaluation Kit
2 _______________________________________________________________________________________
MAX115 Stand-Alone EV Kit
The MAX115 EV kit provides a proven PC board layout
to facilitate evaluation of the MAX115. It must be inter-
faced to appropriate timing signals for proper opera-
tion. Dual power supplies (±8VDC min, ±20VDC max)
should be applied to P1-5, P1-9, with ground at P1-1.
Connect active-low read strobe to P1-38, connect write
strobe to P1-37, and connect memory mapped chip
selects to P1-35 and P1-36. Refer to Figure 1, MAX115
EV Kit Schematic for board schematic. Refer to the
MAX115 data sheet for timing requirements.
MAX115 EV System
The MAX115/MAX116 EV systems operate from a user-
supplied +13V to +20V DC power supply. Windows
3.1/95 software running on an IBM PC interfaces to the
EV system board through the computer’s serial commu-
nications port. The software can be operated with or
without a mouse. Refer to Quick Start section for setup
and operating instructions.
The MAX115 software is designed for use with the
complete evaluation system MAX115EVB16 or
MAX116EVB16 (includes 68HC16MOD-16WIDE mod-
ule together with MAX115EVKIT or MAX116EVKIT). If
the MAX115 evaluation software will not be used, the
MAX115EVKIT board can be purchased by itself with-
out the microcontroller.
To evaluate the MAX116, order the complete evaluation
system MAX116EVB16 or just the interface board
MAX116EVKIT.
Quick Start
Before you begin, you will need:
•Maxim’s MAX115EVB16 (contains MAX115EVKIT
board and 68HC16MOD-16WIDE)
•A small DC power supply (+13V to +20V DC at
250mA)
•An IBM PC-compatible computer running Windows
3.1 or Windows 95
•A spare serial communications port (9-pin plug)
•A serial cable to connect the computer’s serial port
to the Maxim 68HC16MOD-16WIDE module
1) Carefully connect the boards by aligning the two
40-pin headers of the MAX115 EV kit with the two
40-pin connectors of the 68HC16MOD-16WIDE
module. Gently press them together. The two
boards should be flush against one another.
2) Connect a +13V to +20V DC 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.
3) 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.
4) Install the MAX115 EV kit software on your comput-
er by running the INSTALL.EXE program on the
floppy disk. The program files are copied and icons
are created for them in the Windows 3.1 Program
Manager (or the Windows 95 Start Menu).
5) Start the MAX115 program by opening its icon in
the Program Manager (or Start Menu).
6) 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
click OK. The program will automatically download
KIT125.B16 to the module.
7) Apply input signals to the inputs labeled CH1A-
CH4A at the bottom edge of the MAX115 EV kit
board. Observe the readout on the screen.
Detailed Description
of Software
The MAX115 digitizes up to four inputs from either the A
or B input bank. Conversion time is determined by the
number of enabled inputs. The software collects sam-
ples at a maximum throughput of 40ksps (one channel)
to 26ksps (four channels). The various program func-
tions are grouped into dialog boxes, which are accessi-
ble from the Window menu on the main menu bar.
Keyboard Navigation
If a mouse or other pointing device is not available,
operate the program using the following keyboard
shortcuts. Press ALT+W to bring up the Window menu
and then select a tool window. Press the TAB key to
select controls within the selected tool window. Buttons
are activated by pressing the space bar. Check boxes,
radio buttons, and combo boxes respond to the
up/down arrow keys. Refer to Table 1, Keyboard
Navigation Shortcuts.
Table 1. Keyboard Navigation Shortcuts
Low-Speed Data Logging
Readings can be taken automatically from user-selected
channels at regular intervals up to ten samples per sec-
ond by selecting “Scan Tool” from the “Window”menu.
The Channel Selection and Configuration group con-
trols which channels shall be scanned, and (where
applicable) configures each channel for bipolar and/or
differential input. The Bipolar and Differential controls
are disabled because the MAX115 inputs are always
bipolar and never differential. The scan rate combo box
controls the rate at which measurements are made.
Readings are displayed in the Recent Values text
area. Readings may optionally be recorded into a data
log file. Click on the “New Log” button to begin or end
data logging. This brings up the "Log File Format" dia-
log box. One complete line of data is written after all
enabled channels have been sampled. The first line of
the log file contains the column headings. Each subse-
quent line of the log file contains all enabled channels,
separated by commas, tabs, or spaces (previously
selected in the Log File Format dialog box). Once a log
file has been opened, it can be paused or resumed
with the corresponding Log menu commands. The pro-
gram continues to write data to the log file until the
Stop Log button is clicked.
One-Shot Read Tool
The One-Shot Read Tool allows direct control of the
A/D configuration. Select the channel and mode of
operation to update the Control Byte display, or
change the Control Byte bits directly and observe the
change in the channel selection control. The Read Now
button writes the configuration information to the A/D,
and performs one reading.
Power Cycling Tool
To reduce average supply current demand, the
MAX115 can be shut down between conversions. From
the “Window” menu, select “Power Cycling Tool”. The
amount of power savings depends primarily on how
long the part is off between conversions. The accuracy
of the conversions depends on the power-up delay, the
reference capacitor, and the time in power-down.
Adjust the off-time with the delay between samples
command. Adjust the on-time with the power-up delay
command.
Using an adequate power-up delay will ensure the
desired conversion accuracy during power cycling
modes. The reference must be allowed enough time to
stabilize before the measurement is performed. Start
with zero power-up delay and increase the delay time
until no further change in accuracy is observed. The
power-up delay requirement depends on the value of
the reference capacitor and the off-time.
The MAX115 EV kit software performs power-up by
writing a configuration word with the shutdown bit set.
After powering up, the power-up delay is executed to
allow time for the reference voltage to stabilize so that
an accurate measurement may be performed.
Sampling Tool
To sample data at rates up to 40ksps (samples per
second), select “Sampling Tool” from the “Window”
menu, make your selections, and click on the Start but-
ton. The timing delays may be adjusted as appropriate
to control the sample rate. The effective sample rate
can be estimated by taking the reciprocal of the sum of
the delay between samples, the power-up delay and
the conversion time. Sample size is restricted to a
power of two, so that the data can be processed by the
FFT tool. The sample size control controls the number
of samples collected on each selected channel. After
the samples have been collected, the data is automati-
cally uploaded to the host and is graphed. Once dis-
played, the data can optionally be saved to a file.
FFT Tool
The MAX115 evaluation software includes an FFT (Fast
Fourier Transform) tool that can display the spectral
content of data collected with the high-speed sampling
tool. To view the spectral content of a waveform, first
select a data sample that was previously collected with
the high-speed sampling tool. Then, select “FFT Tool”
from the “Window” menu. Check the output plots
desired, and click on the Start button. A data window-
ing function preprocesses a data sample before per-
forming the FFT. When the input signal is not synchro-
nized to the sampling clock, spectral energy appears
to leak into nearby frequency buckets. A suitable data
Evaluates: MAX115/MAX116
MAX115 Evaluation Kit
_______________________________________________________________________________________ 3
KEY FUNCTION
TAB Select next control
ALT + W Window menu
ALT + space System menu of main program window
ALT + minus System menu of child window
Space Bar Click on the selected button
ALT + Print
Screen
Copy the image of main window onto the
clipboard
Evaluates: MAX115/MAX116
window tapers the raw data to zero amplitude at the
beginning and end, reducing this spectral leakage. For
more information on the fast fourier transform and data
windowing functions, refer to W.H.Press et al,
Numerical Recipes in Pascal: the Art of Scientific
Computing, Cambridge University Press, 1989, ISBN 0-
521-37516-9.
Device Characteristics
The device characteristics dialog box contains parame-
ters that are not expected to change often. The device
selection is used to evaluate devices similar to the main
device type.
Evaluating the MAX116
The MAX115 software can evaluate the MAX116 directly.
From the “Window” menu, pick “Device Characteristics”.
Next, change the device type from MAX115 to MAX116.
This tells the program that the input voltage span is
±VREF instead of ±2VREF.
Changing the Reference Voltage
The MAX115 EV kit software assumes a +2.5V refer-
ence voltage, unless otherwise specified. Apply an
external +2.5V reference to the REFIN pad to overdrive
the internal reference. See the MAX115 data sheet for
more information. From the “Window” menu, select
“Device Characteristics”. Type the new reference volt-
age into the reference voltage edit box.
Detailed Description
of Hardware
The MAX115 (U1) is a high-speed, multichannel, 12-bit
data-acquisition system with simultaneous track/holds.
Linear regulators (U2 and U4) make clean analog ±5V
power supplies for the MAX115. R8 and C1 filter digital
noise out of the analog power supply. U3 isolates the
CS, RD, WR, and CONVST signals from the main sys-
tem bus to further prevent digital noise from entering
the MAX115. Refer to Figure 1, MAX115 EV Kit
Schematic and the MAX115 data sheet.
CS7 is the chip-select output for the 7E000 memory-
mapped I/O area, which the EV system uses to write
the configuration byte to, and read data from the
MAX115. CS8 is the chip-select output for the 7E800
memory-mapped I/O area, which the EV system uses to
generate the conversion start strobe that signals the
MAX115 to sample its inputs.
Measuring Supply Current
EV kit supply current can be monitored by measuring the
voltage across resistor R1 (for the +5V supply) or R6 (for
the -5V supply). These resistors are 100Ω±1%, thus
0.001V across R1 represents 10µA of supply current.
Troubleshooting
Problem: No output measurement. System seems to
report zero voltage, or fails to make a measurement.
Check +5V and -5V supply voltages. Check the 2.5V
REFOUT reference voltage using a digital voltmeter.
Use an oscilloscope to verify that the 16MHz clock is
running and that the conversion-start signal is being
strobed.
Problem: Measurements are erratic, unstable; poor
accuracy.
Check the reference voltage using a digital voltmeter.
Use an oscilloscope to check for noise. When probing
for noise, keep the oscilloscope ground return lead as
short as possible, preferably less than 1/2 in (10mm).
Problem: Inputs appear on wrong channels.
Check the MAX115 clock pin with an oscilloscope. A
crystal oscillator module with fast rise/fall times can
overshoot or undershoot the power supply rails, violat-
ing device operation limits. Use a lowpass filter (such
as R7 and C11 on the MAX115 EV kit) to eliminate
clock overshoot.
MAX115 Evaluation Kit
4 _______________________________________________________________________________________
Evaluates: MAX115/MAX116
MAX115 Evaluation Kit
_______________________________________________________________________________________ 5
4
3
2
1
35
34
33
32
25
CH1A
R8
10Ω
CH1B
CH2A
CH2B
CH3B
CH3A
CH4B
CH4A
CLK
+5V
JU1 C11
100pF
C5
0.1µF
C6
0.1µF
21
22
23
24
17 5
MAX115
MAX116
U1
15
16
19
20
13
14
6
7
9
10
11
12
27
28
30
P2-4
P2-3
P2-2
P2-1
P1-38
P1-37
P2-8
P2-7
P2-6
P2-5
P2-10
P2-9
P2-14
P2-13
P2-12
P2-11
P1-20
26
18
29 8
36
A0
A1
D0/A2 (LSB)
D1/A3
D2
D3
D4
D5
D6
D7
D8
D9
D10
D11
INT
RD
WR
CS
CONVST
DGND
AVSS
CH1A
CH1B
CH2A
CH2B
CH3B
CH3A
CH4B
CH4A
CLK
REFIN
REFOUT
AGND
AGND
P1-6
P1-5 1
2
3
45
6
7
8IN
GND
GND
N.C.
OUT
GND
GND
N.C.
CS8
CS7
+5V
GND
P1-4
P1-3
P1-2
P1-1
REFIN
C7
4.7µF
6.3V
REFOUT
DVDD AVDD
U2
LM78L05ACM
C1
0.1µF
R7
10Ω
+5V
R3
10kΩ
R6
100Ω
R5
10kΩ
R4
10kΩ
R2
10kΩ
C2
0.1µF
+5V
C4
0.1µF
R1
100Ω
+12V C3
10µF
25V
P1-9 1
2
3
45
6
7
8N.C.
IN
IN
GND
OUT
IN
IN
N.C.
-5V
-12V
U4
LM79L05ACM
C9
0.1µF
C10
0.1µF
C8
10µF
25V
1
78
14
U5
16MHz
OSCILLATOR
9
74HCT244
7
5
317
15
13
11 A0
A1
A2
A3
Y0
Y1
Y2
Y3
19 OE
U3B
18
74HCT244
16
14
128
6
+5V
+5V
+5V
+5V
4
2A0
A1
A2
A3
Y0
Y1
Y2
Y3
1OE
P1-36
P1-35
CS8/7E800
U3A
RD
WR
31
CS7/7E000
Figure 1. MAX115/MAX116 EV Kit Schematic
Evaluates: MAX115/MAX116
MAX115 Evaluation Kit
6 _______________________________________________________________________________________
Figure 2. MAX115/MAX116 EV Kit Component Placement
Guide Figure 3. MAX115/MAX116 EV Kit PC Board Layout —
Component Side
1.0"
Evaluates: MAX115/MAX116
MAX115 Evaluation Kit
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.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 _____________________ 7
© 2001 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.
Figure 4. MAX115/MAX116 EV Kit PC Board Layout — Solder
Side
1.0"
