19-1197; Rev 0; 3/97
E
MODUL
6811D
BLE
AVAILA
MAX1202 Evaluation Kit
____________________________Features
o
Proven PC Board Layout
o
Complete Evaluation System
o
Convenient On-Board Test Points
o
Data-Logging Software
o
3V/5V Logic Interface
o
Fully Assembled and Tested
_______________General Description
The MAX1202 evaluation system (EV system) is a com-
plete, 8-channel data-acquisition system consisting of a
MAX1202 evaluation kit (EV kit) and a Maxim 3V
68L11D microcontroller (µC) module.
The MAX1202 is a low-power, +5V, 8-channel, 12-bit
analog-to-digital converter (ADC) that connects directly
to 3V and 5V microprocessors (µPs). Windows 3.1™/
Windows 95™ software provides a handy user interface
to exercise the MAX1202’s features.
Order the EV system for comprehensive evaluation of
the MAX1202 using a personal computer. Order the EV
kit if you have already purchased the 68L11D µC mod-
ule with a previous Maxim EV system, or for custom use
in other µC-based systems.
The MAX1202 EV kit and EV system can also be used
to evaluate the MAX1203. Simply order a free sample of
the MAX1203BCPP along with the MAX1202 EV kit. For
3V-only applications, refer to the MAX147 data sheet.
Evaluates: MAX1202/MAX1203
______________Ordering Information
PART
MAX1202EVKIT-DIP
MAX1202EVL11-DIP
TEMP. RANGE
0°C to +70°C
0°C to +70°C
BOARD TYPE
Through-Hole
Through-Hole
____________________Component List
DESIGNATION
C1–C8, C13
C9, C10, C11,
C14, C15
C12
J1
JU1, JU2
JU3
JU4
R1–R8
TP1
U1
U2
U3
None
None
QTY
9
5
1
1
2
1
0
8
1
1
1
1
1
1
1
DESCRIPTION
0.01µF ceramic capacitors
0.1µF ceramic capacitors
4.7µF, 10V tantalum capacitor
2 x 20 right-angle socket
3-pin jumper blocks
2-pin jumper block
Open
300Ω, 5% resistors
8-pin header
Maxim MAX1202BCPP
20-pin socket
Maxim ICL7660CPA
78L05 voltage regulator
PC board
Software disk,
“MAX1202 EVALUATION KIT”
MAX1202EVL11
___________System Component List
PART
MAX1202EVKIT-DIP
68L11DMODULE
QTY
1
1
DESCRIPTION
MAX1202 Evaluation Kit
68L11D µC Module
_____MAX1202 Stand-Alone EV Kit
The MAX1202 EV kit provides a proven PC board lay-
out to facilitate evaluation of the MAX1202. It must be
interfaced to appropriate timing signals for proper
operation. Refer to the MAX1202 data sheet for timing
requirements.
Cut JU4 and apply the +5V analog supply between the
+5V pad and the pad marked GND. Connect the
VLOGIC pad to the microprocessor's power supply. Set
JU1 to the 2-3 position (V
SS
= -5V) to allow input sig-
nals between ±4V (Table 1).
Windows is a registered trademark of Microsoft Corporation.
________________________________________________________________
Maxim Integrated Products
1
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800
MAX1202 Evaluation Kit
Evaluates: MAX1202/MAX1203
______________MAX1202 EV System
The MAX1202 EV system operates from a user-
supplied 9V to 15V DC power supply. The Maxim
68L11D 3V µC board uses a MAX667 linear regulator to
generate the 3V logic supply. The MAX1202 board
uses a 78L05 linear regulator to generate its own 5V
analog supply. No level translators are necessary
because the MAX1202 VL pin is connected to the 3V
logic supply.
Table 1. Jumper Functions
∫
JUMPER
JU1
STATE
1-2
2-3
Open
1-2
2-3
FUNCTION
V
SS
tied to GND
V
SS
tied to -5V
V
SS
must be supplied by the user.
SHDN
tied to GND; power-down
SHDN
tied to +5V; internal com-
pensation
SHDN
floating; external compen-
sation
REFADJ = +5V; VREF must be
supplied by the user.
REFADJ = open; VREF = 4.096V
internal reference (MAX1202)
Quick Start
1) Install the MAX1202 EV kit software on your comput-
er by running the
INSTALL.EXE
program on the flop-
py disk. The Windows 3.1 Program Manager (or the
Windows 95 Start Menu) copies the program files
and creates icons for them.
2) Check the jumper settings on the EV board. Refer to
Tables 1 and 2.
3) Carefully connect the boards by aligning the EV kit’s
40-pin header with the µC module’s 40-pin connec-
tor. Gently press them together. The two boards
should be flush against one another.
4) Connect a 9V to 15V DC power source to the µC
module at the terminal block located next to the
on/off switch, in the upper-right corner of the µC
module. Observe the polarity marked on the board.
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 is 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 MAX1202 program by opening its icon in
the Program Manager (or Start Menu).
7) The program will prompt
module and turn its power
position. Select the correct
The program automatically
to the module.
you to connect the µC
on. Slide SW1 to the on
serial port and click OK.
downloads
KIT1202.L11
JU2
Open
Closed
JU3
Open
JU4
Current-sense jumper. The
Closed
MAX1202 draws its +5V analog
(default trace)
supply through this trace.
Open
Do not operate kit with JU4 open.
Table 2. Default Jumper Settings
JUMPER
JU1
JU2
JU3
JU4
DEFAULT
STATE
2-3
2-3
Open
Closed
FUNCTION
V
SS
tied to -5V
SHDN
tied to +5V
REFADJ = open; VREF = 4.096V
internal reference (MAX1202)
The MAX1202 draws its +5V
analog supply through this trace.
Evaluating the MAX1203
To evaluate the MAX1203, turn off the power to the EV kit,
close JU3, and replace U1 with a MAX1203BCPP.
Connect the external voltage reference to the VREF
pad. No other hardware changes are necessary. Refer
to the section
Changing the Reference Voltage.
8) Apply input signals to the CH0–CH7 inputs at the
right edge of the MAX1202 EV board. Observe the
readout on the screen.
2
_______________________________________________________________________________________
MAX1202 Evaluation Kit
__Detailed Description of Software
Shutdown Power Cycling
The MAX1202 can be shut down between conversions
to reduce average supply-current demand. From the
“Power” menu, select full power-down (FULLPD) or fast
power-down (FASTPD) mode. In fast power-down
mode, the bandgap reference remains active. The
amount of power saved depends primarily on how long
the part is off between conversions. The conversion
accuracy depends on the power-up delay, the refer-
ence capacitor, and the time in power-down. Adjust off-
time with the “Delay Between Samples” command.
Adjust on-time with the “Power-Up Delay” command.
Using an adequate power-up delay ensures conversion
accuracy during power-cycling modes. The reference
must be allowed enough time to stabilize before the
measurement is performed. The “Power-Up Delay”
command controls power-up delay. Increase the delay
until accuracy is constant. The power-up delay require-
ment depends on the off-time (delay between samples)
and the value of the reference capacitor (C12).
The MAX1202 EV kit software performs power-up by
starting a conversion in FASTPD mode and discarding
the reading. FASTPD mode turns on the reference, but
leaves the MAX1202’s other circuitry powered down.
An accurate reference-voltage measurement can be
performed after the power-up delay is complete.
The MAX1203 requires an external reference, so
FULLPD mode can always be used, assuming the exter-
nal reference is always stable when measurements are
performed. In this case, set power-up delay to 0.
subsequent line of the log file contains all enabled
channels, separated by commas, tabs, or spaces. The
program continues to write data to the log file until the
“Done” command is selected from the “Log” menu.
Evaluates: MAX1202/MAX1203
High-Speed Data Sampling
The high-speed sampling commands can be used for
sampling rates over 10 samples/sec. Data can be col-
lected from any single channel at high speed, using the
commands on the “Sample” menu. First select the num-
ber of samples. Then set the sampling rate either by
inserting a delay between samples, or by choosing one
of the preset sample rates. Use the “Collect” command
to begin collecting data. After the samples are collect-
ed, the data is automatically uploaded to the host and
graphed. Additionally, the data can be saved to a file.
Changing the Reference Voltage
The MAX1202 EV kit software assumes a 4.096V refer-
ence voltage, unless otherwise specified. The refer-
ence-voltage assumption can be changed using “Set
Reference Voltage” under the “Device” menu.
If an external reference is used, it must have a tempera-
ture coefficient of 20ppm/°C or less to achieve accuracy
to within four LSBs over the 0°C to +70°C range. For 12-
bit accuracy over this range, the reference must have a
temperature coefficient of 4ppm/°C or less.
Detailed Description
________________________of Hardware
Components
The MAX1202 (U1) is an 8-channel, 12-bit, low-power
analog-to-digital converter (ADC) with serial interface
and shutdown. R1–R8 and C1–C8 are anti-aliasing
input filters. The analog supply rails are VDD, VSS, and
GND. The digital interface is powered by the VL pin.
The
SHDN
jumper controls hardware shutdown and
selects internal/external-compensation mode. Refer to
the MAX1202 data sheet for more information.
The ICL7660 (U2) is a charge pump that converts +5V
to -5V for V
SS
.
The 78L05 (U3) is a +5V linear regulator that provides a
clean analog supply for the MAX1202.
Measuring Supply Current
On the EV board, the MAX1202 draws all of its +5V
analog power through jumper JU4, which is wired
closed when the board is shipped from the factory. To
measure the MAX1202’s supply current, modify the
board (with the power off) by cutting jumper JU4 and
connecting a current meter across JU4.
Low-Speed Data Logging
The RS-232 serial link limits the data-logging sample
rate to no more than 10 samples/sec. The “Log” menu
can be used to write data to a user-specified file in
comma-spaced-value text format. From the “Log”
menu, choose “Select Channels”, and select the chan-
nels you want to log. Then choose the “New Log File”
command from the “Log” menu. Once a log file has
been opened, it can be paused or resumed with the
“Pause” command. 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
Input Filtering
The MAX1202 EV kit has an RC filter on each input with
a time constant (τ)
of approximately 3µs (R = 300Ω,
C = 0.01µF). The MAX1202’s acquisition time with a
2MHz clock is 1.5µs. The RC filter’s settling time can
increase the acquisition time required for full accuracy
when switching input channels.
_______________________________________________________________________________________
3
MAX1202 Evaluation Kit
Evaluates: MAX1202/MAX1203
+5V
R1
300Ω
CH0
R2
300Ω
CH1
R3
300Ω
CH2
R4
300Ω
CH3
R5
300Ω
CH4
R6
300Ω
CH5
R7
300Ω
CH6
R8
300Ω
CH7
C1
0.01µF
2
C2
0.01µF
3
C3
0.01µF
4
C4
0.01µF
5
C5
0.01µF
6
C6
0.01µF
7
C7
0.01µF
8
C8
0.01µF
9
VSS
SHDN
CH7
GND
JU3
CH5
DOUT
CH1
U3
+9V TO
78L05
1
3 +15V
OUT
IN
COM
2
J1-5
J1-6
1
CH0
V
DD
20
C15
0.1µF
19
JU4
U1
MAX1202
SCLK
J1-37
CH2
CS
18
J1-31
CH3
DIN
17
J1-36
CH4
SSTRB
16
J1-29
15
J1-35
J1-7
CH6
VL
14
C14
0.1µF
13
GND
+5V
VSS
REFADJ
12
C13
0.01µF
11
C12
4.7µF
10V
REFADJ
J1-3
J1-4
VREF
J1-1
J1-2
VLOGIC
J1-8
C11
0.1µF
1
+5V
8
V+
2
JU1
3
10
SHDN
REF
+5V
OSC
7
5
2
-5V
C9
0.1µF
C10
0.1µF
2
3
JU2
1
1
6
3
N.C.
LV
GND
U2
TEST POINTS
TP-1
TP-2
TP-3
TP-4
TP-5
TP-6
TP-7
TP-8
VREF
ICL7660
VOUT
CAP+
CAP-
4
SSTRB
CS
SCLK
Figure 1. MAX1202 EV Kit Schematic
4
_______________________________________________________________________________________
DOUT
+3V
DIN
MAX1202 Evaluation Kit
Evaluates: MAX1202/MAX1203
1.0"
Figure 2. MAX1202 EV Kit Component Placement Guide—
Top Silkscreen
1.0"
1.0"
Figure 3. MAX1202 EV Kit PC Board Layout—Component Side
Figure 4. MAX1202 EV Kit PC Board Layout—Solder Side
_______________________________________________________________________________________
5
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