U1
_____MAX1110 Stand-Alone EV Kit
The MAX1110 EV kit provides a proven PC board lay-
out to facilitate evaluation of the MAX1110. It must be
interfaced to appropriate timing signals for proper
operation. Refer to the MAX1110 data sheet for timing
requirements. Apply your supply voltage between the
VDD pad and the GND pad. Refer to Table 1 for jumper
configurations.
______________MAX1110 EV System
The MAX1110 EV system operates from a user-sup-
plied 9V to 15V DC power supply. The Maxim 68L11D
3V C board uses a MAX667 linear regulator to gener-
ate the 3V logic supply.
Quick Start
1) Install the MAX1110 EV kit software on your comput-
er by running the INSTALL.EXE program on the flop-
py 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).
2) Check the jumper settings on the MAX1110 EV kit
board. Refer to Table 1,
Jumper Functions, and
Table 2,
Default Jumper Settings.
3) Carefully connect the boards by aligning the 40-pin
header of the MAX1110 EV kit with the 40-pin con-
nector of the C module. Gently press them togeth-
er. The two boards should be flush against one
another.
_______________General Description
The MAX1110 evaluation system (EV system) is a com-
plete, 8-channel data-acquisition system consisting of a
MAX1110 evaluation kit (EV kit) and a Maxim 3V 68L11D
microcontroller (C) module. It is designed to evaluate
the MAX1110, a low-power, +3V, 8-channel, 8-bit ana-
log-to-digital converter (ADC) with an internal 2.048V ref-
erence that directly interfaces to 3V microprocessors.
Windows 3.1
/Windows 95
software provides a handy
user interface to exercise the MAX1110's features.
The EV system is intended for comprehensive evalua-
tion of the MAX1110 using a personal computer. Order
the stand-alone EV kit if the 68L11D C module has
already been purchased with a previous Maxim EV sys-
tem, or for custom use in other C-based systems.
The MAX1110 EV kit and EV system can also be used to
evaluate the MAX1112, which operates on +5V and has
a 4.096V internal reference. Simply order a free sample
of the MAX1112CPP along with the MAX1110 EV kit.
____________________________Features
o
Proven PC Board Layout
o
Complete Evaluation System Samples to 5ksps
o
Convenient Test Points Provided on Board
o
Data-Logging Software
o
Fully Assembled and Tested
Evaluates: MAX1110/MAX1112
MAX1110 Evaluation System/
Evaluation Kit
________________________________________________________________
Maxim Integrated Products
1
19-1201; Rev 0; 3/97
PART
TEMP. RANGE
BOARD TYPE
MAX1110EVKIT-DIP
0C to +70C
Surface Mount
QTY
DESCRIPTION
MAX1110EVKIT-DIP
1
MAX1110 evaluation kit
68L11DMODULE
1
68L11D C module
PART
MAX1110 EV System
____________________Component List
MAX1110 EV Kit
____________________Component List
______________Ordering Information
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800
MAX1110EVL11-DIP
0C to +70C
Surface Mount
DESIGNATION QTY
DESCRIPTION
C1C8
8
0.01F ceramic capacitors
C9, C11
2
4.7F, 10V tantalum capacitors
C10
1
0.1F ceramic capacitor
J1
1
2x20 right-angle socket
J2
1
8-pin header
JU1, JU2, JU3
3
2-pin jumper blocks
JU4
1
3-pin jumper block
JU5
0
Open
R1R8
8
10k
, 5% resistors
R9
1
10
, 5% resistor
1
Maxim MAX1110CPP
U1
1
20-pin socket
None
1
PC board
None
1
Software disk,
"MAX1110 EVALUATION KIT"
Windows is a registered trademark of Microsoft Corp.
6811D MODULE
AVAILABLE
Evaluates: MAX1110/MAX1112
4) Connect a 9V to 15V DC power source to the C
module at the terminal block located next to the
on/off switch, in the upper-right corner of the C
module. Observe the polarity marked on the board.
5) Connect a cable from the computer's serial port to
the C module. If using a 9-pin serial port, connect
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 MAX1110 program by opening its icon in
the Program Manager (or Start Menu).
7) The program prompts you to connect the C mod-
ule and turn its power on. Slide SW1 to the ON posi-
tion. Select the correct serial port, and click OK. The
program automatically downloads KIT1110.L11 to
the module.
8) Apply input signals to the CH0CH7 inputs at the
right edge of the MAX1110 EV kit board. Observe
the readout on the screen.
Evaluating the MAX1112
To evaluate the MAX1112, turn off power to the kit,
replace U1 with a MAX1112CPP, and set V
DD
to 5V by
adjusting trim pot R2 on the 68L11D module. No other
hardware changes are necessary. Start the MAX1110
software, and change the assumed reference voltage
from 2.048V to 4.096V. Refer to the section
Changing
the Reference Voltage.
__Detailed Description of Software
Shutdown Power Cycling
To reduce average supply-current demand, the
MAX1110 can be shut down between conversions.
From the Power menu, select Full Power-Down mode.
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 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 com-
mand controls the power-up delay. Increase the delay
until no further change in accuracy is observed. The
power-up delay requirement depends on the value of
the reference capacitor (C9) and the off-time (delay
between samples).
The MAX1110 EV kit software performs power-up by
starting a conversion and discarding the reading. When
the power-up delay is complete, the reference voltage
is correct, and an accurate measurement can be per-
formed.
Measuring Supply Current
On the EV kit board, the MAX1110 draws all its power
through jumper JU5, which is wired closed when the
board is shipped from the factory. To measure the
MAX1110's supply current, modify the board (with the
power off) by cutting jumper JU5 and connecting a cur-
rent meter across JU5.
Low-Speed Data Logging
The RS-232 serial link limits the data-logging sample
rate to no more than 10 samples per second. The Log
menu can be used to write data to a user-specified file
in comma-spaced-value text format. From the Log
menu, select Select Channels, and select the channels
you want to log. Next, pick 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 subsequent
line of the log file contains all enabled channels, sepa-
rated by commas, tabs, or spaces. The program con-
tinues to write data to the log file until the Done com-
mand is selected from the Log menu.
High-Speed Data Sampling
For sampling rates up to 5ksps, the high-speed sam-
pling commands can be used. Data can be collected
from any single channel at high speed, using the com-
mands on the Sample menu. First, select the number of
samples. Then, set the sampling rate by inserting a
delay between samples, or choosing one of the preset
sample rates. To begin collecting data, use the Collect
command. After the samples have been collected, the
data is automatically uploaded to the host and is
graphed. The data can optionally be saved to a file.
Changing the Reference Voltage
The MAX1110 EV kit software assumes a 2.048V refer-
ence voltage, unless otherwise specified. To change
the reference voltage assumption, use Set Reference
Voltage under the Device menu.
MAX1110 Evaluation System/
Evaluation Kit
2
_______________________________________________________________________________________
Detailed Description
________________________of Hardware
U1, the MAX1110, is an 8-channel, 8-bit, low-power
analog-to-digital converter (ADC) with serial interface
and a shutdown mode. R1R8 and C1C8 act as anti-
aliasing input filters. V
DD
and GND are the analog sup-
ply rails. Refer to the MAX1110 data sheet for additional
information.
C9 and C11 are 4.7F bypass capacitors for the refer-
ence and the power supply. For reduced board size
and/or lower cost, C9 and C11 may be reduced to 1F.
R9 and C10 filter the digital noise out of the analog
power supply.
Input Filtering
The EV kit has an RC filter on each input with a time con-
stant of approximately 100s (R = 10k
, C = 0.01F).
Acquisition time with a 500kHz clock is 4s. The RC fil-
ter's settling time may increase the acquisition time
required for full accuracy when switching input channels.
Evaluates: MAX1110/MAX1112
MAX1110 Evaluation System/
Evaluation Kit
_______________________________________________________________________________________
3
JUMPER
STATE
FUNCTION
open
Use an external user-supplied refer-
ence.
closed
Use the internal reference (REFIN is
connected to REFOUT).
open
Analog common voltage must be set
by user.
closed
Analog common (COM) = GND.
open
MAX1110 is active with internal
reference enabled.
12
SHDN = V
DD
; MAX1110 is active with
internal reference disabled.
open
SHDN is allowed to float or be driven
by JU4.
closed
SHDN is driven by the C module.
23
SHDN = GND; MAX1110 is inactive.
closed
Current-sense jumper. The MAX1110
draws its power through this trace.
open
Do not operate kit with JU5 open.
JU1
JU2
JU3
JU5
JUMPER
STATE
FUNCTION
JU1
closed
Use the internal reference (REFIN is
connected to REFOUT).
closed
COM = GND.
JU2
JU3
JU4
open
SHDN is allowed to float or be driven
by JU4.
open
MAX1110 is active with internal refer-
ence enabled.
JU5
closed
The MAX1110 draws its power through
this trace.
Table 1. Jumper Functions
Table 2. Default Jumper Settings
JU4
Evaluates: MAX1110/MAX1112
MAX1110 Evaluation System/
Evaluation Kit
4
_______________________________________________________________________________________
Listing 1. MAX1110 Pseudo-Code Example
Evaluates: MAX1110/MAX1112
MAX1110 Evaluation System/
Evaluation Kit
_______________________________________________________________________________________
5
Listing 2. Bit-Banging Substitute for SPI Port
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