MAXIM MAX1247EVKIT

19-1161; Rev 1; 6/97
MAX1246/MAX1247 Evaluation Systems
MAX1246/MAX1247 EV Kits
___________________ Component List
DESIGNATION QTY
____________________________Features
♦ Proven PC Board Layout
♦ Complete Evaluation System
♦ Convenient On-Board Test Points
♦ Data-Logging Software
♦ Source Code Provided
♦ Fully Assembled and Tested
______________Ordering Information
PART
TEMP. RANGE
MAX1246EVKIT-QSOP
0°C to +70°C
Surface Mount
PIN-PACKAGE
MAX1246EVL11-QSOP
0°C to +70°C
Surface Mount
MAX1247EVKIT-QSOP
0°C to +70°C
Surface Mount
MAX1247EVL11-QSOP
0°C to +70°C
Surface Mount
MAX1246EVL11
____________________Component List
DESCRIPTION
QTY
DESCRIPTION
C1, C7–C10
5
0.01µF ceramic surface-mount capacitors
1
MAX1246EVKIT-QSOP
C2, C4, C6,
C11
4
0.1µF ceramic surface-mount capacitors
1
68L11D µC MODULE (68L11D MODULE)
C13
1
0.1µF ceramic surface-mount capacitor
(MAX1247 EV kit only)
C3
1
4.7µF surface-mount tantalum capacitor
C5
1
10µF surface-mount tantalum capacitor
C12
1
0.047µF ceramic surface-mount capacitor
(MAX1247 EV kit only)
H1
1
10-pin header
J1
1
2 x 20 header
JU1, JU2,
JU5, JU6
4
2-pin headers
R1–R4
4
1kΩ, 5% surface-mount resistors
R5
1
100Ω, 5% surface-mount resistor
R6, R7
2
1MΩ, 5% surface-mount resistors
U1
1
MAX1247BCEE or MAX1246BCEE
U2
1
MAX872CSA (MAX1247 EV kit only)
U3
1
MAX393CSE
U4
1
MAX495CSA
None
1
Printed circuit board
MAX1247EVL11
____________________Component List
QTY
DESCRIPTION
1
MAX1247EVKIT-QSOP
1
68L11D µC MODULE (68L11D MODULE)
_______________Stand-Alone EV Kits
The MAX1246/MAX1247 EV kit provides a proven PC
board layout to facilitate evaluation of the MAX1246 or
MAX1247. It must be interfaced to appropriate timing
signals for proper operation. Refer to the MAX1246/
MAX1247 data sheet for timing requirements.
Systems that have 5V as well as 3V logic must provide
level translation for the MAX1246/MAX1247 DOUT and
SSTRB outputs. No level translation is necessary on the
digital interface inputs.
________________________________________________________________ Maxim Integrated Products
1
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.
For small orders, phone 408-737-7600 ext. 3468.
Evaluate: MAX1246/MAX1247
_______________General Description
The MAX1247 evaluation kit (EV kit) is an assembled
and tested surface-mount PC board that demonstrates
the 3V, 12-bit, 4-channel MAX1247 analog-to-digital
converter.
The MAX1247 evaluation system (EV system) is a complete, low-cost, 4-channel data-acquisition system consisting of a MAX1247 EV kit and a Maxim 3V microcontroller (µC) module. IBM PC-compatible software provides a handy user interface to exercise the MAX1247’s
features. Source code is provided.
The MAX1246 EV kit and EV system are identical to the
MAX1247 EV kit and EV system except that the
MAX1247 is replaced by the MAX1246, which has an
internal 2.5V reference.
Order the EV system for comprehensive evaluation of
the MAX1247 or MAX1246 using a personal computer.
Order the EV kit if you have already purchased the 3V
µC module with a previous Maxim EV system, or for
custom use in other µC-based systems.
Evaluate: MAX1246/MAX1247
MAX1246/MAX1247 Evaluation Systems
__________ EV Systems Quick Start
A single program, “MAX1247”, is used for both the
MAX1246 and the MAX1247 EV systems.
1) Copy the files from the distribution disk to your hard
disk or to blank floppy disks. The EV kit software
should be in its own directory. The necessary files
are in the distribution disk’s root directory, and the
source code is in the SOURCE subdirectory. The
SOURCE subdirectory is not required to operate
the EV kit.
2) Make sure that the jumpers are configured according to Table 1. Table 2 lists the functions associated
with each jumper.
3) Carefully connect the boards by aligning the
EV kit’s 40-pin header with the µC module’s
40-pin connector. Gently press them together. The
two boards should be flush against each other.
4) Connect a 5V DC power source (16V max) 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 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 “MAX1247” (for the MAX1246, type
“MAX1247 FASTPD”). Do not turn off or disconnect the µC module while the program is running; if
you do, you will have to restart the program.
2
Table 1. Default Jumper Settings
JUMPER
MAX1246
JUMPER
STATE
MAX1247
JUMPER
STATE
JU1
Closed
Closed
Drive SHDN pin
JU2
Open
Closed
See Table 2
JU3
Closed
(trace)
Closed
(trace)
Bypass
supply-current
measurement
JU4
Closed
(trace)
Closed
(trace)
Drive COM pin
JU5
Open
Closed
See Table 2
JU6
Open
Open
FUNCTION
VREF not connected
to VDD
7) The program will ask which port the µC module is
connected to. Press the space bar until the correct
PC serial port is highlighted, then press ENTER.
The program will be in terminal-emulation mode.
8) Turn on the power for the µC module. The µC module 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
will prompt 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 successfully downloaded.
11) Apply input signals to CH0–CH3 on the EV board.
Observe the readout on the screen. Table 3 lists the
commands that are available from the control panel
screen.
12) Before turning off power to the EV kit, exit the program by pressing ALT+X.
_______________________________________________________________________________________
MAX1246/MAX1247 Evaluation Systems
JUMPER
JU1
STATE
Closed
Open
Closed
JU2
JU2
Open
Closed
JU3
JU4
JU5*
JU6*
Open
Closed
Open
Closed
Open
Closed
Open
FUNCTION
Drive SHDN pin with pin 34 of the µC module.
Force SHDN to float.
REFADJ = VDD. Disable the internal reference buffer (see JU5 and JU6 settings).
REFADJ = Open. Enable the internal reference buffer. Refer to the MAX1246/MAX1247 data sheet for
additional information.
Current-sense jumper (in series with VDD)
Do not operate the kit with JU3 open. Supply current may be measured by cutting JU3 open and
connecting a current meter across JU3.
Drive the COM pin with buffer U4.
COM disconnected from U4; COM must be driven directly by the user.
VREF = MAX872 reference (MAX872 not supplied with MAX1246 EV kit).
MAX872 disconnected from the MAX1247’s VREF input.
VREF = VDD
VDD disconnected from the VREF input.
*Note: Jumpers JU5 and JU6 should not both be closed.
Detailed Description
________________________of Hardware
The MAX872 is a micropower 2.5V reference supplied
with the MAX1247 EV kit.
The MAX495 is a low-voltage Rail-to-Rail® op amp with
a 500kHz gain-bandwidth product. The MAX495
buffers the external COM input source.
The MAX393 analog switch allows the EV kit software to
route the MAX1246/MAX1247 COM pin to ground or to
the external COM input. In addition, the external COM
input can be routed to input channel 0. Typical systems
connect COM directly to analog ground or the analog
common voltage.
Changing the Reference Voltage
To supply a different external reference, open JU2 and
apply the reference voltage between VREF and GND or
J10 (REFADJ) and GND. Refer to the MAX1246/
MAX1247 data sheet for additional information.
The RC filter’s settling time may increase the acquisition time required for full accuracy when switching
input channels.
Detailed Description
________________________of Software
The software allows all features of the MAX1246/
MAX1247 to be exercised. Refer to Tables 3 and 4 for a
complete listing of available features.
The EV kit default software program (“KIT1247.L11”)
that is loaded into the 68L11D module operates at a
throughput rate of 6.41ksps. For faster throughput,
download the program “FAST1247.L11” at step 9 of the
Quick Start section. This program has a throughput rate
of approximately 13ksps.
Listing 1 shows an example of interfacing the MAX1246/
MAX1247 to the 68HC11 processor.
Input Filtering
The EV kit has an RC filter on each input with a time
constant (τ) of 10µs. The MAX1246/MAX1247’s acquisition time with a 1MHz clock is 3µs.
Rail-to-Rail is a registered trademark of Nippon Motorola Ltd.
_______________________________________________________________________________________
3
Evaluate: MAX1246/MAX1247
Table 2. Jumper Settings
Evaluate: MAX1246/MAX1247
MAX1246/MAX1247 Evaluation Systems
Table 3. Command Reference
KEY
FUNCTION
0, 1, 2, 3
Enables or disables the corresponding input channel 0, 1, 2, or 3. The EV kit software scans all enabled channels.
C
Displays the conversion results in decimal form.
D
Delay between samples. Delays longer than one second are handled by the IBM PC; otherwise, the µC module
handles the delay. Timing is approximate and should be verified with an oscilloscope.
L
Enables or disables data logging. If the -L command-line option was not specified, the L command prompts for a
log-file name.
O
Oscilloscope demo. Samples are collected and discarded as fast as possible. Observe waveforms and timing with
an oscilloscope.
P
Power-up delay. Timing is approximate and should be verified with an oscilloscope. When using an external reference, power-up delay is not necessary and should be set to zero. Power-up delay is used regardless of which
power-cycling mode is selected.
S
Samples one of the four inputs at high speed. The sampling rate is controlled by the P and D delays. Due to program overhead, the O and S commands operate at different rates. Timing should be verified with an oscilloscope.
V
Displays the conversion results in volts.
Selects input scale (unipolar, bipolar, unipolar differential, bipolar differential) for all enabled channels. Disabled
channels are unaffected.
Writes a marker into the data-log file.
Measures the value of a user-applied COM voltage.
Changes the assumed value of VREF.
F1
F3
F4
F5
Changes the assumed voltage at COM. Selecting G connects the COM pin to ground; selecting E connects the
COM pin to the EXTCOM input pad.
F6
F7
F8
⇑, ⇓
Internal clock mode
External clock mode
Selects power-down mode.
Switches back to terminal mode.
Exits to DOS.
ALT+T
ALT+X
Table 4. Command-Line Options
when Starting Software
COMMAND
FASTPD
4
FUNCTION
Enables the fast power-down mode
for the MAX1246.
1
2
Defaults to COM1 PC serial port.
Defaults to COM2 PC serial port.
MONO
For use with monochrome or LCD
display.
-Lfilename
Opens file filename for data logging
and enables the data-logging
commands.
VREF vvv
Specifies the actual measured voltage at the VREF pin (nominally 2.5V).
COM vvv
?
Specifies the voltage at the COM pin.
Lists command-line options.
_______________________________________________________________________________________
MAX1246/MAX1247 Evaluation Systems
Evaluate: MAX1246/MAX1247
Listing 1. Reading the MAX1246/MAX1247 with the 68HC11/68L11 SPI Interface
_______________________________________________________________________________________
5
Evaluate: MAX1246/MAX1247
MAX1246/MAX1247 Evaluation Systems
JU3
U3A
IN0
COMCHO
IN1
C5, 10µF
CHO
EXTCHO
1k
J4
11
R1
9
J3
10
VDD
R2
C4, 0.1µF
1
VDD
2
CHO
CS 15
3
CH1
4
CH2
MAX1246 DIN 14
MAX1247 SSTRB 13
5
CH3
DOUT 12
6
COM
DGND 11
7
SHDN
AGND 10
8
VREF
REFADJ 9
1k
J5
IN2
R3
1k
J6
IN3
SCLK 16
R4
1k
J12
C10
C9
C8
C7
0.01µF
0.01µF
0.01µF
0.01µF
C2
0.1µF
C3
4.7µF V
DD
EXTCOM
R5
100
4
C13*
3
0.1µF
4
U3C
U3B
J1–3 GND
J1–4 GND
SCLK
CS
DIN
SSTRB
DOUT
SHDN
COMSEL
COMCH0
VDD
12, 13
VDD
GND
4, 5
J1–7 VDD
J1–8 VDD
CHO
6
SCLK
DOUT
DIN
SSTRB
CS
COMSEL
COMCH0
PA7/SHDN
U3D
GND
VDD
5
1M
COMSEL
7
J1–27 PA0/IC3
J1–28 PA1/IC2
J1–29 PA2/IC1
J1–30 PA3/IC4/0C5
J1–31 PA4/0C4
J1–32 PA5/0C3
J1–33 PA6/0C2
J1–34 PA7/OC1/PAIN
MAX393 (U3) SWITCH SETTINGS
COMCHO = L: CHO = NORMAL
COMCHO = H: CHO = EXTCOM
COMSEL = L: COM = GND
COMSEL = H: COM = EXTCOM
DOUT
DIN
SCLK
CS
J1–35 MISO
J1–36 MOSI
J1–37 SCK
J1–38 RESERVED
J1–40 SS INPUT
Figure 1. MAX1246/MAX1247 EV Kit Schematic
6
JU6
J1–1 GND
J1–2 GND
R6
TEST POINTS
U3: MAX393
GND
C12*
0.047µF
JU5
J2
J11
H1–1
H1–2
H1–3
H1–4
H1–5
H1–6
H1–7
H1–8
H1–9
H1–10
7
*MAX1247 EV KIT ONLY
14
16
1
8
VREF
VOUT 6
15
COMCHO
1M
VIN
MAX495
R7
J10
COMP 8
2
U4
C11
0.1µF
JU2
JU4
3
3
VDD
C1
MAX872*
2
VDD
J7
DOUT
0.01µF
1
0.1µF
6
SSTRB
U2
C6
7
DIN
J9
SHDN
2
CS
JU1
PA7/SHDN
J8
SCLK
U1
_______________________________________________________________________________________
MAX1246/MAX1247 Evaluation Systems
Evaluate: MAX1246/MAX1247
1.0"
Figure 2. MAX1246/MAX1247 EV Kit Component Placement Guide
1.0"
1.0"
Figure 3. MAX1246/MAX1247 EV Kit PC Board Layout—
Component Side
Figure 4. MAX1246/MAX1247 EV Kit PC Board Layout—
Solder Side
_______________________________________________________________________________________
7
Evaluate: MAX1246/MAX1247
MAX1246/MAX1247 Evaluation Systems
NOTES
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.
8 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 1997 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.