MAX1247EVL11-QSOP [MAXIM]
Convenient On-Board Test Points;型号: | MAX1247EVL11-QSOP |
厂家: | MAXIM INTEGRATED PRODUCTS |
描述: | Convenient On-Board Test Points |
文件: | 总8页 (文件大小:116K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
19-1161; Rev 1; 6/97
MAX1 2 4 6 /MAX1 2 4 7 Eva lu a t io n S ys t e m s
Evluate:6/MAX1247
_______________Ge n e ra l De s c rip t io n
____________________________Fe a t u re s
♦ Proven PC Board Layout
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.
♦ Complete Evaluation System
♦ Convenient On-Board Test Points
♦ Data-Logging Software
The MAX1247 evaluation system (EV system) is a com-
plete, low-cost, 4-channel data-acquisition system con-
sisting of a MAX1247 EV kit and a Maxim 3V microcon-
troller (µC) module. IBM PC-compatible software pro-
vides a handy user interface to exercise the MAX1247’s
features. Source code is provided.
♦ Source Code Provided
♦ Fully Assembled and Tested
The MAX1246 EV kit and EV system are identical to the
MAX1247 EV kit a nd EV s ys te m e xc e p t tha t the
MAX1247 is replaced by the MAX1246, which has an
internal 2.5V reference.
______________Ord e rin g In fo rm a t io n
PART
TEMP. RANGE PIN-PACKAGE
MAX1246EVKIT-QSOP
MAX1246EVL11-QSOP
MAX1247EVKIT-QSOP
MAX1247EVL11-QSOP
0°C to +70°C
0°C to +70°C
0°C to +70°C
0°C to +70°C
Surface Mount
Surface Mount
Surface Mount
Surface Mount
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.
MAX1 2 4 6 /MAX1 2 4 7 EV Kit s
___________________ Co m p o n e n t Lis t
MAX1 2 4 6 EVL1 1
____________________Co m p o n e n t Lis t
DESIGNATION QTY
DESCRIPTION
QTY
DESCRIPTION
MAX1246EVKIT-QSOP
68L11D µC MODULE (68L11D MODULE)
C1, C7–C10
5
0.01µF ceramic surface-mount capacitors
1
1
C2, C4, C6,
C11
4
0.1µF ceramic surface-mount capacitors
0.1µF ceramic surface-mount capacitor
(MAX1247 EV kit only)
C13
1
MAX1 2 4 7 EVL1 1
____________________Co m p o n e n t Lis t
C3
C5
1
1
4.7µF surface-mount tantalum capacitor
10µF surface-mount tantalum capacitor
QTY
DESCRIPTION
MAX1247EVKIT-QSOP
68L11D µC MODULE (68L11D MODULE)
0.047µF ceramic surface-mount capacitor
(MAX1247 EV kit only)
C12
1
1
1
H1
J1
1
1
10-pin header
2 x 20 header
JU1, JU2,
JU5, JU6
4
2-pin headers
_______________S t a n d -Alo n e EV Kit s
1kΩ, 5% surface-mount resistors
100Ω, 5% surface-mount resistor
1MΩ, 5% surface-mount resistors
MAX1247BCEE or MAX1246BCEE
MAX872CSA (MAX1247 EV kit only)
MAX393CSE
R1–R4
R5
4
1
2
1
1
1
1
1
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.
R6, R7
U1
U2
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.
U3
U4
MAX495CSA
None
Printed circuit board
________________________________________________________________ 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.
MAX1 2 4 6 /MAX1 2 4 7 Eva lu a t io n S ys t e m s
__________ EV S ys t e m s Qu ic k S t a rt
Table 1. Default Jumper Settings
A single program, “MAX1247”, is used for both the
MAX1246 and the MAX1247 EV systems.
MAX1246
JUMPER
STATE
MAX1247
JUMPER
STATE
JUMPER
FUNCTION
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.
JU1
JU2
Closed
Open
Closed
Closed
Drive SHDN pin
See Table 2
Bypass
supply-current
measurement
Closed
(trace)
Closed
(trace)
JU3
Closed
(trace)
Closed
(trace)
2) Make sure that the jumpers are configured accord-
ing to Table 1. Table 2 lists the functions associated
with each jumper.
JU4
JU5
JU6
Drive COM pin
Open
Open
Closed
Open
See Table 2
VREF not connected
to V
DD
3) Ca re fully c onne c t the b oa rd s b y a lig ning 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.
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.
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.
8) Turn on the power for the µC module. The µC mod-
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 s oftwa re c he c ks the mod e m s ta tus line s
(CTS, DSR, DCD) to confirm that the correct port
has been selected.
ule 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.
Evluate:6/MAX1247
10) Press ALT+C to switch to the Control Panel screen
after the RAM resident program has been success-
fully downloaded.
6) Start the software on the IBM PC by setting the cur-
rent directory to match the directory that contains
the Maxim programs, and then type the program
na me “MAX1247” (for the MAX1246, typ e
“MAX1247 FASTPD”). Do not turn off or discon-
nect the µC module while the program is running; if
you do, you will have to restart the program.
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 pro-
gram by pressing ALT+X.
2
_______________________________________________________________________________________
MAX1 2 4 6 /MAX1 2 4 7 Eva lu a t io n S ys t e m s
Evluate:6/MAX1247
Table 2. Jumper Settings
JUMPER
STATE
Closed
Open
FUNCTION
Drive SHDN pin with pin 34 of the µC module.
Force SHDN to float.
JU1
Closed
REFADJ = V . Disable the internal reference buffer (see JU5 and JU6 settings).
DD
JU2
REFADJ = Open. Enable the internal reference buffer. Refer to the MAX1246/MAX1247 data sheet for
additional information.
Open
Closed
Open
Current-sense jumper (in series with V
)
DD
JU3
Do not operate the kit with JU3 open. Supply current may be measured by cutting JU3 open and
connecting a current meter across JU3.
Closed
Open
Drive the COM pin with buffer U4.
JU4
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.
Closed
Open
JU5*
JU6*
Closed
Open
VREF = V
DD
V
DD
disconnected from the VREF input.
*Note: Jumpers JU5 and JU6 should not both be closed.
The RC filter’s settling time may increase the acquisi-
tion time required for full accuracy when switching
input channels.
De t a ile d De s c rip t io n
________________________o f Ha rd w a re
The MAX872 is a micropower 2.5V reference supplied
with the MAX1247 EV kit.
De t a ile d De s c rip t io n
The MAX495 is a low-voltage Rail-to-Rail® op amp with
a 500kHz g a in-b a nd wid th p rod uc t. The MAX495
buffers the external COM input source.
________________________o f S o ft w a re
The s oftwa re a llows a ll fe a ture s of the MAX1246/
MAX1247 to be exercised. Refer to Tables 3 and 4 for a
complete listing of available features.
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.
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.
Ch a n g in g t h e Re fe re n c e Vo lt a g e
To supply a different external reference, open JU2 and
apply the reference voltage between VREF and GND or
J 10 (REFADJ ) a nd GND. Re fe r to the MAX1246/
MAX1247 data sheet for additional information.
Listing 1 shows an example of interfacing the MAX1246/
MAX1247 to the 68HC11 processor.
In p u t Filt e rin g
The EV kit has an RC filter on each input with a time
constant (τ) of 10µs. The MAX1246/MAX1247’s acquisi-
tion time with a 1MHz clock is 3µs.
Rail-to-Rail is a registered trademark of Nippon Motorola Ltd.
_______________________________________________________________________________________
3
MAX1 2 4 6 /MAX1 2 4 7 Eva lu a t io n S ys t e m s
Table 3. Command Reference
KEY
0, 1, 2, 3
C
FUNCTION
Enables or disables the corresponding input channel 0, 1, 2, or 3. The EV kit software scans all enabled channels.
Displays the conversion results in decimal form.
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.
D
L
Enables or disables data logging. If the -L command-line option was not specified, the L command prompts for a
log-file name.
Oscilloscope demo. Samples are collected and discarded as fast as possible. Observe waveforms and timing with
an oscilloscope.
O
Power-up delay. Timing is approximate and should be verified with an oscilloscope. When using an external refer-
ence, 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.
P
Samples one of the four inputs at high speed. The sampling rate is controlled by the P and D delays. Due to pro-
gram overhead, the O and S commands operate at different rates. Timing should be verified with an oscilloscope.
S
V
Displays the conversion results in volts.
Selects input scale (unipolar, bipolar, unipolar differential, bipolar differential) for all enabled channels. Disabled
channels are unaffected.
F1
F3
F4
F5
Writes a marker into the data-log file.
Measures the value of a user-applied COM voltage.
Changes the assumed value of VREF.
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
Evluate:6/MAX1247
Table 4. Command-Line Options
when Starting Software
COMMAND
FUNCTION
Enables the fast power-down mode
for the MAX1246.
FASTPD
1
2
Defaults to COM1 PC serial port.
Defaults to COM2 PC serial port.
For use with monochrome or LCD
display.
MONO
-Lfilename
VREF vvv
Opens file filename for data logging
and enables the data-logging
commands.
Specifies the actual measured volt-
age at the VREF pin (nominally 2.5V).
COM vvv
?
Specifies the voltage at the COM pin.
Lists command-line options.
4
_______________________________________________________________________________________
MAX1 2 4 6 /MAX1 2 4 7 Eva lu a t io n S ys t e m s
Evluate:6/MAX1247
Listing 1. Reading the MAX1246/MAX1247 with the 68HC11/68L11 SPI Interface
_______________________________________________________________________________________
5
MAX1 2 4 6 /MAX1 2 4 7 Eva lu a t io n S ys t e m s
JU3
U3A
VDD
C5, 10µF
J3
J4
J5
J6
R1
COMCHO
IN0
IN1
IN2
IN3
CHO
EXTCHO
1k
R2
C4, 0.1µF
1
SCLK 16
CS 15
V
DD
SCLK
CS
U1
1k
R3
2
3
4
5
6
7
8
CHO
CH1
14
13
12
11
10
DIN
SSTRB
DOUT
MAX1246
MAX1247
DIN
CH2
1k
R4
SSTRB
DOUT
CH3
DGND
AGND
COM
SHDN
VREF
V
DD
C1
1k
C10
C9
C8
C7
JU2
REFADJ
9
J12
J10
0.01µF
0.01µF
0.01µF
0.01µF
0.01µF
JU1
J9
J8
PA7/SHDN
U2
C2
C3
VREF
SHDN
0.1µF
4.7µF
V
DD
MAX872*
1
2
3
4
COMP
8
7
6
5
JU6
C6
C12*
VIN
0.1µF
0.047µF
JU4
JU5
VOUT
C13*
0.1µF
GND
J2
V
DD
*MAX1247 EV KIT ONLY
3
14
2
7
R5
100
A
J1–1 GND
J1–2 GND
J1–3 GND
J1–4 GND
15
16
6
2
1
U3B
J7
U4
3
U3C
R6
C11
4
MAX495
EXTCOM
R7
0.1µF
1M
COMSEL
6
J1–7 V
DD
V
J11
DD
COMCHO
8
J1–8 V
DD
CHO
7
1M
TEST POINTS
J1–27 PA0/IC3
SCLK
DOUT
DIN
U3D
J1–28 PA1/IC2
H1–1
H1–2
H1–3
H1–4
H1–5
H1–6
H1–7
H1–8
H1–9
GND
V
DD
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
SCLK
CS
SSTRB
CS
DIN
COMSEL
SSTRB
DOUT
SHDN
COMSEL
COMCH0
COMCH0
PA7/SHDN
MAX393 (U3) SWITCH SETTINGS
J1–35 MISO
J1–36 MOSI
J1–37 SCK
DOUT
DIN
COMCHO = L: CHO = NORMAL
COMCHO = H: CHO = EXTCOM
H1–10
SCLK
CS
J1–38 RESERVED
V
DD
GND
COMSEL = L: COM = GND
U3: MAX393
12, 13 4, 5
COMSEL = H: COM = EXTCOM
J1–40 SS INPUT
Figure 1. MAX1246/MAX1247 EV Kit Schematic
_______________________________________________________________________________________
6
MAX1 2 4 6 /MAX1 2 4 7 Eva lu a t io n S ys t e m s
Evluate:6/MAX1247
1.0"
Figure 2. MAX1246/MAX1247 EV Kit Component Placement Guide
1.0"
1.0"
Figure 4. MAX1246/MAX1247 EV Kit PC Board Layout—
Solder Side
Figure 3. MAX1246/MAX1247 EV Kit PC Board Layout—
Component Side
_______________________________________________________________________________________
7
MAX1 2 4 6 /MAX1 2 4 7 Eva lu a t io n S ys t e m s
NOTES
Evluate:6/MAX1247
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
_____________________Ma x im In t e g ra t e d P ro d u c t s , 1 2 0 S a n Ga b rie l Drive , S u n n yva le , CA 9 4 0 8 6 4 0 8 -7 3 7 -7 6 0 0
© 1997 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.
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