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.