19-1201; Rev 0; 3/97 E MODUL 6811D LE B A IL A AV MAX1110 Evaluation System/ Evaluation Kit The MAX1110 evaluation system (EV system) is a complete, 8-channel data-acquisition system consisting of a MAX1110 evaluation kit (EV kit) and a Maxim 3V 68L11D microcontroller (µC) module. It is designed to evaluate the MAX1110, a low-power, +3V, 8-channel, 8-bit analog-to-digital converter (ADC) with an internal 2.048V reference 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 evaluation of the MAX1110 using a personal computer. Order the stand-alone EV kit if the 68L11D µC module has already been purchased with a previous Maxim EV system, or for custom use in other µC-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. MAX1110 EV System ____________________Component List PART QTY MAX1110EVKIT-DIP 1 MAX1110 evaluation kit DESCRIPTION 68L11DMODULE 1 68L11D µC module MAX1110 EV Kit ____________________Component List DESIGNATION QTY DESCRIPTION C1–C8 8 0.01µF ceramic capacitors C9, C11 2 4.7µF, 10V tantalum capacitors C10 1 0.1µF 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 R1–R8 8 10kΩ, 5% resistors R9 1 10Ω, 5% resistor U1 U1 1 Maxim MAX1110CPP 1 20-pin socket None 1 PC board None 1 Software disk, “MAX1110 EVALUATION KIT” ____________________________Features ♦ Proven PC Board Layout ♦ Complete Evaluation System Samples to 5ksps ♦ Convenient Test Points Provided on Board ♦ Data-Logging Software ♦ Fully Assembled and Tested ______________Ordering Information PART MAX1110EVKIT-DIP MAX1110EVL11-DIP TEMP. RANGE 0°C to +70°C 0°C to +70°C BOARD TYPE Surface Mount Surface Mount _____MAX1110 Stand-Alone EV Kit The MAX1110 EV kit provides a proven PC board layout 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-supplied 9V to 15V DC power supply. The Maxim 68L11D 3V µC board uses a MAX667 linear regulator to generate the 3V logic supply. Quick Start 1) Install the MAX1110 EV kit software on your computer by running the INSTALL.EXE program on the floppy 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 connector of the µC module. Gently press them together. The two boards should be flush against one another. Windows is a registered trademark of Microsoft Corp. ________________________________________________________________ Maxim Integrated Products 1 For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800 Evaluates: MAX1110/MAX1112 _______________General Description Evaluates: MAX1110/MAX1112 MAX1110 Evaluation System/ Evaluation Kit 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, 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 µC module and turn its power on. Slide SW1 to the ON position. Select the correct serial port, and click OK. The program automatically downloads KIT1110.L11 to the module. 8) Apply input signals to the CH0–CH7 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 VDD 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 powerdown. Adjust the off-time with the Delay Between Samples command. Adjust the on-time with the PowerUp 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 the power-up delay. Increase the delay until no further change in accuracy is observed. The 2 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 performed. 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 current 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, 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. High-Speed Data Sampling For sampling rates up to 5ksps, the high-speed sampling commands can be used. Data can be collected from any single channel at high speed, using the commands 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 reference voltage, unless otherwise specified. To change the reference voltage assumption, use Set Reference Voltage under the Device menu. _______________________________________________________________________________________ MAX1110 Evaluation System/ Evaluation Kit and/or lower cost, C9 and C11 may be reduced to 1µF. R9 and C10 filter the digital noise out of the analog power supply. U1, the MAX1110, is an 8-channel, 8-bit, low-power analog-to-digital converter (ADC) with serial interface and a shutdown mode. R1–R8 and C1–C8 act as antialiasing input filters. VDD and GND are the analog supply rails. Refer to the MAX1110 data sheet for additional information. C9 and C11 are 4.7µF bypass capacitors for the reference and the power supply. For reduced board size The EV kit has an RC filter on each input with a time constant of approximately 100µs (R = 10kΩ, C = 0.01µF). Acquisition time with a 500kHz clock is 4µs. The RC filter’s settling time may increase the acquisition time required for full accuracy when switching input channels. Table 1. Jumper Functions Table 2. Default Jumper Settings JUMPER STATE closed Use the internal reference (REFIN is connected to REFOUT). closed Use the internal reference (REFIN is connected to REFOUT). JU2 closed COM = GND. open Analog common voltage must be set by user. JU3 open SHDN is allowed to float or be driven by JU4. Analog common (COM) = GND. JU4 open SHDN is allowed to float or be driven by JU4. MAX1110 is active with internal reference enabled. JU5 closed open SHDN is driven by the µC module. 1–2 SHDN = VDD; MAX1110 is active with internal reference disabled. 2–3 SHDN = GND; MAX1110 is inactive. closed Current-sense jumper. The MAX1110 draws its power through this trace. open The MAX1110 draws its power through this trace. MAX1110 is active with internal reference enabled. open JU5 FUNCTION JU1 closed JU4 STATE Use an external user-supplied reference. closed JU3 JUMPER open JU1 JU2 FUNCTION Input Filtering Do not operate kit with JU5 open. _______________________________________________________________________________________ 3 Evaluates: MAX1110/MAX1112 Detailed Description ________________________of Hardware Evaluates: MAX1110/MAX1112 MAX1110 Evaluation System/ Evaluation Kit Listing 1. MAX1110 Pseudo-Code Example 4 _______________________________________________________________________________________ MAX1110 Evaluation System/ Evaluation Kit Evaluates: MAX1110/MAX1112 Listing 2. Bit-Banging Substitute for SPI Port _______________________________________________________________________________________ 5 GND 6 J1–34 J1–35 J1–28 J1–36 J1–29 J1–37 J1–27 J1–38 J1–31 J1–30 J1–4 J1–3 J1–2 J1–1 J1–8 J1–7 Figure 1. MAX1110 EV Kit Schematic _______________________________________________________________________________________ 1 2 3 JU4 VDD C11 4.7µF 10V R9 10Ω JU3 VDD COM SHDN DOUT DIN SCLK CS SSTRB JU2 C10 0.1µF JU5 CUT HERE VDD 9 10 15 17 19 18 16 14 13 20 COM SHDN DOUT DIN SCLK CS SSTRB DGND AGND VDD MAX1110 U1 4 3 2 1 12 11 CH7 CH6 CH5 8 7 6 CH4 5 CH3 CH2 CH1 CH0 REFOUT REFIN C8 0.01µF C6 0.01µF C4 0.01µF C2 0.01µF JU1 C7 0.01µF C5 0.01µF C3 0.01µF C1 0.01µF R8 10k R7 10k R6 10k R5 10k R4 10k R3 10k R2 10k R1 10k C9 4.7µF 10V CH7 CH6 CH5 CH4 CH3 CH2 CH1 CH0 REF SHDN DOUT SSTRB DIN CS SCLK VDD J2–8 J2–7 J2–6 J2–5 J2–4 J2–3 J2–2 J2–1 Evaluates: MAX1110/MAX1112 MAX1110 Evaluation System/ Evaluation Kit MAX1110 Evaluation System/ Evaluation Kit 1.0" Figure 2. MAX1110 EV Kit Component Placement Guide Figure 3. MAX1110 EV Kit PC Board Layout—Component Side _______________________________________________________________________________________ 7 Evaluates: MAX1110/MAX1112 1.0" Evaluates: MAX1110/MAX1112 MAX1110 Evaluation System/ Evaluation Kit 1.0" Figure 4. MAX1110 EV Kit PC Board Layout—Solder Side 8 _______________________________________________________________________________________