EL5825 Rev A. Demo Board ® Technical Brief December 22, 2004 Description The EL5825 REV A demo board is designed for demonstrating the operation of Intersil's high precision reference voltage generator, the EL5825. For a detailed description, please refer to the data sheet. A parallel port Visual Basic program is used to drive the SDI, SCLK, and ENA pins for the channel and voltage selection. 8-Channel Circuit Description Please refer to Figure 1 and the single demo board circuit. On the board, VS is the supply voltage (5V to 16V). VSD is the digital supply (3.3V to 5V). REFH is the high reference output voltage (REFL < REFH ≤ VS). REFL is the low reference output voltage (0 ≤ REFL < REFH). REFH and REFL voltage are supplied by EL5220 and can be adjusted by the 10K Trim POT. R20 to R23, R26, R28 to R30 are 1.5k load resistors. C6, C11, and C21 are the 0.1µF local bypass capacitors. C1 to C10 are 180pF load capacitors. If bigger capacitors are required, then, a serial resistor (20Ω to 100Ω) must be used between the output and the capacitor. TB436.0 "Send" button outputs a 16-bit single channel data. The "SendAll" button outputs 8-channel data. The "Write to File" button can save the setup to a file and the "Read From File" button can load the setup from the file. Dual Board Control (16-Channel) When you click the EL5825dual.exe icon on your Windows desktop, a dual board control panel shows up (See Figure 4). On the panel, you can set your reference high and reference low voltage for board one and board two. You can set the voltage for each channel. On our 16-channel configuration, the reference high on board two is shorted to reference low in board one. So, the VREF Low 1-8 must have the same value as VREF High 9-16. The "Send" button outputs a 32 bit dual channel data. The "SendAll" button outs 16 channel data. The "Write to File" button can save the setup to a file and the "Read From File" button can load the setup from the file. For the dual board connection, the OSC pins are shorted together. If no external oscillator is used, then board one can set to the external oscillator mode and use the internal oscillator output in board two. 16-Channel Circuit Description A 16-channel voltage reference generator can be simply formed by connecting two single boards together (See Figure 2). The resistors and capacitors connections are the same as the 8-channel connection for each board. Board one contains channel 1 to channel 8 and board two contains channel 9 to channel 16. The parallel port on board two drives the logic signals. The SDO pin on board two is shorted to SDI pin on board one. The REFL pin in board one is shorted to REFH in board two. Those make the channels in board one, high voltage references, and the channels in board two, low voltage references. Control Software For 8-channel and 16-channel configuration, two separated Visual Basic programs are used to drive the parallel port to output the data stream for SDI, SCLK, and ENA inputs. To install the software, just copy the EL5825.exe and EL5825dual.exe to your Windows desktop. If your operating system is Win98, copy the files "ntport.dll and zntport.sys" to the directory: C:\windows\system. If your operating system is NT or Win2000, copy the files "ntport.dll and zntport.sys" to the directory: C:\winnt\system32. Single Board Control (8-Channel) Click the EL5825.exe icon on your windows desktop, a single board control panel shows up (See Figure 3). On the panel, you can set your reference high and reference low voltage. You can set the voltage for each channel. The 1 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 1-888-INTERSIL or 321-724-7143 | Intersil (and design) is a registered trademark of Intersil Americas Inc. Copyright Intersil Americas Inc. 2004. All Rights Reserved All other trademarks mentioned are the property of their respective owners. Technical Brief 436 EL5825IL Rev A. Demo Board Circuit C16 REFL VSD GND VS SDI SCLK NC LOAD NC EXT OSC J1 VSD D4 4.7µF BAT42 VS C17 4.7µF REFL EXT OSC LOAD C24 C22 OPEN OPEN REFH SDI C25 OPEN SCLK 0Ω 180pF R3 20 21 22 24 1 VSD R5 19 C3 0Ω C6 0.1µF 2 18 3 17 C6 4 16 5 15 6 14 7 13 180pF C11 0.1µF 0Ω 180pF R23 1.5kΩ C5 R26 180pF 1.5kΩ R9 0Ω 180pF R11 0Ω BG REFL OUTC VS OUTD VSD OUTF OUTH R28 180pF 1.5kΩ C9 C21 0.1µF OUTB NC C8 R10 0Ω REFH OUTG 0Ω 12 C20 10pF 11 REFL 10 C9 10pF J2 OUTA OUTE C4 R8 REFH 1K 2 R24 14 1K LOAD 1 R22 1.5kΩ R7 VS 8 22 9 21 8 20 7 19 6 18 5 17 SCLK 4 R27 16 1K SDI 3 R25 23 180pF 9 24 11 23 R21 1.5kΩ C2 0Ω JUMPER S1 25 OPEN R20 1.5kΩ C1 R1 C19 NC NC R29 1.5kΩ NC EXT_OSC C10 180pF R30 1.5kΩ SDO SDI NC D1 LOAD D2 VSD D3 2 REFH VSD GND VS SDO SCLK NC LOAD NC EXT OSC BAT42 TB436.0 Technical Brief 436 C16 4.7µF REFL VSD GND VS SDI SCLK NC LOAD J1 VSD NC EXT OSC EL5825IRE Rev A. Demo Board Circuit D4 BAT42 VS C17 4.7µF REFL EXT OSC C24 C22 OPEN LOAD OPEN REFH SDI C25 C19 OPEN OPEN SCLK 1 SCLK SDI 24 2 SDO ENA 23 3 OSC OUTA 22 4 VSD OUTB 21 5 NC OUTC 20 JUMPER S1 25 C6 22 9 21 8 20 7 19 6 18 5 17 4 R27 SCLK 16 1K SDI 3 R25 1K 2 R24 LOAD 14 1K 1 R20 1.5K C2 R21 180pF 1.5K C3 R22 180pF 1.5K C4 R23 R1 VSD 24 11 23 C1 180pF 0.1µF 0 R5 6 VS 0.1µF GND 18 R7 8 REFL OUTE 17 9 GND OUTF 16 180pF R9 C9 10pF R10 REFL C20 10pF 10 NC OUTG 15 11 BG OUTH 14 12 NC NC 13 REFL OUTC VS OUTD VSD OUTF OUTG C5 R26 180pF 1.5K C7 R28 180pF 1.5K C8 R29 180pF 1.5K OUTH 0 0 NC NC 0 R11 0 NC NC EXT_OSC BG C21 1.5K 0 R8 REFH OUTB OUTE OUTD 19 7 REFH REFH 0 0 VS C11 R3 J2 OUTA 0.1µF C10 R30 180pF 1.5K SDI SDO SCLK NC D1 LOAD D2 VSD D3 BAT42 3 REFH VSD GND VS SDO SCLK NC LOAD NC EXT OSC J4 TB436.0 Technical Brief 436 EL5825IY Rev A. Demo Board Circuit EL5220IY (MSOP-8) VS+ JP1 REFH R16 0Ω 10kΩ 1 JP1 2 R18 10kΩ BG 8 7 - REFL 0Ω + 3 - 6 + 4 VS- 5 R17 R19 10kΩ 10kΩ CONTROLS REFH AND REFL FOR EL5825I J1 Connector supplies Power, reference voltages and daisy chained control signals for a second board Test Points or Power Connections J2 Output Voltages connector may also be used for Power, High & Low Reference Voltages, also serial control Interface. J3 Connector to PC, connects to Parallel port REFH and REFL provided by EL5220. J4 Connector For second board FIGURE 1. 8-CHANNEL 4 TB436.0 Technical Brief 436 EL5825I Rev A. Demo Board Circuit VS and VSD for BOTH Board One and Board Two Board Two Channel 9 to Channel 16 J1 PC Connector to Parallel Port J2 Output Voltages, connector may also be used for Power, High & Low Reference Voltages, also Serial Control Interface Power Inputs REFH and REFL, for Board Two Only. Supplied by EL5220 Board One Channel 1 to Channel 8 J1 PC Connector not used for Board One J2 Output Voltages, connector may also be used for Power, High & Low Reference Voltages, also Serial Control Interface Power Input REFH for Board One Only Provide by EL5220 FIGURE 2. 16-CHANNEL 5 TB436.0 Technical Brief 436 FIGURE 3. 6 TB436.0 Technical Brief 436 FIGURE 4. All Intersil U.S. products are manufactured, assembled and tested utilizing ISO9000 quality systems. Intersil Corporation’s quality certifications can be viewed at www.intersil.com/design/quality Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries. For information regarding Intersil Corporation and its products, see www.intersil.com 7 TB436.0