UNIVERSAL EVALUATION BOARD FOR DUAL PRECISION OP AMPS IN 8-PIN DIPs DUAL OP-AMP EVAL. BD )/94 EVICES Figure 9.9 A schematic of the AD8001 800MHz 50mW current feedback op amp evaluation board for the 8-lead soic package is shown in Figure 9. 10. The board is designed for a non- inverting gain of 2. Boards for inverting and non-inverting modes are available for both the 8-lead SoIC and the Dip package) Decoupling on both the and-supplies consists of 1000p and 0.01uF surface mount chip ceramic capacitors in addition to a 10u F/25V surface mount tantalum electrolytic. The top view of the PC board is shown in Figure 9.10, and the bottom view in Figure 9 12
1 1 UNIVERSAL EVALUATION BOARD FOR DUAL PRECISION OP AMPS IN 8-PIN DIPs Figure 9.9 A schematic of the AD8001 800MHz 50mW current feedback op amp evaluation board for the 8-lead SOIC package is shown in Figure 9.10. The board is designed for a non-inverting gain of 2. (Boards for inverting and non-inverting modes are available for both the 8-lead SOIC and the DIP package). Decoupling on both the + and – supplies consists of 1000pF and 0.01µF surface mount chip ceramic capacitors in addition to a 10µF/25V surface mount tantalum electrolytic. The top view of the PC board is shown in Figure 9.10, and the bottom view in Figure 9.12
AD8001AR (SOIC)800MHz OP AMP: NON-INVERTING MODE EVALUATION BOARD SCHEMATIC 0.01F AD8001 RT 49 1000pF Figure 9.10 AD8001AR (SOIC)EVALUATION BOARD- TOP VIEW 厂 S0 NONINVERTER Fiqure 9.11
1 2 AD8001AR (SOIC) 800MHz OP AMP: NON-INVERTING MODE EVALUATION BOARD SCHEMATIC Figure 9.10 AD8001AR (SOIC) EVALUATION BOARD - TOP VIEW Figure 9.11
AD8001AR(SOIC)EVALUATION BOARD-BOTTOM VIEW 9.12 Figure 9. 12(bottom side of board) shows the surface mount resistors and capacitors Notice that the ceramic chip capacitors are mounted as close as possible to the power pins as possible. The input and output runs are 50ohm transmission lines. The input from the Sma connector is terminated in a 50ohm chip resistor at the op amp and the output has a 50ohm source termination for driving a 50ohm cable through the output SMa connector al resistors are surface mount film resistors. Notice that the ground plane is etched away from the area immediately surrounding the inputs of the op amp to minimize stray capacitance Slightly different resistor values are required to achieve optimum performance in the soic and the dip packages(see Figure 9. 13), because the soic package has slightly lower parasitic capacitance and inductance than the DiP. The criteria for selection of the components was maximum 0. 1dB bandwidth
1 3 AD8001AR (SOIC) EVALUATION BOARD -BOTTOM VIEW Figure 9.12 Figure 9.12 (bottom side of board) shows the surface mount resistors and capacitors. Notice that the ceramic chip capacitors are mounted as close as possible to the power pins as possible. The input and output runs are 50ohm transmission lines. The input from the SMA connector is terminated in a 50ohm chip resistor at the op amp, and the output has a 50ohm source termination for driving a 50ohm cable through the output SMA connector. All resistors are surface mount film resistors. Notice that the ground plane is etched away from the area immediately surrounding the inputs of the op amp to minimize stray capacitance. Slightly different resistor values are required to achieve optimum performance in the SOIC and the DIP packages (see Figure 9.13), because the SOIC package has slightly lower parasitic capacitance and inductance than the DIP. The criteria for selection of the components was maximum 0.1dB bandwidth
OPTIMUM VALUES OF R AND R FOR AD800 DIP AND SOIC PACKAGES(MAXIMUM 0.1dB BANDWIDTH) AD8001AN (DIP)GAIN Component 10 +100 R 649210507509470910002 64927505110 Small Signal BW 340MHz880MHz460MHz 20MHz 0.1dB Flatness 105MHz70MHz105MHz AD8001AR(SOIC)GAIN mponent +100 604995396819470910009 R 6049 6810519 Small Signal BW 370MHz710MHz 440MHz 260MHz20MHz 0.1dBFlatness 130MHz 120MHz. Figure 9.13 ADC evaluation boards include more support circuitry than op amp boards. An example is the AD7714 (22-bit precision measurement sigma-delta ADC)evaluation board(see Figure 9. 14 for a simplified block diagram). Included on the evaluation board are an ad780 precision reference, a 2.45 76MHz crystal and digital buffers to buffer the signal to and from the edge connectors AD7714 ADC EVALUATION BOARD 9-WAY DTYPE CONNECTOR INPUTS AD7714 BUFFERS PRINTER PORT XTAL Figure 9.14 Interfacing to this board is provided either through a 36-Way Centronics connector or through a 9-Way D-type connector. The Centronics connector is intended for connection to the printer port of a PC External sockets are provided for the analog inputs, an external reference input option, and an external master clock option Included in the evaluation board package is a PC-compatible dos-based disk which contains software for controlling and evaluating the performance of the AD7714 using the printer port. There are two files on the disk, an executable file, and a readme"text file which gives details of the functions available in the executable
1 4 OPTIMUM VALUES OF RF AND RG FOR AD8001 DIP AND SOIC PACKAGES (MAXIMUM 0.1dB BANDWIDTH) Figure 9.13 ADC evaluation boards include more support circuitry than op amp boards. An example is the AD7714 (22-bit precision measurement sigma-delta ADC) evaluation board (see Figure 9.14 for a simplified block diagram). Included on the evaluation board are an AD780 precision reference, a 2.4576MHz crystal and digital buffers to buffer the signal to and from the edge connectors. AD7714 ADC EVALUATION BOARD Figure 9.14 Interfacing to this board is provided either through a 36-Way Centronics connector or through a 9-Way D-type connector. The Centronics connector is intended for connection to the printer port of a PC. External sockets are provided for the analog inputs, an external reference input option, and an external master clock option. Included in the evaluation board package is a PC-compatible DOS-based disk which contains software for controlling and evaluating the performance of the AD7714 using the printer port. There are two files on the disk, an executable file, and a "readme" text file which gives details of the functions available in the executable
program. The evaluation software is run by running the executable file. the program provides a number of different menu-type screens, each screen containing several function options The first menu gives options on the type of PC being used. The next menu in the sequence is the Main Menu which contains various options. These allow reading from the AD7714 Data Register, configuration of the Communications Register, file options (read and write data to files), noise analysis, printer port setup, and resetting the AD7714 The Noise Menu allows the user to get statistical results from the data, to plot the raw data, plot a histogram of the data on the screen, or perform a rolling average of the data. a photograph of the AD7714 evaluation board is shown in Figure 9.15 Notice the parallel printer connector on the left and the use of low-profile sockets for convenience. It should be noted that although the use of sockets is discouraged, any sockets used on evaluation boards have been proven to cause minimal performance degradation AD7714 EVALUATION BOARD PHOTO Figure 9.15 Evaluation boards for high speed sampling AD Cs contain the required support circuitry for proper evaluation of the converter Figure 9.16 shows a block diagram of the AD9026(12-bit, 31MSPS)evaluation board. The analog input is connected directly to the ADC input via an SMa connector. The sampling clock(Encode Input) is conditioned by the low-jitter high-speed AD9698 dual comparator The parallel gital outputs of the aD9026 are buffered by latches which drive the output connector as well as the aD9713 12-bit DAC. The daC output is connected to an output SMa connector
1 5 program. The evaluation software is run by running the executable file. The program provides a number of different menu-type screens, each screen containing several function options. The first menu gives options on the type of PC being used. The next menu in the sequence is the Main Menu which contains various options. These allow reading from the AD7714 Data Register, configuration of the Communications Register, file options (read and write data to files), noise analysis, printer port setup, and resetting the AD7714. The Noise Menu allows the user to get statistical results from the data, to plot the raw data, plot a histogram of the data on the screen, or perform a rolling average of the data. A photograph of the AD7714 evaluation board is shown in Figure 9.15. Notice the parallel printer connector on the left and the use of low-profile sockets for convenience. It should be noted that although the use of sockets is discouraged, any sockets used on evaluation boards have been proven to cause minimal performance degradation. AD7714 EVALUATION BOARD PHOTO Figure 9.15 Evaluation boards for high speed sampling ADCs contain the required support circuitry for proper evaluation of the converter. Figure 9.16 shows a block diagram of the AD9026 (12-bit, 31MSPS) evaluation board. The analog input is connected directly to the ADC input via an SMA connector. The sampling clock (Encode Input) is conditioned by the low-jitter high-speed AD9698 dual comparator. The parallel digital outputs of the AD9026 are buffered by latches which drive the output connector as well as the AD9713 12-bit DAC. The DAC output is connected to an output SMA connector