National Semiconductor Application Note 2095 Hooman Hashemi November 1, 2010 General Description Several components are mounted on the board bottom, while the DUT is installed on the top layer, for best performance. Here is a list of these components: Rf, RGa, C4, and RGND. For SOT23-6 devices with schematic pin 5 used for the disable function, resistor RTdis can be used (normally 50Ω) while an input at J4 can act as a disable signal. For a SOT23-5 device, schematic pin 5 is non-existent and the said components are thus “don’t care”. All board components are the SMT 0603 type, except the following listed in Table 1 The LMH730316 evaluation board is designed to aid in the characterization of National Semiconductor’s high speed and / or low distortion Operational Amplifiers and is sold without any components installed for easy application adoption. This 4 layer board is designed to improve speed and reduce harmonic distortion by careful placement and routing of components and traces. Use the evaluation board as a guide for high frequency layout and as a tool to aid in device testing and characterization. Basic Operation TABLE 1. Board Components which are not "0603" type This evaluation board supports both inverting and non-inverting configurations. For component locations refer to the schematic in Figure 1 . Note that the pin numbers correspond to the SOT23-6 package. For the SOT23-5 package, schematic pin 6 (VCC) is normally called pin 5 and schematic pin 5 does not exist (open). The board uses end mounted SMA connectors. On the +IN input, resistor RINa provides input termination. The resistors RTp and RINb are normally open and short, respectively, and are included for added flexibility (e.g. filtering, divider / attenuation, etc.) in configuring the amplifier. When using the evaluation board for non-inverting applications, load resistor RGa only (RGb and RTn left open). The resistors RGb and RTn are for use in the inverting configuration. When using this board for inverting applications, do not load RGa; instead load RGb and an appropriate value of RTn. Ro and RTo resistors comprise the output connection network which is usually configured for 50Ω operation (Ro= 50Ω , RTo= open). Reference Designator Description D1 Schottky diode, 1N5859, 40V (or equivalent) RGND Shorting jumper (single supply operation only) Diode D1 (optional) is meant as protection to clamp the supplies in case VCC and VEE are accidentally reversed. For single-supply operation (VCC), short RGND to connect VEE to GND and do not power VEE pins on J5. When using a single supply it is important to pay attention to DC bias voltages. This board consists of four layers. All four layers are detailed in Figure 2 through Figure 5. LMH730316 SOT23-5 / SOT23-6 High Performance Amplifier Evaluation Board LMH730316 SOT23-5 / SOT23-6 High Performance Amplifier Evaluation Board AN-2095 © 2010 National Semiconductor Corporation 301394 www.national.com AN-2095 30139401 FIGURE 1. Evaluation Board Schematic www.national.com 2 AN-2095 30139402 FIGURE 2. Evaluation Board Top Layer 30139403 FIGURE 3. Evaluation Board Bottom Layer (bottom view) 3 www.national.com AN-2095 30139404 FIGURE 4. Evaluation Board Layer 2 (bottom view) 30139405 FIGURE 5. Evaluation Board Layer 3 (bottom view) www.national.com 4 AN-2095 5 www.national.com LMH730316 SOT23-5 / SOT23-6 High Performance Amplifier Evaluation Board For more National Semiconductor product information and proven design tools, visit the following Web sites at: www.national.com Products Design Support Amplifiers www.national.com/amplifiers WEBENCH® Tools www.national.com/webench Audio www.national.com/audio App Notes www.national.com/appnotes Clock and Timing www.national.com/timing Reference Designs www.national.com/refdesigns Data Converters www.national.com/adc Samples www.national.com/samples Interface www.national.com/interface Eval Boards www.national.com/evalboards LVDS www.national.com/lvds Packaging www.national.com/packaging Power Management www.national.com/power Green Compliance www.national.com/quality/green Switching Regulators www.national.com/switchers Distributors www.national.com/contacts LDOs www.national.com/ldo Quality and Reliability www.national.com/quality LED Lighting www.national.com/led Feedback/Support www.national.com/feedback Voltage References www.national.com/vref Design Made Easy www.national.com/easy www.national.com/powerwise Applications & Markets www.national.com/solutions Mil/Aero www.national.com/milaero PowerWise® Solutions Serial Digital Interface (SDI) www.national.com/sdi Temperature Sensors www.national.com/tempsensors SolarMagic™ www.national.com/solarmagic PLL/VCO www.national.com/wireless www.national.com/training PowerWise® Design University THE CONTENTS OF THIS DOCUMENT ARE PROVIDED IN CONNECTION WITH NATIONAL SEMICONDUCTOR CORPORATION (“NATIONAL”) PRODUCTS. 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