THS4271/75EVM User’s Guide DEVICE EVM TITLE USER’S GUIDE DESCRIPTION SHUTDOWN THS4271 THS4271EVM THS4271/75EVM Configurable for gains ≥ +2/-1 No THS4275 THS4275EVM THS4271/75EVM Configurable for gains ≥ +2/-1 Yes THS4271 THS4271EVM-UG THS4271 Unity Gain EVM Noninverting unity gain configuration only No October 2002 High Performance Linear Products SLOU143
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EVM IMPORTANT NOTICE Texas Instruments (TI) provides the enclosed product(s) under the following conditions: This evaluation kit being sold by TI is intended for use for ENGINEERING DEVELOPMENT OR EVALUATION PURPOSES ONLY and is not considered by TI to be fit for commercial use.
EVM WARNINGS AND RESTRICTIONS It is important to operate this EVM within the specified input and output ranges described in the EVM User’s Guide. The input supply voltage (±VS) should be no greater than ±7.5 V for dual supply (VS should be no greater than 15 V for single supply operation). The differential input signal (VID) should be no greater than ± 3 V. The output current (IO) should be no greater than 100 mA.
Information About Cautions and Warnings Preface Read This First Information About Cautions and Warnings This book may contain cautions and warnings. This is an example of a caution statement. A caution statement describes a situation that could potentially damage your software or equipment. This is an example of a warning statement. A warning statement describes a situation that could potentially cause harm to you. The information in a caution or a warning is provided for your protection.
Trademarks This EVM contains components that can potentially be damaged by electrostatic discharge. Always transport and store the EVM in its supplied ESD bag when not in use. Handle using an antistatic wristband. Operate on an antistatic work surface. For more information on proper handling, refer to SSYA008. Related Documentation From Texas Instruments The URL’s below are correct as of the date of publication of this manual. Texas Instruments applications apologizes if they change over time.
Contents Contents 1 Introduction and Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 1.1 Evaluation Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 2 Using the EVM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 3 EVM Applications . . . . . . . . . . . . . . . . . . . .
Chapter 1 Introduction and Description This EVM provides a platform for testing the THS4271 and THS4275 in 8-pin MSOP (DGN) and 8-pin LLP (DRB) with and without power down. It contains the high-speed op amp, a number of passive components, and various features and footprints that enable the user to experiment, test, and verify various operational amplifier circuit implementations. If the user wants to evaluate a unity gain noninverting buffer, that configuration is not recommended with this EVM.
Evaluation Schematic Figure 1-1. Schematic of the THS4271/75EVM Vs+ J9 Power Down R8 * { R5 Vs+ R3 249 J1 Vin- R2 0 7 8 U1 2 6 3 + THS4275 4 1 THS4271 Vs- J2 Vin+ C8 { 0.1 F 249 R4 49.9 J7 Vs- VsR6 J6 GND J4 Vout 453 J8 Power Down Ref R1 0{ R9 * { R7 49.9 C7 * { J5 Vs+ TP1 FB1 FB2 Vs- C5 100 pF C6 0.1 F * Not Installed on the THS4275EVM { Not Installed on the THS4271EVM 1-2 C1 + 22 F Vs+ + C2 22 F C3 0.
Chapter 2 Using the EVM Figure 2-1 shows how to connect power supplies, signal source and monitoring instrument. It is recommended that the user connect the EVM as shown to avoid damage to the EVM or the op amp installed on the board. Figure 2-1.
Chapter 3 EVM Applications Example applications are presented in this chapter. These applications demonstrate the most popular circuits, but many other circuits can be constructed. The purpose of the EVM board is for the user to experiment with different circuits, exploring new and creative design techniques, which is the function of an evaluation board. 3.1 Default Configuration Figure 3-1. Default Configuration R5 Vs+ R3 249 R2 0 J2 Vin+ Note: 7 2 3 + 4 249 U1 6 R6 J4 Vout 453 R7 49.
Noninverting Gain Stage If the user provides an external load, R7 may be removed, and R6 replaced with a 0-Ω jumper. The EVM then provides a gain of 2 (6 dB) at the output connector J4. A gain of 2 is often used to compensate for the voltage division effect when series and termination resistors are used for stage impedance matching. 3.2 Noninverting Gain Stage The default configuration of the EVM is a noninverting gain stage with a voltage divider on the output.
Inverting Gain Stage 3.3 Inverting Gain Stage If unity gain inverting operation is desired, the user should: - Change R6 to 0 Ω - Remove R7 - Change R4 to 0 Ω - Change R2 to 61.9 Ω (R3 in parallel with R2 equals 50 Ω for termination of the input) as shown in Figure 3-3. Figure 3-3. Inverting Gain Stage R5 249 Vs+ R3 249 J1 Vin- R2 61.9 7 2 3 + U1 6 R6 0 J4 Vout 4 Vs- R4 0 The gain for this circuit with a 50-Ω source is: V O + * R5 V R3 I when the input voltage is measured at J1.
Power-Down Reference Operation—THS4275EVM Only Figure 3-4. Power-Down Reference Operation J9 Power Down R5 249 Vs+ R3 J1 Vin- 249 R2 C8 0.1 F 7 8 U1 2 6 3 + THS4275 R6 4 1 Vs- J4 Vout 453 J8 Power-Down Ref R7 49.9 J2 Vin+ R4 49.9 Note: C7 0.1 F This schematic reflects the default THS4275EVM configuration. The reference pin allows the user the ability to control the logic levels of the power-down pin.
Chapter 4 EVM Hardware Description This chapter describes the EVM hardware. It includes the EVM parts list, and printed circuit board layout. Table 4-1. THS4271EVM Bill of Materials Item Description SMD Size Reference Designator PCB QTY Manufacturer’s Part Number Distributor’s Part Number 1 Bead, ferrite, 3A, 80 Ω 1206 FB1, FB2 2 (Steward) HI1206N800R-00 (Digi-Key) 240-1010-1-ND 2 Cap., 22 µF, tantalum, 25 V, 10% D C1, C2 2 (AVX) TAJD226K025R (Garrett) TAJD226K025R 3 Cap.
Table 4-2. THS4275EVM Bill of Materials Item Description SMD Size Reference Designator 1 Bead, ferrite, 3A, 80 Ω 1206 FB1, FB2 2 Capacitor, 22 µF, tantalum, 25 V, 10% D 3 Manufacturer’s Part Number Distributor’s Part Number 2 (Steward) HI1206N800R-00 (Digi-Key) 240-1010-1-ND C1, C2 2 (AVX) TAJD226K025R (Garrett) TAJD226K025R Capacitor, 100 pF, ceramic, 150 AQ12 V, 5%, C4, C5 2 (AVX) AQ12EM101JAJME (TTI) AQ12EM101JAJME 4 5 Open 1206 C7 Capacitor, 0.
Figure 4-1.
