THS4062 Dual High Speed Amplifier Evaluation Module User’s Guide March 1999 Mixed-Signal Products SLOU040
IMPORTANT NOTICE Texas Instruments and its subsidiaries (TI) reserve the right to make changes to their products or to discontinue any product or service without notice, and advise customers to obtain the latest version of relevant information to verify, before placing orders, that information being relied on is current and complete.
Preface Related Documentation From Texas Instruments J J THS4062 DUAL HIGH-SPEED OPERATIONAL AMPLIFIER (literature number SLOS234). This is the data sheet for the THS4062 operational amplifier integrated circuit that is used in the THS4062 evaluation module. PowerPAD Thermally Enhanced Package (literature number SLMA002). This is the Texas Instruments technical brief detailing the PowerPAD package of the THS4062 operational amplifier integrated circuit that is used in the THS4062 evaluation module.
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Running Title—Attribute Reference Contents 1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 1.1 Feature Highlights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2 1.2 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3 1.
Running Title—Attribute Reference Figures 1–1 1–2 1–3 1–4 1–5 1–6 1–7 1–8 1–9 THS4062 Evaluation Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3 THS4062 EVM Schematic — Noninverting Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4 THS4062 EVM Schematic — Inverting Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7 THS4062 EVM Schematic — Differential Input (Noninverting Operation) . . . .
Chapter 1 General This chapter details the Texas Instruments (TI) THS4062 dual high-speed amplifier evaluation module (EVM), SLOP235. It includes a list of EVM features, a brief description of the module illustrated with a pictorial and a schematic diagram, EVM specifications, details on connecting and using the EVM, and discussions on high-speed amplifier design and thermal considerations. Topic Page 1.1 Feature Highlights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Feature Highlights 1.
Description 1.2 Description The TI THS4062 dual high-speed amplifier evaluation module (EVM) is a complete dual high-speed amplifier circuit. It consists of the TI THS4062 dual high-speed amplifier IC, along with a small number of passive parts, mounted on a small circuit board measuring approximately 1.9 inch by 2.2 inch (Figure 1–1).
THS4062 EVM Noninverting Operation 1.3 THS4062 EVM Noninverting Operation The THS4062 EVM is shipped preconfigured for dual-channel noninverting operation, as shown in Figure 1–2. Note that compensation capacitors C3 and C6 are not installed. Figure 1–2. THS4062 EVM Schematic — Noninverting Operation C3 x µF J2 –VCC 1 GND 2 +VCC 3 –VCC C1 6.8 µF C2 6.8 µF +VCC R5 301 Ω R6 301 Ω +VCC 2 – 8 U1:A THS4062 J1 Vin1 R1 49.9 Ω R3 0Ω 3 C5 0.1 µF J3 Vout1 1 + C4 0.
THS4062 EVM Noninverting Operation Any of the resistors on the EVM board can be replaced with a resistor of a different value; however, care must be taken because the surface-mount solder pads on the board are somewhat fragile and will not survive many desoldering/soldering operations. External factors can significantly affect the effective gain of the EVM.
Using the THS4062 EVM In The Noninverting Mode 1.4 Using the THS4062 EVM In The Noninverting Mode The THS4062 EVM operates from power-supply voltages ranging from ± 5 V to ± 15 V. As shipped, the EVM is configured for noninverting operation and the gain is set to 2. Signal inputs on the module are terminated for 50-Ω nominal source impedance. An oscilloscope is typically used to view and analyze the EVM output signal.
THS4062 EVM Inverting Operation 1.5 THS4062 EVM Inverting Operation Although the THS4062 EVM is shipped preconfigured for dual-channel noninverting operation, it can be reconfigured for inverting operation by making the following component changes: 1) Move resistor R3 to the R2 location on the board. 2) Move resistor R11 to the R10 location on the board. 3) Remove resistors R5 and R12. 4) Add resistors R4 and R13 with values appropriate for the input termination required for the application.
THS4062 EVM Inverting Operation The gain of the EVM can easily be changed to support a particular application by simply changing the ratio of resistors R6 and R4 (channel 1) and R14 and R12 (channel 2) as described in the following equation: Inverting Gain + –R + –RR46 R F G and –R14 R12 In addition, some applications, such as those for video, may require the use of 75-Ω cable and 75-Ω EVM input termination and output isolation resistors.
THS4062 EVM Inverting Operation Any of the resistors on the EVM board can be replaced with a resistor of a different value; however, care must be taken because the surface-mount solder pads on the board are somewhat fragile and will not survive many desoldering/soldering operations. External factors can significantly affect the effective gain of the EVM.
Using the THS4062 EVM In The Inverting Mode 1.6 Using the THS4062 EVM In The Inverting Mode The THS4062 EVM operates from power-supply voltages ranging from ± 5 V to ± 15 V. As shipped, the EVM is configured for noninverting operation. Move the resistors as detailed above to configure the EVM for inverting operation, which sets the gain to –3. Signal inputs on the module are terminated for 50-Ω nominal source impedance. An oscilloscope is typically used to view and analyze the EVM output signal.
THS4062 EVM Differential Input 1.7 THS4062 EVM Differential Input The THS4062 EVM is shipped preconfigured for dual-channel, single-ended noninverting operation. It can be reconfigured for single-channel, differential operation, either noninverting or inverting. 1.7.1 Differential Input, Noninverting Operation Configure the THS4062 EVM for differential noninverting operation by removing two resistors and adding a resistor on the board: 1) Remove resistors R1 and R9.
THS4062 EVM Differential Input The gain of the EVM can easily be changed to support a particular application by simply changing the ratio of resistors R6 and R5 (channel 1) and R14 and R13 (channel 2) as described in the following equation: Noninverting Gain + 1 ) RR + 1 ) RR65 F and 1 G ) RR14 13 In addition, some applications, such as those for video, may require the use of 75-Ω cable and 75-Ω EVM input termination and output isolation resistors.
THS4062 EVM Differential Input Figure 1–5. THS4062 EVM Schematic — Differential Input (Inverting Operation) C3 x µF J2 –VCC 1 GND 2 +VCC 3 –VCC +VCC C1 6.8 µF R6 301 Ω C2 6.8 µF +VCC R4 100 Ω J1 Vin1 2 3 – 8 C5 0.1 µF U1:A THS4062 R7 49.9 Ω J3 Vout1 1 + C4 0.1 µF 4 R2 0Ω C6 x µF –VCC R8 200 Ω R14 301 Ω R12 100 Ω J4 Vin2 6 – U1:B THS4062 + 7 R15 49.
THS4062 EVM Differential Input Any of the resistors on the EVM board can be replaced with a resistor of a different value; however, care must be taken because the surface-mount solder pads on the board are somewhat fragile and will not survive many desoldering/soldering operations. External factors can significantly affect the effective gain of the EVM.
Using the THS4062 EVM With Differential Inputs 1.8 Using the THS4062 EVM With Differential Inputs The THS4062 EVM operates from power-supply voltages ranging from ± 5 V to ± 15 V. Move resistors on the board as detailed above for either noninverting or inverting operation to configure the EVM for differential input operation. Signal inputs on the module are terminated for 50-Ω nominal source impedance. An oscilloscope is typically used to view and analyze the EVM output signal.
THS4062 EVM Performance 1.10 THS4062 EVM Performance Figure 1–6 shows the typical phase and frequency response of the THS4062 EVM with a ± 5-V power supply using the noninverting configuration (G = 2). Typical –0.1 dB bandwidth is 4.5 MHz and the –3 dB bandwidth is 45 MHz with a 100° phase margin. 7 30 6 0 5 –30 4 –60 3 –90 Gain Phase –120 2 1 0 VCC = ±5 V AV = 2 VO = 0.2 VRMS RL = 100 Ω Both channels –1 100k Output Phase — Degrees Output Amplitude — dB Figure 1–6.
General High-Speed Amplifier Design Considerations 1.11 General High-Speed Amplifier Design Considerations The THS4062 EVM layout has been designed and optimized for use with high-speed signals and can be used as an example when designing THS4062 applications. Careful attention has been given to component selection, grounding, power supply bypassing, and signal path layout.
General PowerPAD Design Considerations 1.12 General PowerPAD Design Considerations The THS4062DGN IC is mounted in a special package incorporating a thermal pad that transfers heat from the IC die directly to the PCB. The PowerPAD package is constructed using a downset leadframe. The die is mounted on the leadframe but is electrically isolated from it. The bottom surface of the lead frame is exposed as a metal thermal pad on the underside of the package and makes physical contact with the PCB.
General PowerPAD Design Considerations 8) With these preparatory steps in place, the THS4062DGN IC is simply placed in position and run through the solder reflow operation as any standard surface mount component. This results in a part that is properly installed. The actual thermal performance achieved with the THS4062DGN in its PowerPAD package depends on the application.
General PowerPAD Design Considerations Correct PCB layout and manufacturing techniques are critical for achieving adequate transfer of heat away from the PowerPAD IC package. More details on proper board layout can be found in the THS4062 LOW-NOISE DUAL DIFFERENTIAL RECEIVER data sheet (SLOS228). For more general information on the PowerPAD package and its thermal characteristics, see the Texas Instruments Technical Brief, PowerPAD Thermally Enhanced Package (SLMA002).
Chapter 2 Reference This chapter includes a complete schematic, parts list, and PCB layout illustrations for the THS4062 EVM. Topic Page 2.1 THS4062 EVM Complete Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–2 2.1 THS4062 Dual High-Speed Amplifier EVM Parts List . . . . . . . . . . . . . 2–3 2.2 THS4062 EVM Board Layouts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
THS4062 EVM Complete Schematic 2.1 THS4062 EVM Complete Schematic Figure 2–1 shows the complete THS4062 EVM schematic. The EVM is shipped preconfigured for dual-channel, single-ended inverting operation. Components showing a value of X are not supplied on the board, but can be installed by the user to reconfigure the EVM for noninverting and/or differential operation. Figure 2–1. THS4062 EVM Schematic C3 x µF J2 –VCC GND +VCC 1 –VCC 2 3 +VCC C1 6.8 µF C2 6.
THS4062 Dual High-Speed Amplifier EVM Parts List 2.2 THS4062 Dual High-Speed Amplifier EVM Parts List Table 2–1. THS4062 EVM Parts List Reference Description Size Manufacturer/Supplier Part Number C1, C2 Capacitor, 6.8 µF, 35 V, Tantalum, SM C4, C5 Capacitor, 0.1 µF, Ceramic, 10%, SM J2 3-Pin Terminal Block (On Shore Tech.) Digi-Key ED1515–ND J1, J3, J4, J5 Connector, SMA 50-Ω vertical PC mount, through-hole Amphenol ARF1205–ND R1, R7, R9, R15 Resistor, 49.
THS4062 EVM Board Layouts 2.3 THS4062 EVM Board Layouts Board layout examples of the THS4062 EVM PCB are shown in the following illustrations. They are not to scale and appear here only as a reference. Figure 2–2.
THS4062 EVM Board Layouts Figure 2–3.
THS4062 EVM Board Layouts Figure 2–4.
