Texas Instruments THS3001 User Manual

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THS3001

High Speed Current

Feedback

Operational Amplifier

Evaluation Module User's Guide

March 1999

Mixed-SignalProducts

SLOU021A

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. All products are sold subject to the terms and conditions of sale supplied at the time of order acknowledgement, including those pertaining to warranty, patent infringement, and limitation of liability.

TI warrants performance of its semiconductor products to the specifications applicable at the time of sale in accordance with TI's standard warranty. Testing and other quality control techniques are utilized to the extent TI deems necessary to support this warranty. Specific testing of all parameters of each device is not necessarily performed, except those mandated by government requirements.

CERTAIN APPLICATIONS USING SEMICONDUCTOR PRODUCTS MAY INVOLVE POTENTIAL RISKS OF DEATH, PERSONAL INJURY, OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE (ªCRITICAL APPLICATIONSº). TI SEMICONDUCTOR PRODUCTS ARE NOT DESIGNED, AUTHORIZED, OR WARRANTED TO BE SUITABLE FOR USE IN LIFE-SUPPORTDEVICES OR SYSTEMS OR OTHER CRITICAL APPLICATIONS. INCLUSION OF TI PRODUCTS IN SUCH APPLICATIONS IS UNDERSTOOD TO BE FULLY AT THE CUSTOMER'S RISK.

In order to minimize risks associated with the customer's applications, adequate design and operating safeguards must be provided by the customer to minimize inherent or procedural hazards.

TI assumes no liability for applications assistance or customer product design. TI does not warrant or represent that any license, either express or implied, is granted under any patent right, copyright, mask work right, or other intellectual property right of TI covering or relating to any combination, machine, or process in which such semiconductor products or services might be or are used. TI's publication of information regarding any third party's products or services does not constitute TI's approval, warranty or endorsement thereof.

Copyright 1999, Texas Instruments Incorporated

Preface

Related Documentation From Texas Instruments

JTHS3001 HIGH-SPEEDCURRENT-FEEDBACKOPERATIONAL AMPLIFIER(literature number SLOS217) This is the data sheet for the THS3001 operational amplifier integrated circuit that is used in the THS3001 evaluation module.

FCC Warning

This equipment is intended for use in a laboratory test environment only. It generates, uses, and can radiate radio frequency energy and has not been tested for compliance with the limits of computing devices pursuant to subpart J of part 15 of FCC rules, which are designed to provide reasonable protection against radio frequency interference. Operation of this equipment in other environments may cause interference with radio communications, in which case the user at his own expense will be required to take whatever measures may be required to correct this interference.

Trademarks

TI is a trademark of Texas Instruments Incorporated.

Chapter TitleÐAttribute Reference

iii

iv

Running TitleÐAttribute Reference

Contents

1 General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-1

1.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-21.2 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-21.3 THS3001 EVM Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-51.4 Using The THS3001 EVM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-61.5 THS3001 EVM Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-71.6 GeneralHigh-SpeedAmplifier Design Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . .1-8

2 Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

2.1 THS3001 High-SpeedOperational Amplifier EVM Parts List . . . . . . . . . . . . . . . . . . . . . .2-22.2 THS3001 EVM Board Layouts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-22.3 THS3001 Rev. AHigh-SpeedOperational Amplifier EVM Parts List . . . . . . . . . . . . . . .2-42.4 THS3001 Rev. A. EVM Board Layouts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-4

Figures

1±1 THS3001 Evaluation Module ± Original Version . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-21±2 THS3001 Rev. A Evaluation Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-31±3 THS3001 EVM Schematic ± Original Version . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-31±4 THS3001 Rev. A EVM Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-41±5 THS3001 EVM Frequency Response with Gain = 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-71±6 THS3001 EVM Frequency Response with Inverting Gain = 1 . . . . . . . . . . . . . . . . . . . . . . .1-72±1 THS3001 EVM Component Placement Silkscreen and Solder Pads . . . . . . . . . . . . . . . . .2-22±2 THS3001 EVM PC Board Layout ± Component Side . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-32±3 THS3001 EVM PC Board Layout ± Back Side . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-32±4 THS3001 Rev. A EVM Component Placement Silkscreen and Solder Pads . . . . . . . . . . .2-42±5 THS3001 Rev. A EVM PC Board Layout ± Component Side . . . . . . . . . . . . . . . . . . . . . . . .2-52±6 THS3001 Rev. A EVM PC Board Layout ± Back Side . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-5

Tables

2±1

THS3001 EVM Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2-2

2±2

THS3001 Rev. A EVM Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2-4

Contents v

vi

Chapter 1

General Information

This chapter details the Texas Instruments (TI ) THS3001 high-speedoperational amplifier evaluation module (EVM), SLOP130. 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 a discussion onhigh-speedamplifier design considerations.

Topic

 

Page

 

 

 

1.1

Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . 1±2

1.2

Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. 1±2

1.3

THS3001 EVM Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. 1±5

1.4

Using The THS3001 EVM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. 1±6

1.5

THS3001 EVM Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. 1±7

1.6

General High-SpeedAmplifier Design Considerations . . . . . . . . . .

. 1±8

 

 

 

General Information

1-1

Features

1.1 Features

THS3001 operational amplifier EVM features include:

J J

High Bandwidth Ð 340 MHz, ±3 dB at ± 15 VCC & Gain = 2

± 5-Vto± 15-VOperation

JInverting and Noninverting Single-EndedInputs

JModule Gain Set to +2 (Noninverting) and ±1 (Inverting) Ð Adjustable Through Component Change.

JNominal 50-Ω Impedance Inputs and Outputs

JStandard SMA Miniature RF Connectors

JGood Example of High-SpeedAmplifier Design and Layout

1.2 Description

The TI THS3001 high-speedcurrent-feedbackoperational amplifier evaluation module (EVM) is a completehigh-speedamplifier circuit. It consists of the TI THS3001high-speedcurrent-feedbackoperational amplifier IC, along with a small number of passive parts, mounted on a small circuit board measuring approximately 1.7 inch by 1.4 inch. The EVM uses standard SMA miniature RF connectors for inputs and outputs and is completely assembled, fully tested, and ready to use Ð just connect it to power, a signal source, and a load (if desired).

Two versions of the THS3001 EVM are available. The original appears in Figure 1±1 and the Rev. A version appears in Figure 1±2.

Figure 1±1. THS3001 Evaluation Module ± Original Version

±VCC

 

+VCC

J3

GND

 

 

 

C3

 

 

±IN

+ +

C1

GND

R5

 

 

 

INVERTING

 

R1

 

U1

C2

 

 

 

R4

J2

NONINVERTING

 

 

 

 

 

R2

R3

 

C4

+IN

 

 

GND

 

 

J1

LITERATURE NO

 

 

SLOP 130

 

009957

THS3001 EVM

 

OUT GND

1-2

General Information

Description

Figure 1±2. THS3001 Rev. A Evaluation Module

 

 

 

 

J1

 

 

 

 

 

±VCC

 

 

+VCC

 

J2

C1

GND

C2

 

 

 

 

±IN

 

 

 

 

 

GND

 

+

+

TEXAS

 

 

 

R2

 

Rev. A

 

 

 

INSTRUMENTS

INVERTING

 

 

 

 

 

R4

J4

 

 

 

 

 

NONINVERTING R1

 

 

C3

 

 

 

 

+IN

R3

R5

 

GND

U1

C4

OUT

 

GND

 

 

 

 

J3

 

 

SLOP130 Rev A

THS3001 EVM Board

The THS3001 EVM is equipped with both noninverting and inverting inputs. The noninverting input is set for a gain of 2 and the inverting input is set for a gain of 1. Each input is terminated with a 50-Ω resistor to provide correct line impedance matching (Figure 1±3 for original version and Figure 1±4 for Rev. A). The amplifier IC output is routed through a50-Ω resistor both to provide correct line impedance matching and to help isolate capacitive loading on the output of the amplifier. Capacitive loading directly on the output of the IC decreases the amplifier's phase margin and can result in peaking or oscillations.

Figure 1±3. THS3001 EVM Schematic ± Original Version

 

 

C2

VCC

 

+

 

 

 

0.1 μF

 

 

 

 

 

 

R1

 

C1

 

 

 

 

6.8 μF/35 V

 

 

J1

 

1 k Ω

 

 

 

Non-

3

7

 

 

 

 

 

 

 

Inverting

 

+

 

 

 

 

 

 

 

J2

Input

 

 

 

 

 

 

R3

U1

 

6

R2

 

 

49.9 Ω

THS3001

 

Output

 

 

2

±

 

 

49.9 Ω

 

 

 

 

 

 

 

 

 

 

 

 

J3

R5

4

 

 

 

Inverting

1 k Ω

 

 

 

 

 

 

 

 

 

 

Input

 

R4

C4

 

C3

 

 

 

+

6.8 μF/35 V

 

 

49.9 Ω

0.1 μF

 

 

 

±VCC

General Information

1-3

Description

Figure 1±4. THS3001 Rev. A EVM Schematic

 

J1

 

 

 

 

VCC

C2

 

 

 

 

 

 

 

6.8 μF

 

±VCC

1

±VCC

 

 

 

 

 

2

 

 

 

 

+

 

GND

 

 

 

 

 

C3

 

 

 

 

 

 

 

 

VCC

3

VCC

 

R2

R4

 

0.1 μF

 

 

J2

 

 

 

 

 

±IN

1 kΩ

1 kΩ

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Inverting

R1

 

 

7

 

 

 

 

 

 

 

 

 

 

 

 

49.9 Ω

 

2

 

 

 

 

 

 

±

R5

J4

 

 

 

 

 

 

Rev. A

 

 

 

 

 

U1

6 49.9Ω

 

 

 

 

 

Out

 

 

J3

 

 

THS3001

 

 

+IN

 

3

 

 

 

 

 

+

C4

 

 

 

Noninverting

 

 

 

 

 

 

R3

 

 

4

0.1 μF

 

 

 

 

49.9 Ω

 

 

 

 

 

 

 

 

 

 

 

 

C1

 

 

 

 

 

 

 

 

6.8 μF

 

 

 

 

 

 

 

 

+

 

 

 

 

 

 

 

±VCC

 

 

Even though the THS3001 is a current-feedbackamplifier, the gain of the EVM can easily be changed to support a particular application by simply changing the ratio of resistors R1, R4, and R5 (R1, R2, and R4 for Rev. A) as described in the following equations:

Inverting Gain +

* RF

+

* R1

+

* R4

(Rev.A)

 

RG

 

R5

R2

 

 

 

 

 

 

 

 

 

 

 

 

Noninverting Gain + 1 )

RF

+ 1 )

 

 

R1

 

+ 1 )

 

R4

 

(Rev.A)

RG

R4) R5

R2) R1

 

 

 

 

 

 

In addition, some applications, such as those for video, may require the use of 75-Ω cable and75-Ω EVM input termination and output isolation resistors.

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-mountsolder pads on the board are somewhat fragile and will not survive many desoldering/soldering operations.

Because of the current feedback architecture, extra care must be taken to ensure that a feedback resistor is always included in the design. In addition, there must never be a capacitor directly in the feedback path between the amplifier output and the noninverting input. Disregarding this guideline will likely result in a part that oscillates.

1-4

General Information