Texas Instruments THS4012 User Manual

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THS4012

Dual High Speed

Operational Amplifier

Evaluation Module

User's Guide

May 1999

Mixed-SignalProducts

SLOU041

IMPORTANT NOTICE

Texas Instruments (TI) reserves the right to make changes to its products or to discontinue any semiconductor product or service without notice, and advises its customers to obtain the latest version of relevant information to verify, before placing orders, that the information being relied on is current.

TI warrants performance of its semiconductor products and related software 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, INTENDED, AUTHORIZED, OR WARRANTED TO BE SUITABLE FOR USE IN LIFE-SUPPORTAPPLICATIONS, DEVICES OR SYSTEMS OR OTHER CRITICAL APPLICATIONS.

Inclusion of TI products in such applications is understood to be fully at the risk of the customer. Use of TI products in such applications requires the written approval of an appropriate TI officer. Questions concerning potential risk applications should be directed to TI through a local SC sales office.

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

TI assumes no liability for applications assistance, customer product design, software performance, or infringement of patents or services described herein. Nor does TI 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.

Copyright 1999, Texas Instruments Incorporated

Preface

Related Documentation From Texas Instruments

JTHS4012 DUAL LOW-NOISEHIGH-SPEEDOPERATIONAL AMPLIFIER(literature number SLOS216) This is the data sheet for the THS4012 operational amplifier integrated circuit that is used in the THS4012 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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-1

1.1 Feature Highlights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-21.2 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-31.3 THS4012 EVM Noninverting Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-41.4 Using The THS4012 EVM In The Noninverting Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-61.5 THS4012 EVM Inverting Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-71.6 Using The THS4012 EVM In The Inverting Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-91.7 THS4012 EVM Differential Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-101.8 Using The THS4012 EVM WIth Differential Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-141.9 THS4012 EVM Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-141.10 THS4012 EVM Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-151.11 GeneralHigh-SpeedAmplifier Design Considerations . . . . . . . . . . . . . . . . . . . . . . . . . .1-161.12 General PowerPAD Design Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-17

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

2.1 THS4012 EVM Complete Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-22.1 THS4012 DualHigh-SpeedOperational Amplifier EVM Parts List . . . . . . . . . . . . . . . . .2-32.2 THS4012 EVM Board Layouts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-4

Chapter TitleÐAttribute Reference

v

Running TitleÐAttribute Reference

Figures

1±1

THS4012 Evaluation Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. 1-3

1±2

THS4012 EVM Schematic Ð Noninverting Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. 1-4

1±3

THS4012 EVM Schematic Ð Inverting Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. 1-7

1±4

THS4012 EVM Schematic Ð Differential Input (Noninverting Operation) . . . . . . . . . . . .

1-10

1±5

THS4012 EVM Schematic Ð Differential Input (Inverting Operation) . . . . . . . . . . . . . . . .

1-12

1±6

THS4012 EVM Frequency Response with Gain = 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-15

1±7

THS4012 EVM Phase Response with Gain = 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-15

1±8

PowerPAD PCB Etch and Via Pattern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-17

1±9

Maximum Power Dissipation vs Free-AirTemperature . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-18

2±1

THS4012 EVM Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. 2-2

2±2

THS4012 EVM Component Placement Silkscreen and Solder Pads . . . . . . . . . . . . . . . .

. 2-4

2±2

THS4012 EVM PC Board Layout ± Component Side . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. 2-5

2±3

THS4012 EVM PC Board Layout ± Back Side . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. 2-6

Tables

2±1 THS4012 EVM Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2-3

vi

Chapter 1

General

This chapter details the Texas Instruments (TI ) THS4012 dual high-speedoperational amplifier evaluation module (EVM), SLOP230. 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 onhigh-speedamplifier design and thermal considerations.

Topic

 

Page

 

 

 

1.1

Feature Highlights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . 1±2

1.2

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

. . 1±3

1.3

THS4012 EVM Noninverting Operation . . . . . . . . . . . . . . . . . . . . . . . . .

. 1±4

1.4

Using The THS4012 EVM In The Noninverting Mode . . . . . . . . . . . .

. 1±6

1.5

THS4012 EVM Inverting Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. 1±7

1.6

Using The THS4012 EVM In The Inverting Mode . . . . . . . . . . . . . . . .

. 1±9

1.7

THS4012 EVM Differential Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1±10

1.8

Using The THS4012 EVM With Differential Inputs . . . . . . . . . . . . . .

1±14

1.9

THS4012 EVM Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1±14

1.10

THS4012 EVM Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1±15

1.11

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

1±16

1.12

General PowerPAD Design Considerations . . . . . . . . . . . . . . . . . . . .

1±17

 

 

 

General 1-1

Feature Highlights

1.1 Feature Highlights

THS4012 Dual High-SpeedOperational Amplifier EVM features include:

JHigh Bandwidth Ð 75 MHz, ±3 dB at ± 15 VCC and Gain = 2

J± 5-Vto± 15-VOperation

JNoninverting Single-EndedInputs ÐInverting-CapableThrough Component Change

JModule Gain Set to 2 (Noninverting) Ð Adjustable Through Component Change

JNominal 50-Ω Impedance Inputs and Outputs

JStandard SMA Input and Output Connectors

JGood Example of High-SpeedAmplifier Design and Layout

1-2

General

Description

1.2 Description

The TI THS4012 dual high-speedoperational amplifier evaluation module (EVM) is a complete dualhigh-speedamplifier circuit. It consists of the TI THS4012 duallow-noisehigh-speedoperational 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). The EVM uses standard SMA miniature RF connectors for inputs and outputs and is completely assembled, tested, and ready to use Ð just connect it to power, a signal source, and a load (if desired).

Figure 1±1. THS4012 Evaluation Module

±VCC GND +VCC

 

C1

J2

J1

 

+

C2

 

Vin1

+

J3

Vout1

R1

R2

R3

R4

R5

R6

C3

R7

R8

C4

U1

TEXAS

C5

INSTRUMENTS

 

J4

 

 

 

 

 

 

J5

Vin2

 

 

 

 

 

 

Vout2

R9

R10

R11

R12

R13

R14

C6

R15

SLOP230

THS4012 EVM Board

Note: The EVM is shipped with the following component locations empty: C3, C6,

R2, R4, R8, R10, R12

Although the THS4012 EVM is shipped with components installed for dual-channelsingle-endednoninverting operation, it can also be configured forsingle-channeldifferential and/or inverting operation by moving components. Noninverting gain is set to 2 with the installed components. The input of each channel is terminated with a50-Ω impedance to provide correct line impedance matching. The amplifier IC outputs are routed through50-Ω resistors both to provide correct line impedance matching and to help isolate capacitive loading on the outputs 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.

General 1-3

THS4012 EVM Noninverting Operation

1.3 THS4012 EVM Noninverting Operation

The THS4012 EVM is shipped preconfigured for dual-channelnoninverting operation, as shown in Figure 1±2. Note that compensation capacitors C3 and C6 are not installed.

Figure 1±2. THS4012 EVM Schematic Ð Noninverting Operation

 

J2

 

 

 

 

 

 

 

C3

 

 

±VCC

1

 

 

±VCC

 

 

 

 

x μF

 

 

2

 

 

 

 

 

 

 

 

 

GND

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

+VCC

3

 

 

+VCC

R5

 

 

 

R6

 

 

C1

 

 

 

 

 

 

 

 

C2

1 kΩ

 

 

 

1 kΩ

 

 

 

6.8

μ

F

6.8 μF

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

+VCC

C5

 

 

 

 

 

 

 

 

 

 

 

0.1 μF

 

 

 

 

 

 

 

 

2

±

8

U1:A

R7

 

 

 

 

 

 

 

 

THS4012

J3

 

 

 

 

J1

 

 

 

 

49.9 Ω

 

 

 

 

 

 

 

 

1

 

Vout1

 

Vin1

 

 

 

 

+

 

 

 

 

 

R1

R3

3

4

C4

 

 

 

 

 

 

0 Ω

 

 

 

0.1 μF

 

 

 

 

 

 

49.9 Ω

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

R13

1 kΩ

J4

Vin2

 

 

 

R9

R11

 

 

 

0

Ω

 

 

 

49.9 Ω

 

 

 

 

 

 

 

 

 

 

 

 

 

±VCC

C6

 

 

 

 

 

x μF

 

 

 

 

 

R14

 

 

 

 

 

1 kΩ

 

 

6

 

 

U1:B

R15

 

±

THS4012

J5

 

 

 

 

49.9 Ω

 

 

 

7

 

Vout2

 

+

 

 

 

5

 

 

 

 

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 )

RF

+ 1 )

R6

and 1 )

R14

RG

R5

R13

 

 

 

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.

1-4

General