Texas Instruments THS3062EVM User manual

THS3062EVM
September 2002 High Performance Linear Products
User’s Guide
SLOU146

IMPORTANT NOTICE
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Mailing Address:
Texas Instruments
Post Office Box 655303
Dallas, Texas 75265
Copyright 2002, Texas Instruments Incorporated

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. As such, the goods being provided
may not be complete in terms of required design-, marketing-, and/or manufacturing-related protective
considerations, including product safety measures typically found in the end product incorporating the goods.
As a prototype, this product does not fall within the scope of the European Union directive on electromagnetic
compatibility and therefore may not meet the technical requirements of the directive.
Should this evaluation kit not meet the specifications indicated in the EVM User’s Guide, the kit may be returned
within 30 days from the date of delivery for a full refund. THE FOREGOING WARRANTY IS THE EXCLUSIVE
WARRANTY MADE BY SELLER TO BUYER AND IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED,
IMPLIED, OR STATUTORY, INCLUDING ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR ANY
PARTICULAR PURPOSE.
The user assumes all responsibility and liability for proper and safe handling of the goods. Further, the user
indemnifies TI from all claims arising from the handling or use of the goods. Please be aware that the products
received may not be regulatory compliant or agency certified (FCC, UL, CE, etc.). Due to the open construction
of the product, it is the user’s responsibility to take any and all appropriate precautions with regard to electrostatic
discharge.
EXCEPT TO THE EXTENT OF THE INDEMNITY SET FORTH ABOVE, NEITHER PARTY SHALL BE LIABLE
TO THE OTHER FOR ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES.
TI currently deals with a variety of customers for products, and therefore our arrangement with the user is not
exclusive.
TI assumesno liability for applications assistance, customer product design, software performance, or
infringement of patents or services described herein.
Please read the EVM User’s Guide and, specifically, the EVM Warnings and Restrictions notice in the EVM
User’s Guide prior to handling the product. This notice contains important safety information about temperatures
and voltages. For further safety concerns, please contact the TI application engineer.
Persons handling the product must have electronics training and observe good laboratory practice standards.
No license is granted under any patent right or other intellectual property right of TI covering or relating to any
machine, process, or combination in which such TI products or services might be or are used.
Mailing Address:
Texas Instruments
Post Office Box 655303
Dallas, Texas 75265
Copyright 2002, Texas Instruments Incorporated

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 must not exceed ±15 V for dual supply or 30 V
for single supply. The differential input signal must not exceed ±3 V. The output current must
not exceed 150 mA.
Exceeding the specified input range may cause unexpected operation and/or irreversible
damage to the EVM. If there are questions concerning the input range, please contact a TI
field representative prior to connecting the input power.
Applying loads outside of the specified output range may result in unintended operation and/or
possible permanent damage to the EVM. Please consult the EVM User’s Guide prior to
connecting any load to the EVM output. If there is uncertainty as to the load specification,
please contact a TI field representative.
During normal operation, some circuit components may have case temperatures greater than
xxx°C. The EVM is designed to operate properly with certain components above xxx°C as
long as the input and output ranges are maintained. These components include but are not
limited to linear regulators, switching transistors, pass transistors, and current sense
resistors. These types of devices can be identified using the EVM schematic located in the
EVM User’s Guide. When placing measurement probes near these devices during operation,
please be aware that these devices may be very warm to the touch.
Mailing Address:
Texas Instruments
Post Office Box 655303
Dallas, Texas 75265
Copyright 2002, Texas Instruments Incorporated

Information About Cautions and Warnings
iii
Preface
Read This First
How to Use This Manual
This document contains the following chapters:
-Chapter 1—Introduction and Description
-Chapter 2—Using The THS3062EVM
-Chapter 3—THS3062EVM Applications
-Chapter 4—EVM Hardware Description
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.
Please read each caution and warning carefully.

Trademarks
iv
FCC Warning
This equipment is intended for use in a laboratory test environment only. It gen-
erates, 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 en-
vironments 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.
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.
-THS3062 data sheet (SLOS394)
-Application report (SLOA069), How (Not) to Decouple High Speed Op
Amp Circuits, http://www-s.ti.com/sc/psheets/sloa069/sloa069.pdf
-Application report (SLMA002), PowerPAD Thermally Enhanced Package,
http://www-s.ti.com/sc/psheets/slma004/slma002.pdf
-Application report (SLMA004), PowerPAD Made Easy,
http://www-s.ti.com/sc/psheets/slma004/slma004.pdf
-Application report (SSYA008), Electrostatic Discharge (ESD),
http://www-s.ti.com/sc/psheets/ssya008/ssya008.pdf
-High-Speed Amplifier PCB Layout Tips,
http://www-s.ti.com/sc/psheets/sloa102/sloa102.pdf
Trademarks
PowerPAD is a trademark of Texas Instruments.

Contents
v
Contents
1 Introduction and Description 1-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.1 Evaluation Schematic 1-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2 Using the THS3062EVM 2-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3 THS3062EVM Applications 3-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.1 Inverting Gain Stage 3-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.2 Noninverting Gain Stage 3-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.3 Applications for EVM Channel 2 3-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4 EVM Hardware Description 4-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figures
1-1 Schematic of the THS3062EVM 1-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-1 THS3062EVM Interconnection Diagram 2-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-1 Inverting Gain Stage 3-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-2 Noninverting Gain Stage 3-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-1 Top Layer 1 (Signals and Silkscreen) for THS3062EVM 4-2. . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-2 Internal Plane (Layer 2) Ground Plane 4-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-3 Internal Plane (Layer 3) Power Layer 4-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-4 Bottom (Layer 4) Ground and Signal 4-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tables
4-1 THS3062EVM Bill of Materials 4-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Contents
vi

1-1
Introduction and Description
Introduction and Description
This chapter provides a description of the THS3062EVM dual high-speed
operational amplifier along with a schematic diagram.
1.1 Evaluation Schematic
As delivered, the EVM has a fully functional example circuit, requiring added
power supplies, a signal source, and a monitoring instrument. The default
schematic diagram is provided in Figure 1-1. The user can change the gain
by changing the ratios of the feedback and gain resistors (see the device data
sheet for recommended resistor values). The complete EVM
schematic—showing all components—is shown in this chapter.
EVM Channel 1:
The default configuration for EVM channel 1 is designed to provide a voltage
gain of -1 and a gain of about +2 depending on which input is connected to
the signal source. This voltage gain is the ratio of the voltage at the output pin
of the amplifier (pin 1) to the voltage at the input at J2 or J3 respectively.
For optimum frequency response and stability at either -1 or +2 gain, a
feedback resistor, R6 (562 Ω), is chosen. R1 is set to the same value to provide
a gain in the inverting configuration of -1. To match the signal generator,
source impedance R2 was set to 54.9 Ω. This is the closest value when placed
in parallel with R3 (562 Ω) that terminates the inverting input to 50 Ω. R4 is set
to 953 Ωbecause when a high impedance instrument is connected to the
output connector, J1, the amplifier is loaded at about 1 kΩ.
When EVM channel 1 is used as an inverting amplifier in the default
configuration connected to a 50-Ωinput device, R4 causes a slight gain error.
The total voltage gain is the negative ratio of the feedback resistor, R6, and the
gain resistor, R3, times the voltage divider created by R5, R4 and the
measurement device input termination resistance. This gain follows the
following equation:
VO
VI+*R6 R1 ǒR4 ø50 W
R4 ø50 W)R5Ǔ+*0.475 (1)
Chapter 1

Evaluation Schematic
1-2
The noninverting gain of the EVM channel 1 amplifier, when using the default
configuration, is affected by the same slight gain error plus the gain error im-
posed by the inverting input termination resistor, R2. The following equation
shows the gain for this situation:
VO
VI+ǒ1)R6 R1 )R2ǓǒR4 ø50 W
R4 ø50 W)R5Ǔ+0.908 (2)
EVM Channel 2:
The default configuration for EVM channel 2 provides for a voltage gain of +1.
This voltage gain is the ratio of the voltage at the output pin of the amplifier (pin
7) to the voltage at the input at J5. For optimum frequency response and stabil-
ity at a gain of +1 the feedback resistor, R7, of 750 Ω was chosen.
The noninverting gain of the EVM channel 2 amplifier, when using the default
configuration, is affected by the same slight gain error caused by R12 as
shown in Equation 1 and indicated in the following equation:
VO
VI+ǒ*R12 ø50 W
R12 ø50 W)R11Ǔ+*0.475 (3)
THS3062 dual high-speed operational amplifier EVM features include:
-Wide operating supply voltage range: dual supply ±5 Vdc to dual supply
±15 Vdc operation (see the device data sheet). Single supply operation is
obtained by connecting both J6 (GND) and J7 (VS-) to ground.
-Convenient GND test point (TP1).
-Power supply ripple rejection provided by inductors FB1 and FB2 followed
by tantalum capacitors C5 and C6.
-Decoupling capacitors, C7and C8, populated with 0.1 µF and capacitors,
C9 and C10, populated with 100 pF—design final decoupling in accor-
dance with SLOA069.
-Nominal 50-Ωinput impedance for each of the configured inputs, V1in-,
V1in+ and V2in+. Termination can be configured according to the applica-
tion requirement.
-A good example of high-speed amplifier PCB design and layout. Also see
High-Speed Amplifier PCB Layout Tips, SLOA102.
-50-Ωseries matching resistors (R5 and R11).
-953-Ωresistor to ground provide minimum load through 1 kΩon each
amplifier.
-PowerPAD heatsinking capability.

Evaluation Schematic
1-3
Introduction and Description
Figure 1-1.Schematic of the THS3062EVM
R1
R7
R5
+
-
U1B
5
67
C9
100 pF
R6
R3
R4
R12
GND
J3
V1in+ -VS
8
J2
V1in-
J6
V2out
R10
TP1
4
+
-
3
21
TP2
J4
V2in-
R2
U1A
C10
100 pF C8
+VS
J1
V1out
J8
R11
J5
V2in+
C7
+VS(IN)
FB2
+
C6
J7J9
+C5 -VS
-VS(IN)
FB1
+VS
THS3062
R8 *
R9 *
*R10
22 mF 22 mF
562 W
0.1 mF
562 W
54.9 W49.9 W0.1 mF
49.9 W
953 W
750 W
49.9 W
49.9 W
953 W

1-4

2-1
Using the THS3062EVM
Using the THS3062EVM
This chapter shows how to connect the THS3062EVM to test equipment. It is
recommended that the user connect the EVM as described in this chapter to
avoid damage to the EVM or the THS3062 installed on the board. Figure 2.1
shows how to connect power supplies, a 50-Ωsignal source, and a 50-Ω
monitoring instrument.
Figure 2-1.THS3062EVM Interconnection Diagram
Figure 2-1 shows the connections to measure the output of output 1 while a
signal is inserted into EVM channel 1’s noninverting input. The signal source
can instead be connected to J2 for an inverting signal path. If the oscilloscope
input is connected to J6 and the signal source is connected to J5, EVM channel
2 is also configured for a noninverting signal path.
Chapter 2

2-2

3-1
THS3062EVM Applications
THS3062EVM Applications
Example applications are presented in this chapter. These applications
demonstrate the most popular circuits to the user, but many other circuits can
be constructed. The user is encouraged to experiment with different circuits,
exploring new and creative design techniques.
3.1 Inverting Gain Stage
The circuit described in chapter 2 is an inverting gain stage with a voltage
divider on the output. Equation 1 indicates the gain when connected to a 50-Ω
measurement input device. R4, 953 Ω, was included to provide a 1-k load to
the amplifier, the user may remove it as shown in Figure 3-1. When this is done
the voltage gain equation from J2 to J1 is simplified as shown in the following
equation:
VO
VI+*R6 R1 ǒ50 W 50 W)R5Ǔ+*0.5 (4)
R5 is used to match the output impedance of the amplifier to the line being
driven and the instrument taking measurements. For short transmission line
length, R5 can be replaced with a jumper.
R5 can also be used to isolate the amplifier from extremely large capacitive
loads.
Figure 3-1.Inverting Gain Stage
R5
R2
R6
J1
1 out
J2
1 in-
Vs-
-
+
U1A
THS3062
2
36
7
4
R1
Vs+
R3
562 W
562 W
54.9 W
49.9 W
49.9 W
Chapter 3

Noninverting Gain Stage
3-2
3.2 Noninverting Gain Stage
For a noninverting stage in EVM channel 1, the EVM can be modified to
eliminatethe gain error imposed by R2 by replacing R2 with a 0-Ω resistor. This
is shown in Figure 3-2. R4 has been removed as shown in the inverting gain
stage example above. The following equation indicates the voltage gain from
J3 to J1:
VO
VI+ǒ1)R6 R1Ǔǒ50 W 50 W)R5Ǔ+1(5)
Figure 3-2.Noninverting Gain Stage
R2
0
R5
R3
-
+
U1A
THS3062
2
36
7
4
Vs-
R6
J1
1 out
Vs+
R1
J3
1 in+
562 W
49.9 W
562 W
49.9 W
This is a common amplifier configuration used to drive a transmission line. The
49.9-Ωresistor in series with the output matches the effective output
impedance of the amplifier to the line impedance. In test and measurement
instruments the nominal line impedance is assumed to be 50 Ω, for video the
nominal line impedance is assumed to be 75 Ω. If testing this device as a video
linear driver we recommend changing the value of R5 to 75Ω.
Due to the nature of current feedback high speed amplifiers the gain of the
THS3062 can be increased by decreasing the values of R1 and R8 with little
change in bandwidth. R6 should be reduced to maintain optimum
compensation. Refer to the data sheet for recommended resistor values.
3.3 Applications for EVM Channel 2
Since the board layout of EVM channel 2 is identical to EVM channel 1, the
applications above can be applied identically. The only physical difference is
that different values have been installed in the default configuration for
different EVM channels. In addition, the components are labeled differently for
each EVM channel. Refer to complete schematic and board silkscreen to
resolve these issues.

4-1
EVM Hardware Description
EVM Hardware Description
This chapter describes the EVM hardware. It includes the EVM parts list,
component placement diagram, and printed-circuit board layout.
Table 4-1.THS3062EVM Bill of Materials
Item Description SMD
Size Reference Designator PCB QTY Manufacturer’s Part Number Distributor’s Part Number
1Bead, ferrite, 3A, 80 Ω1206 FB1, FB2 2 (Steward)
HI1206N800R-00 (Digi-Key) 240-1010-1-ND
2Cap, 22 µF, tanatalum, 25 V,
10% DC5, C6 2 (AVX) TAJD226K025R (Garrett) TAJD226K025R
3Cap, 0.1 µF, ceramic, X7R,
50 V 0805 C7, C8 2 (AVX) 08055C104KAT2A (Garrett) 08055C104KAT2A
4Cap, 100 pF, ceramic, 5%,
150 V AQ12 C9, C10 2 (AVX) AQ12EM101JAJME (TTI) AQ12EM101JAJME
5 Open 0805 R8 1
6Resistor, 750 Ω, 1/8 W, 1% 0805 R7 1 (Phycomp)
9C08052A7500FKHFT (Garrett) 9C08052A7500FKHFT
7Resistor, 562 Ω, 1/8 W, 1% 0805 R1, R6 2 (Phycomp)
9C08052A5620FKHFT (Garrett) 9C08052A5620FKHFT
8 Open 1206 R9 1
9Resistor, 54.9 Ω, 1/4W, 1% 1206 R2 1 (Phycomp)
9C12063A54R9FKRFT (Garrett) 9C12063A54R9FKRFT
10 Resistor, 49.9 , 1/4 W, 1% 1206 R3, R5,
R10, R11 1 (Phycomp) 9C12063A49R9FKRFT (Garrett) 9C12063A49R9FKRFT
11 Resistor, 953 Ω, 1/8 W, 1% 1206 R4, R12 2 (Phycomp)
9C08052A9530FKHFT (Garrett) 9C12063A9530FKRFT
12 Jack, banana receptance,
0.25”Dia. Hole J7, J8, J9 (HH Smith) 101 (Newark) 35F865
13 Test Point, Black TP1, TP2 2(Keystone) 5001 (Allied) 839-3601
14 Connector, EDGE, SMA PCB
Jack J1, J2, J3, J4, J5, J6 6 (Johnson) 142-0701-801 (Allied) 528-0238
15 IC, THS3062 U1 1 (TI) THS3062DGN
16 Printed-circuit board 1(TI) EDGE #6440283
Chapter 4

4-2
Figure 4-1.Top Layer 1 (Signals and Silkscreen) for THS3062EVM
Figure 4-2.Internal Plane (Layer 2) Ground Plane

4-3
EVM Hardware Description
Figure 4-3.Internal Plane (Layer 3) Power Layer
Figure 4-4.Bottom (Layer 4) Ground and Signal

4-4