Datasheet

ManualsBrandsTEXAS INSTRUMENTS ManualsLinear ICsLinear IC - Op-amp Voltage feedback SOIC 8

IN-

IN+

ADC

, R

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1) Set R

1 1

R R

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LMH6551

www.ti.com

SNOSAK7C –FEBRUARY 2005–REVISED MARCH 2013

LMH6551 Differential, High Speed Op Amp

Check for Samples: LMH6551

FEATURES

DESCRIPTION

The LMH™6551 is a high performance voltage

• 370 MHz −3 dB Bandwidth (V

OUT

= 0.5 V

)

feedback differential amplifier. The LMH6551 has the

• 50 MHz 0.1 dB Bandwidth

high speed and low distortion necessary for driving

• 2400 V/µs Slew Rate

high performance ADCs as well as the current

handling capability to drive signals over balanced

• 18 ns Settling Time to 0.05%

transmission lines like CAT 5 data cables. The

• −94/−96 dB HD2/HD3 @ 5 MHz

LMH6551 can handle a wide range of video and data

formats.

APPLICATIONS

With external gain set resistors, the LMH6551 can be

• Differential AD Driver

used at any desired gain. Gain flexibility coupled with

• Video Over Twisted Pair

high speed makes the LMH6551 suitable for use as

an IF amplifier in high performance communications

• Differential Line Driver

equipment.

• Single End to Differential Converter

The LMH6551 is available in the space saving SOIC

• High Speed Differential Signaling

and VSSOP packages.

• IF/RF Amplifier

• SAW Filter Buffer/Driver

Typical Application

Figure 1. Single Ended to Differential ADC Driver

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

2LMH is a trademark of Texas Instruments.

3All other trademarks are the property of their respective owners.

PRODUCTION DATA information is current as of publication date.

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.

Summary of content (28 pages)

PAGE 1
LMH6551 www.ti.com SNOSAK7C – FEBRUARY 2005 – REVISED MARCH 2013 LMH6551 Differential, High Speed Op Amp Check for Samples: LMH6551 FEATURES DESCRIPTION 1 • • • • • 23 The LMH™6551 is a high performance voltage feedback differential amplifier. The LMH6551 has the high speed and low distortion necessary for driving high performance ADCs as well as the current handling capability to drive signals over balanced transmission lines like CAT 5 data cables.
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LMH6551 SNOSAK7C – FEBRUARY 2005 – REVISED MARCH 2013 www.ti.com Connection Diagram -IN VCM V+ +OUT 1 2 8 - + 7 3 6 4 5 +IN NC V- -OUT Figure 2. 8-Pin SOIC & VSSOP - Top View See Package Number D0008A and DGK0008A These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the MOS gates.
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LMH6551 www.ti.com SNOSAK7C – FEBRUARY 2005 – REVISED MARCH 2013 ±5V Electrical Characteristics (1) Single ended in differential out, TA= 25°C, G = +1, VS = ±5V, VCM = 0V, RF = RG = 365Ω, RL = 500Ω; Unless specified Boldface limits apply at the temperature extremes. Symbol Parameter Conditions Min (2) Typ (3) Max (2) Units AC Performance (Differential) SSBW Small Signal −3 dB Bandwidth VOUT = 0.
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LMH6551 SNOSAK7C – FEBRUARY 2005 – REVISED MARCH 2013 www.ti.com ±5V Electrical Characteristics (1) (continued) Single ended in differential out, TA= 25°C, G = +1, VS = ±5V, VCM = 0V, RF = RG = 365Ω, RL = 500Ω; Unless specified Boldface limits apply at the temperature extremes. Symbol Parameter Conditions VCM CMRR Min VID = 0V, 1V step on VCM pin, measure VOD (2) Typ (3) Max (2) 75 ΔVO,CM/ΔVCM 0.995 0.999 Single Ended, Peak to Peak ±7.38 ±7.18 ±7.8 V ±3.69 ±3.
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LMH6551 www.ti.com SNOSAK7C – FEBRUARY 2005 – REVISED MARCH 2013 5V Electrical Characteristics (1) (continued) Single ended in differential out, TA= 25°C, G = +1, VS = 5V, VCM = 2.5V, RF = RG = 365Ω, RL = 500Ω; Unless specifiedBoldface limits apply at the temperature extremes. Symbol Parameter Conditions Min (2) Typ (3) Max (2) Units Input Characteristics (Differential) VOSD IBIAS CMRR VICM Input Offset Voltage Differential Mode, VID = 0, VCM = 0 0.
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LMH6551 SNOSAK7C – FEBRUARY 2005 – REVISED MARCH 2013 3.3V Electrical Characteristics www.ti.com (1) Single ended in differential out, TA= 25°C, G = +1, VS = 3.3V, VCM = 1.65V, RF = RG = 365Ω, RL = 500Ω; Unless specifiedBoldface limits apply at the temperature extremes. Symbol Parameter Conditions Min (2) Typ (3) Max (2) Units SSBW Small Signal −3 dB Bandwidth RL = 500Ω, VOUT = 0.
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LMH6551 www.ti.com SNOSAK7C – FEBRUARY 2005 – REVISED MARCH 2013 3.3V Electrical Characteristics (1) (continued) Single ended in differential out, TA= 25°C, G = +1, VS = 3.3V, VCM = 1.65V, RF = RG = 365Ω, RL = 500Ω; Unless specifiedBoldface limits apply at the temperature extremes. Symbol CMVR Parameter Conditions Min (2) Typ (3) Max (2) Units Output Common Mode Voltage Range VID = 0, VCMpin = 1.2V and 2.1V 2.1 1.
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LMH6551 SNOSAK7C – FEBRUARY 2005 – REVISED MARCH 2013 www.ti.com Typical Performance Characteristics (TA = 25°C, VS = ±5V, RL = 500Ω, RF = RG = 365Ω; Unless Specified). Frequency Response vs. Supply Voltage 2 1 1 0 0 -1 -1 VOD = 2 VPP -2 GAIN (dB) GAIN (dB) Frequency Response 2 -3 -4 VOD = 0.5 VPP -5 -6 SINGLE ENDED INPUT VS = 5V -7 -8 1 10 100 1 1000 10 1000 FREQUENCY (MHz) Figure 3. Figure 4. Frequency Response vs. VOUT Frequency Response vs.
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LMH6551 www.ti.com SNOSAK7C – FEBRUARY 2005 – REVISED MARCH 2013 Typical Performance Characteristics (continued) (TA = 25°C, VS = ±5V, RL = 500Ω, RF = RG = 365Ω; Unless Specified). 1 VPP Pulse Response Single Ended Input 2 VPP Pulse Response Single Ended Input 0.8 2.5 2 VOUT DIFFERENTIAL (V) VOUT DIFFERENTIAL (V) 0.6 0.4 0.2 0 -0.2 -0.4 VS = 3.3V RL = 500: -0.6 RF = 360: -0.8 1.5 1 0.5 0 -0.5 -1 VS = 5V -1.5 RL = 500: -2 RF = 360: -2.
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LMH6551 SNOSAK7C – FEBRUARY 2005 – REVISED MARCH 2013 www.ti.com Typical Performance Characteristics (continued) (TA = 25°C, VS = ±5V, RL = 500Ω, RF = RG = 365Ω; Unless Specified). Distortion vs. Frequency Distortion vs. Supply Voltage (Split Supplies) -30 -50 VOUT = 2 VPP f = 5 MHz VS = 3.3V HD3 VOUT = 1 VPP VCM = VS/2 VCM = 1.
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LMH6551 www.ti.com SNOSAK7C – FEBRUARY 2005 – REVISED MARCH 2013 Typical Performance Characteristics (continued) (TA = 25°C, VS = ±5V, RL = 500Ω, RF = RG = 365Ω; Unless Specified). Closed Loop Output Impedance Closed Loop Output Impedance 100 100 VS = 5V VS = 3.3V VIN = 0V VIN = 0V 10 |Z| (:) |Z| (:) 10 1 1 0.1 0.1 0.01 0.01 0.01 1 0.1 10 100 0.01 1000 1 0.1 Figure 21. Figure 22.
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LMH6551 SNOSAK7C – FEBRUARY 2005 – REVISED MARCH 2013 www.ti.com APPLICATION SECTION The LMH6551 is a fully differential amplifier designed to provide low distortion amplification to wide bandwidth differential signals. The LMH6551, though fully integrated for ultimate balance and distortion performance, functionally provides three channels. Two of these channels are the V+ and V− signal path channels, which function similarly to inverting mode operational amplifiers and are the primary signal paths.
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LMH6551 www.ti.com SNOSAK7C – FEBRUARY 2005 – REVISED MARCH 2013 500 50: 100: TWISTED PAIR 250 + 2 VPP a VCM 250 2 VPP 50: 500 GAIN = 2 Figure 28. Fully Differential Cable Driver With up to 15 VPP differential output voltage swing and 80 mA of linear drive current the LMH6551 makes an excellent cable driver as shown in Figure 28. The LMH6551 is also suitable for driving differential cables from a single ended source.
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LMH6551 SNOSAK7C – FEBRUARY 2005 – REVISED MARCH 2013 www.ti.com SINGLE ENDED INPUT TO DIFFERENTIAL OUTPUT The LMH6551 provides excellent performance as an active balun transformer. Figure 31 shows a typical application where an LMH6551 is used to produce a differential signal from a single ended source. In single ended input operation the output common mode voltage is set by the VCM pin as in fully differential mode.
PAGE 15
LMH6551 www.ti.com SNOSAK7C – FEBRUARY 2005 – REVISED MARCH 2013 In Figure 31 closed loop gain = VO / VI ≊ RF / RG, where VI =VS / 2, as long as RM << RG. Note that in single ended to differential operation VI is measured single ended while VO is measured differentially. This means that gain is really 1/2 or 6 dB less when measured on either of the output pins separately. Additionally, note that the input signal at RT (labeled as VI) is 1/2 of VS when RT is chosen to match RS to RIN.
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LMH6551 SNOSAK7C – FEBRUARY 2005 – REVISED MARCH 2013 www.ti.com RF1 56 RG1 ADC12LO66 39 pF + VI a VCM RG2 7 - 8 pF 39 pF 56 VREF RF2 1V LOW IMPEDANCE VOLTAGE REFERENCE Figure 33. Driving an ADC The amplifier and ADC should be located as closely together as possible. Both devices require that the filter components be in close proximity to them.
PAGE 17
LMH6551 www.ti.com SNOSAK7C – FEBRUARY 2005 – REVISED MARCH 2013 VIN * AV * N § ¨ ¨ © VL = § 2 ROUT * N2 ¨ +1 ¨ RL © WHERE VIN = DIFFERENTIAL INPUT VOLTAGE § ¨ ¨ © § SECONDARY ¨ ¨ PRIMARY © N = TRANSFORMER TURNS RATIO = AV = CLOSED LOOP AMPLIFIER GAIN ROUT = SERIES OUTPUT MATCHING RESISTOR RL = LOAD RESISTOR VL = VOLTAGE ACROSS LOAD RESISTOR Figure 35.
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LMH6551 SNOSAK7C – FEBRUARY 2005 – REVISED MARCH 2013 www.ti.com CAPACITIVE DRIVE As noted in DRIVING ANALOG TO DIGITAL CONVERTERS, capacitive loads should be isolated from the amplifier output with small valued resistors. This is particularly the case when the load has a resistive component that is 500Ω or higher. A typical ADC has capacitive components of around 10 pF and the resistive component could be 1000Ω or higher.
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LMH6551 www.ti.com SNOSAK7C – FEBRUARY 2005 – REVISED MARCH 2013 Follow these steps to determine the Maximum power dissipation for the LMH6551: 1. Calculate the quiescent (no-load) power: PAMP = ICC* (VS) where • VS = V+ - V− (1) Be sure to include any current through the feedback network if VOCM is not mid rail. 2.
PAGE 20
LMH6551 SNOSAK7C – FEBRUARY 2005 – REVISED MARCH 2013 www.ti.com EVALUATION BOARD Texas Instruments offers evaluation board(s) to aid in device testing and characterization and as a guide for proper layout. Generally, a good high frequency layout will keep power supply and ground traces away from the inverting input and output pins. Parasitic capacitances on these nodes to ground will cause frequency response peaking and possible circuit oscillations (see Application Note OA-15 for more information).
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LMH6551 www.ti.com SNOSAK7C – FEBRUARY 2005 – REVISED MARCH 2013 REVISION HISTORY Changes from Revision B (March 2013) to Revision C • Page Changed layout of National Data Sheet to TI format ..........................................................................................................
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PACKAGE OPTION ADDENDUM www.ti.
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PACKAGE OPTION ADDENDUM www.ti.com 1-Nov-2013 Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties.
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PACKAGE MATERIALS INFORMATION www.ti.com 23-Sep-2013 TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Pins Type Drawing SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant LMH6551MAX/NOPB SOIC D 8 2500 330.0 12.4 6.5 5.4 2.0 8.0 12.0 Q1 LMH6551MM VSSOP DGK 8 1000 178.0 12.4 5.3 3.4 1.4 8.0 12.0 Q1 LMH6551MM/NOPB VSSOP DGK 8 1000 178.0 12.4 5.3 3.4 1.4 8.0 12.
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PACKAGE MATERIALS INFORMATION www.ti.com 23-Sep-2013 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) LMH6551MAX/NOPB SOIC D 8 2500 367.0 367.0 35.0 LMH6551MM VSSOP DGK 8 1000 210.0 185.0 35.0 LMH6551MM/NOPB VSSOP DGK 8 1000 210.0 185.0 35.0 LMH6551MMX/NOPB VSSOP DGK 8 3500 367.0 367.0 35.
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