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LMH6629

www.ti.com

SNOSB18G –APRIL 2010–REVISED MARCH 2013

LMH6629 Ultra-Low Noise, High-Speed Operational Amplifier with Shutdown

Check for Samples: LMH6629

FEATURES

DESCRIPTION

The LMH6629 is a high-speed, ultra low-noise

• Specified for V

= 5V, R

= 100Ω, A

= 10V/V

amplifier designed for applications requiring wide

WSON-8 Package, unless Specified

bandwidth with high gain and low noise such as in

– –3dB Bandwidth 900 MHz

communication, test and measurement, optical and

– Input Voltage Noise 0.69 nV/√Hz

ultrasound systems.

– Input Offset Voltage Max. Over

The LMH6629 operates on 2.7 to 5.5V supply with an

Temperature ±0.8 mV

input common mode range that extends below

ground and outputs that swing to within 0.8V of the

– Slew Rate 1600 V/ μs

rails for ease of use in single supply applications.

– HD2 @ f = 1MHz, 2V

−90 dBc

Heavy loads up to ±250 mA can be driven by high-

– HD3 @ f = 1MHz, 2V

−94 dBc

frequency large signals with the LMH6629's –3dB

bandwidth of 900 MHz and 1600 V/µs slew rate. The

– Supply Voltage Range 2.7V to 5.5V

LMH6629 (WSON-8 package only) has user-

– Typical Supply Current 15.5 mA

selectable internal compensation for minimum gains

– Selectable Min. Gain ≥4 or ≥10 V/V

of 4 or 10 controlled by pulling the COMP pin low or

– Enable Time 75 ns

high, thereby avoiding the need for external

compensation capacitors required in competitive

– Output Current ±250 mA

devices. Compensation for the SOT-23-5 package is

– WSON-8 and SOT-23-5 Packages

internally set for a minimum stable gain of 10 V/V.

The WSON-8 package also provides the power-down

APPLICATIONS

enable/ disable feature.

• Instrumentation Amplifiers

The low-input noise (0.69nV/√Hz and 2.6 pA/√Hz),

low distortion (HD2/ HD3 = −90 dBc/−94 dBc) and

• Ultrasound Pre-amps

ultra-low DC errors (800 µV V

maximum over

• Wide-band Active Filters

temperature, ±0.45 µV/°C drift) allow precision

• Opto-Electronics

operation in both AC- and DC-coupled applications.

• Medical Imaging Systems

The LMH6629 is fabricated in Texas Instruments'

• Base-Station Amplifiers

proprietary SiGe process and is available in a 3mm x

3mm 8-pin WSON, as well as the SOT-23-5,

• Low-Noise Single Ended to Differential

package.

Conversion

• Trans-Impedance Amplifier

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.

2All 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 (38 pages)

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LMH6629 www.ti.com SNOSB18G – APRIL 2010 – REVISED MARCH 2013 LMH6629 Ultra-Low Noise, High-Speed Operational Amplifier with Shutdown Check for Samples: LMH6629 FEATURES DESCRIPTION • The LMH6629 is a high-speed, ultra low-noise amplifier designed for applications requiring wide bandwidth with high gain and low noise such as in communication, test and measurement, optical and ultrasound systems.
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LMH6629 SNOSB18G – APRIL 2010 – REVISED MARCH 2013 www.ti.com Typical Application Circuit CF 0.6 pF (1.2 pF (2) series) +5VDC D1 RF 1.2k CD = 10 pF ID +5VDC LMH 6629 +5VDC RL 500 R2 2k C1 0.1 PF R1 3k Vout = 3VDC - 1200 x ID Figure 1. Transimpedance Amplifier 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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LMH6629 www.ti.com SNOSB18G – APRIL 2010 – REVISED MARCH 2013 Absolute Maximum Ratings ESD Tolerance (1) (2) (3) (4) Human Body Model 2kV Machine Model 200V Charge-Device Model 750V −0.5 to 6.0V Positive Supply Voltage Differential Input Voltage 3V Analog Input Voltage Range −0.5 to VS Digital Input Voltage −0.5 to VS Junction Temperature +150°C −65°C to +150°C Storage Temperature Range Soldering Information http://www.ti.
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LMH6629 SNOSB18G – APRIL 2010 – REVISED MARCH 2013 www.ti.com 5V Electrical Characteristics The following specifications apply for single supply with VS = 5V, RL = 100Ω terminated to 2.5V, gain = 10V/V, VO = 2VPP, VCM = VS/2, COMP Pin = HI (WSON-8 package), unless otherwise noted. Boldface limits apply at the temperature extremes. (1). Symbol Parameter Conditions Min (2) Typ (2) Max (2) Units DYNAMIC PERFORMANCE SSBW LSBW Small signal −3dB bandwidth Large signal −3dB bandwidth 0.
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LMH6629 www.ti.com SNOSB18G – APRIL 2010 – REVISED MARCH 2013 5V Electrical Characteristics (continued) The following specifications apply for single supply with VS = 5V, RL = 100Ω terminated to 2.5V, gain = 10V/V, VO = 2VPP, VCM = VS/2, COMP Pin = HI (WSON-8 package), unless otherwise noted. Boldface limits apply at the temperature extremes. (1).
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LMH6629 SNOSB18G – APRIL 2010 – REVISED MARCH 2013 www.ti.com 3.3V Electrical Characteristics The following specifications apply for single supply with VS = 3.3V, RL = 100Ω terminated to 1.65V, gain = 10V/V, VO = 1VPP, VCM = VS/2, COMP Pin = HI (WSON-8 package), unless otherwise noted. Boldface limits apply at the temperature extremes. (1) Symbol Parameter Conditions Min (2) Typ (2) Max (2) Units DYNAMIC PERFORMANCE SSBW LSBW Small signal −3dB bandwidth Large signal −3dB bandwidth 0.
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LMH6629 www.ti.com SNOSB18G – APRIL 2010 – REVISED MARCH 2013 3.3V Electrical Characteristics (continued) The following specifications apply for single supply with VS = 3.3V, RL = 100Ω terminated to 1.65V, gain = 10V/V, VO = 1VPP, VCM = VS/2, COMP Pin = HI (WSON-8 package), unless otherwise noted. Boldface limits apply at the temperature extremes. (1) Symbol Parameter Conditions Min (2) Typ (2) Max (2) Units ANALOG I/O CMRR > 70 dB, WSON-8 package CMVR VO Input voltage range −0.30 2.
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LMH6629 SNOSB18G – APRIL 2010 – REVISED MARCH 2013 www.ti.com Typical Performance Characteristics Unless otherwise specified, VS = ±2.5V, Rf = 240Ω, RL = 100Ω, VO = 2VPP, COMP pin = HI, AV = +10 V/V, WSON-8 and SOT23-5 packages (unless specifically noted). Inverting Frequency Response 1 Inverting Frequency Response 1 Vo = 1Vpp Vs = +/-1.
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LMH6629 www.ti.com SNOSB18G – APRIL 2010 – REVISED MARCH 2013 Typical Performance Characteristics (continued) Unless otherwise specified, VS = ±2.5V, Rf = 240Ω, RL = 100Ω, VO = 2VPP, COMP pin = HI, AV = +10 V/V, WSON-8 and SOT23-5 packages (unless specifically noted). 1 Non-Inverting Frequency Response with Varying VO, WSON-8 Package Non-Inverting Frequency Response with Varying VO, SOT-23-5 Package 2 Av = 10V/V NORMALIZED GAIN (dB) Normalized Gain (dB) -1 Vo = 0.
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LMH6629 SNOSB18G – APRIL 2010 – REVISED MARCH 2013 www.ti.com Typical Performance Characteristics (continued) Unless otherwise specified, VS = ±2.5V, Rf = 240Ω, RL = 100Ω, VO = 2VPP, COMP pin = HI, AV = +10 V/V, WSON-8 and SOT23-5 packages (unless specifically noted). Frequency Response with Cap. Loading 2 Frequency Response Cap. Loading, WSON-8 Package 2 1 0 Normalized Gain (dB) Normalized Gain (dB) 0 -1 33 pF, Riso = 17: -2 -3 4.
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LMH6629 www.ti.com SNOSB18G – APRIL 2010 – REVISED MARCH 2013 Typical Performance Characteristics (continued) Unless otherwise specified, VS = ±2.5V, Rf = 240Ω, RL = 100Ω, VO = 2VPP, COMP pin = HI, AV = +10 V/V, WSON-8 and SOT23-5 packages (unless specifically noted). Distortion vs. Swing, WSON-8 Package -60 Distortion vs. Swing, SOT-23-5 Package -50 20 MHz HD2 20 MHz HD2 -60 -70 -70 HD (dBc) HD (dBc) -80 HD3 -90 -80 HD3 -90 -100 -100 -110 0.0 0.5 1.0 1.5 2.0 Vo (Vpp) 2.5 -110 0.
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LMH6629 SNOSB18G – APRIL 2010 – REVISED MARCH 2013 www.ti.com Typical Performance Characteristics (continued) Unless otherwise specified, VS = ±2.5V, Rf = 240Ω, RL = 100Ω, VO = 2VPP, COMP pin = HI, AV = +10 V/V, WSON-8 and SOT23-5 packages (unless specifically noted). Distortion vs. Frequency, WSON-8 Package -40 Distortion vs.
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LMH6629 www.ti.com SNOSB18G – APRIL 2010 – REVISED MARCH 2013 Typical Performance Characteristics (continued) Unless otherwise specified, VS = ±2.5V, Rf = 240Ω, RL = 100Ω, VO = 2VPP, COMP pin = HI, AV = +10 V/V, WSON-8 and SOT23-5 packages (unless specifically noted). Output Source Current, WSON-8 Package Open Loop Gain/Phase Response 4.0 80 160 Gain, COMP HI 3.5 Vo from V+ (V) 80 PHASE (°) GAIN (dB) 125°C 120 40 Gain, COMP LO 1M 10M 2.0 1.5 -40°C 0.5 Phase, COMP HI 0 100k 2.5 1.
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LMH6629 SNOSB18G – APRIL 2010 – REVISED MARCH 2013 www.ti.com Typical Performance Characteristics (continued) Unless otherwise specified, VS = ±2.5V, Rf = 240Ω, RL = 100Ω, VO = 2VPP, COMP pin = HI, AV = +10 V/V, WSON-8 and SOT23-5 packages (unless specifically noted). Large Signal Step Response Vo (0.2V/Div) Vo (0.5V/DIV) Large Signal Step Response Av = +4V/V COMP Pin = LO Time (4 ns/Div) TIME (10 ns/DIV) Figure 40. Figure 41.
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LMH6629 www.ti.com SNOSB18G – APRIL 2010 – REVISED MARCH 2013 Typical Performance Characteristics (continued) Unless otherwise specified, VS = ±2.5V, Rf = 240Ω, RL = 100Ω, VO = 2VPP, COMP pin = HI, AV = +10 V/V, WSON-8 and SOT23-5 packages (unless specifically noted). 1.0 Supply Current vs. Supply Voltage Turn-Off Waveform, WSON-8 Package 3 18.0 Vo 2 17.0 0.5 0 Is (mA) 0.0 PD\ (V) Vo (V) 1 125°C 16.0 25°C 15.0 -40°C -1 -0.5 PD\ 14.0 -2 -1.0 13.0 2.5 -3 3.0 3.
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LMH6629 SNOSB18G – APRIL 2010 – REVISED MARCH 2013 www.ti.com APPLICATION SECTION INTRODUCTION The LMH6629 is a high gain bandwidth, ultra low-noise voltage feedback operational amplifier. The excellent noise and bandwidth enables applications such as medical diagnostic ultrasound, magnetic tape & disk storage and fiberoptics to achieve maximum high frequency signal-to-noise ratios. The following discussion will enable the proper selection of external components to achieve optimum system performance.
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LMH6629 www.ti.com SNOSB18G – APRIL 2010 – REVISED MARCH 2013 The SOT-23-5 package has the following differences relative to the WSON-8 package: 1. No power down (shutdown) capability. 2. No COMP pin to set the minimum stable gain. SOT-23–5 package minimum stable gain is internally fixed to be 10V/V. 3. No feedback (FB) pin. From a performance point of view, the WSON-8 and the SOT-23-5 packages perform very similarly except in the following areas: 1. SSBW, Peaking, and 0.
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LMH6629 SNOSB18G – APRIL 2010 – REVISED MARCH 2013 www.ti.com This circuit operates by increasing the Noise Gain (NG) beyond the minimum stable gain of the LMH6629 while maintaining a positive loop gain phase angle at 0dB.
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LMH6629 www.ti.com SNOSB18G – APRIL 2010 – REVISED MARCH 2013 The non-inverting circuit is used here as an example. To cancel the bias current errors of the non-inverting configuration, the parallel combination of the gain setting (Rg) and feedback (Rf) resistors should equal the equivalent source resistance (Rseq) as defined in Figure 55.
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LMH6629 SNOSB18G – APRIL 2010 – REVISED MARCH 2013 www.ti.com TOTAL INPUT NOISE vs. SOURCE RESISTANCE To determine maximum signal-to-noise ratios from the LMH6629, an understanding of the interaction between the amplifier’s intrinsic noise sources and the noise arising from its external resistors is necessary. Figure 57 describes the noise model for the non-inverting amplifier configuration showing all noise sources.
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LMH6629 www.ti.com SNOSB18G – APRIL 2010 – REVISED MARCH 2013 Figure 59 illustrates the equivalent noise model using this assumption. Figure 60 is a plot of eni against equivalent source resistance (Rseq) with all of the contributing voltage noise source of Equation 4. This plot gives the expected eni for a given (Rseq) which assumes Rf||Rg = Rseq for bias current cancellation. The total equivalent output voltage noise (eno) is eni*AV. Figure 59.
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LMH6629 SNOSB18G – APRIL 2010 – REVISED MARCH 2013 www.ti.
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LMH6629 www.ti.com SNOSB18G – APRIL 2010 – REVISED MARCH 2013 SINGLE-SUPPLY OPERATION The LMH6629 can be operated with single power supply as shown in Figure 62. Both the input and output are capacitively coupled to set the DC operating point. Figure 62. Single-Supply Operation LOW-NOISE TRANSIMPEDANCE AMPLIFIER Figure 63 implements a high-speed, single-supply, low-noise Transimpedance amplifier commonly used with photo-diodes. The transimpedance gain is set by RF. CF 0.6 pF (1.
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LMH6629 SNOSB18G – APRIL 2010 – REVISED MARCH 2013 www.ti.com OP AMP OPEN LOOP GAIN GAIN (dB) I-V GAIN (:) NOISE GAIN (NG) 1 + sRF (CIN + CF) 1 + sRFCF 1+ CIN CF 0 dB FREQUENCY fz # 1 2SRFCIN fP = 1 GBWP 2SRFCF Figure 64. Transimpedance Amplifier Noise Gain & Transfer Function The optimum value of CF is given by Equation 8 resulting in the I-V -3dB bandwidth shown in Equation 9, or around 200 MHz in this case (assuming GBWP= 4GHz with COMP pin = HI for WSON-8 package).
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LMH6629 www.ti.com SNOSB18G – APRIL 2010 – REVISED MARCH 2013 Current Noise Density (pA/ Hz) 16 14 ini 12 10 8 it en/RF 6 in 4 2 0 100 1k 10k Rf (:) Figure 65. Current Noise Density vs. Feedback Resistance Equation 10: Noise Equation for Transimpedance Amplifier (10) +5VDC D1 CD = 10 pF RF (Noiseless) ID ini Noiseless Op Amp Figure 66. Transimpedance Amplifier Equivalent Input Source Model From Figure 65, it is clear that with LMH6629’s extremely low-noise characteristics, for RF < 2.
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LMH6629 SNOSB18G – APRIL 2010 – REVISED MARCH 2013 www.ti.com LOW-NOISE INTEGRATOR Figure 67 shows a deBoo integrator implemented with the LMH6629. Positive feedback maintains integration linearity. The LMH6629’s low input offset voltage and matched inputs allow bias current cancellation and provide for very precise integration. Keeping RG and RS low helps maintain dynamic stability. KO VO # VIN KO = 1 + ; sRSC RF RG RB VO RS + VIN C R - 50: 50: RF RG R F = RB RG = RS||R Figure 67.
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LMH6629 www.ti.com SNOSB18G – APRIL 2010 – REVISED MARCH 2013 For higher selectivity, use high C values; for wider bandwidth, use high L values, while keeping the product of L and C values the same to keep fc intact. The integrator’s -3dB roll-off is set by 1 2SC1(R1 + R) (12) If 1 << 2SC1R1 ´ ¶C (13) the integrator and the bandpass filter frequency interaction is minimized so that the operating frequencies of each can be set independently.
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LMH6629 SNOSB18G – APRIL 2010 – REVISED MARCH 2013 www.ti.com single-ended (SE) to Differential converter / driver for such an application is challenging, especially when there is some gain required. In addition, the input driver’s linearity (harmonic distortion) must also be high enough such that the spurs that get through to the ADC input are below the ADC’s LSB threshold or -73 dBc (= 20*log (1/ 212)) or lower in this case.
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LMH6629 www.ti.com Vnoise # SNOSB18G – APRIL 2010 – REVISED MARCH 2013 >en (1 + K / 2)@ 2 . 23 + >(eRin _ thermal) K / 2)@2. 2 2 + >(eRg _ thermal ) K)@2 Equation 14: Converter Noise Expression (14) en is the LMH6629 input noise voltage and eRin_thermal is the thermal noise of RIN. The “23” and the “22” multipliers account for the different instances of each noise source (2 for en, and 1 for eRin_thermal). Equation 14 evaluated for the circuit example of Figure 71 is shown below: Vnoise # >0.
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LMH6629 SNOSB18G – APRIL 2010 – REVISED MARCH 2013 www.ti.com REVISION HISTORY Changes from Revision F (March 2013) to Revision G • 30 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 11-Apr-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 26-Mar-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) LMH6629MF/NOPB SOT-23 DBV 5 1000 178.0 8.4 LMH6629MFE/NOPB SOT-23 DBV 5 250 178.0 LMH6629MFX/NOPB SOT-23 DBV 5 3000 178.0 LMH6629SD/NOPB WSON NGQ 8 1000 LMH6629SDE/NOPB WSON NGQ 8 LMH6629SDX/NOPB WSON NGQ 8 3.2 3.2 1.4 4.0 8.0 Q3 8.4 3.
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PACKAGE MATERIALS INFORMATION www.ti.com 26-Mar-2013 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) LMH6629MF/NOPB SOT-23 DBV 5 1000 210.0 185.0 35.0 LMH6629MFE/NOPB SOT-23 DBV 5 250 210.0 185.0 35.0 LMH6629MFX/NOPB SOT-23 DBV 5 3000 210.0 185.0 35.0 LMH6629SD/NOPB WSON NGQ 8 1000 213.0 191.0 55.0 LMH6629SDE/NOPB WSON NGQ 8 250 213.0 191.0 55.0 LMH6629SDX/NOPB WSON NGQ 8 4500 367.0 367.
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MECHANICAL DATA NGQ0008A SDA08A (Rev A) www.ti.
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