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LMP8350

www.ti.com

SNOSB80B –FEBRUARY 2011–REVISED MARCH 2013

LMP8350 Ultra Low Distortion Fully Differential Precision ADC Driver with Selectable

Power Modes

Check for Samples: LMP8350

FEATURES

DESCRIPTION

The LMP8350 is an ultra low distortion fully

234

• Differential Input and Output

differential amplifier designed for driving high-

• Tri-Level Power Settings with Shutdown

performance precision analog-to-digital converters

• Ultra Low HD2/HD3 and THD+N Distortion

(ADC). As part of the PowerWise™ family, a unique

mode enable pin allows the user to choose from three

• Adjustable Output Common Mode Level

different operating modes, trading power

• Fully Balanced Differential Architecture

consumption for dynamic performance.

• Single or Dual Supply Operation

The high power mode is optimized for highest AC

performance. The low noise, wide bandwidth and fast

APPLICATIONS

slew rate makes the LMP8350 ideal for driving 24bit

• High Resolution Differential ADC Driver

ADCs with input sampling rates of 10MHz or less.

The medium power mode is optimized for precision

• Portable instrumentation

DC performance, and can be used to drive 24-bit

• Precision Line Driver

ADCs with input sampling rates of 6MHz or less. The

low power mode is a trade-off between AC

KEY SPECIFICATIONS

performance and quiescent current for power

sensitive applications. The disable mode fully shuts-

= 25°C, V

= +10V, R

= 2kΩ//20pF, typical

down the amplifier for further standby power savings.

values unless otherwise specified)

The fully differential architecture of this device allows

• Operating Voltage Range 4.5V to 12V

for easy implementation of a single-ended to fully-

• Supply Current 3 to 13mA

differential output conversion. Driving a 3Vpp, 1kHz

• Total THD+N @ 1KHz 0.000097%

output sine wave with the amplifier powered by ±3.3V

• HD2 / HD3 Distortion @ 1KHz < –124 dBc

rails in high power mode yields 0.000098% THD+N.

• Bandwidth 118 mHz

The LMP8350 is part of the LMP™ precision amplifier

family. It is offered in the 8-Pin SOIC package and

• Settling to 0.1% 20 ns

has an operating temperature range of −40°C to

• Low Offset Drift 0.4 µV/°C

+85°C.

• Offset Voltage 80µV

• Voltage Noise 4.6nV/Hz

• Operating temperature range −40°C to +85°C

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.

2LMP is a trademark of Texas Instruments.

3PowerWise is a trademark of National Semiconductor Corporation.

4All 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 (31 pages)

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LMP8350 www.ti.com SNOSB80B – FEBRUARY 2011 – REVISED MARCH 2013 LMP8350 Ultra Low Distortion Fully Differential Precision ADC Driver with Selectable Power Modes Check for Samples: LMP8350 FEATURES DESCRIPTION • • • • • • The LMP8350 is an ultra low distortion fully differential amplifier designed for driving highperformance precision analog-to-digital converters (ADC).
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LMP8350 SNOSB80B – FEBRUARY 2011 – REVISED MARCH 2013 www.ti.com Typical Application +VREF +V +V VREFP VA VIO +V RF1 RO1 RG1 VINN CS - + VOCM + VINP CS LMP8350 SCLK 24 Bit A/D RO2 VINP - VINN + RG2 SDI SDO MicroController VREFN AGND DGND RF2 Typical Application Circuit Connection Diagram -IN VOCM V+ +OUT 1 2 8 - + 7 3 6 4 5 +IN EN V- -OUT Figure 1.
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LMP8350 www.ti.com SNOSB80B – FEBRUARY 2011 – REVISED MARCH 2013 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. Absolute Maximum Ratings (1) (2) ESD Tolerance (3) Human Body Model 2500 V Machine Model 200V Charge-Device Model 1250V See (4) Output Short Circuit Duration V+ relative to V- -0.3 to +12.
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LMP8350 SNOSB80B – FEBRUARY 2011 – REVISED MARCH 2013 www.ti.com +10V Electrical Characteristics (1) Unless otherwise specified, all limits are ensured for TA = 25°C, Avcl = +1, RF = RG = 1kΩ, Fully differential input, VS = +10V, RL = 2 kΩ//20pF differentially, Input CMR and VOCM=mid supply and HP mode unless otherwise noted. Boldface limits apply at the temperature extremes. Symbol Conditions (2) Typ (4) Max (3) High Power ±0.6 ±4 ±4.05 Mid Power ±0.08 ±2 ±2.03 Low Power ±0.1 ±2.5 ±2.
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LMP8350 www.ti.com SNOSB80B – FEBRUARY 2011 – REVISED MARCH 2013 +10V Electrical Characteristics(1) (continued) Unless otherwise specified, all limits are ensured for TA = 25°C, Avcl = +1, RF = RG = 1kΩ, Fully differential input, VS = +10V, RL = 2 kΩ//20pF differentially, Input CMR and VOCM=mid supply and HP mode unless otherwise noted. Boldface limits apply at the temperature extremes.
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LMP8350 SNOSB80B – FEBRUARY 2011 – REVISED MARCH 2013 www.ti.com +10V Electrical Characteristics(1) (continued) Unless otherwise specified, all limits are ensured for TA = 25°C, Avcl = +1, RF = RG = 1kΩ, Fully differential input, VS = +10V, RL = 2 kΩ//20pF differentially, Input CMR and VOCM=mid supply and HP mode unless otherwise noted. Boldface limits apply at the temperature extremes.
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LMP8350 www.ti.com SNOSB80B – FEBRUARY 2011 – REVISED MARCH 2013 +6.6V Electrical Characteristics (1) Unless otherwise specified, all limits are ensured for TA = 25°C, Avcl = +1, RF = RG = 1kΩ, Fully differential input, VS = +6.6V, RL = 2 kΩ//20pF differentially, Input CMR and VOCM=mid supply and HP mode unless otherwise noted. Boldface limits apply at the temperature extremes.. Symbol Conditions (2) Typ (4) Max (3) High Power ±0.3 ±3.5 ±3.54 Mid Power ±0.1 ±2.8 ±2.83 Low Power ±0.1 ±2.5 ±2.
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LMP8350 SNOSB80B – FEBRUARY 2011 – REVISED MARCH 2013 www.ti.com +6.6V Electrical Characteristics(1) (continued) Unless otherwise specified, all limits are ensured for TA = 25°C, Avcl = +1, RF = RG = 1kΩ, Fully differential input, VS = +6.6V, RL = 2 kΩ//20pF differentially, Input CMR and VOCM=mid supply and HP mode unless otherwise noted. Boldface limits apply at the temperature extremes..
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LMP8350 www.ti.com SNOSB80B – FEBRUARY 2011 – REVISED MARCH 2013 +6.6V Electrical Characteristics(1) (continued) Unless otherwise specified, all limits are ensured for TA = 25°C, Avcl = +1, RF = RG = 1kΩ, Fully differential input, VS = +6.6V, RL = 2 kΩ//20pF differentially, Input CMR and VOCM=mid supply and HP mode unless otherwise noted. Boldface limits apply at the temperature extremes..
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LMP8350 SNOSB80B – FEBRUARY 2011 – REVISED MARCH 2013 www.ti.com +5V Electrical Characteristics (1) Unless otherwise specified, all limits are ensured for TA = 25°C, Avcl = +1, RF=RG = 1kΩ, Fully differential input, VS = +5V, RL = 2 kΩ//20pF differentially, Input CMR and VOCM=mid supply and HP mode unless otherwise noted. Boldface limits apply at the temperature extremes. Symbol Typ (3) Max (2) High Power ±0.2 ±3.2 ±3.6 Mid Power ±0.1 ±2.0 ±2.3 Low Power ±0.1 ±2.0 ±2.3 High Power ±0.
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LMP8350 www.ti.com SNOSB80B – FEBRUARY 2011 – REVISED MARCH 2013 +5V Electrical Characteristics(1) (continued) Unless otherwise specified, all limits are ensured for TA = 25°C, Avcl = +1, RF=RG = 1kΩ, Fully differential input, VS = +5V, RL = 2 kΩ//20pF differentially, Input CMR and VOCM=mid supply and HP mode unless otherwise noted. Boldface limits apply at the temperature extremes.
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LMP8350 SNOSB80B – FEBRUARY 2011 – REVISED MARCH 2013 www.ti.com +5V Electrical Characteristics(1) (continued) Unless otherwise specified, all limits are ensured for TA = 25°C, Avcl = +1, RF=RG = 1kΩ, Fully differential input, VS = +5V, RL = 2 kΩ//20pF differentially, Input CMR and VOCM=mid supply and HP mode unless otherwise noted. Boldface limits apply at the temperature extremes.
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LMP8350 www.ti.com SNOSB80B – FEBRUARY 2011 – REVISED MARCH 2013 Typical Performance Characteristics Unless otherwise specified, TA = 25°C, Avcl = +1, RF=RG = 1kΩ, fully differential input, VS = +10V, RL = 2 kΩ//20pF differentially, Input CMR and VOCM = mid supply and HP mode unless otherwise noted.
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LMP8350 SNOSB80B – FEBRUARY 2011 – REVISED MARCH 2013 www.ti.com Typical Performance Characteristics (continued) Unless otherwise specified, TA = 25°C, Avcl = +1, RF=RG = 1kΩ, fully differential input, VS = +10V, RL = 2 kΩ//20pF differentially, Input CMR and VOCM = mid supply and HP mode unless otherwise noted. Distortion at 10V, High Power Distortion at 6.
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LMP8350 www.ti.com SNOSB80B – FEBRUARY 2011 – REVISED MARCH 2013 Typical Performance Characteristics (continued) Unless otherwise specified, TA = 25°C, Avcl = +1, RF=RG = 1kΩ, fully differential input, VS = +10V, RL = 2 kΩ//20pF differentially, Input CMR and VOCM = mid supply and HP mode unless otherwise noted. Distortion at 5V, High Power THD+N at 10V 1 -40 f = 1 kHz BW = 22 kHz f = 1KHz 0.1 -80 THD+N (%) DISTORTION (dBc) -60 HD3 -100 LP 0.01 HP 0.001 -120 -140 0.
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LMP8350 SNOSB80B – FEBRUARY 2011 – REVISED MARCH 2013 www.ti.com Typical Performance Characteristics (continued) Unless otherwise specified, TA = 25°C, Avcl = +1, RF=RG = 1kΩ, fully differential input, VS = +10V, RL = 2 kΩ//20pF differentially, Input CMR and VOCM = mid supply and HP mode unless otherwise noted.
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LMP8350 www.ti.com SNOSB80B – FEBRUARY 2011 – REVISED MARCH 2013 Typical Performance Characteristics (continued) Unless otherwise specified, TA = 25°C, Avcl = +1, RF=RG = 1kΩ, fully differential input, VS = +10V, RL = 2 kΩ//20pF differentially, Input CMR and VOCM = mid supply and HP mode unless otherwise noted. Pulse Response at 10V Pulse Response at 6.6V 1.5 MP HP DIFFERENTIAL OUTPUT (Vpp) DIFFERENTIAL OUTPUT (Vpp) 1.5 1.0 0.5 0.0 -0.5 LP -1.0 MP -1.5 0 40 0.5 0.0 -0.5 LP -1.0 MP -1.
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LMP8350 SNOSB80B – FEBRUARY 2011 – REVISED MARCH 2013 www.ti.com APPLICATION SECTION The LMP8350 is a fully differential voltage feedback amplifier designed to drive precision differential ADC converters. The LMP8350, 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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LMP8350 www.ti.com SNOSB80B – FEBRUARY 2011 – REVISED MARCH 2013 The voltage at the EN pin can be generated with a resistive voltage divider or a buffer connected to a voltage source or a DAC. The schematic diagram below shows how to generate EN voltage with a resistive voltage divider. Values of RA and RB can be calculated to achieve the voltages in Table 2, however their sum should be below 50kΩ to keep the voltage at the enable pin stable. Recommended values for Ra and Rb are given in Table 3. Table 3.
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LMP8350 SNOSB80B – FEBRUARY 2011 – REVISED MARCH 2013 www.ti.com FULLY DIFFERENTIAL OPERATION The LMP8350 will perform best when used with split supplies and in a fully differential configuration. See Figure 30 for recommend circuits. RF1 RO RG1 + VI a CL VOCM RL VO RG2 RO RF2 EN Figure 30. Typical Fully Differential Application The circuit shown in Figure 30 is a typical fully differential application as might be used to drive a Sigma Delta ADC.
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LMP8350 www.ti.com SNOSB80B – FEBRUARY 2011 – REVISED MARCH 2013 With up to 15 VPP differential output voltage swing and 80 mA of linear drive current, the LMP8350 makes an excellent precision cable driver as shown in Figure 31. The LMP8350 is also suitable for driving differential cables from a single ended source. RF RO RG RS VI + a RT RL CL VOCM VO RG RM RO RF EN SET RM = RT||RS 1 - 1 RIN § ¨¨ © § 1 ¨R © S RIN = RG RF § 1- ¨ 2 * (R F + RG) © § ¨¨ © SET RT = Figure 32.
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LMP8350 SNOSB80B – FEBRUARY 2011 – REVISED MARCH 2013 www.ti.com RF RO VO1 RG RS VI1 + VI a RL CL VOCM RT VO RG VI2 VO2 RM RO RF EN *VCM = VO1 + VO2 VICM = VOCM * 2 *BY DESIGN (RG + RM) (RG + RM + RF) =a VOCM 1 + AV WHERE RM << RG Figure 33. Relating AV to Input/Output Common Mode Voltages In Figure 33 the differential closed loop gain is = AV= RF/RG. Please note that in single ended to differential operation VIN is measured single ended while VOUT is measured differentially.
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LMP8350 www.ti.com SNOSB80B – FEBRUARY 2011 – REVISED MARCH 2013 + V 0.01 PF 10 PF + VOCM 0.1 PF 0.1 PF 0.01 PF 10 PF V - Figure 35. Split Supply Bypassing Capacitors The 0.01 µF and 0.1 µF capacitors should be leadless surface mount (SMT) ceramic capacitors and should be no more than 3 mm from the supply pins. The SMT capacitors should be connected directly to a ground plane. Thin traces or small vias will reduce the effectiveness of bypass capacitors. V + 0.01 PF 0.1 PF 10 PF + VOCM 0.
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LMP8350 SNOSB80B – FEBRUARY 2011 – REVISED MARCH 2013 www.ti.com RF1 RISO1 RG1 + VI a VOCM CS - A/D 8-18 pF RG2 RISO2 RF2 VREF EN LOW IMPEDANCE VOLTAGE REFERENCE Figure 37. Driving an ADC The amplifier and ADC should be located as close together as possible. Both devices require that the filter components be in close proximity to them.
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LMP8350 www.ti.com SNOSB80B – FEBRUARY 2011 – REVISED MARCH 2013 ESD PROTECTION The LMP8350 is protected against electrostatic discharge (ESD) on all pins. The LMP8350 will survive 2000V Human Body model and 200V Machine model events. Under normal operation the ESD diodes have no effect on circuit performance. There are occasions, however, when the ESD diodes will be evident. If the LMP8350 is driven by a large signal while the device is powered down the ESD diodes will conduct .
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LMP8350 SNOSB80B – FEBRUARY 2011 – REVISED MARCH 2013 www.ti.com REVISION HISTORY Changes from Revision A (March 2013) to Revision B • 26 Page Changed layout of National Data Sheet to TI format ..........................................................................................................
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PACKAGE OPTION ADDENDUM www.ti.
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PACKAGE MATERIALS INFORMATION www.ti.com 8-Apr-2013 TAPE AND REEL INFORMATION *All dimensions are nominal Device LMP8350MAX/NOPB Package Package Pins Type Drawing SOIC D 8 SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) 2500 330.0 12.4 Pack Materials-Page 1 6.5 B0 (mm) K0 (mm) P1 (mm) 5.4 2.0 8.0 W Pin1 (mm) Quadrant 12.
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PACKAGE MATERIALS INFORMATION www.ti.com 8-Apr-2013 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) LMP8350MAX/NOPB SOIC D 8 2500 367.0 367.0 35.
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