THS4531 www.ti.com SLOS358B – SEPTEMBER 2011 – REVISED MARCH 2012 Ultra Low Power, Rail-to-Rail Output, Fully-Differential Amplifier Check for Samples: THS4531 FEATURES DESCRIPTION • The THS4531 is a low-power, fully-differential op amp with input common-mode range below the negative rail and rail-to-rail output. The device is designed for low-power data acquisition systems and high density applications where power consumption and dissipation is critical.
THS4531 SLOS358B – SEPTEMBER 2011 – REVISED MARCH 2012 www.ti.com This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage. ESD damage can range from subtle performance degradation to complete device failure.
THS4531 www.ti.com SLOS358B – SEPTEMBER 2011 – REVISED MARCH 2012 ELECTRICAL CHARACTERISTICS: VS = 2.7 V Test conditions at TA = 25°C, VS+ = 2.7 V, VS– = 0 V, VOCM = open, VOUT = 2 VPP, RF = 2 kΩ, RL = 2 kΩ differential, G = 1 V/V, single-ended input, differential output, and input and output referenced to mid-supply, unless otherwise noted.
THS4531 SLOS358B – SEPTEMBER 2011 – REVISED MARCH 2012 www.ti.com ELECTRICAL CHARACTERISTICS: VS = 2.7 V (continued) Test conditions at TA = 25°C, VS+ = 2.7 V, VS– = 0 V, VOCM = open, VOUT = 2 VPP, RF = 2 kΩ, RL = 2 kΩ differential, G = 1 V/V, single-ended input, differential output, and input and output referenced to mid-supply, unless otherwise noted.
THS4531 www.ti.com SLOS358B – SEPTEMBER 2011 – REVISED MARCH 2012 ELECTRICAL CHARACTERISTICS: VS = 2.7 V (continued) Test conditions at TA = 25°C, VS+ = 2.7 V, VS– = 0 V, VOCM = open, VOUT = 2 VPP, RF = 2 kΩ, RL = 2 kΩ differential, G = 1 V/V, single-ended input, differential output, and input and output referenced to mid-supply, unless otherwise noted.
THS4531 SLOS358B – SEPTEMBER 2011 – REVISED MARCH 2012 www.ti.com ELECTRICAL CHARACTERISTICS: VS = 5 V Test conditions at TA = +25°C, VS+ = 5 V, VS– = 0 V, VOCM = open, VOUT = 2 VPP, RF = 2 kΩ, RL = 2 kΩ differential, G = 1 V/V, single-ended input, differential output, and input and output referenced to mid-supply, unless otherwise noted.
THS4531 www.ti.com SLOS358B – SEPTEMBER 2011 – REVISED MARCH 2012 ELECTRICAL CHARACTERISTICS: VS = 5 V (continued) Test conditions at TA = +25°C, VS+ = 5 V, VS– = 0 V, VOCM = open, VOUT = 2 VPP, RF = 2 kΩ, RL = 2 kΩ differential, G = 1 V/V, single-ended input, differential output, and input and output referenced to mid-supply, unless otherwise noted.
THS4531 SLOS358B – SEPTEMBER 2011 – REVISED MARCH 2012 www.ti.com ELECTRICAL CHARACTERISTICS: VS = 5 V (continued) Test conditions at TA = +25°C, VS+ = 5 V, VS– = 0 V, VOCM = open, VOUT = 2 VPP, RF = 2 kΩ, RL = 2 kΩ differential, G = 1 V/V, single-ended input, differential output, and input and output referenced to mid-supply, unless otherwise noted.
THS4531 www.ti.
THS4531 SLOS358B – SEPTEMBER 2011 – REVISED MARCH 2012 www.ti.com TABLE OF GRAPHS Description VS = 2.
THS4531 www.ti.com SLOS358B – SEPTEMBER 2011 – REVISED MARCH 2012 TYPICAL CHARACTERISTICS: VS = 2.7V Test conditions unless otherwise noted: VS+ = 2.7 V, VS– = 0V, CM = open, VOUT = 2Vpp, RF = 2kΩ, RL = 2kΩ Differential, G = 1V/V, Single-Ended Input, Differential Output, Input and Output Referenced to mid-supply unless otherwise noted. LARGE-SIGNAL FREQUENCY RESPONSE G = 1 V/V G = 2 V/V G = 5 V/V G = 10 V/V 10M Normalized Gain (dB) 100M Frequency (Hz) 1M 10M Figure 2. Figure 3.
THS4531 SLOS358B – SEPTEMBER 2011 – REVISED MARCH 2012 www.ti.com TYPICAL CHARACTERISTICS: VS = 2.7V (continued) Test conditions unless otherwise noted: VS+ = 2.7 V, VS– = 0V, CM = open, VOUT = 2Vpp, RF = 2kΩ, RL = 2kΩ Differential, G = 1V/V, Single-Ended Input, Differential Output, Input and Output Referenced to mid-supply unless otherwise noted. HARMONIC DISTORTION vs FREQUENCY VS = 2.
THS4531 www.ti.com SLOS358B – SEPTEMBER 2011 – REVISED MARCH 2012 TYPICAL CHARACTERISTICS: VS = 2.7V (continued) Test conditions unless otherwise noted: VS+ = 2.7 V, VS– = 0V, CM = open, VOUT = 2Vpp, RF = 2kΩ, RL = 2kΩ Differential, G = 1V/V, Single-Ended Input, Differential Output, Input and Output Referenced to mid-supply unless otherwise noted. HARMONIC DISTORTION vs LOAD at 1 MHz HARMONIC DISTORTION vs VOCM at 1 MHz 0 0 VS = 2.
THS4531 SLOS358B – SEPTEMBER 2011 – REVISED MARCH 2012 www.ti.com TYPICAL CHARACTERISTICS: VS = 2.7V (continued) Test conditions unless otherwise noted: VS+ = 2.7 V, VS– = 0V, CM = open, VOUT = 2Vpp, RF = 2kΩ, RL = 2kΩ Differential, G = 1V/V, Single-Ended Input, Differential Output, Input and Output Referenced to mid-supply unless otherwise noted. SINGLE-ENDED OUTPUT SATURATION VOLTAGE vs LOAD CURRENT MAIN AMPLIFIER DIFFERENTIAL OUTPUT IMPEDANCE vs FREQUENCY 100 0.8 0.6 0.4 VS = 2.
THS4531 www.ti.com SLOS358B – SEPTEMBER 2011 – REVISED MARCH 2012 TYPICAL CHARACTERISTICS: VS = 2.7V (continued) Test conditions unless otherwise noted: VS+ = 2.7 V, VS– = 0V, CM = open, VOUT = 2Vpp, RF = 2kΩ, RL = 2kΩ Differential, G = 1V/V, Single-Ended Input, Differential Output, Input and Output Referenced to mid-supply unless otherwise noted. REJECTION RATIO vs FREQUENCY TURN-ON TIME −50 −60 −70 VS = 2.7 V G = 1 V/V RF = 2 kΩ RL = 200 Ω 0.
THS4531 SLOS358B – SEPTEMBER 2011 – REVISED MARCH 2012 www.ti.com TYPICAL CHARACTERISTICS: VS = 2.7V (continued) Test conditions unless otherwise noted: VS+ = 2.7 V, VS– = 0V, CM = open, VOUT = 2Vpp, RF = 2kΩ, RL = 2kΩ Differential, G = 1V/V, Single-Ended Input, Differential Output, Input and Output Referenced to mid-supply unless otherwise noted.
THS4531 www.ti.com SLOS358B – SEPTEMBER 2011 – REVISED MARCH 2012 TYPICAL CHARACTERISTICS: VS = 2.7V (continued) Test conditions unless otherwise noted: VS+ = 2.7 V, VS– = 0V, CM = open, VOUT = 2Vpp, RF = 2kΩ, RL = 2kΩ Differential, G = 1V/V, Single-Ended Input, Differential Output, Input and Output Referenced to mid-supply unless otherwise noted. VOCM INPUT IMPEDANCE vs FREQUENCY INPUT OFFSET CURRENT HISTOGRAM 200k 600 VS = 2.7 V THS4531ID VS = 2.
THS4531 SLOS358B – SEPTEMBER 2011 – REVISED MARCH 2012 www.ti.com TYPICAL CHARACTERISTICS: VS = 2.7V (continued) Test conditions unless otherwise noted: VS+ = 2.7 V, VS– = 0V, CM = open, VOUT = 2Vpp, RF = 2kΩ, RL = 2kΩ Differential, G = 1V/V, Single-Ended Input, Differential Output, Input and Output Referenced to mid-supply unless otherwise noted.
THS4531 www.ti.com SLOS358B – SEPTEMBER 2011 – REVISED MARCH 2012 TYPICAL CHARACTERISTICS: VS = 5V Test conditions unless otherwise noted: VS+ = 5 V, VS– = 0V, VOCM = open, VOUT = 2Vpp, RF = 2kΩ, RL = 2kΩ Differential, G = 1V/V, Single-Ended Input, Differential Output, Input and Output Referenced to mid-supply, TA = 25°Cunless otherwise noted. LARGE-SIGNAL FREQUENCY RESPONSE G = 1 V/V G = 2 V/V G = 5 V/V G = 10 V/V Gain (dB) 10M 100M Frequency (Hz) 1M 10M Figure 35. Figure 36.
THS4531 SLOS358B – SEPTEMBER 2011 – REVISED MARCH 2012 www.ti.com TYPICAL CHARACTERISTICS: VS = 5V (continued) Test conditions unless otherwise noted: VS+ = 5 V, VS– = 0V, VOCM = open, VOUT = 2Vpp, RF = 2kΩ, RL = 2kΩ Differential, G = 1V/V, Single-Ended Input, Differential Output, Input and Output Referenced to mid-supply, TA = 25°Cunless otherwise noted.
THS4531 www.ti.com SLOS358B – SEPTEMBER 2011 – REVISED MARCH 2012 TYPICAL CHARACTERISTICS: VS = 5V (continued) Test conditions unless otherwise noted: VS+ = 5 V, VS– = 0V, VOCM = open, VOUT = 2Vpp, RF = 2kΩ, RL = 2kΩ Differential, G = 1V/V, Single-Ended Input, Differential Output, Input and Output Referenced to mid-supply, TA = 25°Cunless otherwise noted.
THS4531 SLOS358B – SEPTEMBER 2011 – REVISED MARCH 2012 www.ti.com TYPICAL CHARACTERISTICS: VS = 5V (continued) Test conditions unless otherwise noted: VS+ = 5 V, VS– = 0V, VOCM = open, VOUT = 2Vpp, RF = 2kΩ, RL = 2kΩ Differential, G = 1V/V, Single-Ended Input, Differential Output, Input and Output Referenced to mid-supply, TA = 25°Cunless otherwise noted. SINGLE-ENDED OUTPUT SATURATION VOLTAGE vs LOAD CURRENT MAIN AMPLIFIER DIFFERENTIAL OUTPUT IMPEDANCE vs FREQUENCY 100 1 0.8 0.
THS4531 www.ti.com SLOS358B – SEPTEMBER 2011 – REVISED MARCH 2012 TYPICAL CHARACTERISTICS: VS = 5V (continued) Test conditions unless otherwise noted: VS+ = 5 V, VS– = 0V, VOCM = open, VOUT = 2Vpp, RF = 2kΩ, RL = 2kΩ Differential, G = 1V/V, Single-Ended Input, Differential Output, Input and Output Referenced to mid-supply, TA = 25°Cunless otherwise noted. REJECTION RATIO vs FREQUENCY TURN-ON TIME −60 −70 −80 CMRR PSRR −90 1M Frequency (Hz) 10M 1 1 0.
THS4531 SLOS358B – SEPTEMBER 2011 – REVISED MARCH 2012 www.ti.com TYPICAL CHARACTERISTICS: VS = 5V (continued) Test conditions unless otherwise noted: VS+ = 5 V, VS– = 0V, VOCM = open, VOUT = 2Vpp, RF = 2kΩ, RL = 2kΩ Differential, G = 1V/V, Single-Ended Input, Differential Output, Input and Output Referenced to mid-supply, TA = 25°Cunless otherwise noted.
THS4531 www.ti.com SLOS358B – SEPTEMBER 2011 – REVISED MARCH 2012 TYPICAL CHARACTERISTICS: VS = 5V (continued) Test conditions unless otherwise noted: VS+ = 5 V, VS– = 0V, VOCM = open, VOUT = 2Vpp, RF = 2kΩ, RL = 2kΩ Differential, G = 1V/V, Single-Ended Input, Differential Output, Input and Output Referenced to mid-supply, TA = 25°Cunless otherwise noted.
THS4531 SLOS358B – SEPTEMBER 2011 – REVISED MARCH 2012 www.ti.com TYPICAL CHARACTERISTICS: VS = 5V (continued) Test conditions unless otherwise noted: VS+ = 5 V, VS– = 0V, VOCM = open, VOUT = 2Vpp, RF = 2kΩ, RL = 2kΩ Differential, G = 1V/V, Single-Ended Input, Differential Output, Input and Output Referenced to mid-supply, TA = 25°Cunless otherwise noted.
THS4531 www.ti.com SLOS358B – SEPTEMBER 2011 – REVISED MARCH 2012 APPLICATION INFORMATION TYPICAL CHARACTERISTICS TEST CIRCUITS Figure 68 shows the general test circuit built on the EVM that was used for testing the THS4531. For simplicity, power supply decoupling is not shown – please see layout in the applications section for recommendations. Depending on the test conditions, component values are changed per Table 2 and Table 3, or as otherwise noted.
THS4531 SLOS358B – SEPTEMBER 2011 – REVISED MARCH 2012 www.ti.com Due to the voltage divider on the output formed by the load component values, the amplifier’s output is attenuated. The column “Atten” in Table 3 shows the attenuation expected from the resistor divider. When using a transformer at the output as shown in Figure 68, the signal will see slightly more loss due to transformer and line loss, and these numbers will be approximate.
THS4531 www.ti.com SLOS358B – SEPTEMBER 2011 – REVISED MARCH 2012 VIN+ RG Input From 50-Ω Test Equipment RF PD RIT RO VOUT– RO VOUT+ VS+ + 0.22 μF VOCM – 0.22 μF VIN– THS4531 VS– RG No Connection RF Output to Test Equipment RIT 0.22 μF Installed to Balance Amplifier Output to Test Equipment 49.9 Ω Figure 69.
THS4531 SLOS358B – SEPTEMBER 2011 – REVISED MARCH 2012 www.ti.com Power Supply Network Analyzer Cal Diff Probe VIN+ RF RG RO No Connection VS+ RIT VOUT– + VOCM – 0.22 μF VIN– VS– Measure With Diff Probe ROT THS4531 VOUT+ RG RO No Connection RF RIT Figure 71. PSRR Test Circuit VOCM Input The circuit shown in Figure 72 is used to measure the transient response, frequency response and input impedance of the VOCM input. For these tests, the cal point is across the 49.
THS4531 www.ti.com SLOS358B – SEPTEMBER 2011 – REVISED MARCH 2012 Balance Error The circuit shown in Figure 73 is used to measure the balance error of the main differential amplifier. A network analyzer is used as the signal source and the measurement device. The output impedance of the network analyzer is 50Ω and is DC coupled. RIT and RG are chosen to impedance match to 50Ω and maintain the proper gain. To balance the amplifier, a 49.9Ω resistor to ground is inserted across RIT on the alternate input.
THS4531 SLOS358B – SEPTEMBER 2011 – REVISED MARCH 2012 www.ti.com APPLICATION CIRCUITS The following circuits show application information for the THS4531. For simplicity, power supply decoupling capacitors are not shown in these diagrams – please see the EVM and Layout Recommendations section for recommendations. For more detail on the use and operation of fully differential op amps refer to application report “Fully-Differential Amplifiers” SLOA054D.
THS4531 www.ti.com SLOS358B – SEPTEMBER 2011 – REVISED MARCH 2012 Input Common-Mode Voltage Range The input common-model voltage of a fully differential op amp is the voltage at the “+ and –“ input pins of the op amp. It is important to not violate the input common-mode voltage range (VICR) of the op amp. Assuming the op amp is in linear operation the voltage across the input pins is only a few millivolts at most.
THS4531 SLOS358B – SEPTEMBER 2011 – REVISED MARCH 2012 www.ti.com Low Power Applications and the Effects of Resistor Values on Bandwidth The THS4531 is designed for the nominal value of RF to be 2 kΩ. This gives excellent distortion performance, maximum bandwidth, best flatness, and best pulse response. It also loads the amplifier. For example; in gain of 1 with RF = RG = 2 kΩ, RG to ground, and VOUT+ = 4V, 1mA of current will flow through the feedback path to ground.
THS4531 www.ti.com SLOS358B – SEPTEMBER 2011 – REVISED MARCH 2012 200 RO (Ω) 100 10 VS = 2.7 V G = 1 V/V RF = 2 kΩ RL = 2 kΩ 1 1 10 100 CLOAD (pF) 1k 2k G068 Figure 78. Recommended Series Output Resistor vs Capacitive Load for Flat Frequency Response 3 0 Gain (dB) −3 −6 −9 −12 −15 −18 −21 100k VS = 2.
THS4531 SLOS358B – SEPTEMBER 2011 – REVISED MARCH 2012 www.ti.com RG 10 RF VIN– VOUT– 100 pF VS+ + From Analyzer VOCM – THS4531 To Analyzer 0.22 μF RG 10 VOUT+ VIN+ RF 100 pF Figure 80. THS4531 Audio Analyzer Test Circuit −95 VS = 5 V G = 1 V/V VOUT = 1 VRMS RF = 2 kΩ RL = 600 Ω No Weighting A−Weighting −97 −99 THD+N (dB) −101 −103 −105 −107 −109 −111 −113 −115 0 5k 10k 15k Frequency (Hz) 20k 24k G070 Magnitude (dBV) Figure 81.
THS4531 www.ti.com SLOS358B – SEPTEMBER 2011 – REVISED MARCH 2012 Audio On/Off Pop Performance The THS4531 is tested to show on and off pop performance by connecting a speaker between the differential outputs and switching on and off the power supply, and also by using the power down function of the THS4531. Testing was done with and without tones. During these tests no audible pop could be heard. 5 2.5 4 2 VS = 5 V G = 2 V/V RF = 2 kΩ RL = 200 Ω 3 1 2 1 0 1.
THS4531 SLOS358B – SEPTEMBER 2011 – REVISED MARCH 2012 www.ti.com Power Down (V) 4 VS = 5 V G = 2 V/V RF = 2 kΩ RL = 200 Ω 3 1.5 2 1 1 0.5 0 0 50m 100m Time (s) 150m Output Voltage (V) 2.5 Power Down VOUT + VOUT − 2 5 0 200m G074 Figure 85. PD Enable Pop Performance AUDIO ADC DRIVER PERFORMANCE: THS4531 AND PCM4204 COMBINED PERFORMANCE To show achievable performance with a high performance audio ADC, the THS4531 is tested as the drive amplifier for the PCM4204.
THS4531 www.ti.com SLOS358B – SEPTEMBER 2011 – REVISED MARCH 2012 An audio analyzer is used to provide an analog audio input to the EVM and the PCM formatted digital output is read by the digital input on the analyzer. Data was taken at fS = 96kHz, and audio output uses PCM format. Other data rates and formats are expected to show similar performance in line with that shown in the data sheet. Figure 87 shows the THD+N vs Frequency with no weighting and Figure 88 shows an FFT with 1kHz input tone.
THS4531 SLOS358B – SEPTEMBER 2011 – REVISED MARCH 2012 www.ti.com The standard ADS8321 EVM and THS4531 EVM are modified to implement the schematic in Figure 89 and used to test the performance of the THS4531 as a drive amplifier. With single supply +5V supply the output commonmode of the THS4531 defaults to +2.5V as required at the input of the ADS8321 so the VOCM input of the THS4531 simply bypassed to GND with 0.22µF capacitor.
THS4531 www.ti.com SLOS358B – SEPTEMBER 2011 – REVISED MARCH 2012 The standard ADS7945 EVM and THS4531 EVM are modified to implement the schematic in Figure 91 and used to test the performance of the THS4531 as a drive amplifier. With single supply +5V supply the output commonmode of the THS4531 defaults to +2.5V as required at the input of the ADS7945 so the VOCM input of the THS4531 simply bypassed to GND with 0.22µF capacitor.
THS4531 SLOS358B – SEPTEMBER 2011 – REVISED MARCH 2012 www.ti.com EVM AND LAYOUT RECOMMENDATIONS The THS4531 EVM (SLOU334) should be used as a reference when designing the circuit board. It is recommended to follow the EVM layout of the external components near to the amplifier, ground plane construction, and power routing as closely as possible. General guidelines are: 1. Signal routing should be direct and as short as possible into and out of the op amp. 2.
THS4531 www.ti.com SLOS358B – SEPTEMBER 2011 – REVISED MARCH 2012 REVISION HISTORY NOTE: Page numbers for previous revisions may differ from page numbers in the current version. Changes from Revision A (January 2012) to Revision B Page • Deleted DC Performance, Input-referred offset voltage parameter typical specifications for TA = 0°C to +70°C, –40°C to +85°C, and –40°C to +125°C in 2.7 V Electrical Characteristics table .................................................................
THS4531 SLOS358B – SEPTEMBER 2011 – REVISED MARCH 2012 www.ti.com Changes from Original (SEPTEMBER 2011) to Revision A • 44 Page Changed from product preview to production data ...............................................................................................................
PACKAGE OPTION ADDENDUM www.ti.
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.
PACKAGE MATERIALS INFORMATION www.ti.com 16-Aug-2012 TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Pins Type Drawing THS4531IDGKR VSSOP DGK SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) B0 (mm) K0 (mm) P1 (mm) 1.4 8.0 12.0 Q1 8 2500 330.0 12.4 5.3 3.4 W Pin1 (mm) Quadrant THS4531IDR SOIC D 8 2500 330.0 12.4 6.4 5.2 2.1 8.0 12.0 Q1 THS4531IRUNR QFN RUN 10 3000 180.0 8.4 2.3 2.3 1.15 4.0 8.
PACKAGE MATERIALS INFORMATION www.ti.com 16-Aug-2012 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) THS4531IDGKR VSSOP DGK 8 2500 366.0 364.0 50.0 THS4531IDR SOIC D 8 2500 340.5 338.1 20.6 THS4531IRUNR QFN RUN 10 3000 210.0 185.0 35.0 THS4531IRUNT QFN RUN 10 250 210.0 185.0 35.
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