OPA1652 OPA1654 Burr-Brown Audio SBOS477 – DECEMBER 2011 www.ti.com ™ Low Noise and Distortion, General-Purpose, FET-Input AUDIO OPERATIONAL AMPLIFIERS Check for Samples: OPA1652, OPA1654 FEATURES DESCRIPTION • Low Noise: 4.5 nV/√Hz at 1 kHz • Low Distortion: 0.00005% at 1 kHz • Low Quiescent Current: 2 mA Per Channel • Low Input Bias Current: 10 pA • Slew Rate: 10 V/μs • Wide Gain Bandwidth: 18 MHz (G = +1) • Unity Gain Stable • Rail-to-Rail Output • Wide Supply Range: ±2.25 V to ±18 V, or +4.5 V to +36 V • Dual and Quad Versions Available • Small Package Sizes: DUAL: SO-8 and MSOP-8 QUAD: SO-14 and TSSOP-14 The OPA1652 (dual) and OPA1654 (quad) FET-input operational amplifiers achieve a low 4.5 nV/√Hz noise density with an ultralow distortion of 0.00005% at 1 kHz. The OPA1652 and OPA1654 op amps offer rail-to-rail output swing to within 800 mV with 2-kΩ load, which increases headroom and maximizes dynamic range. These devices also have a high output drive capability of ±30 mA. APPLICATIONS The OPA1652 and OPA1654 temperature ranges are specified from –40°C to +85°C. SoundPlus™ 1 234 • • • • • • Analog and Digital Mixers Audio Effects Processors Musical Instruments A/V Receivers DVD and Blu-Ray™ Players Car Audio Systems These devices operate over a very wide supply range of ±2.25 V to ±18 V, or +4.5 V to +36 V, on only 2 mA of supply current per channel. The OPA1652 and OPA1654 op amps are unity-gain stable and provide excellent dynamic behavior over a wide range of load conditions. These devices also feature completely independent circuitry for lowest crosstalk and freedom from interactions between channels, even when overdriven or overloaded. 1 2 3 4 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. SoundPlus is a trademark of Texas Instruments Incorporated. Blu-Ray is a trademark of Blu-Ray Disc Association. All 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. Copyright © 2011, Texas Instruments Incorporated OPA1652 OPA1654 SBOS477 – DECEMBER 2011 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. Precision integrated circuits may be more susceptible to damage because very small parametric changes could cause the device not to meet its published specifications. PACKAGE INFORMATION (1) PRODUCT PACKAGE-LEAD PACKAGE DESIGNATOR PACKAGE MARKING SO-8 D OP1652 MSOP-8 DGK OUPI SO-14 D OP1654 TSSOP-14 PW OP1654 OPA1652 OPA1654 (1) For the most current package and ordering information see the Package Option Addendum at the end of this document, or see the TI web site at www.ti.com. ABSOLUTE MAXIMUM RATINGS (1) Over operating free-air temperature range (unless otherwise noted). OPA1652, OPA1654 UNIT 40 V VS = (V+) – (V–) Supply Voltage Input Voltage (V–) – 0.5 to (V+) + 0.5 V ±10 mA Input Current (All pins except power-supply pins) Output Short-Circuit (2) Continuous Operating Temperature –55 to +125 °C Storage Temperature –65 to +150 °C Junction Temperature 200 °C Human Body Model (HBM) 2 kV Charged Device Model (CDM) 1 kV 200 V ESD Ratings Machine Model (MM) (1) (2) Stresses above these ratings may cause permanent damage. Exposure to absolute maximum conditions for extended periods may degrade device reliability. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those specified is not supported. Short-circuit to VS/2 (ground in symmetrical dual supply setups), one amplifier per package. PIN CONFIGURATIONS OPA1652: D AND DGK PACKAGES SO-8 AND MSOP-8 (TOP VIEW) OUT A 1 -IN A 2 +IN A 3 V- 4 A B 8 V+ 7 OUT B 6 -IN B 5 +IN B OPA1654: D AND PW PACAKGES SO-14 AND TSSOP-14 (TOP VIEW) Out A 1 -In A 2 A 14 Out D 13 -In D D +In A 3 12 +In D V+ 4 11 V- + In B 5 10 + In C B C -In B 6 9 -In C Out B 7 8 Out C 2 Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA1652 OPA1654 OPA1652 OPA1654 SBOS477 – DECEMBER 2011 www.ti.com ELECTRICAL CHARACTERISTICS: VS = ±15 V At TA = +25°C, RL = 2 kΩ, and VCM = VOUT = midsupply, unless otherwise noted. OPA1652, OPA1654 PARAMETER TEST CONDITIONS MIN TYP MAX UNIT AUDIO PERFORMANCE THD+N IMD Total harmonic distortion + noise Intermodulation distortion G = +1, f = 1 kHz, VO = 3 VRMS G = +1, VO = 3 VRMS 0.00005 % –126 dB SMPTE/DIN Two-Tone, 4:1 (60 Hz and 7 kHz) 0.00005 % –126 dB DIM 30 (3-kHz square wave and 15-kHz sine wave) 0.00005 % –126 dB CCIF Twin-Tone (19 kHz and 20 kHz) 0.00005 % –126 dB FREQUENCY RESPONSE GBW Gain-bandwidth product G = +1 18 SR Slew rate G = –1 10 MHz V/μs Full power bandwidth (1) VO = 1 VP 1.6 MHz Overload recovery time G = –10 Channel separation (dual and quad) f = 1 kHz Input voltage noise f = 20 Hz to 20 kHz 5.4 μVPP Input voltage noise density f = 1 kHz 4.5 nV/√Hz Input current noise density f = 1 kHz 0.5 pA/√Hz 1 μs –120 dB NOISE en In OFFSET VOLTAGE VOS Input offset voltage PSRR Power-supply rejection ratio VS = ±2.25 V to ±18 V ±0.5 ±1.5 VS = ±2.25 V to ±18 V, TA = –40°C to +85°C (2) 2 8 μV/°C VS = ±2..25 V to ±18 V 3 8 μV/V mV INPUT BIAS CURRENT IB Input bias current VCM = 0 V ±10 ±100 pA IOS Input offset current VCM = 0 V ±10 ±100 pA INPUT VOLTAGE RANGE VCM Common-mode voltage range (V–) + 0.5 CMRR Common-mode rejection ratio 100 (V+) – 2 110 V dB INPUT IMPEDANCE Differential Common-mode 100 || 6 MΩ || pF 6000 || 2 GΩ || pF OPEN-LOOP GAIN Open-loop voltage gain (V–) + 0.8 V ≤ VO ≤ (V+) – 0.8 V, RL = 2 kΩ VOUT Voltage output RL = 2 kΩ IOUT Output current ZO Open-loop output impedance ISC Short-circuit current (3) ±50 mA CLOAD Capacitive load drive 100 pF AOL 106 114 dB OUTPUT (V+) – 0.8 (V–) + 0.8 See Typical Characteristics f = 1 MHz V mA Ω See Typical Characteristics POWER SUPPLY VS IQ (1) (2) (3) ±2.25 Specified voltage Quiescent current (per channel) IOUT = 0 A IOUT = 0 A, TA = –40°C to +85°C (2) 2.0 ±18 V 2.5 mA 2.8 mA Full-power bandwidth = SR/(2π × VP), where SR = slew rate. Specified by design and characterization. One channel at a time. 3 Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA1652 OPA1654 OPA1652 OPA1654 SBOS477 – DECEMBER 2011 www.ti.com ELECTRICAL CHARACTERISTICS: VS = ±15 V (continued) At TA = +25°C, RL = 2 kΩ, and VCM = VOUT = midsupply, unless otherwise noted. OPA1652, OPA1654 PARAMETER TEST CONDITIONS MIN TYP MAX UNIT TEMPERATURE Specified range –40 +85 °C Operating range –55 +125 °C THERMAL INFORMATION: OPA1652 OPA1652 THERMAL METRIC (1) D (SO) DGK (MSOP) 8 PINS 8 PINS θJA Junction-to-ambient thermal resistance 143.6 218.9 θJCtop Junction-to-case (top) thermal resistance 76.9 78.6 θJB Junction-to-board thermal resistance 61.8 103.7 ψJT Junction-to-top characterization parameter 27.8 14.6 ψJB Junction-to-board characterization parameter 61.3 101.8 θJCbot Junction-to-case (bottom) thermal resistance N/A N/A (1) UNITS °C/W For more information about traditional and new thermal metrics, see the IC Package Thermal Metrics application report, SPRA953. THERMAL INFORMATION: OPA1654 OPA1654 THERMAL METRIC (1) D (SO) PW (TSSOP) 14 PINS 14 PINS θJA Junction-to-ambient thermal resistance 90.1 126.9 θJCtop Junction-to-case (top) thermal resistance 54.8 46.6 θJB Junction-to-board thermal resistance 44.4 58.6 ψJT Junction-to-top characterization parameter 19.9 5.5 ψJB Junction-to-board characterization parameter 44.2 57.8 θJCbot Junction-to-case (bottom) thermal resistance N/A N/A (1) UNITS °C/W For more information about traditional and new thermal metrics, see the IC Package Thermal Metrics application report, SPRA953. 4 Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA1652 OPA1654 OPA1652 OPA1654 SBOS477 – DECEMBER 2011 www.ti.com TYPICAL CHARACTERISTICS At TA = +25°C, VS = ±15 V, and RL = 2 kΩ, unless otherwise noted. INPUT VOLTAGE NOISE DENSITY vs FREQUENCY 0.1Hz TO 10Hz NOISE Voltage Noise (500 nV/div) Voltage Noise (nV/ Hz) 100 10 1 1 10 100 1k Frequency (Hz) 10k 100k Time (1 s/div) Figure 1. Figure 2. VOLTAGE NOISE vs SOURCE RESISTANCE MAXIMUM OUTPUT VOLTAGE vs FREQUENCY 20 10k E2o = e2n + (inRS)2 + 4KTRS 18 RS Output Voltage (V) Voltage Noise (nV/ Hz) EO 1k G002 G001 OPA166x 100 OPA165x 10 VS = ± 15 V 15 12 10 8 5 VS = ± 2.25 V 2 Resistor Noise 1 100 1k 10k 100k 0 10k 1M Source Resistance (W) 100k 1M Frequency (Hz) G003 Figure 3. G004 Figure 4. GAIN AND PHASE vs FREQUENCY CLOSED-LOOP GAIN vs FREQUENCY 180 140 40 Gain Phase 120 Gain = −1 V/V Gain = +1 V/V Gain = +10 V/V 135 100 90 60 40 0 45 20 Gain (dB) 20 80 Phase (°) Gain (dB) 10M 0 CL = 10 pF −20 10 100 1k 10k 100k Frequency (Hz) 1M 10M 0 100M G005 CL = 10 pF −20 100k 1M 10M Frequency (Hz) Figure 5. 100M G006 Figure 6. 5 Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA1652 OPA1654 OPA1652 OPA1654 SBOS477 – DECEMBER 2011 www.ti.com TYPICAL CHARACTERISTICS (continued) At TA = +25°C, VS = ±15 V, and RL = 2 kΩ, unless otherwise noted. THD+N RATIO vs FREQUENCY G = 10 V/V, RL = 600 Ω G = 10 V/V, RL = 2 kΩ G = +1 V/V, RL = 600 Ω G = +1 V/V, RL = 2 kΩ G = −1 V/V, RL = 600 Ω G = −1 V/V, RL = 2 kΩ 0.001 THD+N RATIO vs FREQUENCY 0.01 VOUT = 3 VRMS BW = 80 kHz -15V 0.0001 0.00001 VOUT = 3 VRMS BW = 80 kHz +15V RL 0.001 0.0001 20 100 1k Frequency (Hz) 10k 0.00001 20k 20 100 1k Frequency (Hz) G007 Figure 7. VOUT = 3 VRMS BW = 500 kHz VOUT = 3 VRMS BW = 500 kHz +15V RS = 0 W RS = 30 W RS = 60 W RS = 1 kW RSOURCE OPA1652 -15V THD+N (%) THD+N (%) G008 THD+N RATIO vs FREQUENCY 0.0001 0.001 RL 0.0001 20 100 1k Frequency (Hz) 10k 0.00001 100k 1k Frequency (Hz) 10k 100k G010 Figure 10. THD+N RATIO vs OUTPUT AMPLITUDE INTERMODULATION DISTORTION vs OUTPUT AMPLITUDE 0.01 DIM 30: 3 kHz − Square Wave, 15 kHz Sine Wave CCIF Twin Tone: 19 kHz and 20 kHz SMPTE / DIN: Two −Tone 4:1, 60 Hz and 7 KHz THD+N (%) 0.001 0.00001 1m 100 Figure 9. f = 1 kHz BW = 80 kHz RS = 0 Ω 0.0001 20 G009 0.01 THD+N (%) 20k 0.01 G = 10 V/V, RL = 600 Ω G = 10 V/V, RL = 2 kΩ G = +1 V/V, RL = 600 Ω G = +1 V/V, RL = 2 kΩ G = −1 V/V, RL = 600 Ω G = −1 V/V, RL = 2 kΩ 0.001 10k Figure 8. THD+N RATIO vs FREQUENCY 0.01 0.00001 RS = 0 W RS = 30 W RS = 60 W RS = 1 kW RSOURCE OPA1652 THD+N (%) THD+N (%) 0.01 G = 10 V/V, RL = 600 Ω G = 10 V/V, RL = 2 kΩ G = +1 V/V, RL = 600 Ω G = +1 V/V, RL = 2 kΩ G = −1 V/V, RL = 600 Ω G = −1 V/V, RL = 2 kΩ 10m 0.001 0.0001 100m 1 Output Amplitude (Vrms) 10 20 G = +1 V/V 0.00001 100m G011 Figure 11. 1 Output Amplitude (Vrms) 10 20 G012 Figure 12. 6 Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA1652 OPA1654 OPA1652 OPA1654 SBOS477 – DECEMBER 2011 www.ti.com TYPICAL CHARACTERISTICS (continued) At TA = +25°C, VS = ±15 V, and RL = 2 kΩ, unless otherwise noted. CHANNEL SEPARATION vs FREQUENCY CMRR AND PSRR vs FREQUENCY (Referred to Input) 140 −80 VOUT = 3 VRMS Gain = +1 V/V 120 CMRR, PSRR (dB) Crosstalk (dB) −100 −120 −140 100 80 60 40 20 −160 100 1k 10k 0 100 100k Frequency (Hz) 1k G013 10k 100k 1M Frequency (Hz) 10M 100M G014 Figure 13. Figure 14. SMALL-SIGNAL STEP RESPONSE (100mV) SMALL-SIGNAL STEP RESPONSE (100mV) VIN VOUT Voltage (25 mV/div) Voltage (25 mV/div) VIN VOUT G = −1 V/V CL = 100 pF G = +1 V/V CL = 100 pF Time (0.2 ms/div) Time (0.2 ms/div) G015 G016 Figure 15. Figure 16. LARGE-SIGNAL STEP RESPONSE LARGE-SIGNAL STEP RESPONSE VIN VOUT G = + 1V/V RF = 2 kW CL = 100 pF Time (1 ms/div) G = −1 V/V CL = 100 pF Voltage (2.5 V/div) VIN VOUT Voltage (2.5 V/div) +PSRR −PSRR CMRR G017 Figure 17. Time (1 ms/div) G018 Figure 18. 7 Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA1652 OPA1654 OPA1652 OPA1654 SBOS477 – DECEMBER 2011 www.ti.com TYPICAL CHARACTERISTICS (continued) At TA = +25°C, VS = ±15 V, and RL = 2 kΩ, unless otherwise noted. SMALL-SIGNAL OVERSHOOT vs CAPACITIVE LOAD 50 50 RS = 0 W RS = 25 W RS = 50 W 45 40 35 RS OPA1652 30 VOUT = 100 mVPP G = +1 V/V 20 RL -15 V CL 25 10 5 5 100 150 200 250 Capacitance (pF) 300 350 VOUT = 100 mVPP G = −1 V/V 20 15 50 CL -15 V 30 10 0 RS OPA1652 35 15 0 RS = 0 W RS = 25 W RS = 50 W RF = 2 kW +15 V 40 +15 V 25 RI = 2 kW 45 Overshoot (%) Overshoot (%) SMALL-SIGNAL OVERSHOOT vs CAPACITIVE LOAD 0 400 0 50 100 150 200 250 Capacitance (pF) G019 Figure 19. 300 350 400 G020 Figure 20. SMALL-SIGNAL OVERSHOOT vs FEEDBACK CAPACITOR (100mV Output Step) OPEN-LOOP GAIN vs TEMPERATURE 4 25 VOUT = 100 mVPP G = −1 V/V RS = 0 W 20 CF RI = 2 kW RF = 2 kW 3 RS OPA1652 15 AOL (µV) Overshoot (%) +15 V CL -15 V 10 2 1 0 5 RL = 2 kΩ 0 0 1 2 3 Capacitance (pF) 4 −1 −40 5 −15 G021 Figure 21. IB AND IOS vs TEMPERATURE 110 135 G022 IB AND IOS vs COMMON-MODE VOLTAGE Ibn Ibp Ios Ibp Ibn Ios 6 0 −400 −800 −1200 −1600 −2000 −40 85 8 Ib and Ios Current (pA) Ib and Ios Current (pA) 400 35 60 Temperature (°C) Figure 22. 1200 800 10 4 2 0 −2 −4 −6 −15 10 35 60 Temperature (°C) 85 110 135 G023 −8 −18 −15 −12 −9 −6 −3 0 3 6 9 Common − Mode Voltage (V) Figure 23. 12 15 18 G024 Figure 24. 8 Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA1652 OPA1654 OPA1652 OPA1654 SBOS477 – DECEMBER 2011 www.ti.com TYPICAL CHARACTERISTICS (continued) At TA = +25°C, VS = ±15 V, and RL = 2 kΩ, unless otherwise noted. SUPPLY CURRENT vs SUPPLY VOLTAGE 3 2.5 2.5 Supply Current (mA) Supply Current (mA) SUPPLY CURRENT vs TEMPERATURE 3 2 1.5 1 2 1.5 1 0.5 0.5 0 −40 −15 10 35 60 Temperature (°C) 85 110 0 135 0 4 8 12 16 20 24 Supply Voltage (V) G025 Figure 25. 30 80 G026 +Isc −Isc 60 20 40 10 0 −40 C −25 C 0C 25 C 85 C 125 C −10 −20 −30 0 5 10 15 20 25 30 35 40 Output Current (mA) 45 50 55 20 0 −20 −40 −60 −80 60 −100 −40 −15 10 G029 Figure 27. 35 60 Temperature (°C) 85 110 135 G028 Figure 28. PHASE MARGIN vs CAPACITIVE LOAD PERCENT OVERSHOOT vs CAPACITIVE LOAD 90 50 G = +1 V/V 80 G = +1 V/V VIN = 100 mVPP 40 70 60 Overshoot (%) Phase Margin (°) 36 SHORT-CIRCUIT CURRENT vs TEMPERATURE 100 Isc (mA) Output Volage Swing (V) OUTPUT VOLTAGE vs OUTPUT CURRENT 50 40 30 20 30 20 10 VS = ± 2.25 V VS = ± 18 V 10 0 32 Figure 26. 40 −40 28 0 50 100 150 200 250 Capacitance (pF) 300 350 400 0 0 50 G031 Figure 29. 100 150 200 250 Capacitance (pF) 300 350 400 G032 Figure 30. 9 Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA1652 OPA1654 OPA1652 OPA1654 SBOS477 – DECEMBER 2011 www.ti.com TYPICAL CHARACTERISTICS (continued) At TA = +25°C, VS = ±15 V, and RL = 2 kΩ, unless otherwise noted. NEGATIVE OVERLOAD RECOVERY POSITIVE OVERLOAD RECOVERY 20 kW VIN VOUT 20 kW +18 V 2 kW +18 V 2 kW OPA1652 Output Voltage (5 V/div) Output Voltage (5 V/div) G = −10 V/V VOUT VIN -18 V G = -10 VIN VOUT VOUT OPA1652 VIN -18 V G = −10 V/V G = -10 Time (0.4 ms/div) Time (0.4 ms/div) G033 Figure 31. OPEN-LOOP OUTPUT IMPEDANCE vs FREQUENCY NO PHASE REVERSAL 1k 20 +18 V 15 Voltage (V) 10 Impedance (Ω) G027 Figure 32. 100 5 G = +1 V/V OPA1652 -18 V 37VPP Sine Wave (±18.5 V) 0 −5 −10 VIN VOUT −15 10 10 100 1k 10k 100k Frequency (Hz) 1M 10M 100M −20 G030 Figure 33. Time (125 ms/div) G034 Figure 34. 10 Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA1652 OPA1654 OPA1652 OPA1654 SBOS477 – DECEMBER 2011 www.ti.com APPLICATION INFORMATION The OPA1652 and OPA1654 are unity-gain stable, precision dual and quad op amps with very low noise. Applications with noisy or high-impedance power supplies require decoupling capacitors close to the device pins. In most cases, 0.1-μF capacitors are adequate. Figure 35 shows a simplified schematic of the OPA165x (one channel shown). OPERATING VOLTAGE The OPA165x series op amps operate from ±2.25 V to ±18 V supplies while maintaining excellent performance. The OPA165x series can operate with as little as +4.5V between the supplies and with up to +36 V between the supplies. However, some applications do not require equal positive and negative output voltage swing. With the OPA165x series, power-supply voltages do not need to be equal. For example, the positive supply could be set to +25 V with the negative supply at –5 V. In all cases, the common-mode voltage must be maintained within the specified range. In addition, key parameters are assured over the specified temperature range of TA = –40°C to +85°C. Parameters that vary significantly with operating voltage or temperature are shown in the Typical Characteristics. V+ Tail Current VBIAS1 VIN+ Class AB Control Circuitry VO VINVBIAS2 V- Figure 35. OPA165x Simplified Schematic 11 Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA1652 OPA1654 OPA1652 OPA1654 SBOS477 – DECEMBER 2011 www.ti.com The input terminals of the OPA1652 and OPA1654 are protected from excessive differential voltage with back-to-back diodes, as Figure 36 illustrates. In most circuit applications, the input protection circuitry has no consequence. However, in low-gain or G = +1 circuits, fast ramping input signals can forward bias these diodes because the output of the amplifier cannot respond rapidly enough to the input ramp. If the input signal is fast enough to create this forward bias condition, the input signal current must be limited to 10 mA or less. If the input signal current is not inherently limited, an input series resistor (RI) and/or a feedback resistor (RF) can be used to limit the signal input current. This resistor degrades the low-noise performance of the OPA165x and is examined in the following Noise Performance section. Figure 36 shows an example configuration when both current-limiting input and feeback resistors are used. The equation in Figure 37 shows the calculation of the total circuit noise, with these parameters: • en = Voltage noise • in = Current noise • RS = Source impedance • k = Boltzmann’s constant = 1.38 × 10–23 J/K • T = Temperature in Kelvins (K) 10k E2o = e2n + (inRS)2 + 4KTRS Voltage Noise (nV/ Hz ) INPUT PROTECTION 1k OPA166X 100 OPA165X 10 Resistor Noise 1 100 RF 1k 10k Source Resistance (Ω) OPA165x Input 1M G003 Figure 37. Noise Performance of the OPA165x in Unity-Gain Buffer Configuration - RI 100k Output BASIC NOISE CALCULATIONS + Figure 36. Pulsed Operation NOISE PERFORMANCE Figure 37 shows the total circuit noise for varying source impedances with the op amp in a unity-gain configuration (no feedback resistor network, and therefore no additional noise contributions). The OPA165x (GBW = 18 MHz, G = +1) is shown with total circuit noise calculated. The op amp itself contributes both a voltage noise component and a current noise component. The voltage noise is commonly modeled as a time-varying component of the offset voltage. The current noise is modeled as the time-varying component of the input bias current and reacts with the source resistance to create a voltage component of noise. Therefore, the lowest noise op amp for a given application depends on the source impedance. For low source impedance, current noise is negligible, and voltage noise generally dominates. The voltage noise of the OPA165x series op amps makes them a better choice for source impedances greater than or equal to 1 kΩ. Design of low-noise op amp circuits requires careful consideration of a variety of possible noise contributors: noise from the signal source, noise generated in the op amp, and noise from the feedback network resistors. The total noise of the circuit is the root-sum-square combination of all noise components. The resistive portion of the source impedance produces thermal noise proportional to the square root of the resistance. Figure 37 plots this equation. The source impedance is usually fixed; consequently, select the op amp and the feedback resistors to minimize the respective contributions to the total noise. Figure 38 illustrates both inverting and noninverting op amp circuit configurations with gain. In circuit configurations with gain, the feedback network resistors also contribute noise. The current noise of the op amp reacts with the feedback resistors to create additional noise components. The feedback resistor values can generally be chosen to make these noise sources negligible. The equations for total noise are shown for both configurations. 12 Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA1652 OPA1654 OPA1652 OPA1654 SBOS477 – DECEMBER 2011 www.ti.com A) Noise in Noninverting Gain Configuration Noise at the output: R2 2 R2 EO2 = 1 + R1 R1 2 en2 + R2 R1 2 e12 + e22 + 1 + R2 R1 es2 EO RS Where eS = 4kTRS = thermal noise of RS e1 = 4kTR1 = thermal noise of R1 e2 = 4kTR2 = thermal noise of R2 VS B) Noise in Inverting Gain Configuration Noise at the output: R2 2 R2 2 EO = 1 + R1 RS e n2 + R 1 + RS e12 + e22 + 2 R2 R 1 + RS e s2 EO VS Note: R1 + RS 2 R2 Where eS = 4kTRS = thermal noise of RS e1 = 4kTR1 = thermal noise of R1 e2 = 4kTR2 = thermal noise of R2 For the OPA165x series of op amps at 1kHz, en = 4.5nV/√Hz. Figure 38. Noise Calculation in Gain Configurations 13 Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA1652 OPA1654 OPA1652 OPA1654 SBOS477 – DECEMBER 2011 www.ti.com TOTAL HARMONIC DISTORTION MEASUREMENTS The OPA165x series op amps have excellent distortion characteristics. THD + noise is below 0.0002% (G = +1, VO = 3 VRMS, BW = 80 kHz) throughout the audio frequency range, 20 Hz to 20 kHz, with a 2-kΩ load (see Figure 7 for characteristic performance). The distortion produced by the OPA165x series op amps is below the measurement limit of many commercially available distortion analyzers. However, a special test circuit (such as Figure 39 shows) can be used to extend the measurement capabilities. Op amp distortion can be considered an internal error source that can be referred to the input. Figure 39 shows a circuit that causes the op amp distortion to be gained up (refer to the table in Figure 39 for the distortion gain factor for various signal gains). The addition of R3 to the otherwise standard noninverting amplifier configuration alters the feedback factor or noise gain of the circuit. The closed-loop gain is unchanged, but the feedback available for error correction is reduced by the distortion gain factor, thus extending the resolution by the same amount. Note that the input signal and load applied to the op amp are the same as with conventional feedback without R3. The value of R3 should be kept small to minimize its effect on the distortion measurements. R1 The validity of this technique can be verified by duplicating measurements at high gain and/or high frequency where the distortion is within the measurement capability of the test equipment. Measurements for this data sheet were made with an Audio Precision System Two distortion/noise analyzer, which greatly simplifies such repetitive measurements. The measurement technique can, however, be performed with manual distortion measurement instruments. CAPACITIVE LOADS The dynamic characteristics of the OPA1652 and OPA1654 have been optimized for commonly encountered gains, loads, and operating conditions. The combination of low closed-loop gain and high capacitive loads decreases the phase margin of the amplifier and can lead to gain peaking or oscillations. As a result, heavier capacitive loads must be isolated from the output. The simplest way to achieve this isolation is to add a small resistor (RS equal to 50 Ω, for example) in series with the output. This small series resistor also prevents excess power dissipation if the output of the device becomes shorted. Figure 19 illustrates a graph of Small-Signal Overshoot vs Capacitive Load for several values of RS. Also, refer to Applications Bulletin AB-028 (literature number SBOA015, available for download from the TI web site) for details of analysis techniques and application circuits. R2 SIGNAL DISTORTION GAIN GAIN R3 Signal Gain = 1+ OPA165x VO = 3 VRMS R2 R1 Distortion Gain = 1+ R2 R1 II R3 Generator Output R1 R2 R3 ¥ 1 kW 10 W +1 101 -1 101 4.99 kW 4.99 kW 49.9 W +10 110 549 W 4.99 kW 49.9 W Analyzer Input Audio Precision System Two(1) with PC Controller Load (1) For measurement bandwidth, see Figure 7 through Figure 12. Figure 39. Distortion Test Circuit 14 Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA1652 OPA1654 OPA1652 OPA1654 SBOS477 – DECEMBER 2011 www.ti.com POWER DISSIPATION The OPA1652 and OPA1654 series op amps are capable of driving 2-kΩ loads with a power-supply voltage up to ±18V and full operating temperature range. Internal power dissipation increases when operating at high supply voltages. Copper leadframe construction used in the OPA165x series op amps improves heat dissipation compared to conventional materials. Circuit board layout can also help minimize junction temperature rise. Wide copper traces help dissipate the heat by acting as an additional heat sink. Temperature rise can be further minimized by soldering the devices to the circuit board rather than using a socket. ELECTRICAL OVERSTRESS Designers often ask questions about the capability of an operational amplifier to withstand electrical overstress. These questions tend to focus on the device inputs, but may involve the supply voltage pins or even the output pin. Each of these different pin functions have electrical stress limits determined by the voltage breakdown characteristics of the particular semiconductor fabrication process and specific circuits connected to the pin. Additionally, internal electrostatic discharge (ESD) protection is built into these circuits to protect them from accidental ESD events both before and during product assembly. These ESD protection diodes also provide in-circuit, input overdrive protection, as long as the current is limited to 10 mA as stated in the Absolute Maximum Ratings. Figure 40 shows how a series input resistor may be added to the driven input to limit the input current. The added resistor contributes thermal noise at the amplifier input and its value should be kept to a minimum in noise-sensitive applications. V+ IOVERLOAD 10 mA max Device VOUT VIN 5 kW Figure 40. Input Current Protection An ESD event produces a short duration, high-voltage pulse that is transformed into a short duration, high-current pulse as it discharges through a semiconductor device. The ESD protection circuits are designed to provide a current path around the operational amplifier core to prevent it from being damaged. The energy absorbed by the protection circuitry is then dissipated as heat. When the operational amplifier connects into a circuit, the ESD protection components are intended to remain inactive and not become involved in the application circuit operation. However, circumstances may arise where an applied voltage exceeds the operating voltage range of a given pin. Should this condition occur, there is a risk that some of the internal ESD protection circuits may be biased on, and conduct current. Any such current flow occurs through ESD cells and rarely involves the absorption device. If there is an uncertainty about the ability of the supply to absorb this current, external zener diodes may be added to the supply pins. The zener voltage must be selected such that the diode does not turn on during normal operation. However, its zener voltage should be low enough so that the zener diode conducts if the supply pin begins to rise above the safe operating supply voltage level. 15 Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA1652 OPA1654 OPA1652 OPA1654 SBOS477 – DECEMBER 2011 www.ti.com APPLICATION CIRCUIT An additional application idea is shown in Figure 41. 820 W 2200 pF +VA (+15 V) 0.1 mF 330 W IOUTL+ OPA165x 2700 pF -VA (-15 V) 680 W 620 W Audio DAC with Differential Current Outputs 0.1 mF +VA (+15 V) 0.1 mF 100 W 820 W OPA165x 8200 pF 2200 pF +VA (+15 V) L Ch Output -VA (-15 V) 0.1 mF 0.1 mF 680 W 620 W IOUTLOPA165x 330 W 2700 pF -VA (-15 V) 0.1 mF Figure 41. Audio DAC I/V Converter and Output Filter 16 Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA1652 OPA1654 PACKAGE OPTION ADDENDUM www.ti.com 28-Mar-2012 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Drawing Pins Package Qty Eco Plan (2) Lead/ Ball Finish MSL Peak Temp (3) OPA1652AID ACTIVE SOIC D 8 75 Green (RoHS & no Sb/Br) OPA1652AIDGK ACTIVE MSOP DGK 8 80 Green (RoHS & no Sb/Br) CU NIPDAUAGLevel-1-260C-UNLIM OPA1652AIDGKR ACTIVE MSOP DGK 8 2500 Green (RoHS & no Sb/Br) CU NIPDAUAGLevel-1-260C-UNLIM OPA1652AIDR ACTIVE SOIC D 8 2500 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR OPA1654AID ACTIVE SOIC D 14 50 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR OPA1654AIDR ACTIVE SOIC D 14 2500 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR OPA1654AIPW ACTIVE TSSOP PW 14 90 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR OPA1654AIPWR ACTIVE TSSOP PW 14 2000 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR Samples (Requires Login) CU NIPDAU Level-2-260C-1 YEAR (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability information and additional product content details. TBD: The Pb-Free/Green conversion plan has not been defined. Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes. Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above. Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material) (3) MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature. Addendum-Page 1 PACKAGE OPTION ADDENDUM www.ti.com 28-Mar-2012 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. TI has taken and continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release. In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis. Addendum-Page 2 PACKAGE MATERIALS INFORMATION www.ti.com 19-Apr-2012 TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Pins Type Drawing OPA1652AIDGKR MSOP DGK OPA1652AIDR SOIC OPA1654AIDR SOIC OPA1654AIPWR TSSOP SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant 8 2500 330.0 12.4 5.3 3.4 1.4 8.0 12.0 Q1 D 8 2500 330.0 12.4 6.4 5.2 2.1 8.0 12.0 Q1 D 14 2500 330.0 16.4 6.5 9.0 2.1 8.0 16.0 Q1 PW 14 2000 330.0 12.4 6.9 5.6 1.6 8.0 12.0 Q1 Pack Materials-Page 1 PACKAGE MATERIALS INFORMATION www.ti.com 19-Apr-2012 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) OPA1652AIDGKR MSOP DGK 8 2500 364.0 364.0 27.0 OPA1652AIDR SOIC D 8 2500 346.0 346.0 29.0 OPA1654AIDR SOIC D 14 2500 346.0 346.0 33.0 OPA1654AIPWR TSSOP PW 14 2000 346.0 346.0 29.0 Pack Materials-Page 2 IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time and to discontinue any product or service without notice. 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