OPA835 OPA2835 SLOS713D – JANUARY 2011 – REVISED OCTOBER 2011 www.ti.com Ultra Low-Power, Rail-to-Rail Out, Negative Rail In, VFB Op Amp Check for Samples: OPA835, OPA2835 FEATURES DESCRIPTION • Fabricated using the industry-leading BiCom-3x (SiGe complimentary bipolar) process, the OPA835 and OPA2835 are single and dual ultra low-power, rail-to-rail output, negative rail input, voltage-feedback operational amplifiers designed to operate over a power supply range of 2.5 V to 5.5 V Single Supply and ±1.25 V to ±2.75 V dual supply. Consuming only 250 µA per channel and a unity gain bandwidth of 56MHz, these amplifiers set an industry leading power-to-performance ratio for rail-to-rail amplifiers. 1 • • • • • • • • • • • • • • • Ultra Low Power – Supply Voltage: 2.5 V to 5.5 V – Quiescent Current: 250 µA (typ) – Power Down Mode: 0.5 µA (typ) Bandwidth: 56 MHz Slew Rate: 160 V/µs Rise Time: 10 ns (2 VSTEP) Settling Time: 45 ns (2VSTEP) Overdrive Recovery Time: 195ns SNR: 0.00015% (–116.4dBc) at 1 kHz (1V RMS) THD: 0.00003% (–130 dBc) at 1 kHz (1 VRMS) HD2/HD3: –70 dBc/–73 dBc at 1 MHz (2 Vpp) Input Voltage Noise: 9.3 nV/rtHz (f = 100 kHz) Input Offset Voltage: 100 µV (500 µV max) CMRR: 113 dB Output Current Drive: 40 mA RRO – Rail-to-Rail Output Input Voltage Range: –0.2 V to 3.9 V (5 V supply) Operating Temperature Range: –40°C–125°C APPLICATIONS • • • • • • • Low Power Signal Conditioning Audio ADC Input Buffer Low Power SAR and ΔΣ ADC Driver Portable Systems Low Power Systems High Density Systems Ultrasonic Flow Meter For battery powered portable applications where power is of key importance, the OPA835's and OPA2835's low power consumption and high frequency performance offers designers performance versus power not attainable in other devices. Coupled with a power savings mode to reduce current to <1.5 μA, the device offers an attractive solution for high frequency amplifiers in battery powered applications. The OPA835 and OPA2835 are offered in following package options: • OPA835 Single: SOT23-6 (DBV), and 10 pin WQFN (RUN) with integrated gain resistors. • OPA2835 Dual: SOIC-8 (D), VSSOP (MSOP) -10 (DGS), and 10 pin WQFN (RUN). The OPA835 RUN package option includes integrated gain setting resistors for smallest possible footprint on a printed circuit board (≈ 2mm x 2mm). By adding circuit traces on the PCB, gains of +1, -1, -1.33, +2, +2.33, -3, +4, -4, +5, -5.33, +6.33, -7, +8 and inverting attenuations of -0.1429, -0.1875, -0.25, -0.33, -0.75 can be achieved. See Application Information section for details. The devices are characterized for operation over the extended industrial temperature range –40°C to 125°C. OPA835 Related Products 0 -20 VSIG 0V 2.7V 4.02k 1.35V 5V 2k SINGLES DUALS TRIPLES QUADS — OPA2830 — OPA4830 Rail-to-Rail, Low Power OPA836 OPA2836 — — Rail-to-Rail, Fixed Gain OPA832 OPA2832 OPA3832 — General-Purpose, High Slew Rate OPA690 OPA2690 OPA3690 — Low-Noise, DC Precision OPA820 OPA2822 — OPA4820 Rail-to-Rail 100 OPA835 4.02k V S- AIN - dBc 2.5V V S+ VIN -40 DESCRIPTION 2.7V VSIG +In VDD 2.2nF REF ADS8326 -In -60 2k 2k -80 -100 -120 -140 0 20,000 40,000 60,000 80,000 Frequency (Hz) 100,000 120,000 1 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. 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 OPA835 OPA2835 SLOS713D – JANUARY 2011 – REVISED OCTOBER 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. PACKAGING/ORDERING INFORMATION (1) PRODUCT CHANNEL COUNT PACKAGE – LEAD PACKAGE DESIGNATOR SPECIFIED TEMPERATURE RANGE PACKAGE MARKING OPA835 1 SOT23-6 DBV –40°C to 125°C QUM OPA835IDBVT TAPE and REEL, 250 OPA835 1 SOT23-6 DBV –40°C to 125°C QUM OPA835IDBVR TAPE and REEL, 3000 OPA835 1 WQFN-10 RUN –40°C to 125°C 835 OPA835IRUNT TAPE and REEL, 250 OPA835 1 WQFN-10 RUN –40°C to 125°C 835 OPA835IRUNR TAPE and REEL, 3000 OPA2835 2 SOIC-8 D –40°C to 125°C 2835 OPA2835ID RAIL, 75 OPA2835 2 SOIC-8 D –40°C to 125°C 2835 OPA2835IDR TAPE and REEL, 2500 OPA2835 2 VSSOP-10 DGS –40°C to 125°C 2835 OPA2835IDGS RAIL, 80 OPA2835 2 VSSOP-10 DGS –40°C to 125°C 2835 OPA2835IDGSR TAPE and REEL, 2500 OPA2835 2 WQFN-10 RUN –40°C to 125°C 2835 OPA2835IRUNT TAPE and REEL, 250 OPA2835 2 WQFN-10 RUN –40°C to 125°C 2835 OPA2835IRUNR TAPE and REEL, 3000 (1) ORDERING NUMBER TRANSPORT MEDIA, QUANTITY 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 UNITS VS– to VS+ Supply voltage VI Input voltage 5.5 VID Differential input voltage 1V II Continuous input current 0.85 mA IO Continuous output current VS– - 0.7V to VS+ + 0.7V 60 mA Continuous power dissipation See Thermal Characteristics Specification TJ Maximum junction temperature TA Operating free-air temperature range –40°C to 125°C 150°C Tstg Storage temperature range –65°C to 150°C HBM 6 kV ESD ratings CDM 1 kV MM 200 V THERMAL INFORMATION THERMAL METRIC (1) OPA835 OPA835 OPA2835 OPA2835 OPA2835 SOT23-6 (DBV) WQFN-10 (RUN) SOT23-6 (D) VSSOP (MSOP) - 10 (DGS) WQFN-10 (RUN) 6 PINS 10 PINS 8 PINS 10 PINS 10 PINS 194 145.8 150.1 206 145.8 θJA Junction-to-ambient thermal resistance θJCtop Junction-to-case (top) thermal resistance 129.2 75.1 83.8 75.3 75.1 θJB Junction-to-board thermal resistance 39.4 38.9 68.4 96.2 38.9 ψJT Junction-to-top characterization parameter 25.6 13.5 33.0 12.9 13.5 ψJB Junction-to-board characterization parameter 38.9 104.5 67.9 94.6 104.5 θJCbot Junction-to-case (bottom) thermal resistance n/a n/a n/a n/a n/a (1) 2 UNITS °C/W For more information about traditional and new thermal metrics, see the IC Package Thermal Metrics application report, SPRA953. Submit Documentation Feedback Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA835 OPA2835 OPA835 OPA2835 SLOS713D – JANUARY 2011 – REVISED OCTOBER 2011 www.ti.com SPECIFICATIONS: VS = 2.7 V Test conditions unless otherwise noted: VS+ = +2.7 V, VS– = 0 V, VOUT = 1 VPP, RF = 0 Ω, RL = 2 kΩ, G = 1 V/V, Input and Output Referenced to mid-supply. TA = 25°C. Unless otherwise noted PARAMETER CONDITIONS MIN TYP MAX UNITS TEST LEVEL (1) MHz C AC PERFORMANCE Small-signal bandwidth VOUT = 100 mVPP, G = 1 51 VOUT = 100 mVPP, G = 2 22.5 VOUT = 100 mVPP, G = 5 7.2 VOUT = 100 mVPP, G = 10 3 Gain-bandwidth product VOUT = 100 mVPP, G = 10 30 MHz C Large-signal bandwidth VOUT = 1 VPP, G = 1 24 MHz C Bandwidth for 0.1dB flatness VOUT = 1 VPP, G = 2 4 MHz C 110/130 V/µs C Slew rate, Rise/Fall Rise/Fall time 9.5/9 ns C Settling time to 1%, Rise/Fall 35/30 ns C 60/65 ns C Settling time to 0.01%, Rise/Fall 120/90 ns C Overshoot/Undershoot 0.5/0.2 % C Settling time to 0.1%, Rise/Fall nd 2 Order Harmonic Distortion 3rd Order Harmonic Distortion VOUT = 1VSTEP, G = 2 f = 10 kHz, VIN_CM = mid-supply – 0.5V -133 f = 100 kHz, VIN_CM = mid-supply – 0.5V -110 f = 1 MHz, VIN_CM = mid-supply – 0.5V -73 f = 10 kHz, VIN_CM = mid-supply – 0.5V -137 f = 100 kHz, VIN_CM = mid-supply – 0.5V -125 C dBc C C C dBc C f = 1 MHz, VIN_CM = mid-supply – 0.5V -78 dBc C 3rd Order Intermodulation Distortion f = 1 MHz, 200 kHz Tone Spacing, VOUT Envelope = 1 VPP, VIN_CM = mid-supply – 0.5V -75 -81 dBc C Input voltage noise f = 100 KHz 9.3 nV/√Hz C 147 Hz C 0.45 pA/√Hz C 14.7 2nd Order Intermodulation Distortion Voltage Noise 1/f corner frequency Input current noise f = 1 MHz Current Noise 1/f corner frequency kHz C 140/125 ns C f = 100 kHz 0.028 Ω C f = 10 kHz -120 dB C Overdrive recovery time, Over/Under Overdrive = 0.5 V Closed-loop output impedance Channel to channel crosstalk (OPA2835) (1) C Test levels (all values set by characterization and simulation): (A) 100% tested at 25°C; over temperature limits by characterization and simulation. (B) Not tested in production; limits set by characterization and simulation. (C) Typical value only for information. Submit Documentation Feedback Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA835 OPA2835 3 OPA835 OPA2835 SLOS713D – JANUARY 2011 – REVISED OCTOBER 2011 www.ti.com SPECIFICATIONS: VS+ = 2.7 V Test conditions unless otherwise noted: VS+ = +2.7 V, VS– = 0 V, VOUT = 1 VPP, RF = 0 Ω, RL = 2 kΩ, G = 1 V/V, Input and Output Referenced to mid-supply. TA = 25°C. Unless otherwise noted PARAMETER CONDITIONS MIN TYP MAX UNITS TEST LEVEL (1) dB A DC PERFORMANCE Open-loop voltage gain (AOL) 100 Input referred offset voltage Input offset voltage drift (2) Input bias current Input offset current Input offset current drift (2) ±500 ±880 TA = 0°C to 70°C TA = –40°C to 85°C ±1040 TA = –40°C to 125°C ±1850 TA = 0°C to 70°C ±1.4 TA = –40°C to 85°C ±1.5 ±9 TA = –40°C to 125°C ±2.25 ±13.5 200 400 A µV B ±8.5 TA = 25°C 50 TA = 0°C to 70°C 47 410 TA = –40°C to 85°C 45 425 TA = –40°C to 125°C 45 530 ±0.25 ±1.4 TA = –40°C to 85°C ±0.175 ±1.05 TA = –40°C to 125°C TA = 0°C to 70°C Input bias current drift (2) 120 ±100 TA = 25°C ±0.185 ±1.1 TA = 25°C ±13 ±100 TA = 0°C to 70°C ±13 ±100 TA = –40°C to 85°C ±13 ±100 TA = –40°C to 125°C ±13 ±100 TA = 0°C to 70°C ±0.205 ±1.230 TA = –40°C to 85°C ±0.155 ±0.940 TA = –40°C to 125°C ±0.155 ±0.940 TA = 25°C, <3dB degradation in CMRR limit –0.2 TA = –40°C to 125°C, <3dB degradation in CMRR limit –0.2 µV/°C B A nA nA/°C B B A nA B nA/°C B 0 V A 0 V B INPUT Common-mode input range low Common-mode input range high TA = 25°C, <3dB degradation in CMRR limit 1.5 1.6 V A TA = –40°C to 125°C, <3dB degradation in CMRR limit 1.5 1.6 V B Common-mode rejection ratio 88 Input impedance common mode Input impedance differential mode dB A 200||1.2 110 kΩ || pF C 200||1 kΩ || pF C OUTPUT Linear output voltage low Linear output voltage high Output saturation voltage, High / Low Linear output current drive (1) (2) 4 TA = 25°C, G = 5 0.15 0.2 V A TA = –40°C to 125°C, G = 5 0.15 0.2 V B V A TA = 25°C, G = 5 2.45 TA = –40°C to 125°C, G = 5 2.45 TA = 25°C, G = 5 TA = 25°C ±25 TA = –40°C to 125°C ±20 2.5 V B 45/13 2.5 mV C ±35 mA A mA B Test levels (all values set by characterization and simulation): (A) 100% tested at 25°C; over temperature limits by characterization and simulation. (B) Not tested in production; limits set by characterization and simulation. (C) Typical value only for information. Input Offset Voltage Drift, Input Bias Current Drift, and Input Offset Current Drift are average values calculated by taking data at the end points, computing the difference, and dividing by the temperature range. Submit Documentation Feedback Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA835 OPA2835 OPA835 OPA2835 SLOS713D – JANUARY 2011 – REVISED OCTOBER 2011 www.ti.com SPECIFICATIONS: VS+ = 2.7 V (continued) Test conditions unless otherwise noted: VS+ = +2.7 V, VS– = 0 V, VOUT = 1 VPP, RF = 0 Ω, RL = 2 kΩ, G = 1 V/V, Input and Output Referenced to mid-supply. TA = 25°C. Unless otherwise noted PARAMETER CONDITIONS MIN TYP MAX UNITS TEST LEVEL (1) GAIN SETTING RESISTORS (OPA835IRUN ONLY) Resistor FB1 to FB2 DC resistance 2376 2400 2424 Ω A Resistor FB2 to FB3 DC resistance 1782 1800 1818 Ω A Resistor FB3 to FB4 DC resistance 594 600 606 Ω A Resistor Tolerance DC resistance ±1 % A Resistor Temperature Coefficient DC resistance PPM C <10 POWER SUPPLY Specified operating voltage Quiescent operating current per amplifer 2.5 TA = 25°C 175 TA = –40°C to 125°C 135 Power supply rejection (±PSRR) 88 245 5.5 V B 340 µA A 345 µA B dB A V A V A 105 POWER DOWN (PIN MUST BE DRIVEN) Enable voltage threshold Specified "on" above VS–+ 2.1 V Disable voltage threshold Specified "off" below VS–+ 0.7 V Powerdown pin bias current PD = 0.5 V 20 500 nA A Powerdown quiescent current PD = 0.5 V 0.5 1.5 µA A Turn-on time delay Time from PD = high to VOUT = 90% of final value 250 ns C Turn-off time delay Time from PD = low to VOUT = 10% of original value 50 ns C 1.4 0.7 2.1 1.4 Submit Documentation Feedback Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA835 OPA2835 5 OPA835 OPA2835 SLOS713D – JANUARY 2011 – REVISED OCTOBER 2011 www.ti.com SPECIFICATIONS: VS = 5 V Test conditions unless otherwise noted: VS+ = +5 V, VS– = 0 V, VOUT = 2 VPP, RF = 0 Ω, RL = 2 kΩ, G = 1 V/V, Input and Output Referenced to mid-supply. TA = 25°C. Unless otherwise noted. PARAMETER CONDITIONS MIN TYP MAX UNITS TEST LEVEL (1) MHz C AC PERFORMANCE Small-signal bandwidth VOUT = 100 mVPP, G = 1 56 VOUT = 100 mVPP, G = 2 22.5 VOUT = 100 mVPP, G = 5 7.4 VOUT = 100 mVPP, G = 10 3.1 Gain-bandwidth product VOUT = 100 mVPP, G = 10 31 MHz C Large-signal bandwidth VOUT = 2 VPP, G = 1 31 MHz C Bandwidth for 0.1dB flatness VOUT = 2 VPP, G=2 14.5 MHz C 160/260 V/µs C 10/7 ns C 45/45 ns C 50/55 ns C 82/85 ns C 2.5/1.5 % C Slew rate, Rise/Fall Rise/Fall time Settling time to 1%, Rise/Fall Settling time to 0.1%, Rise/Fall VOUT = 2 V Step, G = 2 Settling time to 0.01%, Rise/Fall Overshoot/Undershoot nd 2 Order Harmonic Distortion 3rd Order Harmonic Distortion 2nd Order Intermodulation Distortion 3rd Order Intermodulation Distortion f = 10 kHz –135 f = 100 kHz –105 f = 1 MHz -70 f = 10 kHz –139 f = 100 kHz –122 dBc C C C dBc C f = 1 MHz -73 f = 1 MHz, 200 kHz Tone Spacing, VOUT Envelope = 2 VPP –70 dBc C –83 dBc C Signal to Noise Ratio, SNR f = 1kHz, VOUT = 1 VRMS, 22kHz bandwidth Total Harmonic Distortion, THD f = 1kHz, VOUT = 1 VRMS Input voltage noise f = 100 KHz Voltage Noise 1/f corner frequency Input current noise C f = 1 MHz Current Noise 1/f corner frequency 0.00015 -116.4 0.00003 -130 C % dBc C % C dBc C 9.3 nV/√Hz C 147 Hz C 0.45 pA/√Hz C 14.7 Hz C 195/135 ns C Overdrive recovery time, Over/Under Overdrive = 0.5 V Closed-loop output impedance f = 100 kHz 0.028 Ω C Channel to channel crosstalk (OPA2835) f = 10 kHz -120 dB C (1) 6 Test levels (all values set by characterization and simulation): (A) 100% tested at 25°C; over temperature limits by characterization and simulation. (B) Not tested in production; limits set by characterization and simulation. (C) Typical value only for information. Submit Documentation Feedback Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA835 OPA2835 OPA835 OPA2835 SLOS713D – JANUARY 2011 – REVISED OCTOBER 2011 www.ti.com SPECIFICATIONS: VS = 5 V Test conditions unless otherwise noted: VS+ = +5 V, VS– = 0 V, VO = 2 VPP, RF = 0 Ω, RL = 2 kΩ, G = 1 V/V, Input and Output Referenced to mid-supply. TA = 25°C. Unless otherwise noted. PARAMETER CONDITIONS MIN TYP MAX UNITS TEST LEVEL (1) dB A DC PERFORMANCE Open-loop voltage gain (AOL) 100 Input referred offset voltage Input offset voltage drift (2) Input bias current Input offset current Input offset current drift (2) ±500 ±880 TA = 0°C to 70°C TA = –40°C to 85°C ±1040 TA = –40°C to 125°C ±1850 TA = 0°C to 70°C ±1.4 TA = –40°C to 85°C ±1.5 ±9 TA = –40°C to 125°C ±2.25 ±13.5 200 400 A µV B ±8.5 TA = 25°C 50 TA = 0°C to 70°C 47 410 TA = –40°C to 85°C 45 425 TA = –40°C to 125°C 45 530 ±0.25 ±1.4 TA = –40°C to 85°C ±0.175 ±1.05 TA = –40°C to 125°C TA = 0°C to 70°C Input bias current drift (2) 120 ±100 TA = 25°C ±0.185 ±1.1 TA = 25°C ±13 ±100 TA = 0°C to 70°C ±13 ±100 TA = –40°C to 85°C ±13 ±100 TA = –40°C to 125°C ±13 ±100 TA = 0°C to 70°C ±0.205 ±1.23 TA = –40°C to 85°C ±0.155 ±0.94 TA = –40°C to 125°C ±0.155 ±0.94 TA = 25°C, <3dB degradation in CMRR limit –0.2 TA = –40°C to 125°C, <3dB degradation in CMRR limit –0.2 µV/°C B A nA nA/°C B B A nA B nA/°C B 0 V A 0 V B INPUT Common-mode input range low Common-mode input range high TA = 25°C, <3dB degradation in CMRR limit 3.8 3.9 V A TA = –40°C to 125°C, <3dB degradation in CMRR limit 3.8 3.9 V B 91 113 dB A 200||1.2 kΩ || pF C 200||1 kΩ || pF C Common-mode rejection ratio Input impedance common mode Input impedance differential mode OUTPUT Linear output voltage low Linear output voltage high Output saturation voltage, High / Low Linear output current drive (1) (2) TA = 25°C, G = 5 0.15 0.2 V A TA = –40°C to 125°C, G = 5 0.15 0.2 V B V A TA = 25°C, G = 5 4.75 TA = –40°C to 125°C, G = 5 4.75 TA = 25°C, G = 5 TA = 25°C ±30 TA = –40°C to 125°C ±25 4.8 V B 70/25 4.8 mV C ±40 mA A mA B Test levels (all values set by characterization and simulation): (A) 100% tested at 25°C; over temperature limits by characterization and simulation. (B) Not tested in production; limits set by characterization and simulation. (C) Typical value only for information. Input Offset Voltage Drift, Input Bias Current Drift, and Input Offset Current Drift are average values calculated by taking data at the end points, computing the difference, and dividing by the temperature range. Submit Documentation Feedback Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA835 OPA2835 7 OPA835 OPA2835 SLOS713D – JANUARY 2011 – REVISED OCTOBER 2011 www.ti.com SPECIFICATIONS: VS = 5 V (continued) Test conditions unless otherwise noted: VS+ = +5 V, VS– = 0 V, VO = 2 VPP, RF = 0 Ω, RL = 2 kΩ, G = 1 V/V, Input and Output Referenced to mid-supply. TA = 25°C. Unless otherwise noted. PARAMETER CONDITIONS MIN TYP MAX UNITS TEST LEVEL (1) GAIN SETTING RESISTORS (OPA835IRUN ONLY) Resistor FB1 to FB2 DC resistance 2376 2400 2424 Ω A Resistor FB2 to FB3 DC resistance 1782 1800 1818 Ω A Resistor FB3 to FB4 DC resistance 594 600 606 Ω A Resistor Tolerance DC resistance ±1 % A Resistor Temperature Coefficient DC resistance PPM C <10 POWER SUPPLY Specified operating voltage Quiescent operating current per amplifier 2.5 TA = 25°C 200 TA = –40°C to 125°C 150 Power supply rejection (±PSRR) 90 250 5.5 V B 350 µA A 365 µA B dB A V A V A A 110 POWER DOWN (PIN MUST BE DRIVEN) Enable voltage threshold Specified "on" above VS–+ 2.1 V Disable voltage threshold Specified "off" below VS–+ 0.7 V Powerdown pin bias current PD = 0.5 V Powerdown quiescent current Turn-on time delay Turn-off time delay Time from PD = low to VOUT = 10% of original value 8 1.4 0.7 2.1 1.4 20 500 nA PD = 0.5 V 0.5 1.5 µA A Time from PD = high to VOUT = 90% of final value 200 ns C 60 ns C Submit Documentation Feedback Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA835 OPA2835 OPA835 OPA2835 SLOS713D – JANUARY 2011 – REVISED OCTOBER 2011 www.ti.com DEVICE INFORMATION PIN CONFIGURATIONS OPA835 (TOP VIEW) OPA835 (TOP VIEW) SOT23-6 (DBV) WFQN-10 (RUN) VS+ VOUT 1 6 VS+ VS- 2 5 PD VIN+ 3 4 VIN- VOUT 1 VIN- 2 VIN+ 3 PD 4 10 9 FB1 8 FB2 7 FB3 6 FB4 2.4k + - - + 1.8k 600 5 VS- OPA2835 (TOP VIEW) OPA2835 (TOP VIEW) SOIC-8 (D) VSSOP (MSOP) -10 (DGS) VOUT1 1 VIN1- 2 VIN1+ 3 VS- 4 + + VOUT1 1 VOUT2 VIN1- 2 6 VIN2- VIN1+ 3 5 VIN2+ VS- 4 PD1 5 8 VS+ 7 10 + + VS+ 9 VOUT2 8 VIN2- 7 VIN2+ 6 PD2 OPA2835 (TOP VIEW) WQFN-10 (RUN) VS+ VOUT1 1 VIN1- 2 VIN1+ 3 PD1 4 10 9 VOUT2 8 VIN2- 7 VIN2+ 6 PD2 + - - + 5 VS- Submit Documentation Feedback Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA835 OPA2835 9 OPA835 OPA2835 SLOS713D – JANUARY 2011 – REVISED OCTOBER 2011 www.ti.com PIN FUNCTIONS PIN NUMBER DESCRIPTION NAME OPA835 DBV PACKAGE 1 VOUT Amplifier output 2 VS– Negative power supply input 3 VIN+ Amplifier non-inverting input 4 VIN– Amplifier inverting input 5 PD Amplifier Power Down, low = low power mode, high = normal operation (PIN MUST BE DRIVEN) 6 VS+ Positive power supply input OPA835 RUN PACKAGE 1 VOUT Amplifier output 2 VIN– Amplifier inverting input 3 VIN+ Amplifier non-inverting input 4 PD Amplifier Power Down, low = low power mode, high = normal operation (PIN MUST BE DRIVEN) 5 VS– Negative power supply input 6 FB4 Connection to bottom of 250 Ω internal gain setting resistors 7 FB3 Connection to junction of 750 and 250 Ω internal gain setting resistors 8 FB2 Connection to junction of 1k and 750 Ω internal gain setting resistors 9 FB1 Connection to top of 1kΩ internal gain setting resistors 10 VS+ Positive power supply input OPA2835 D PACKAGE 1 VOUT1 Amplifier 1 output 2 VIN1– Amplifier 1 inverting input 3 VIN1+ Amplifier 1 non-inverting input 4 VS– 5 VIN2+ Negative power supply input Amplifier 2 non-inverting input 6 VIN2– Amplifier 2 inverting input 7 VOUT2 Amplifier 2 output 8 VS+ Positive power supply input OPA2835 DSG PACKAGE 1 VOUT1 Amplifier 1 output 2 VIN1– Amplifier 1 inverting input 3 VIN1+ Amplifier 1 non-inverting input 4 VS– Negative power supply input 5 PD1 Amplifier 1 Power Down, low = low power mode, high = normal operation (PIN MUST BE DRIVEN) 6 PD2 Amplifier 2 Power Down, low = low power mode, high = normal operation (PIN MUST BE DRIVEN) 7 VIN2+ Amplifier 2 non-inverting input 8 VIN2– Amplifier 2 inverting input 9 VOUT2 Amplifier 2 output 10 VS+ Positive power supply input OPA2835 RUN PACKAGE 10 1 VOUT1 Amplifier 1 output 2 VIN1– Amplifier 1 inverting input 3 VIN1+ Amplifier 1 non-inverting input 4 PD1 Amplifier 1 Power Down, low = low power mode, high = normal operation (PIN MUST BE DRIVEN) 5 VS– Negative power supply input 6 PD2 Amplifier 2 Power Down, low = low power mode, high = normal operation (PIN MUST BE DRIVEN) 7 VIN2+ Amplifier 2 non-inverting input Submit Documentation Feedback Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA835 OPA2835 OPA835 OPA2835 SLOS713D – JANUARY 2011 – REVISED OCTOBER 2011 www.ti.com PIN FUNCTIONS (continued) PIN NUMBER DESCRIPTION NAME 8 VIN2– Amplifier 2 inverting input 9 VOUT2 Amplifier 2 output 10 VS+ Positive power supply input SPACER TYPICAL PERFORMANCE GRAPHS: VS = 2.7 V Test conditions unless otherwise noted: VS+ = +2.7 V, VS– = 0 V, VOUT = 1 Vpp, RF = 0 Ω, RL = 2 kΩ, G = 1 V/V, Input and Output Referenced to mid-supply unless otherwise noted. TA = 25°C. Table of Graphs FIGURES Small Signal Frequency Response Figure 1 Large Signal Frequency Response Figure 2 Noninverting Pulse Response Figure 3 Inverting Pulse Response Figure 4 Slew rate vs Output Voltage Step Output Overdrive Recovery Figure 5 Figure 6 Harmonic Distortion vs Frequency Figure 7 Harmonic Distortion vs Load Resistance Figure 8 Harmonic Distortion vs Output Voltage Figure 9 Harmonic Distortion vs Gain Figure 10 Output Voltage Swing vs Load Resistance Figure 11 Output Saturation Voltage vs Load Current Figure 12 Output Impedance vs Frequency Figure 13 Frequency Response with Capacitive Load Figure 14 Series Output Resistor vs Capacitive Load Figure 15 Input Referred Noise vs Frequency Figure 16 Open Loop Gain vs Frequency Figure 17 Common Mode/Power Supply Rejection Ratios vs Frequency Figure 18 Crosstalk vs Frequency Figure 19 Power Down Response Figure 20 Input Offset Voltage Figure 21 Input Offset Voltage vs Free-Air Temperature Figure 22 Input Offset Voltage Drift Figure 23 Input Offset Current Figure 24 Input Offset Current vs Free-Air Temperature Input Offset Current Drift Figure 25 Figure 26 Submit Documentation Feedback Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA835 OPA2835 11 OPA835 OPA2835 SLOS713D – JANUARY 2011 – REVISED OCTOBER 2011 www.ti.com TYPICAL PERFORMANCE GRAPHS: VS = 2.7 V 21 21 VS = 2.7 V, VOUT = 100 mVpp, G = 10 18 15 G=5 G=5 12 Gain Magnitude - dB Gain Magnitude - dB RL = 2 kW RL = 2 kW 15 VS = 2.7 V, VOUT = 1 Vpp, G = 10 18 9 6 G=2 3 12 9 6 G=2 G=1 3 0 0 -3 -3 G=1 G = -1 -6 -6 G = -1 -9 100k 1M 10M f - Frequency - Hz -9 100k 100M 10M 100M f - Frequency - Hz Figure 1. Small Signal Frequency Response Figure 2. Large Signal Frequency Response 3 2.5 VS = 2.7 V, G = 1, RF = 0 W VS = 2.7 V, G = -1, RF = 2 kW 2.5 RL = 2 kW VO - Output Voltage - V 2 R = 2 kW L VO - Output Voltage - V 1M 1.5 VOUT = 1.5 Vpp 1 0.5 VOUT = 2 Vpp 2 1.5 VOUT = 0.5 Vpp 1 0.5 VOUT = 0.5 Vpp 0 500 t - Time - ns 0 1000 Figure 3. Noninverting Pulse Response 1000 Figure 4. Inverting Pulse Response 0.75 140 VS = 2.7 V, G = 2, 120 R = 2 kW F 3.75 VS = 2.7 V, G = 5, RF = 2 kW, RL = 2 kW 0.5 100 Falling VI - Input Voltage - V Slew Rate - V/ms 500 t - Time - ns 80 Rising 60 VIN 3.25 VOUT 2.75 RL = 2 kW 2.25 1.75 1.25 0.25 0.75 0.25 40 VO - Output Voltage - V 0 0 0 -0.25 20 -0.75 0 0.5 0.6 0.7 0.8 Output Voltage Step - V 0.9 Figure 5. Slew Rate vs Output Voltage Step 12 1 -0.25 0 500 1000 t - Time - ns 1500 -1.25 2000 Figure 6. Output Overdrive Recovery Submit Documentation Feedback Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA835 OPA2835 OPA835 OPA2835 SLOS713D – JANUARY 2011 – REVISED OCTOBER 2011 www.ti.com TYPICAL PERFORMANCE GRAPHS: VS = 2.7 V (continued) -50 -30 VS = 2.7 V, G = 1, VOUT = 1 Vpp, -40 RF = 0 W, RL = 2 kW -60 -70 -80 -90 HD2 -100 HD3 -110 -60 Harmonic Distortion - dBc Harmonic Distortion - dBc -50 VS = 2.7 V, G = 1, f = 1 MHz, RF = 0 W VOUT = 1 Vpp -55 -65 HD2 -70 -75 HD3 -80 -120 -85 -130 -90 100 -140 f - Frequency - Hz 1k RLOAD - Load Resistance - W Figure 7. Harmonic Distortion vs Frequency Figure 8. Harmonic Distortion vs Load Resistance 10k 1M 100k 10M -30 -40 VS = 2.7 V, G = 1, f = 1 MHz, RF = 0 W, VS = 2.7 V, G = 1, f = 1 MHz, VOUT = 1 Vpp, -45 -50 RL = 2 kW Harmonic Distortion - dBc Harmonic Distortion - dBc -40 -50 -60 HD2 -70 RL = 2 kW -55 -60 HD3 -65 -70 HD2 -75 -80 -80 HD3 -85 -90 -90 0 1 VO - Output Voltage - Vpp 1 2 Figure 9. Harmonic Distortion vs Output Voltage 3 2 3 4 5 6 Gain - V/V 7 8 9 10 Figure 10. Harmonic Distortion vs Gain 1 VS = 2.7 V, G = 5, RF = 2 kW 2.5 VS = 2.7 V, G = 5, RF = 2 kW VOUT = High VSAT - Saturation Voltage - V VO - Output Voltage - V 10k 2 1.5 1 0.1 VOUT = High VOUT = Low 0.01 0.5 VOUT = Low 0 10 100 1k 10k 0.001 0.1 RL - Load Resistance - W Figure 11. Output Voltage Swing vs Load Resistance 1 10 IL - Load Current - mA 100 Figure 12. Output Saturation Voltage vs Load Current Submit Documentation Feedback Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA835 OPA2835 13 OPA835 OPA2835 SLOS713D – JANUARY 2011 – REVISED OCTOBER 2011 www.ti.com TYPICAL PERFORMANCE GRAPHS: VS = 2.7 V (continued) 1000 3 VS = 2.7 V, G=1 100 CL = 10 pF Gain Magnitude - dB ZO - Output Impedance - W 0 10 1 RO = 0 W CL = 100 pF CL = 22 pF RO = 40.2 W RO = 76.8 W CL = 220 pF -3 CL = 1 pF RO = 24.9 W RO = 0 W CL = 560 pF RO = 13 W -6 0.1 VS = 2.7 V, G = 1, RF = 0 W CL = 1000 pF RO = 10 W RL = 2 kW 0.01 10k 1M 10M f - Frequency - Hz 100k 100M -9 100k 1G Figure 13. Output Impedance vs Frequency 10M f - Frequency - Hz 1M 100M 1G Figure 14. Frequency Response with Capacitive Load 100 100 VS = 2.7 V, G = 1, RF = 0 W, VS = 2.7 V Vn, In - nV/ ÖHz, pa/Ö Hz RO - Output Resistor - W RL = 2 kW 10 Voltage Noise 10 1 Current Noise 1 10 100 0.1 10 1000 100 1k CLOAD - Capacitive Load - pF VS = 2.7 V -50 -10 -100 -20 Open Loop Gain Phase -150 Open Loop Gain Magnitude -200 -250 10 100 1k 10k 100k 1M f - Frequency - Hz 10M 100M Figure 17. Open Loop Gain vs Frequency 14 10M 0 0 VS = 2.7 V 1G CMRR/PSRR - dB 140 130 120 110 100 90 80 70 60 50 40 30 20 10 0 -10 -20 -30 -40 1 1M Figure 16. Input Referred Noise vs Frequency AOL - Phase - deg AOL - Magnitude - dB Figure 15. Series Output Resistor vs Capacitive Load 10k 100k f - Frequency - Hz PSRR -30 -40 CMRR -50 -300 -60 -350 -70 -400 -80 10k 100k 1M f - Frequency - Hz 10M 100M Figure 18. Common Mode/Power Supply Rejection Ratios vs Frequency Submit Documentation Feedback Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA835 OPA2835 OPA835 OPA2835 SLOS713D – JANUARY 2011 – REVISED OCTOBER 2011 www.ti.com TYPICAL PERFORMANCE GRAPHS: VS = 2.7 V (continued) 3 −80 VS = 2.7 V, G = 2, RF = 2 kW 2.5 VPD RL = 2 kW −90 VOUT / VPD Crosstalk (dB) 2 −100 −110 1.5 VOUT 1 −120 0.5 −130 −140 0 20 100 1k 10k 100k Frequency (Hz) 1M 10M 50M 0 500 t - Time - ns Figure 19. Crosstalk vs Frequency 1000 Figure 20. Power Down Response 800 1600 1412 600 1400 VOS - Offset Voltage - mV 1143 1200 962 Count 1000 800 582 600 395 200 0 -200 -400 400 158 -800 -40 >692 <484.4 17 2 1 0 0 0 0 <553.6 <622.8 <692 <276.8 <138.4 <207.6 <0 <69.2 <-138.4 <-69.2 <-276.8 <-207.6 <-415.2 <-346 <-553.6 <-484.4 <-692 <-622.8 -600 52 0 0 0 1 4 13 26 <346 <415.2 112 200 0 400 -20 0 20 40 60 80 100 120 TA - Free-Air Temperature - °C VOS - Offset Voltage - mV Figure 21. Input Offset Voltage Figure 22. Input Offset Voltage vs Free-Air Temperature 3.5 3 1200 0°C to 70°C -40°C to 85°C -40°C to 125°C 967 904 1000 2.5 772 800 695 Count Count 2 1.5 600 402 369 400 1 213 174 200 0.5 9 3 13 16 32 <-45 <-40.5 81 37 24 14 31 4 4 <45 >45 <36 <40.5 <27 <31.5 <22.5 <13.5 <18 <0 <4.5 <9 <-9 <-4.5 <-13.5 -5 -4.5 -4 -3.5 -3 -2.5 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 VOS - Drift - mV/°C <-36 0 <-31.5 <-27 <-22.5 <-18 0 80 36 IOS - Offset Current - nA Figure 23. Input Offset Voltage Drift Figure 24. Input Offset Current Submit Documentation Feedback Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA835 OPA2835 15 OPA835 OPA2835 SLOS713D – JANUARY 2011 – REVISED OCTOBER 2011 www.ti.com TYPICAL PERFORMANCE GRAPHS: VS = 2.7 V (continued) 7 100 80 6 0°C to 70°C -40°C to 85°C -40°C to 125°C 5 40 20 4 Count IOS - Offset Current - nA 60 0 3 -20 -40 2 -60 1 -80 -100 -40 -20 0 20 40 60 80 100 120 0 -250 -200-150-100-50 0 TA - Free-Air Temperature - °C Figure 25. Input Offset Current vs Free-Air Temperature 16 50 100 150 200 250 300 350 400 450 500 550 IOS - Drift - pA/°C Figure 26. Input Offset Current Drift Submit Documentation Feedback Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA835 OPA2835 OPA835 OPA2835 SLOS713D – JANUARY 2011 – REVISED OCTOBER 2011 www.ti.com TYPICAL PERFORMANCE GRAPHS: VS = 5 V Test conditions unless otherwise noted: VS+ = +5 V, VS– = 0 V, VOUT = 2 Vpp, RF = 0 Ω, RL = 2 kΩ, G = 1 V/V, Input and Output Referenced to mid-supply unless otherwise noted. TA = 25°C. Table of Graphs FIGURES Small Signal Frequency Response Figure 27 Large Signal Frequency Response Figure 28 Noninverting Pulse Response Figure 29 Inverting Pulse Response Figure 30 Slew rate vs Output Voltage Step Output Overdrive Recovery Figure 31 Figure 32 Harmonic Distortion vs Frequency Figure 33 Harmonic Distortion vs Load Resistance Figure 34 Harmonic Distortion vs Output Voltage Figure 35 Harmonic Distortion vs Gain Figure 36 Output Voltage Swing vs Load Resistance Figure 37 Output Saturation Voltage vs Load Current Figure 38 Output Impedance vs Frequency Figure 39 Frequency Response with Capacitive Load Figure 40 Series Output Resistor vs Capacitive Load Figure 41 Input Referred Noise vs Frequency Figure 42 Open Loop Gain vs Frequency Figure 43 Common Mode/Power Supply Rejection Ratios vs Frequency Figure 44 Crosstalk vs Frequency Figure 45 Power Down Response Figure 46 Input Offset Voltage Figure 47 Input Offset Voltage vs Free-Air Temperature Figure 48 Input Offset Voltage Drift Figure 49 Input Offset Current Figure 50 Input Offset Current vs Free-Air Temperature Input Offset Current Drift Figure 51 Figure 52 Submit Documentation Feedback Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA835 OPA2835 17 OPA835 OPA2835 SLOS713D – JANUARY 2011 – REVISED OCTOBER 2011 www.ti.com TYPICAL PERFORMANCE GRAPHS: VS = 5 V 21 21 VS = 5 V, VOUT = 100 mVpp, G = 10 18 RL = 2 kW G=5 12 9 6 G=2 3 G=1 9 6 G=2 3 0 -3 -3 1M G = -1 G=1 -6 G = -1 -9 100k G=5 12 0 -6 RL = 2 kW 15 Gain Magnitude - dB 10M -9 100k 100M 1M Figure 27. Small Signal Frequency Response 5 VS = 5 V, 4.5 G = -1, RF = 2 kW 4 R = 2 kW 4.5 4 3.5 VOUT = 4 Vpp L VOUT = 4 Vpp VO - Output Voltage - V VO - Output Voltage - V 100M Figure 28. Large Signal Frequency Response 5 VS = 5 V, G = 1, RF = 0 W 3 2.5 RL = 2 kW 2 1.5 1 3.5 3 2.5 VOUT = 0.5 Vpp 2 1.5 1 0.5 0.5 VOUT = 0.5 Vpp 0 0 0 500 t - Time - ns 0 1000 Figure 29. Noninverting Pulse Response 250 500 t - Time - ns 1000 Figure 30. Inverting Pulse Response 300 6.25 1.25 VS = 5 V, G = 2, RF = 2 kW Falling 1 VS = 5 V, G = 5, RF = 2 kW, VIN 5.75 VOUT 5.25 4.75 RL = 2 kW RL = 2 kW 4.25 VI - Input Voltage - V Slew Rate - V/ms 10M f - Frequency - Hz f - Frequency - Hz 200 Rising 150 100 3.75 0.75 3.25 2.75 0.5 2.25 1.75 1.25 0.25 VO - Output Voltage - V Gain Magnitude - dB 15 VS = 5 V, VOUT = 2 Vpp, G = 10 18 0.75 0.25 50 0 0 0 1 2 Output Voltage Step - V 3 Figure 31. Slew Rate vs Output Voltage Step 18 4 -0.25 0 -0.25 500 1000 t - Time - ns 1500 -0.75 -1.25 2000 Figure 32. Output Overdrive Recovery Submit Documentation Feedback Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA835 OPA2835 OPA835 OPA2835 SLOS713D – JANUARY 2011 – REVISED OCTOBER 2011 www.ti.com TYPICAL PERFORMANCE GRAPHS: VS = 5 V (continued) -30 -50 -50 VS = 5 V, G = 1, VOUT = 2 Vpp, -60 RL = 2 kW VS = 5 V, G = 1, f = 1 MHz, RF = 0 W VOUT = 2 Vpp -55 RF = 0 W, Harmonic Distortion - dBc Harmonic Distortion - dBc -40 -70 -80 -90 HD2 -100 -110 HD3 -60 -65 HD2 -70 HD3 -75 -80 -120 -85 -130 -140 10k 100k 1M -90 100 10M f - Frequency - Hz 1k 10k RLOAD - Load Resistance - W Figure 33. Harmonic Distortion vs Frequency Figure 34. Harmonic Distortion vs Load Resistance -40 -40 VS = 5 V, G = 1, f = 1 MHz, RF = 0 W, Harmonic Distortion - dBc -50 VS = 5 V, -45 G = 1, f = 1 MHz, -50 V OUT = 2 Vpp, Harmonic Distortion - dBc -45 RL = 2 kW -55 HD3 -60 HD2 -65 -70 -75 -55 -65 HD2 -70 -75 -80 -85 -85 -90 1 -90 1 2 VO - Output Voltage - Vpp 3 4 2 Figure 35. Harmonic Distortion vs Output Voltage VS = 5 V, G = 5, RF = 2 kW 3 4 5 6 Gain - V/V 7 8 9 10 Figure 36. Harmonic Distortion vs Gain 1 5 HD3 -60 -80 0 RL = 2 kW VOUT = High VS = 5 V, G = 5, RF = 2 kW VSAT - Saturation Voltage - V VO - Output Voltage - V 4 3 2 VOUT = High 0.1 VOUT = Low 1 VOUT = Low 0 10 100 1k 10k 0.01 0.1 RL - Load Resistance - W Figure 37. Output Voltage Swing vs Load Resistance 1 10 IL - Load Current - mA 100 Figure 38. Output Saturation Voltage vs Load Current Submit Documentation Feedback Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA835 OPA2835 19 OPA835 OPA2835 SLOS713D – JANUARY 2011 – REVISED OCTOBER 2011 www.ti.com TYPICAL PERFORMANCE GRAPHS: VS = 5 V (continued) ZO - Output Impedance - W 100 3 VS = 5 V, G=1 VS = 5 V, G = 1, RF = 0 W RL = 2 kW 0 Gain Magnitude - dB 10 1 0.1 CL = 10 pF CL = 100 pF RO = 0 W RO = 40.2 W CL = 220 pF -3 CL = 1 pF RO = 24.9 W RO = 0 W CL = 560 pF CL = 22 pF RO = 13 W RO = 76.8 W CL = 1000 pF -6 RO = 10 W 0.01 10K 100K 1M 10M f - Frequency - Hz 100M -9 100k 1G Figure 39. Output Impedance vs Frequency 10M f - Frequency - Hz 1M 100M 1G Figure 40. Frequency Response with Capacitive Load 100 100 VS = 5 V, G = 1, RF = 0 W, VS = 5 V Vn, In - nV/ ÖHz, pa/Ö Hz RO - Output Resistor - W RL = 2 kW 10 Voltage Noise 10 1 Current Noise 1 10 100 0.1 10 1000 100 1k CLOAD - Capacitive Load - pF VS = 5 V VS = 5 V -50 -10 -100 -20 Open Loop Gain Phase -150 -200 Open Loop Gain Magnitude -250 10 100 1k 10k 100k 1M f - Frequency - Hz 10M 100M Figure 43. Open Loop Gain vs Frequency 20 10M 0 0 CMRR/PSRR - dB 140 130 120 110 100 90 80 70 60 50 40 30 20 10 0 -10 -20 -30 -40 1 1M Figure 42. Input Referred Noise vs Frequency AOL - Phase - deg AOL - Magnitude - dB Figure 41. Series Output Resistor vs Capacitive Load 10k 100k f - Frequency - Hz -30 CMRR -40 -50 -300 -60 -350 -70 -400 1G PSRR -80 10k 100k 1M f - Frequency - Hz 10M 100M Figure 44. Common Mode/Power Supply Rejection Ratios vs Frequency Submit Documentation Feedback Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA835 OPA2835 OPA835 OPA2835 SLOS713D – JANUARY 2011 – REVISED OCTOBER 2011 www.ti.com TYPICAL PERFORMANCE GRAPHS: VS = 5 V (continued) 5 4.5 VS = 5 V, G = 2, RF = 2 kW VPD −80 4 RL = 2 kW 3.5 VOUT / VPD Crosstalk (dB) −90 −100 −110 3 VOUT 2.5 2 1.5 −120 1 −130 0.5 −140 20 100 1k 10k 100k Frequency (Hz) 1M 10M 0 0 50M 500 t - Time - ns Figure 45. Crosstalk vs Frequency 1000 Figure 46. Power Down Response 800 1600 1404 600 1400 VOS - Offset Voltage - mV 1156 1200 965 Count 1000 800 590 600 377 400 200 0 -200 -400 400 170 -600 108 -800 -40 >692 <484.4 <553.6 <622.8 <692 <138.4 <207.6 <0 <69.2 <-138.4 <-69.2 <-276.8 <-207.6 <-415.2 <-346 <-553.6 <-484.4 <-692 <-622.8 0 13 2 1 0 0 0 0 <346 <415.2 53 0 0 0 1 3 11 26 <276.8 200 -20 0 20 40 80 60 100 120 TA - Free-Air Temperature - °C VOS - Offset Voltage - mV Figure 47. Input Offset Voltage Figure 48. Input Offset Voltage vs Free-Air Temperature 3.5 3 1000 0°C to 70°C -40°C to 85°C -40°C to 125°C 948 895 900 800 754 715 700 Count Count 2.5 2 600 500 1.5 397 382 400 300 1 205 188 200 94 0.5 100 36 26 14 5 3 31 <45 >45 <36 <40.5 <27 <31.5 <22.5 <13.5 <18 <0 <4.5 <9 <-9 <-4.5 <-13.5 <-36 <-31.5 <-27 <-22.5 <-18 -5 -4.5 -4 -3.5 -3 -2.5 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 VOS - Drift - mV/°C <-45 0 <-40.5 0 75 37 7 5 9 20 34 IOS - Offset Current - nA Figure 49. Input Offset Voltage Drift Figure 50. Input Offset Current Submit Documentation Feedback Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA835 OPA2835 21 OPA835 OPA2835 SLOS713D – JANUARY 2011 – REVISED OCTOBER 2011 www.ti.com TYPICAL PERFORMANCE GRAPHS: VS = 5 V (continued) 100 9 80 8 7 40 6 20 Count IOS - Offset Current - nA 60 0°C to 70°C -40°C to 85°C -40°C to 125°C 0 5 4 -20 3 -40 -60 2 -80 1 -100 -40 -20 0 20 40 60 80 100 120 0 -250 -200-150-100-50 0 TA - Free-Air Temperature - °C Figure 51. Input Offset Current vs Free-Air Temperature 22 50 100 150 200 250 300 350 400 450 500 550 IOS - Drift - pA/°C Figure 52. Input Offset Current Drift Submit Documentation Feedback Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA835 OPA2835 OPA835 OPA2835 SLOS713D – JANUARY 2011 – REVISED OCTOBER 2011 www.ti.com APPLICATION INFORMATION The following circuits show application information for the OPA835 and OPA2835. For simplicity, power supply decoupling capacitors are not shown in these diagrams. Non-Inverting Amplifier The OPA835 and OPA2835 can be used as non-inverting amplifiers with signal input to the non-inverting input, VIN+. A basic block diagram of the circuit is shown in Figure 53. If we set VIN = VREF + VSIG, then æ RF ö V = VSIG ç 1 + ÷ + VREF OUT RG ø è (1) RF G= 1 + RG , and V The signal gain of the circuit is set by: REF provides a reference around which the input and output signals swing. Output signals are in-phase with the input signals. The OPA835 and OPA2835 are designed for the nominal value of RF to be 2kΩ in gains other than +1. This gives excellent distortion performance, maximum bandwidth, best flatness, and best pulse response. RF = 2kΩ should be used as a default unless other design goals require changing to other values All test circuits used to collect data for this data sheet had RF = 2kΩ for all gains other than +1. Gain of +1 is a special case where RF is shorted and RG is left open. VSIG VS+ VREF VIN RG OPA 835 VOUT GVSIG VREF VS- VREF RF Figure 53. Non-Inverting Amplifier Inverting Amplifier The OPA835 and OPA2835 can be used as inverting amplifiers with signal input to the inverting input, VIN-, through the gain setting resistor RG. A basic block diagram of the circuit is shown in Figure 54. If we set VIN = VREF + VSIG, then æ -R ö VOUT = VSIG ç F ÷ + VREF è RG ø (2) G= -RF RG and V The signal gain of the circuit is set by: REF provides a reference point around which the input and output signals swing. Output signals are 180˚ out-of-phase with the input signals. The nominal value of RF should be 2kΩ for inverting gains. Submit Documentation Feedback Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA835 OPA2835 23 OPA835 OPA2835 SLOS713D – JANUARY 2011 – REVISED OCTOBER 2011 VSIG www.ti.com VS+ VREF VREF VOUT GVSIG OPA 835 RG VIN VREF VSRF Figure 54. Inverting Amplifier Attenuators The non-inverting circuit of Figure 53 has minimum gain of 1. To implement attenuation, a resistor divider can be placed in series with the positive input, and the amplifier set for gain of 1 by shorting VOUT to VIN- and removing RG. Since the op amp input is high impedance, the attenuation is set by the resistor divider. The inverting circuit of Figure 54 can be used as an attenuator by making RG larger than RF. The attenuation is simply the resistor ratio. For example a 10:1 attenuator can be implemented with RF = 2 kΩ and RG = 20 kΩ. Single Ended to Differential Amplifier Figure 55 shows an amplifier circuit that is used to convert single-ended signals to differential, and provides gain and level shifting. This circuit can be used for converting signals to differential in applications like line drivers for CAT 5 cabling or driving differential input SAR and ΔΣ ADCs. By setting VIN = VREF + VSIG, then RF VOUT+ = G x VIN + VREF and VOUT- = -G x VIN + VREF Where: G = 1 + RG (3) The differential signal gain of the circuit is 2x G, and VREF provides a reference around which the output signal swings. The differential output signal is in-phase with the single ended input signal. G x V SIG RO VOUT+ VREF VSIG VREF R1 VIN OPA 835 2R 2R + VREF RO VREF -G x V SIG VOUT- + RG RF VREF OPA 835 Figure 55. Single Ended to Differential Amplifier Line termination on the output can be accomplished with resistors RO. The impedance seen differential from the line will be 2x RO. For example if 100 Ω CAT 5 cable is used with double termination, the amplifier is typically set for a differential gain of 2 V/V (6 dB) with RF = 0 Ω (short) RG = ∞Ω (open), 2R = 2 kΩ, R1 = 0 Ω, R = 1 kΩ to balance the input bias currents, and RO = 49.9 Ω for output line termination. This configuration is shown in Figure 56. For driving a differential input ADC the situation is similar, but the output resistors, RO, are typically chosen along with a capacitor across the ADC input for optimum filtering and settling time performance. 24 Submit Documentation Feedback Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA835 OPA2835 OPA835 OPA2835 SLOS713D – JANUARY 2011 – REVISED OCTOBER 2011 www.ti.com 49.9 VSIG VOUT+ VREF VSIG VREF OPA 835 VIN 2k 2k + 49.9 VREF -VSIG VOUT- VREF OPA 835 + 1k Figure 56. CAT 5 Line Driver with Gain = 2 V/V (6 dB) Differential to Signal Ended Amplifier Figure 57 shows a differential amplifier that is used to convert differential signals to single-ended and provides gain (or attenuation) and level shifting. This circuit can be used in applications like a line receiver for converting a differential signal from a CAT 5 cable to single-ended. If we set VIN+ = VCM + VSIG+ and VIN- = VCM + VSIG-, then æR ö VOUT = (VIN+ - VIN - ) ´ ç F ÷ + VREF è RG ø G= (4) RF RG , V is rejected, and V The signal gain of the circuit is set by: CM REF provides a level shift around which the output signal swings. The single ended output signal is in-phase with the differential input signal. VSIG- RF VCM VINVIN+ VSIG+ VCM RG VOUT OPA835 RG G[(VSIG+)-(VSIG-)] RF VREF VREF Figure 57. Differential to Single Ended Amplifier Line termination can be accomplished with a resistor shunt across the input. The impedance seen differential from the line will be the resistor value in parallel with the amplifier circuit. For low gain and low line impedance the resistor value to add is approximately the impedance of the line. For example, if 100 Ω CAT5 cable is used with a gain of 1 amplifier and RF = RG = 2 kΩ, adding a 100 Ω shunt across the input will give a differential impedance of 99 Ω; this should be adequate for most applications. For best CMRR performance, resistors must be matched. Assuming CMRR ≈ the resistor tolerance; so 0.1% tolerance will provide about 60 dB CMRR. Differential to Differential Amplifier Figure 58 shows a differential amplifier that is used to amplify differential signals. This circuit has high input impedance and is often used in differential line driver applications where the signal source is a high impedance driver like a differential DAC that needs to drive a line. If we set VIN± = VCM + VSIG± then Submit Documentation Feedback Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA835 OPA2835 25 OPA835 OPA2835 SLOS713D – JANUARY 2011 – REVISED OCTOBER 2011 V OUT ± www.ti.com æ 2RF ö = VIN ± ´ ç 1 + ÷ + VCM RG ø è (5) 2RF G= 1 + RG , and V passes with unity gain. The amplifier in essence The signal gain of the circuit is set by: CM combines two non-inverting amplifiers into one differential amplifier with the RG resistor shared, which makes RG effectively ½ its value when calculating the gain. The output signals are in-phase with the input signals. VINVOUT- OPA 835 VSIG- GVSIGVCM VCM RF RG RF GVSIG+ VSIG+ VCM VCM VOUT+ OPA 835 VIN+ Figure 58. Differential to Differential Amplifier Instrumentation Amplifier Figure 59 is an instrumentation amplifier that combines the high input impedance of the differential to differential amplifier circuit and the common-mode rejection of the differential to single-ended amplifier circuit. This circuit is often used in applications where high input impedance is required like taps from a differential line or in cases where the signal source is a high impedance. If we set VIN+ = VCM + VSIG+ and VIN- = VCM + VSIG-, then VOUT = (VIN+ - VIN- ) æ 2RF1 ö æ RF2 ö ´ ç1 + ÷ ç ÷ + VREF RG1 ø è RG2 ø è (6) The signal gain of the circuit is set by: æ 2R F1 ö G = ç1 + ÷ RG 1 ø è swings. The single æ R F2 ö ç ÷ è R G2 ø , VCM is rejected, and VREF provides a level shift around which the output signal ended output signal is in-phase with the differential input signal. VINOPA 835 VSIG- RF2 VCM RF1 RG1 RG2 RG2 VSIG+ OPA 835 VIN+ G[(VSIG+)-(VSIG-)] RF2 VCM VOUT OPA 835 RF1 VREF VREF Figure 59. Instrumentation Amplifier 26 Submit Documentation Feedback Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA835 OPA2835 OPA835 OPA2835 SLOS713D – JANUARY 2011 – REVISED OCTOBER 2011 www.ti.com Integrated solutions are available, but the OPA835 provides a much lower power high frequency solution. For best CMRR performance, resistors must be matched. A rule of thumb is CMRR ≈ the resistor tolerance; so 0.1% tolerance will provide about 60 dB CMRR. Gain Setting with OPA835 RUN Integrated Resistors The OPA835 RUN package option includes integrated gain setting resistors for smallest possible footprint on a printed circuit board (≈ 2mm x 2mm). By adding circuit traces on the PCB, gains of +1, -1, -1.33, +2, +2.33, -3, +4, -4, +5, -5.33, +6.33, -7, +8 and inverting attenuations of -0.1429, -0.1875, -0.25, -0.33, -0.75 can be achieved. Figure 60 shows a simplified view of how the OPA835IRUN integrated gain setting network is implemented. Table 1 shows the required pin connections for various non-inverting and inverting gains (reference Figure 53 and Figure 54). Table 2 shows the required pin connections for various attenuations using the inverting amplifier architecture (reference Figure 54). Due to ESD protection devices being used on all pins, the absolute maximum and minimum input voltage range, VS– - 0.7V to VS+ + 0.7V, applies to the gain setting resistors, and so attenuation of large input voltages will require external resistors to implement. The gain setting resistors are laser trimmed to 1% tolerance with nominal values of 2.4 kΩ, 1.8 kΩ, and 600 Ω. They have excellent temperature coefficient and gain tracking is superior to using external gain setting resistors. The 800 Ω and 1.25 pF capacitor in parallel with the 2.4 kΩ gain setting resistor provide compensation for best stability and pulse response. FB1 FB2 9 FB3 8 2.4 k FB4 7 1.8 k 6 600 800 1.25 pF Figure 60. OPA835IRUN Gain Setting Network Table 1. Gains Setting Non-inverting Gain (Figure 53) Inverting Gain (Figure 54) Short Pins Short Pins Short Pins Short Pins 1 V/V (0 dB) - 1 to 9 2 V/V (6.02 dB) -1 V/V (0 dB) 1 to 9 2 to 8 6 to GND - 2.33 V/V (7.36 dB) -1.33 V/V (2.5 dB) 1 to 9 2 to 8 7 to GND - 4 V/V (12.04 dB) -3 V/V (9.54 dB) 1 to 8 2 to 7 6 to GND - 5 V/V (13.98 dB) -4 V/V (12.04 dB) 1 to 9 2 to 7 or 8 7 to 8 6 to GND 6.33 V/V (16.03 dB) -5.33 V/V (14.54 dB) 1 to 9 2 to 6 or 8 6 to 8 7 to GND 8 V/V (18.06 dB) -7 V/V (16.90 dB) 1 to 9 2 to 7 6 to GND - Table 2. Attenuator Settings Inverting Gain (Figure 54) Short Pins Short Pins Short Pins Short Pins -0.75 V/V (-2.5 dB) 1 to 7 2 to 8 9 to GND - -0.333 V/V (-9.54 dB) 1 to 6 2 to 7 8 to GND - -0.25 V/V (-12.04 dB) 1 to 6 2 to 7 or 8 7 to 8 9 to GND -0.1875 V/V (-14.54 dB) 1 to 7 2 to 6 or 8 6 to 8 9 to GND -0.1429 V/V (-16.90 dB) 1 to 6 2 to 7 9 to GND - Submit Documentation Feedback Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA835 OPA2835 27 OPA835 OPA2835 SLOS713D – JANUARY 2011 – REVISED OCTOBER 2011 www.ti.com Input Common-Mode Voltage Range When the primary design goal is a linear amplifier, with high CMRR, it is important to not violate the input common-mode voltage range (VICR) of an op amp. Common-mode input range low and high specifications in the table data use CMRR to set the limit. The limits are chosen to ensure CMRR will not degrade more than 3dB below its limit if the input voltage is kept within the specified range. The limits cover all process variations and most parts will be better than specified. The typical specifications are from 0.2V below the negative rail to 1.1V below the positive rail. Assuming the op amp is in linear operation the voltage difference between the input pins is very small (ideally 0V) and input common-mode voltage can be analyzed at either input pin and the other input pin is assumed to be at the same potential. The voltage at VIN+ is easy to evaluate. In non-inverting configuration, Figure 53, the input signal, VIN, must not violate the VICR. In inverting configuration, Figure 53, the reference voltage, VREF, needs to be within the VICR. The input voltage limits have fixed headroom to the power rails and track the power supply voltages. For with single 5 V supply, the linear input voltage range is –0.2 V to 3.9 V and with 2.7 V supply it is –0.2 V to 1.6 V. The delta from each power supply rail is the same in either case; –0.2 V and 1.1 V. Output Voltage Range The OPA835 and OPA2835 are rail-to-rail output (RRO) op amps. Rail-to-rail output typically means the output voltage can swing to within a couple hundred milli-volts of the supply rails. There are different ways to specify this; one is with the output still in linear operation and another is with the output saturated. Saturated output voltages are closer to the power supply rails than linear outputs, but the signal is not a linear representation of the input. Linear output is a better representation of how well a device performs when used as a linear amplifier. Both saturation and linear operation limits are affected by the current in the output, where higher currents lead to more loss in the output transistors. Data in the ELECTRICAL SPECIFICATIONS tables list both linear and saturated output voltage specifications with 2kΩ load. Figure 11 and Figure 37 show saturated voltage swing limits versus output load resistance and Figure 12 and Figure 38 show the output saturation voltage versus load current. Given a light load, the output voltage limits have nearly constant headroom to the power rails and track the power supply voltages. For example with 2 kΩ load and single 5 V supply the linear output voltage range is 0.15 V to 4.8 V and with 2.7 V supply it is 0.15 V to 2.5 V. The delta from each power supply rail is the same in either case; 0.15 V and 0.2 V. With devices like the OPA835 and OPA2835, where the input range is lower than the output range, it is typical that the input will limit the available signal swing only in non-inverting gain of 1. Signal swing in non-inverting configurations in gains > +1 and inverting configurations in any gain is generally limited by the output voltage limits of the op amp. Split-Supply Operation (±1.25V to ±2.75V) To facilitate testing with common lab equipment, the OPA835 EVM SLOU314 is built to allow for split-supply operation. This configuration eases lab testing because the mid-point between the power rails is ground, and most signal generators, network analyzers, oscilloscopes, spectrum analyzers and other lab equipment reference their inputs and outputs to ground. Figure 61 shows a simple non-inverting configuration analogous to Figure 53 with ±2.5V supply and VREF equal to ground. The input and output will swing symmetrically around ground. Due to its ease of use, split supply operation is preferred in systems where signals swing around ground, but it requires generation of two supply rails. 28 Submit Documentation Feedback Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA835 OPA2835 OPA835 OPA2835 SLOS713D – JANUARY 2011 – REVISED OCTOBER 2011 www.ti.com +2.5 V RG VSIG VOUT OPA 835 Load -2.5 V RF Figure 61. Split Supply Operation Single-Supply Operation (2.5V to 5.5V) Many newer systems use single power supply to improve efficiency and reduce the cost of the power supply. OPA835 and OPA2835 are designed for use with single-supply power operation and can be used with single-supply power with no change in performance from split supply as long as the input and output are biased within the linear operation of the device. To change the circuit from split supply to single supply, level shift of all voltages by ½ the difference between the power supply rails. For example, changing from ±2.5 V split supply to 5 V single supply is shown conceptually in Figure 62. 5V VSIG RG VOUT OPA 835 Load RF 2.5 V Figure 62. Single Supply Concept A more practical circuit will have an amplifier or other circuit before to provide the bias voltage for the input and the output provides the bias for the next stage. Figure 63 shows a typical non-inverting amplifier situation. With 5V single supply, a mid supply reference generator is needed to bias the negative side via RG. To cancel the voltage offset that would otherwise be caused by the input bias currents, R1 is chosen to be equal to RF in parallel with RG. For example if gain of 2 is required and RF = 2 kΩ, select RG = 2 kΩ to set the gain and R1 = 1 kΩ for bias current cancellation. The value for C is dependent on the reference, but at least 0.1µF is recommended to limit noise. Submit Documentation Feedback Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA835 OPA2835 29 OPA835 OPA2835 SLOS713D – JANUARY 2011 – REVISED OCTOBER 2011 www.ti.com Signal and bias from previous stage VSIG 2.5 V 5V R1 RO OPA 835 5V RG 2.5 V REF VOUT GVSIG 2.5 V C RF Signal and bias to next stage Figure 63. Non-Inverting Single Supply with Reference Figure 64 shows a similar non-inverting single supply scenario with the reference generator replaced by the Thevenin equivalent using resistors and the positive supply. RG’ and RG” form a resistor divider from the 5V supply and are used to bias the negative side with their parallel sum equal to the equivalent RG to set the gain. To cancel the voltage offset that would otherwise be caused by the input bias currents, R1 in is chosen to be equal to RF in parallel with RG’ in parallel with RG” (R1= RF||RG’||RG”). For example if gain of 2 is required and RF = 2 kΩ, selecting RG’ = RG” = 4 kΩ gives equivalent parallel sum of 2 kΩ, sets the gain to 2, and references the input to mid supply (2.5 V). R1 is then set to 1kΩ for bias current cancellation. This can be lower cost, but note the extra current draw required in the resistor divider. Signal and bias from previous stage VSIG 2.5 V 5V R1 RG’ 5V RO OPA 835 VOUT GVSIG 2.5 V RG” RF Signal and bias to next stage Figure 64. Non-Inverting Single Supply with Resistors Figure 65 shows a typical inverting amplifier situation. With 5V single supply, a mid supply reference generator is needed to bias the positive side via R1. To cancel the voltage offset that would otherwise be caused by the input bias currents, R1 is chosen to be equal to RF in parallel with RG. For example if gain of -2 is required and RF = 2 kΩ, select RG = 1 kΩ to set the gain and R1 = 665 Ω for bias current cancellation. The value for C is dependent on the reference, but at least 0.1µF is recommended to limit noise into the op amp. 30 Submit Documentation Feedback Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA835 OPA2835 OPA835 OPA2835 SLOS713D – JANUARY 2011 – REVISED OCTOBER 2011 www.ti.com 5V 5V R1 2.5 V REF RO VOUT OPA 835 C GVSIG 2.5 V RG Signal and bias to next stage RF VSIG 2.5 V Signal and bias from previous stage Figure 65. Inverting Single Supply with Reference Figure 66 shows a similar inverting single supply scenario with the reference generator replaced by the Thevenin equivalent using resistors and the positive supply. R1 and R2 form a resistor divider from the 5V supply and are used to bias the positive side. To cancel the voltage offset that would otherwise be caused by the input bias currents, set the parallel sum of R1 and R2 equal to the parallel sum of RF and RG. C should be added to limit coupling of noise into the positive input. For example if gain of –2 is required and RF = 2 kΩ, select RG = 1 kΩ to set the gain. R1 = R2 = 1.33 kΩ for mid supply voltage bias and for op amp input bias current cancellation. A good value for C is 0.1µF. This can be lower cost, but note the extra current draw required in the resistor divider. 5V 5V R1 RO R2 C OPA 835 VOUT GVSIG 2.5 V RG VSIG RF Signal and bias to next stage 2.5 V Signal and bias from previous stage Figure 66. Inverting Single Supply with Resistors Pulse Application with Single-Supply For pulsed applications, where the signal is at ground and pulses to some positive or negative voltage, the circuit bias voltage considerations are different than with a signal that swings symmetrical about a reference point and the circuit configuration should be adjusted accordingly. Figure 67 shows a pulsed situation where the signal is at ground (0 V) and pulses to a positive value. Submit Documentation Feedback Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA835 OPA2835 31 OPA835 OPA2835 SLOS713D – JANUARY 2011 – REVISED OCTOBER 2011 www.ti.com Signal and bias from previous stage VSIG 0V 5V R1 RO VOUT OPA 835 GVSIG RG 0V RF Signal and bias to next stage Figure 67. Non-Inverting Single Supply with Pulse If the input signal pulses negative from ground, an inverting amplifier is more appropriate as shown in Figure 68. A key consideration in both non-inverting and inverting cases is that the input and output voltages are kept within the limits of the amplifier, and since the VICR of the OPA835 includes the negative supply rail, the op amp lends itself to this application. 5V R1 OPA 835 VOUT GVSIG RG Signal and bias from previous stage 0V VSIG RO 0V RF Signal and bias to next stage Figure 68. Inverting Single Supply with Pulse Power-Down Operation The OPA835 and OPA2835 include a power-down mode. Under logic control, the amplifiers can be switched from normal operation to a standby current of <1.5 µA. When the PD pin is connected high, the amplifier is active. Connecting PD pin low disables the amplifier, and places the output in a high impedance state. Note: the op amp’s output in gain of +1 is high impedance similar to a 3-state high impedance gate, but in other gains the feedback network is a parallel load. The PD pin must be actively driven high or low and should not be left floating. If the power-down mode is not used, PD should be tied to the positive supply rail. PD logic states are TTL with reference to the negative supply rail, VS-. When the op amp is powered from single supply and ground, driving from logic devices with similar VDD voltages to the op amp should not require any special consideration. When the op amp is powered from split supply, VS- is below ground and an open collector type of interface with pull-up resistor is more appropriate. Pull-up resistor values should be lower than 100k and the drive logic should be negated due to the inverting action of an open collector gate. 32 Submit Documentation Feedback Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA835 OPA2835 OPA835 OPA2835 SLOS713D – JANUARY 2011 – REVISED OCTOBER 2011 www.ti.com Low Power Applications and the Effects of Resistor Values on Bandwidth The OPA835 and OPA2835 are designed for the nominal value of RF to be 2 kΩ in gains other than +1. This gives excellent distortion performance, maximum bandwidth, best flatness, and best pulse response. It also loads the amplifier. For example; in gain of 2 with RF = RG = 2 kΩ, RG to ground, and VOUT = 4 V, 1mA of current will flow through the feedback path to ground. In gain of +1, RG is open and no current will flow to ground. In low power applications, it is desirable to reduce this current by increasing the gain setting resistors values. Using larger value gain resistors has two primary side effects (other than lower power) due to their interaction with parasitic circuit capacitance. 1. Lowers the bandwidth. 2. Lowers the phase margin (a) This will cause peaking in the frequency response. (b) And will cause over shoot and ringing in the pulse response. Figure 69 shows the small signal frequency response on OPA835EVM for non-inverting gain of 2 with RF and RG equal to 2 kΩ, 10 kΩ, and 100 kΩ. The test was done with RL = 2 kΩ. Due to loading effects of RL, lower values may reduce the peaking, but higher values will not have a significant effect. 21 Gain Magnitude - dB VS = 5 V, 18 VOUT = 100 Vpp, G = 2, 15 RL = 2 kW RF = 100 kW RF = 10 kW 12 9 RF = 2 kW 6 RF = 100 kW CF = 1 pF 3 0 RF = 10 kW CF = 1 pF -3 -6 -9 0 1 10 100 f - Frequency - MHz Figure 69. Frequency Response with Various Gain Setting Resistor Values As expected, larger value gain resistors cause lower bandwidth and peaking in the response (peaking in frequency response is synonymous with overshoot and ringing in pulse response). Adding 1 pF capacitors in parallel with RF helps compensate the phase margin and restores flat frequency response. Figure 70 shows the test circuit used. VIN RG OPA 835 VOUT 2 kW RF CF Figure 70. G=2 Test Circuit for Various Gain Setting Resistor Values Submit Documentation Feedback Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA835 OPA2835 33 OPA835 OPA2835 SLOS713D – JANUARY 2011 – REVISED OCTOBER 2011 www.ti.com Driving Capacitive Loads The OPA835 and OPA2835 can drive up to a nominal capacitive load of 10pF on the output with no special consideration. When driving capacitive loads greater than this, it is recommended to use a small resister (RO) in series with the output as close to the device as possible. Without RO, capacitance on the output will interact with the output impedance of the amplifier causing phase shift in the loop gain of the amplifier that will reduce the phase margin. This will cause peaking in the frequency response and overshoot and ringing in the pulses response. Interaction with other parasitic elements may lead to instability or oscillation. Inserting RO will isolate the phase shift from the loop gain path and restore the phase margin; however, it will also limit the bandwidth. Figure 71 shows the test circuit and Figure 41 shows the recommended values of RO versus capacitive loads, CL. See Figure 40 for frequency response with various values. RO VIN VOUT OPA835 CL 2 kW Figure 71. RO versus CL Test Circuit Active Filters The OPA835 and OPA2835 can be used to design active filters. Figure 73 and Figure 72 show MFB and Sallen-Key circuits designed using FilterPro™ http://focus.ti.com/docs/toolsw/folders/print/filterpro.html to implement 2nd order low-pass butterworth filter circuits. Figure 74 shows the frequency response. 1.82 kW 220 pF 1.82 kW 4.22 kW OPA 835 1.5 nF Figure 72. MFB 100kHz 2nd Order Low-Pass Butterworth Filter Circuit 2.2 nF 562 W 6.19 kW 330 pF OPA835 Figure 73. Sallen-Key 100kHz 2nd Order Low-Pass Butterworth Filter Circuit 34 Submit Documentation Feedback Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA835 OPA2835 OPA835 OPA2835 SLOS713D – JANUARY 2011 – REVISED OCTOBER 2011 www.ti.com VS = 5 V, VOUT = 100 mVpp Gain Magnitude - dB 0 MFB -10 -20 Sallen-Key -30 -40 1k 10k 100k 1M f - Frequency - Hz Figure 74. MFB and Sallen-Key 2nd Order Low-Pass Butterworth Filter Response MFB and Sallen-Key filter circuits offer similar performance. The main difference is the MFB is an inverting amplifier in the pass band and the Sallen-Key is non-inverting. The primary pro for each is the Sallen-Key in unity gain has no resistor gain error term, and thus no sensitivity to gain error, while the MFB has inherently better attenuation properties beyond the bandwidth of the op amp. Audio Frequency Performance The OPA835 and OPA2835 provide excellent audio performance with very low quiescent power. To show performance in the audio band, a 2700 series Audio Analyzer from Audio Precision was used to test THD+N and FFT at 1 VRMS output voltage. Figure 75 is the test circuit used. Note the 100 pF capacitor to ground on the input helped to decouple noise pick up in the lab and improved noise performance. Figure 76 shows the THD+N performance with 100 kΩ and 300 Ω loads, and with no weighting and A-weighting. With no weighting the THD+N performance is dominated by the noise for both loads. A-weighting provides filtering that improves the noise so a larger difference can be seen between the loads due to more distortion with RL = 300 Ω. Figure 77 and Figure 78 show FFT output with a 1 kHz tone and 100kΩ and 300Ω loads. To show relative performance of the device versus the test set, one channel has the OPA835 in line between generator output and analyzer input and the other channel is in “Gen Mon” loopback mode, which internally connects the signal generator to the analyzer input. With 100 kΩ load, Figure 77, the curves are basically indistinguishable from each other except for noise, which means the OPA835 cannot be directly measured. With 300Ω load, Figure 78, the main difference between the curves is OPA835 shows higher even order harmonics, but odd order is masked by the test set performance. VIN From AP +2.5 V VOUT To AP 100 pF OPA 835 10 W -2.5 V Figure 75. OPA835 AP Analyzer Test Circuit Submit Documentation Feedback Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA835 OPA2835 35 OPA835 OPA2835 SLOS713D – JANUARY 2011 – REVISED OCTOBER 2011 www.ti.com 0 VS = 5 V, VOUT = 1 VRMS, -95 G = 1, RF = 0 W, BW = 80 kHz -100 -20 -30 No weighting RL = 300 W, -40 RL = 100 kW -105 A-weighting RL = 300 W, -110 VS = 5 V, VOUT = 1 VRMS, G = 1, RF = 0 W -10 FFT - dBV THD+N - Total Harmonic Distortion + Noise - dBv -90 -50 -60 -70 -80 -90 RL = 100 kW -100 Gen Mon - 100k -110 -115 -120 RL = 100k -130 -120 10 -140 100 1k f - Frequency - Hz 10k 0 100k Figure 76. OPA835 1 Vrms 20 Hz to 80 kHz THD+N 2k 4k 6k 8k 10k 12k f - Frequency - Hz 14 16k 18k 20k Figure 77. OPA835 and AP Gen Mon 1kHz FFT Plot; VOUT = 1VRMS, RL = 100kΩ 0 VS = 5 V, VOUT = 1 VRMS, G = 1, RF = 0 W -10 -20 -30 -40 FFT - dBV -50 -60 -70 -80 -90 Gen Mon - 300 -100 -110 RL = 300 -120 -130 -140 0 2k 4k 6k 8k 10k 12k f - Frequency - Hz 14 16k 18k 20k Figure 78. OPA835 and AP Gen Mon 1kHz FFT Plot; VOUT = 1VRMS, RL = 300Ω ADC Driver Performance The OPA835 provides excellent performance when driving high performance delta-sigma (ΔΣ) and successive approximation register (SAR) ADCs in low power audio and industrial applications. 36 Submit Documentation Feedback Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA835 OPA2835 OPA835 OPA2835 SLOS713D – JANUARY 2011 – REVISED OCTOBER 2011 www.ti.com OPA835 and ADS8326 Combined Performance To show achievable performance, the OPA835 is tested as the drive amplifier for the ADS8326. The ADS8326 is a 16-bit, micro power, SAR ADC with pseudo-differential inputs and sample rates up to 250kSPS. It offers excellent noise and distortion performance in a small 8-pin SOIC or VSSOP (MSOP) package. Low power and small size make the ADS8326 and OPA835 an ideal solution for portable and battery-operated systems, for remote data-acquisition modules, simultaneous multichannel systems, and isolated data acquisition. The circuit shown in Figure 79 is used to test the performance, Figure 80 is the FFT plot with 10kHz input frequency showing the spectral performance, and the tabulated AC analysis results are in Table 3. 2.7 V VSIG VSIG 0V 2.7V 4.02 k 2k 1.35 V 5V VS+ VIN 2.5 V 100 OPA835 4.02 k 2.2 nF VS- +In VDD REF ADS 8326 -In 2k 2k Figure 79. OPA835 and ADS8326 Test Circuit 0 -20 AIN - dBc -40 -60 -80 -100 -120 -140 0 20 40 60 80 f - Frequency - Hz 100 120 Figure 80. ADS8326 and OPA835 10kHz FFT Table 3. AC Analysis Tone (Hz) Signal (dBFS) SNR (dBc) THD (dBc) SINAD (dBc) SFDR (dBc) 10k –0.85 81.9 –87.5 80.8 89.9 Submit Documentation Feedback Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA835 OPA2835 37 OPA835 OPA2835 SLOS713D – JANUARY 2011 – REVISED OCTOBER 2011 www.ti.com Layout Recommendations OPA835 EVM (SLOU314) 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 an out of the op amp. 2. The feedback path should be short and direct avoiding vias if possible especially with G = +1. 3. Ground or power planes should be removed from directly under the amplifier’s negative input and output pins. 4. A series output resistor is recommended to be placed as near to the output pin as possible. See “Recommended Series Output Resistor vs. Capacitive Load” (Figure 41) for recommended values given expected capacitive load of design. 5. A 2.2 µF power supply decoupling capacitor should be placed within 2 inches of the device and can be shared with other op amps. For spit supply, a capacitor is required for both supplies. 6. A 0.1 µF power supply decoupling capacitor should be placed as near to the power supply pins as possible. Preferably within 0.1 inch. For split supply, a capacitor is required for both supplies. 7. The PD pin uses TTL logic levels. If not used it should tied to the positive supply to enable the amplifier. If used, it must be actively driven. A bypass capacitor is not necessary, but can be used for robustness in noisy environments. Spacer REVISION HISTORY Changes from Revision A (March 2011) to Revision B • Page Changed OPA835 from product preview to production data ................................................................................................ 1 Changes from Revision B (May 2011) to Revision C Page • Added the "The OPA835 RUN package..." text to the DESCRIPTION ................................................................................ 1 • Removed Product Preview from all devices except OPA835IRUNT and OPA835IRUNR ................................................... 2 • Replaced the TBD values in the Thermal Information table ................................................................................................. 2 • Changed - Channel to channel crosstalk (OPA2835) Typ value From: TBD To: -120 dB ................................................... 3 • Changed the Common-mode rejection ratio Min value From: 91 dB To: 88 dB .................................................................. 4 • Added GAIN SETTING RESISTORS (OPA835IRUN ONLY) .............................................................................................. 5 • Changed the Quiescent operating current (TA = 25°C) Min value From: 190 µA To: 175 µA .............................................. 5 • Changed the Power supply rejection (±PSRR) Min value From: 91 dB To: 88 dB .............................................................. 5 • Changed the Powerdown pin bias current CONDITIONS From: PD = 0.7V To: PD = 0.5V ................................................ 5 • Changed the Powerdown quiescent current CONDITIONS From: PD = 0.7V To: PD = 0.5V ............................................. 5 • Changed - Channel to channel crosstalk (OPA2835) Typ value From: TBD To: -120 dB ................................................... 6 • Changed the Common-mode rejection ratio Min value From: 94 dB To: 91 dB .................................................................. 7 • Added GAIN SETTING RESISTORS (OPA835IRUN ONLY) .............................................................................................. 8 • Changed the Quiescent operating current (TA = 25°C) Min value From: 215 µA To: 200 µA .............................................. 8 • Changed the Power supply rejection (±PSRR) Min value From: 93 dB To: 90 dB .............................................................. 8 • Changed the Powerdown quiescent current CONDITIONS From: PD = 0.7V To: PD = 0.5V ............................................. 8 • Changed the Powerdown quiescent current CONDITIONS From: PD = 0.7V To: PD = 0.5V ............................................. 8 • Changed the OPA835 WQFN-10 (RUN) pinout image ........................................................................................................ 9 • Added Figure Crosstalk vs Frequency ................................................................................................................................ 14 • Added Figure Crosstalk vs Frequency ................................................................................................................................ 20 • Added section Single Ended to Differential Amplifier ......................................................................................................... 24 38 Submit Documentation Feedback Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA835 OPA2835 OPA835 OPA2835 SLOS713D – JANUARY 2011 – REVISED OCTOBER 2011 www.ti.com Changes from Revision C (September 2011) to Revision D Page • Removed Product Preview from OPA835IRUNT and OPA835IRUNR ................................................................................ 2 • Changed Resistor Temperature Coefficient From: TBD To: <10 ......................................................................................... 5 • Changed Quiescent operating current To: Quiescent operating current per amplifer .......................................................... 5 • Changed Resistor Temperature Coefficient From: TBD To: <10 ......................................................................................... 8 • Changed Quiescent operating current To: Quiescent operating current per amplifer .......................................................... 8 Submit Documentation Feedback Copyright © 2011, Texas Instruments Incorporated Product Folder Link(s): OPA835 OPA2835 39 PACKAGE OPTION ADDENDUM www.ti.com 31-Oct-2011 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Drawing Pins Package Qty Eco Plan (2) Lead/ Ball Finish MSL Peak Temp (3) OPA2835ID ACTIVE SOIC D 8 75 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR OPA2835IDGS ACTIVE MSOP DGS 10 80 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR OPA2835IDGSR ACTIVE MSOP DGS 10 2500 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR OPA2835IDR ACTIVE SOIC D 8 2500 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR OPA2835IRUNR ACTIVE QFN RUN 10 3000 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR OPA2835IRUNT ACTIVE QFN RUN 10 250 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR OPA835IDBVR ACTIVE SOT-23 DBV 6 3000 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM OPA835IDBVT ACTIVE SOT-23 DBV 6 250 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM OPA835IRUNR ACTIVE QFN RUN 10 3000 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR OPA835IRUNT ACTIVE QFN RUN 10 250 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR Samples (Requires Login) (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. Addendum-Page 1 PACKAGE OPTION ADDENDUM www.ti.com 31-Oct-2011 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. Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. 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Addendum-Page 2 PACKAGE MATERIALS INFORMATION www.ti.com 1-Dec-2011 TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Pins Type Drawing OPA2835IDGSR MSOP DGS SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant 10 2500 330.0 12.4 5.3 3.4 1.4 8.0 12.0 Q1 OPA2835IDR SOIC D 8 2500 330.0 12.4 6.4 5.2 2.1 8.0 12.0 Q1 OPA2835IRUNR QFN RUN 10 3000 330.0 12.4 2.2 2.2 1.1 8.0 12.0 Q2 OPA2835IRUNT QFN RUN 10 250 180.0 12.4 2.2 2.2 1.1 8.0 12.0 Q2 OPA835IDBVR SOT-23 DBV 6 3000 178.0 9.0 3.23 3.17 1.37 4.0 8.0 Q3 OPA835IDBVT SOT-23 DBV 6 250 178.0 9.0 3.23 3.17 1.37 4.0 8.0 Q3 OPA835IRUNR QFN RUN 10 3000 330.0 12.4 2.2 2.2 1.1 8.0 12.0 Q2 OPA835IRUNT QFN RUN 10 250 180.0 12.4 2.2 2.2 1.1 8.0 12.0 Q2 Pack Materials-Page 1 PACKAGE MATERIALS INFORMATION www.ti.com 1-Dec-2011 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) OPA2835IDGSR MSOP DGS 10 2500 366.0 364.0 50.0 OPA2835IDR SOIC D 8 2500 340.5 338.1 20.6 OPA2835IRUNR QFN RUN 10 3000 346.0 346.0 29.0 OPA2835IRUNT QFN RUN 10 250 210.0 212.7 35.0 OPA835IDBVR SOT-23 DBV 6 3000 180.0 180.0 18.0 OPA835IDBVT SOT-23 DBV 6 250 180.0 180.0 18.0 OPA835IRUNR QFN RUN 10 3000 346.0 346.0 29.0 OPA835IRUNT QFN RUN 10 250 210.0 212.7 35.0 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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