Audio-grade low-voltage op-amp

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Bob Masta 17 years ago

I'm looking for a low-voltage op-amp to be used as a difference amp to provide DC coupling to a USB sound card. So far, my quest has only turned up rather s-l-o-o-w-w parts like the LT1013, LMV358, TLV2472, TS914, etc. Typical slew rates are 0.4 V/us to 1 V/us, typical unity gain is 700 kHz to

2.8 MHz... about in the same speed league as the old 741!

This will be a simple, classical difference amp, unity gain overall. (So effectively x2 on the non-inverting input.) I don't require true rail-to-rail operation, but I'd like to get to maybe half a volt, so I can swing +/- 2V about the

2.5V middle of a 5V supply.

For my immediate needs, any of those parts would probably be fine, since at the moment I'm interested in low-frequency measurements. But I'd like to be able to use the whole frequency range of the A/D, which can easily get to 20 kHz with a

48kHz sample rate, and much more for other models.

I'm not really looking for "audiophile" specs, just something with more gain margin at the upper end. (I'd be happy with a TL082 or LF353-equivalent, but could run within a half volt of the rails.)

Any recommendations?

Thanks, and best regards,

Bob Masta DAQARTA v4.51 Data AcQuisition And Real-Time Analysis

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Scope, Spectrum, Spectrogram, Sound Level Meter FREE Signal Generator Science with your sound card!

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John Larkin 17 years ago

LT1632 maybe.

John

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john 17 years ago

I've recently developed an intense liking for the mchip 'MCP6024'.

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DH1 17 years ago

Hello,

I keep a one-few line record of interesting parts as they arrive on market for future reference. 48kHz x 100 (rule of thumb guide) =3D desired bandwidth of the order of 5+MHz. Looking back some possibilities include,

National Semiconductor LMP2021, LMP2022, 5 Mhz, 2.6V/us, zero drift,

- 11 nV/sqrtHz noise at a gain of 1,000 V/V VOS 0.4 =B5V, 0.004 =B5V/=B0C of input offset voltage drift (TCVOS)= ,

2.2-5.5 V, 1.1 mA/channel, -40=B0C to 125=B0C, EMI hardened, 8-pin SOIC and 8-pin MSOP Obviously exceptional DC performance and 5MHz BW, a rare combination, plus low v.power & EMI hardening. (Two other recent near zero Voffset amps are the low bandwidth MAX4208/MAX4209H [750kHz], the TI INA333 [150 kHz]. Also the LTC6078 at 750kHz) Linear Technology LTC6241/2 18MHz, 10V/us typ, 125uVos max., +/-5.5Vmax or +/-6Vmax, 2.4mA/amp, R2RO, -40 -> 85degC., single, dual, DFN, SO8, SSOP16, LM6211 24V 20MHz SOT23-5 R2Routput lownoise Good set of specs. Linear Technology LTC6244 50MHz, 40V/us, 40uVos typ, 325uVos max, 6V or +/-5.25V (HV part), 4.8mA/channel, 8nVsqrtHz, R2R, dual-DFN- MSOP8 National Semiconuctor LMV791/2 17MHz, 8.5V/us, lownoise, 0.1Vos typ (+/-1.65Vos max.), 1.15/1.3mA, R2RO, -40-125degC, TSOT23-6, MSOP-10, LMV796/7 is similar National Semiconductor LME49720, 55 MHz GBW, 20V/us, (THD+N) of 0.00003% (600-Ohm Ro), 0.1Vos typ, 2.7 nV/sqrt Hz, Io 26mA, 10mA Isupply typ. AD8250/1/3 10MHz, 20V/us, +/-15V, 0.27mVos typ (G=3D1), 10ppm/degC gain drift, 4.1mA Isupply, MSOP10 instrumentation opamp, 1,2,4,8 and 1,2,5,10 gains TI TLC070/1/2/3 10MHz, 16V/us typ., 0.39mVos typ. (1.9mV max.), 1.9mA/ channel, 16 Vsupply max., 8/10MSOP (the datasheet claims 60uVos in the features, 1.5mV max. in the intro., then 0.39mVtyp/1.9mVmax. in the specs.) TI OPA2889, 115MHz, 250V/us, 460 =B5A Iquiescent, 18 =B5A when not in use, +/5mV Vos, 2.6 to 12 Vsupply, =B11.3 to =B16 Vsupply, Vo/p swing 8 Vp-p, Io =B140 mA, SOIC-8 & MSOP-10 V.fast, low power, however large Vos.

Regards,

DH

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D

DH1 17 years ago

Hello,

I keep a one-few line record of interesting parts as they arrive on market for future reference. 48kHz x 100 (rule of thumb guide) =3D desired bandwidth of the order of 5+MHz. Looking back some possibilities include,

National Semiconductor LMP2021, LMP2022, 5 Mhz, 2.6V/us, zero drift, 11 nV/sqrtHz noise at a gain of 1,000 V/V VOS 0.4 =B5V, 0.004 =B5V/=B0C of input offset voltage drift (TCVOS)= , 2.2-5.5 V, 1.1 mA/channel, -40=B0C to 125=B0C, EMI hardened, 8-pin SOIC and 8-pin MSOP Obviously exceptional DC performance and 5MHz BW, a rare combination, plus low v.power & EMI hardening. (Two other recent near zero Voffset amps are the low bandwidth MAX4208/MAX4209H [750kHz], the TI INA333 [150 kHz]. Also the LTC6078 at 750kHz)

Linear Technology LTC6241/2 18MHz, 10V/us typ, 125uVos max., +/-5.5Vmax or +/-6Vmax, 2.4mA/amp, R2RO,

-40 -> 85degC., single, dual, DFN, SO8, SSOP16, LM6211 24V 20MHz SOT23-5 R2Routput lownoise Good set of specs.

Linear Technology LTC6244 50MHz, 40V/us, 40uVos typ, 325uVos max, 6V or +/-5.25V (HV part), 4.8mA/channel, 8nVsqrtHz, R2R, dual-DFN- MSOP8

National Semiconuctor LMV791/2 17MHz, 8.5V/us, lownoise, 0.1Vos typ (+/-1.65Vos max.), 1.15/1.3mA, R2RO, -40-125degC, TSOT23-6, MSOP-10, LMV796/7 is similar

National Semiconductor LME49720, 55 MHz GBW, 20V/us, (THD+N) of 0.00003% (600-Ohm Ro), 0.1Vos typ,

2.7 nV/sqrt Hz, Io 26mA, 10mA Isupply typ.

AD8250/1/3 10MHz, 20V/us, +/-15V, 0.27mVos typ (G=3D1), 10ppm/degC gain drift, 4.1mA Isupply, MSOP10 instrumentation opamp, 1,2,4,8 and 1,2,5,10 gains

TI TLC070/1/2/3 10MHz, 16V/us typ., 0.39mVos typ. (1.9mV max.),

1.9mA/ channel, 16 Vsupply max., 8/10MSOP (the datasheet claims 60uVos in the features, 1.5mV max. in the intro., then 0.39mVtyp/ 1.9mVmax. in the specs.)

TI OPA2889, 115MHz, 250V/us, 460 =B5A Iquiescent, 18 =B5A when not in use, +/5mV Vos, 2.6 to 12 Vsupply, =B11.3 to =B16 Vsupply, Vo/p swing 8 Vp-p, Io =B140 mA, SOIC-8 & MSOP-10 V.fast, low power, however large Vos.

Regards,

DH

Vote

D

DH1 17 years ago

Hello,

I keep a one-few line record of interesting parts as they arrive on market for future reference. 48kHz x 100 (rule of thumb guide) =3D desired bandwidth of the order of 5+MHz. Looking back some possibilities include,

National Semiconductor LMP2021, LMP2022, 5 Mhz, 2.6V/us, zero drift, 11 nV/sqrtHz noise at a gain of 1,000 V/V VOS 0.4 =B5V, 0.004 =B5V/=B0C of input offset voltage drift (TCVOS)= , 2.2-5.5 V, 1.1 mA/channel, -40=B0C to 125=B0C, EMI hardened, 8-pin SOIC and 8-pin MSOP Obviously exceptional DC performance and 5MHz BW, a rare combination, plus low v.power & EMI hardening. (Two other recent near zero Voffset amps are the low bandwidth MAX4208/MAX4209H [750kHz], the TI INA333 [150 kHz]. Also the LTC6078 at 750kHz)

Linear Technology LTC6241/2 18MHz, 10V/us typ, 125uVos max., +/-5.5Vmax or +/-6Vmax, 2.4mA/amp, R2RO, -40 -> 85degC., single, dual, DFN, SO8, SSOP16, LM6211 24V 20MHz SOT23-5 R2Routput lownoise Good set of specs.

Linear Technology LTC6244 50MHz, 40V/us, 40uVos typ, 325uVos max, 6V or +/-5.25V (HV part), 4.8mA/channel, 8nVsqrtHz, R2R, dual-DFN- MSOP8

National Semiconuctor LMV791/2 17MHz, 8.5V/us, lownoise, 0.1Vos typ (+/-1.65Vos max.), 1.15/1.3mA, R2RO, -40-125degC, TSOT23-6, MSOP-10, LMV796/7 is similar

National Semiconductor LME49720, 55 MHz GBW, 20V/us, (THD+N) of 0.00003% (600-Ohm Ro), 0.1Vos typ, 2.7 nV/sqrt Hz, Io 26mA, 10mA Isupply typ.

AD8250/1/3 10MHz, 20V/us, +/-15V, 0.27mVos typ (G=3D1), 10ppm/degC gain drift, 4.1mA Isupply, MSOP10 instrumentation opamp, 1,2,4,8 and 1,2,5,10 gains

TI TLC070/1/2/3 10MHz, 16V/us typ., 0.39mVos typ. (1.9mV max.), 1.9mA/channel, 16 Vsupply max., 8/10MSOP (the datasheet claims 60uVos in the features, 1.5mV max. in the intro., then 0.39mVtyp/ 1.9mVmax. in the specs.)

TI OPA2889, 115MHz, 250V/us, 460 =B5A Iquiescent, 18 =B5A when not in use, +/5mV Vos, 2.6 to 12 Vsupply, =B11.3 to =B16 Vsupply, Vo/p swing 8 Vp-p, Io =B140 mA, SOIC-8 & MSOP-10 V.fast, low power, however large Vos.

Regards,

DH

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Audio-grade low-voltage op-amp

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