Datasheet

ManualsBrandsTEXAS INSTRUMENTS ManualsLinear ICsLinear IC - Op-amp Multi-purpose TO 99 8

Dual Low Noise Precision

Difet

OPERATIONAL AMPLIFIER

FEATURES

● LOW NOISE: 100% Tested, 8nV/√Hz max at

10kHz

● LOW BIAS CURRENT: 4pA max

● LOW OFFSET: 500

µV max

● LOW DRIFT: 2.8

µV/°C

● HIGH OPEN-LOOP GAIN: 114dB min

● HIGH COMMON-MODE REJECTION:

96dB min

APPLICATIONS

● PRECISION INSTRUMENTATION

● DATA ACQUISITION

● TEST EQUIPMENT

● PROFESSIONAL AUDIO EQUIPMENT

● MEDICAL EQUIPMENT

● DETECTOR ARRAYS

International Airport Industrial Park • Mailing Address: PO Box 11400 • Tucson, AZ 85734 • Street Address: 6730 S. Tucson Blvd. • Tucson, AZ 85706

Tel: (520) 746-1111 • Twx: 910-952-1111 • Cable: BBRCORP • Telex: 066-6491 • FAX: (520) 889-1510 • Immediate Product Info: (800) 548-6132

BIFET

National Semiconductor Corp.,

Difet

Burr-Brown Corp.

Noise-Free

Cascode*

OPA2111 Simplified Circuit

(Each Amplifier)

Output

–V

–In

+In

*Patented

OPA2111

DESCRIPTION

The OPA2111 is a high precision monolithic

dielectrically isolated FET (

Difet

) operational ampli-

fier. Outstanding performance characteristics allow its

use in the most critical instrumentation applications.

Noise, bias current, voltage offset, drift, open-loop

gain, common-mode rejection, and power supply re-

jection are superior to BIFET

amplifiers.

Very low bias current is obtained by dielectric isola-

tion with on-chip guarding.

Laser trimming of thin-film resistors gives very low

offset and drift. Extremely low noise is achieved with

patented circuit design techniques. A cascode design

allows high precision input specifications and reduced

susceptibility to flicker noise.

Standard dual op amp pin configuration allows up-

grading of existing designs to higher performance

levels.

SBOS140

Summary of content (15 pages)

PAGE 1
® OPA2111 Dual Low Noise Precision Difet ® OPERATIONAL AMPLIFIER FEATURES APPLICATIONS ● LOW NOISE: 100% Tested, 8nV/√Hz max at 10kHz ● PRECISION INSTRUMENTATION ● DATA ACQUISITION ● TEST EQUIPMENT ● ● ● ● ● LOW BIAS CURRENT: 4pA max LOW OFFSET: 500µV max LOW DRIFT: 2.
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SPECIFICATIONS ELECTRICAL At VCC = ±15VDC and TA = +25°C unless otherwise noted . OPA2111AM PARAMETER CONDITION INPUT NOISE Voltage, fO = 10Hz fO = 100Hz fO = 1kHz fO = 10kHz fB = 10Hz to 10kHz fB = 0.1Hz to 10Hz Current, fB = 0.1Hz to 10Hz fO = 0.1Hz to 20kHz OFFSET VOLTAGE(2) Input Offset Voltage Average Drift Match Supply Rejection MIN 100% Tested 100% Tested 100% Tested (1) (1) (1) (1) (1) VCM = 0VDC TA = TMIN to TMAX 90 OPA2111BM TYP MAX 40 15 8 6 0.7 1.6 15 0.
PAGE 3
ELECTRICAL (FULL TEMPERATURE RANGE SPECIFICATIONS) At VCC = ±15VDC and TA = TMIN to TMAX unless otherwise noted. OPA2111AM PARAMETER TEMPERATURE RANGE Specification Range CONDITION MIN Ambient Temp. –25 INPUT OFFSET VOLTAGE(1) Input Offset Voltage Average Drift Match Supply Rejection VOLTAGE RANGE Common-Mode Input Range Common-Mode Rejection +85 –25 TYP OPA2111SM MAX MIN +85 –55 VCM = 0VDC ±125 60 ±1nA ±75 30 ±500 VCM = 0VDC ±75 ±750 ±38 ±375 ±0.08 ±0.75 ±0.5 ±2.8 0.
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DICE INFORMATION PAD FUNCTION 1 2 3 4 5 6 7 8 NC Out A –In A +In A –VS +In B –In B Out B +VS No Connection Substrate Bias: No Connection MECHANICAL INFORMATION Die Size Die Thickness Min. Pad Size OPA2111AD DIE TOPOGRAPHY MILS (0.001") MILLIMETERS 138 x 84 ±5 20 ±3 4x4 3.51 x 2.13 ±0.13 0.51 ±0.08 0.10 x 0.10 Backing Transistor Count None 102 TYPICAL PERFORMANCE CURVES TA = +25°C, and VCC = ±15VDC unless otherwise noted.
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TYPICAL PERFORMANCE CURVES (CONT) TA = +25°C, and VCC = ±15VDC unless otherwise noted. TOTAL(1) INPUT VOLTAGE NOISE SPECTRAL DENSITY vs SOURCE RESISTANCE INPUT OFFSET VOLTAGE WARM-UP DRIFT 1k 40 Offset Voltage Change (µV) RS = 1MΩ 100 RS = 100kΩ BM 10 RS = 100Ω NOTE: (1) Includes contribution from source resistance.
PAGE 6
TYPICAL PERFORMANCE CURVES (CONT) TA = +25°C, and VCC = ±15VDC unless otherwise noted.
PAGE 7
TYPICAL PERFORMANCE CURVES (CONT) TA = +25°C, VCC = ±15VDC unless otherwise noted. COMMON-MODE REJECTION vs FREQUENCY LARGE SIGNAL TRANSIENT RESPONSE 120 15 100 Output Voltage (V) Common-Mode Rejection (dB) 140 80 60 40 0 –15 20 0 1 10 100 1k 10k 100k 1M 25 0 10M OPEN-LOOP FREQUENCY RESPONSE SETTLING TIME vs CLOSED-LOOP GAIN 140 100 Gain φ 80 –90 Phase Margin ≈ 65° 60 40 –135 80 Settling Time (µs) 100 Phase Shift (Degrees) –45 60 0.01% 40 0.
PAGE 8
TYPICAL PERFORMANCE CURVES (CONT) TA = +25°C, VCC = ±15VDC unless otherwise noted.
PAGE 9
GUARDING AND SHIELDING APPLICATIONS CIRCUITS As in any situation where high impedances are involved, careful shielding is required to reduce “hum” pickup in input leads. If large feedback resistors are used, they should also be shielded along with the external input circuitry. Figures 5 through 13 are circuit diagrams of various applications for the OPA2111. Leakage currents across printed circuit boards can easily exceed the bias current of the OPA2111.
PAGE 10
<1pF to prevent gain peaking 100Ω 1000MΩ 10kΩ 2 1/2 OPA2111BM 1 +15V Pin Photodiode UDT Pin-040A 3 5.34MΩ(1) Guard 0.1µF 2 8 1/2 OPA2111 3 0.01µF 5 1000pF 7 4 0.1µF 1000MΩ 1/2 OPA2111BM In Output 1 Out 5.34MΩ(1) 5 x 108V/W 2.67MΩ(1) 500pF –15V Circuit must be well shielded. 2kΩ Q 6 500pF NOTE: (1) For 50Hz use 3.16MΩ and 6.37Ω. Gain = 101 FIGURE 6. Sensitive Photodiode Amplifier. FIGURE 7. High Impedance 60Hz Reject Filter with Gain. 10.5kΩ 0.03µF 0.01µF 73.
PAGE 11
3 IB = ±4pA max Gain = 100 CMRR ≈ 106dB RIN ≈ 1013Ω 1/2 OPA2111BM 1 –In 2 RF 5kΩ RG 101Ω 6 25kΩ 2 RF 5kΩ 25kΩ 5 6 25kΩ 3 Output 1/2 OPA2111BM 25kΩ 7 5 Burr-Brown INA105 Differential Amplifier 1 +In Differential Voltage Gain = 1 + 2RF /RG FIGURE 9. FET Input Instrumentation Amplifier. 10kΩ ≈10pF (1) 1MΩ 6 IN914 2 1/2 OPA2111AM 1/2 OPA2111AM (1) 1 3 Output 7 (1) IN914 Input 5 Droop ≈ 0.5mV/s 2N4117A 0.01µF Polystyrene NOTE: (1) Reverse polarity for negative peak detection.
PAGE 12
100Ω 10kΩ 2 Input 1/2OPA2111 1 10kΩ 3 100Ω 10kΩ Since signal voltage sums directly with N but amplifier noise voltage sums as N, signal-to-noise ratio improves by N. 6 1/2OPA2111 7 10kΩ 5 100Ω AV = –1010 en = 1.9nV/ Hz typ(1) at 10kHz BW = 30kHz typ GBW = 30.3 MHz typ VOS = ±16µV typ(1) ∆VOS/∆T = ±0.
PAGE 13
1/2 OPA2111 E1 –In 1 A1 R2 10kΩ R1 202Ω R2 10kΩ 10kΩ 2 INA106 100kΩ 6 10kΩ 3 5 EO Output 1/2 OPA2111 100kΩ AV = 10 A2 1 E2 +In EO = 10(1 + 2 R2/R1)(E2 – E1) = 1000(E2 – E1) Using the INA106 for an output difference amplifier extends the input common-mode range of an instrumentation amplifier to ±10V. A conventional IA with a unity-gain difference amplifier has an input common-mode range limited to ±5V for an output swing of ±10V.
PAGE 14
PACKAGE OPTION ADDENDUM www.ti.
PAGE 15
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