LT1991 Linear Technology, LT1991 Datasheet
LT1991
Available stocks
Related parts for LT1991
LT1991 Summary of contents
Page 1
... The LT1991 is fully specifi and ±15V supplies and from –40°C to 125°C. The device is available in space saving 10-lead MSOP and low profi le (0.8mm) 3mm × ...
Page 2
... For more information on lead free part marking, go to: For more information on tape and reel specifi cations, go to: 2 Specifi ed Temperature Range (Note 5) LT1991C ............................................... –40°C to 85°C LT1991I ................................................ –40°C to 85°C LT1991H ............................................ –40°C to 125°C + – – 0.2V Maximum Junction Temperature DD Package .......................................................... 125° ...
Page 3
... V = half supply, unless otherwise noted. CM REF CONDITIONS V = ±15V ±10V 10k S OUT LT1991A LT1991 LT1991A LT1991 ±15V ±10V 10k S OUT ±15V ±10V 10k S OUT ...
Page 4
... P1 (M1 = Ground (M3 = Ground (M9 = Ground (P1 = Ground (P3 = Ground (P9 = Ground) l 450k Resistors, LT1991A l Other Resistors, LT1991A l 450k Resistors, LT1991 l Other Resistors, LT1991 l l Absolute Value ±1.35V to ±18V (Note Load ±15V ...
Page 5
... 1kHz 1kHz l P1 (M1 = Ground (M3 = Ground (M9 = Ground (P1 = Ground (P3 = Ground (P9 = Ground) l 450k Resistors l Other Resistors l l Absolute Value LT1991 www.DataSheet4U.com MIN TYP MAX UNITS ±0.08 % ±0. ppm 0.3 3 ppm/°C 77 100 ...
Page 6
... Note 3: A heat sink may be required to keep the junction temperature below absolute maximum ratings. Note 4: Both the LT1991C and LT1991I are guaranteed functional over the –40°C to 85°C temperature range. The LTC1991H is guaranteed functional over the –40°C to 125°C temperature range. ...
Page 7
... OUT T = 25°C A 0.02 0.01 0 –0.01 –0.02 –0.03 REPRESENTATIVE UNITS –0. LOAD CURRENT (mA) LT1991 www.DataSheet4U.com (Difference Amplifi er Confi guration) Output Voltage Swing vs Load Current (Output Low) V 1400 5V –20 1200 T = 85°C A –40 1000 –60 800 T = 25° ...
Page 8
... LT1991 TYPICAL PERFORMANCE CHARACTERISTICS Bandwidth vs Gain 120 25°C A 100 GAIN SETTING (V/V) 1991 G10 Output Impedance vs Frequency 1000 25°C A 100 GAIN = 9 10 GAIN = 3 GAIN = 1 1 0.1 0. 100 1k 10k ...
Page 9
... INM OUT 450k INP LT1991 150k 450k 50k 4pF REF EE LT1991 www.DataSheet4U.com Small Signal Transient Response GAIN = 9 50mV/DIV 5μs/DIV = • (V – V OUT REF P1 M1 – voltage 1991 BD 1991 G20 ) + 3 • ...
Page 10
... LT1991 APPLICATIONS INFORMATION Introduction The LT1991 may be the last op amp you ever have to stock. Because it provides you with several precision matched resistors, you can easily confi gure it into several different classical gain circuits without adding external components. The several pages of simple circuits in this data sheet demonstrate just how easy the LT1991 is to use. It can be confi ...
Page 11
... more than 10mA is allowed to fl ow through these EE pins, there is a risk that the LT1991 will be detrimmed or damaged. The P1 and M1 inputs do not have clamp diodes or substrate diodes or trim circuitry and can be taken well outside the supply rails. The maximum allowed voltage on the P1 and M1 pins is ± ...
Page 12
... One of the benefi the noninverting op amp confi gura- REF tion is that the input impedance is extremely high. The LT1991 maintains this benefi t. Given the fi nite number of available feedback resistors in the LT1991, the number of gain confi gurations is also fi nite. The complete list of such Hi-Z input noninverting gain confi ...
Page 13
... Ground Output 4 Float Ground 5 Float Ground 5.5 Ground Float 7 Ground Ground 10 Ground Float 11 Ground Float 13 Ground Ground 14 Ground Ground LT1991 www.DataSheet4U.com M1 Output Ground Ground Ground Output Float Ground Ground Output Output Float Ground Float Ground Output Output Float Ground Float Ground 13 1991fg ...
Page 14
... – GAIN = Figure 5. Some Implementations of Classical Noninverting Gains Using the LT1991. High Input Z Is Maintained LT1991 OUT OUT 1 REF ...
Page 15
... DRIVING AND GROUNDING AND FLOATING INPUTS R = 450k Figure 6. LT1991 Provides for Easy Attenuation to the Op Amp’s +Input. The P1 Input Can Be Taken Well Outside of the Supplies. Because the attenuations and the noninverting gains are set independently, they can be combined. This provides high gain resolution, about 340 unique gains between 0 ...
Page 16
... GAIN = –4. GAIN IS ACHIEVED BY GROUNDING, FLOATING OR FEEDING BACK THE AVAILABLE RESISTORS TO ARRIVE AT DESIRED R WE PROVIDE YOU WITH <0.1% RESISTORS. Figure 8. The LT1991 as a Classical Inverting Op Amp. Note the Circuit Is Identical to the Noninverting Amplifi er, Except that V and Ground Have Been Swapped Table 3. Confi ...
Page 17
... LT1991 GAIN = –12 Figure Simple to Get Precision Inverting Gains with the LT1991. Input Impedance Varies from 45kΩ (Gain = –13) to 450kΩ (Gain = –1 LT1991 ...
Page 18
... M1 Figure 10. Difference Amplifi er Using the LT1991. Gain Is Set Simply by Connecting the Correct Resistors or Combinations Resistors. Gain Shown, with Dashed Lines Modifying Gain of 1.5. Noise Gain Is Optimal. www.DataSheet4U.com – ...
Page 19
... OUT V OUT 1 REF – GAIN = 12 LT1991 www.DataSheet4U.com + – LT1991 OUT OUT 1 REF – GAIN = 2. – LT1991 OUT ...
Page 20
... R F CLASSICAL DIFFERENCE AMPLIFIER Figure 12. Another Method of Selecting Difference Gain Is “Cross-Coupling.” The Additional Method Means the LT1991 Provides All Integer Gains from 1 to 13. Difference Amplifi er: Additional Integer Gains Using Cross-Coupling Figure 12 shows the basic difference amplifi well as the LT1991 in a difference gain of 3 ...
Page 21
... R attenuate the common mode voltage seen T by the op amp inputs. For the LT1991, the most useful resistors for R are the M1 and P1 450kΩ resistors, be- G cause they do not have diode clamps to the supplies and therefore can be taken outside the supplies ...
Page 22
... LT1991 OUT REF 1.25V P9 4 1.25V V = –2.25V TO 8.95V CM Figure 15. Common Mode Ranges for Various LT1991 Confi gurations – LT1991 OUT OUT REF ...
Page 23
... CC – LT1991 V OUT 1 + REF 2. 2. –18.5V TO 20.7V CM Figure 16. Common Mode Ranges for Various LT1991 Confi gurations – LT1991 OUT OUT REF ...
Page 24
... CC – LT1991 OUT REF – –56V TO 53.2V CM Figure 17. Common Mode Ranges for Various LT1991 Confi gurations – LT1991 OUT OUT REF ...
Page 25
... TYPICAL APPLICATIONS + V M 1/2 LT6011 – 1/2 LT6011 – Micropower Instrumentation Amplifi – + 4pF LT1991 www.DataSheet4U.com V OUT 7 6 4pF LT1991 4 5 1991 TA02 25 1991fg ...
Page 26
... LT1991 PACKAGE DESCRIPTION 3.50 ±0.05 1.65 ±0.05 2.15 ±0.05 (2 SIDES) 0.25 ± 0.05 RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS PIN 1 TOP MARK (SEE NOTE 6) 0.200 REF 26 DD Package 10-Lead Plastic DFN (3mm × 3mm) (Reference LTC DWG # 05-08-1699) 0.675 ±0.05 PACKAGE OUTLINE 0.50 BSC 2.38 ±0.05 (2 SIDES) 1.65 ± 0.10 3.00 ± ...
Page 27
... TYP 0.53 ± 0.152 (.021 ± .006) DETAIL “A” SEATING PLANE 0.17 – 0.27 (.007 – .011) TYP LT1991 www.DataSheet4U.com 0.497 ± 0.076 (.0196 ± .003 REF 3.00 ± 0.102 (.118 ± .004) (NOTE ...
Page 28
... Common Mode, Micropower, Pin Selectable Gain = 1, 10 Micropower, Pin Selectable Gain = – 30MHz, 1000V/μs, Pin Selectable Gain = – Similar Op Amp Performance as Used in LT1991 Difference Amplifi er Lower Noise Gain Confi gurations, Rail-to-Rail Input and Output www.linear.com ● ...