LTC1100CN8

LTC1100 Precision, Zero-Drift Instrumentation Amplifier FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ DESCRIPTIO Offset Voltage: 10µV Max Offset Voltage Drift: 100nV/°C Max Bias Current: 65pA Max Offset Current: 65pA Max Gain Nonlinearity: 20ppm Max Gain Error: ±0.075% Max CMRR: 90dB 0.1Hz to 10Hz Noise: 1.9µVP-P Single 5V Supply Operation 8-Pin MiniDIP The LTC®1100 is a high precision instrumentation amplifier using zero-drift techniques to achieve outstanding DC performance. The input DC offset is typically 1µV while the DC offset drift is typically 5nV/°C; a very low bias current of 65pA is also achieved. The LTC1100 is self-contained; that is, it achieves a differential gain of 100 without any external gain setting resistor or trim pot. The gain linearity is 20ppm and the gain drift is 4ppm/°C. The LTC1100 operates from a single 5V supply up to ± 8V. The output typically swings 300mV from its power supply rails with a 10k load. An optional external capacitor can be added from Pin 7 to Pin 8 to tailor the device’s 18kHz bandwidth and to eliminate any unwanted noise pickup. The LTC1100 is also offered in a 16-pin surface mount package with selectable gains of 10 or 100. The LTC1100 is manufactured using Linear Technology’s enhanced LTCMOSTM silicon gate process. , LTC and LT are registered trademarks of Linear Technology Corporation. LTCMOS is a trademark of Linear Technology Corporation APPLICATIO S ■ ■ ■ Thermocouple Amplifiers Strain Gauge Amplifiers Differential to Single-Ended Converters TYPICAL APPLICATIO Single 5V Supply, DC Instrumentation Amplifier 1 2 –VIN 3 4 LTC1100 8 7 6 5 0.01µF VIN VOUT V+ = 5V 0.1µF VOUT = 100 [VIN – (–VIN)] LTC1100 • TA01 U 1100fc U U 1 LTC1100 ABSOLUTE AXI U RATI GS Operating Temperature Range LTC1100M/AM (OBSOLETE) ........... − 55°C to 125°C LTC1100C ......................................... − 40°C to 85°C Output Short Circuit Duration ......................... Indefinite PACKAGE/ORDER I FOR ATIO TOP VIEW GND REF 1 CMRR 2 –VIN 3 V– 4 8 7 6 5 VOUT COMP VIN V+ ORDER PART NUMBER LTC1100CN8 N8 PACKAGE 8-LEAD PDIP TJMAX = 110°C, θJA = 130°C/W J PACKAGE 8-LEAD CERDIP TJMAX = 150°C, θJA = 100°C/W LTC1100CJ8 LTC1100AMJ8 LTC1100MJ8 OBSOLETE PACKAGE Consider the N Package for an Alternate Source Consult LTC Marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS PARAMETER Gain Error CONDITIONS The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VS = ± 5V, R L = 10k, C C = 1000pF, unless otherwise noted. MIN ● Gain Nonlinearity ● Input Offset Voltage Input Offset Voltage Drift Input Noise Voltage Input Bias Current (Note 2) (Note 2) DC to 10Hz, TA = 25°C ● ● Input Offset Current Common Mode Rejection Ratio Power Supply Rejection Ratio Output Voltage Swing Supply Current VCM = 2.3V to − 4.7V (Note 3) VS = ± 2.375V to ± 8V RL = 2k, VS = ± 8V RL =10k, VS = ± 8V Internal Sampling Frequency Bandwidth 2 U U W WW U W (Note 1) Storage Temperature Range ................ − 65°C to 150°C Total Supply Voltage (V + to V −) ............................. 18V Input Voltage ....................... (V + + 0.3V) to (V − − 0.3V) Lead Temperature (Soldering, 10 sec)................. 300°C TOP VIEW NC 1 GND REF 2 G = 10 3 CMRR 4 NC 5 –VIN 6 V– 7 16 NC 15 VOUT 14 G = 10 13 COMP 12 NC 11 VIN 10 V+ 9 NC ORDER PART NUMBER LTC1100CSW NC 8 SW PACKAGE 16-LEAD PLASTIC SO WIDE TJMAX = 110°C, θJA = 100°C/W LTC1100ACN TYP MAX 0.01 3 12 ±1 ±5 1.9 2.5 50 120 50 0.05 0.10 8 30 ± 10 ± 100 MIN LTC1100CN/CJ TYP MAX 0.01 3 12 ±1 ±5 1.9 2.5 10 65 135 65 0.075 0.150 20 60 ± 10 ± 100 UNITS ±% ±% ppm ppm µV nV/°C µVP-P pA pA pA dB dB ● ● ● ● ● ● 10 104 120 – 7.2 – 7.7 2.4 3.4 2.8 18 115 90 105 6.2 7.5 2.8 4.0 – 7.2 – 7.7 110 6.2 7.5 2.4 3.4 2.8 18 3.3 4.5 V V mA mA kHz kHz 1100fc LTC1100 ELECTRICAL CHARACTERISTICS PARAMETER Gain Error CONDITIONS The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VS = ± 5V, R L = 10k, C C = 1000pF, unless otherwise noted. LTC1100AMJ (Note 4) MIN TYP MAX 0.01 ● MIN LTC1100MJ TYP MAX 0.01 3 ±1 ±5 1.9 5 0.075 0.150 20 65 ± 10 ± 100 65 450 120 UNITS ±% ±% ppm ppm µV nV/°C µVP-P pA pA pA dB dB 0.05 0.11 8 40 ± 10 ± 100 50 300 80 90 95 7.4 6.0 – 7.4 – 7.0 Gain Nonlinearity ● 3 (Note 2) (Note 2) DC to 10Hz, TA = 25°C ● ● Input Offset Voltage Input Offset Voltage Drift Input Noise Voltage Input Bias Current Input Offset Current Common Mode Rejection Ratio Power Supply Rejection Ratio Output Voltage Swing Supply Current ±1 ±5 1.9 5 ● VCM = − 4.7V to 2.3V VS = ± 2.375V to ± 8V RL = 10k, VS = ± 8V RL = 2k, VS = ± 8V ● ● ● ● ● 100 115 – 7.4 – 7.0 2.4 4.2 2.8 18 7.4 6.0 2.4 2.8 18 3.3 4.6 V V mA mA kHz kHz Internal Sampling Frequency Bandwidth ELECTRICAL CHARACTERISTICS PARAMETER Gain Error CONDITIONS TA = 25°C, A V =100 A V =100 A V =10 A V =10 TA = 25°C, A V =100 A V =100 A V =10 A V =10 (Note 2) (Note 2) DC to 10Hz, TA = 25°C The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VS = ± 5V, R L = 10k, C C = 1000pF, unless otherwise specified. MIN ● LTC1100ACS TYP MAX 0.01 0.01 0.05 0.10 0.04 0.10 8 30 8 25 ± 10 ± 100 50 120 50 MIN LTC1100CSW TYP MAX 0.01 0.01 3 12 1 ±1 ±5 1.9 2.5 10 65 135 65 0.075 0.150 0.060 0.150 20 60 10 40 ± 10 ± 100 UNITS ±% ±% ±% ±% ppm ppm ppm ppm µV nV/°C µVP-P pA pA pA dB dB dB ● ● ● Gain Nonlinearity 3 12 1 ±1 Input Offset Voltage Input Offset Voltage Drift Input Noise Voltage Input Bias Current ● ±5 1.9 2.5 ● Input Offset Current Common Mode Rejection Ratio VCM = − 4.7V to 2.3V, A V =100 A V =10 VS = ± 2.375V to ± 8V ● ● ● ● 10 104 95 120 115 90 85 105 110 Power Supply Rejection Ratio 1100fc 3 LTC1100 ELECTRICAL CHARACTERISTICS PARAMETER Output Voltage Swing Supply Current CONDITIONS RL=10k, VS = ± 8V RL= 2k, VS = ± 8V The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VS = ± 5V, R L = 10k, C C = 1000pF, unless otherwise noted. MIN ● ● ● LTC1100ACS TYP MAX 6.2 7.5 2.4 3.4 2.8 18 180 2.8 4.0 MIN – 7.2 – 7.7 LTC1100CSW TYP MAX 6.2 7.5 2.4 3.4 2.8 18 180 3.3 4.5 UNITS V V mA mA kHz kHz kHz – 7.2 – 7.7 Internal Sampling Frequency Bandwidth G = 100 G = 10 Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: These parameters are guaranteed by design. Thermocouple effects preclude measurement of these voltage levels in high speed automatic test systems. VOS is measured to a limit determined by test equipment capability. Note 3: See Applications Information, Single Supply Operation. Note 4: Please consult Linear Technology Marketing. BLOCK DIAGRA S 2 R 7 5 (V ) 99R 1 + – 3 + 6 TYPICAL PERFOR A CE CHARACTERISTICS Gain Error vs Temperature 0.05 0.04 VS = ± 8V RL = 50k DIFFERENTIAL GAIN (dB) 35 PHASE 30 25 20 15 10 GAIN (G = 10) GAIN ERROR (± %) 0.03 0.02 0.01 0 GAIN (G = 100) 150 120 90 60 30 0 GAIN NONLINEARITY (ppm) –0.01 –50 –25 75 0 25 50 TEMPERATURE (°C) 4 UW W R 14 99R 2 90R 9R 4 10 (V+) 9R 90R − + R R 13 – 8 3 6 – 15 + 4 (V –) R = 2.5k 11 + 7 (V – ) R = 2.5k LTC1100 • BD02 LTC1100 • BD01 NOTE: FOR A VOLTAGE GAIN OF 10V/V SHORT PIN 2 TO 3, AND PIN 14 TO 15. Gain, Phase vs Frequency 45 40 210 180 PHASE SHIFT (DEGREES) 25 20 15 10 5 0 Gain Nonlinearity vs Temperature VS = ± 8V RL = 50k 100 125 5 100 1k 10k FREQUENCY (Hz) 100k –30 1M –5 –50 –25 75 0 25 50 TEMPERATURE (°C) 100 125 LTC1100 • TPC01 LTC1100 • TPC02 LTC1100 • TPC03 1100fc LTC1100 TYPICAL PERFOR A CE CHARACTERISTICS Supply Current vs Supply Voltage 4 POWER SUPPLY REJECTION RATIO (dB) TA = – 55°C 3 TA = 25°C COMMON MODE RANGE (V) SUPPLY CURRENT (mA) 2 TA = 125°C 1 0 2 6 10 12 14 16 4 8 TOTAL SUPPLY VOLTAGE V+ TO V – (V) 18 CMRR vs Frequency 120 100 80 CMRR (dB) 60 40 20 0 0.1 G = 100, RC = 100k CC = 10pF ±10 ±9 VOUT ± SWING (V) G = 100, RC = ∞ CC = 0pF ± 8 NEGATIVE ±7 ±6 ±5 NEGATIVE ±4 ±3 ±2 ±1 0 NEGATIVE VS = ± 8V, TA ≤ 85°C POSITIVE VS = ±5V, TA ≤ 85°C POSITIVE VS = ±2.5V, TA ≤ 85°C POSITIVE PEAK-TO-PEAK OUTPUT SWING (V) RC CC 1 3 G = 10, RC = ∞ CC = 0pF 2 – LTC1100 6 + 1 10 100 1k FREQUENCY (Hz) 10k 100k Bias Current vs Common Mode Voltage 360 300 240 BIAS CURRENT (pA) VOLTAGE NOISE DENSITY (nV/ √ Hz) 180 120 60 0 – 60 TA = 125°C SAMPLING FREQUENCY (kHz) TA = 25°C TA = – 55°C –120 –180 –200 –6 –5 –4 –3 –2 –1 0 1 2 COMMON MODE VOLTAGE (V) UW LTC1100 • TPC04 LTC1100 • TPC07 Power Supply Rejection Ratio vs Frequency 150 125 100 75 50 25 0 0.1 1 1k 10 100 FREQUENCY (Hz) 10k 100k 8 6 4 2 0 –2 –4 –6 –8 Common Mode Range vs Supply Voltage TA = 25°C OD ON M E RA NGE POS ITIV E CO MM NEG ATIV E CO MM ON MOD E RA NGE ±2 ±3 ±4 ±6 ±5 SUPPLY VOLTAGE (V) ±7 ±8 LTC1100 • TPC05 LTC1100 • TPC06 Output Voltage Swing vs Load 10 9 8 7 6 5 4 3 2 1 Undistorted Output Swing vs Frequency VS = ±5V RL = 100k RL = 2k 0 1 2 345678 LOAD RESISTANCE (kΩ) 9 10 0 100 1k 10k FREQUENCY (Hz) 100k LTC1100 • TPC09 LTC1100 • TPC08 Voltage Noise vs Frequency VS = ± 5V 105 90 75 60 45 30 15 0 3 4 10 100 1k 10k FREQUENCY (Hz) 100k 0 3 4 Internal Sampling Frequency vs Supply Voltage TA = – 55°C TA = 25°C 2 TA = 125°C 1 2 6 10 12 14 16 4 8 TOTAL SUPPLY VOLTAGE V + TO V – (V) 18 LTC1100 • TPC10 LTC1100 • TPC11 LTC1100 • TPC12 1100fc 5 LTC1100 TYPICAL PERFOR A CE CHARACTERISTICS Large-Signal Transient Response G = 100, VS = ± 5V Small-Signal Transient Response G = 100, VS = ± 5V Overload Recovery G = 100, VS = ± 5V 2V/DIV 2V/DIV 10µs/DIV Large-Signal Transient Response G = 10 (LTC1100CS Only), VS = ± 5V 2V/DIV 10µs/DIV PI FU CTIO S 8-Pin DIP (16-Pin SO) Pin 1 (2) GND REF: Connect to system ground. This sets the zero reference for the internal op amps. Pin 2 (4) CMRR: This pin tailors the gain of the internal amplifiers to maximize AC CMRR. For applications which emphasize CMRR requirements, connect a 100k resistor and a 10pF capacitor in series from CMRR to ground. See the Applications section. Pin 3 (6) –VIN: Inverting Input. Pin 4 (7) V – : Negative Supply. Pin 5 (10) V + : Positive Supply. Pin 6 (11) VIN: Noninverting Input. Pin 7 (13) COMP: This pin reduces the bandwidth of the internal amplifiers for applications at or near DC. Clock feedthrough from the internal sampling clock can also be suppressed by using the COMP pin. The standard compensation circuit is a capacitor from COMP to VOUT, sized to provide an RC pole with the internal 247k resistor (22.5k for LTC1100CS in gain-of-10 mode). See the Applications section. Pin 8 (15) VOUT: Signal Output. 16-Pin SO Package Only (3) G = 10: S hort to p in (2) for gain of 10. Leave disconnected for gain of 100. (14) G = 10: Short to pin (15) for gain of 10. Leave disconnected for gain of 100. NOTE: Both pins must be shorted or open to provide correct gain. (1),(5),(8),(9),(12),(16) NC: No Internal Connection. 1100fc 6 UW LTC1100 • TPC13 LTC1100 • TPC16 1V/DIV 50mV/DIV 10µs/DIV LTC1100 • TPC14 5µs/DIV LTC1100 • TPC15 Small-Signal Transient Response G = 10 (LTC1100CS Only), VS = ± 5V Overload Recovery G = 10 (LTC1100CS Only), VS = ± 5V 1V/DIV 50ms/DIV 2V/DIV 10µs/DIV LTC1100 • TPC17 1µs/DIV LTC1100 • TPC18 U U U LTC1100 APPLICATIO S I FOR ATIO Common Mode Rejection Due to very precise matching of the internal resistors, no trims are required to obtain a DC CMRR of better than 100dB; however, things change as frequency rises. The inverting amplifier is in a gain of 1.01 (1.1 for gain of 10), while the noninverting amplifier is in a gain of 99 (9 for gain of 10). As frequency rises, the higher gain amplifier hits its gain-bandwidth limit long before the low gain amplifier, degrading CMRR. The solution is straightforward — slow down the inverting amplifier to match the noninverting amp. Figure 1 shows the recommended circuit. The problem is less pronounced in the LTC1100CS in gain-of-10 mode; no CMRR trims are necessary. − + 3 − LTC1100 8 6 + 2 100k 10pF LTC1100 • TA02 Figure 1. Improving AC CMRR Overcompensation Many instrumentation amplifier applications process DC or low frequency signals only; consequently, the 18kHz (180kHz for G = 10) bandwidth of the LTC1100 can be reduced to minimize system errors or reduce transmitted clock noise by using the COMP pin. A feedback cap from COMP to VOUT will react with the 247k internal resistor (22.5k for G = 10) to limit the bandwidth, as in Figure 2. CB 3 – + 7 8 f 3dB = 1 2 π R INT × CB LTC1100 6 R INT = 247k FOR G = 100 22.5k FOR G = 10 LTC1100 • TA03 Figure 2. Overcompensation to Reduce System Bandwidth 1100fc Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights. U Aliasing The LTC1100 is a chopper-stabilized instrumentation amplifier; like all sampled systems it exhibits aliasing behavior for input frequencies at or near the internal sampling frequency. The LTC1100 incorporates specialized anti-aliasing circuitry which typically attenuates aliasing products by ≥ 60dB; however, extremely sensitive systems may still have to take precautions to avoid aliasing errors. For more information, see the LTC1051/ LTC1053 data sheet. Single Supply Operation The LTC1100 will operate on a single 5V supply, and the common mode range of the internal op amps includes ground; single supply operation is limited only by the output swing of the op amps. The internal inverting amplifier has a negative saturation limit of 5mV typically, setting the minimum common mode limit at 5mV/1.01 (or 1.1 for gain of 10). The inputs can be biased above ground, as shown in Figure 3. Low cost biasing components can be used since any errors appear as a common mode term and are rejected. The minimum differential input voltage is limited by the swing of the output op amp. Lightly loaded, it will swing down to 5mV, allowing differential input voltages as low as 50µV (450µV for gain of 10). Single supply operation limits the LTC1100 to positive differential inputs only; negative inputs will give a saturated zero output. 5V RBIAS 6 SENSOR 3 5V W UU + − 5 8 OUTPUT 0V TO 5V LTC1100 4, 1 1N4148 LTC1100 • TA04 Figure 3 7 LTC1100 PACKAGE DESCRIPTIO .300 BSC (7.62 BSC) CORNER LEADS OPTION (4 PLCS) .008 – .018 (0.203 – 0.457) 0° – 15° .045 – .068 (1.143 – 1.650) FULL LEAD OPTION NOTE: LEAD DIMENSIONS APPLY TO SOLDER DIP/PLATE OR TIN PLATE LEADS .300 – .325 (7.620 – 8.255) .008 – .015 (0.203 – 0.381) +.035 .325 –.015 +0.889 8.255 –0.381 .065 (1.651) TYP .120 (3.048) .020 MIN (0.508) MIN .018 ± .003 (0.457 ± 0.076) N8 1002 ( ) .030 ±.005 TYP N .420 MIN 1 2 RECOMMENDED SOLDER PAD LAYOUT .005 (0.127) RAD MIN .291 – .299 (7.391 – 7.595) NOTE 4 .010 – .029 × 45° (0.254 – 0.737) 0° – 8° TYP .009 – .013 (0.229 – 0.330) NOTE 3 .016 – .050 (0.406 – 1.270) 8 Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com U J8 Package 8-Lead CERDIP (Narrow .300 Inch, Hermetic) (Reference LTC DWG # 05-08-1110) .200 (5.080) MAX .015 – .060 (0.381 – 1.524) .005 (0.127) MIN .405 (10.287) MAX 8 7 6 5 .023 – .045 (0.584 – 1.143) HALF LEAD OPTION .025 (0.635) RAD TYP 1 .045 – .065 (1.143 – 1.651) .014 – .026 (0.360 – 0.660) .100 (2.54) BSC .125 3.175 MIN J8 0801 .220 – .310 (5.588 – 7.874) 2 3 4 OBSOLETE PACKAGE N8 Package 8-Lead PDIP (Narrow .300 Inch) (Reference LTC DWG # 05-08-1510) .045 – .065 (1.143 – 1.651) .130 ± .005 (3.302 ± 0.127) .400* (10.160) MAX 8 7 6 5 NOTE: 1. DIMENSIONS INCHES ARE MILLIMETERS *THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .010 INCH (0.254mm) .255 ± .015* (6.477 ± 0.381) .100 (2.54) BSC 1 2 3 4 SW Package 16-Lead Plastic Small Outline (Wide .300 Inch) (Reference LTC DWG # 05-08-1620) .050 BSC .045 ±.005 .398 – .413 (10.109 – 10.490) NOTE 4 16 15 14 13 12 11 10 9 N .325 ±.005 NOTE 3 .394 – .419 (10.007 – 10.643) 3 N/2 N/2 NOTE: 1. DIMENSIONS IN 1 2 3 4 5 6 7 8 .093 – .104 (2.362 – 2.642) .037 – .045 (0.940 – 1.143) .050 (1.270) BSC .004 – .012 (0.102 – 0.305) INCHES (MILLIMETERS) 2. DRAWING NOT TO SCALE 3. PIN 1 IDENT, NOTCH ON TOP AND CAVITIES ON THE BOTTOM OF PACKAGES ARE THE MANUFACTURING OPTIONS. THE PART MAY BE SUPPLIED WITH OR WITHOUT ANY OF THE OPTIONS. 4. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm) .014 – .019 (0.356 – 0.482) TYP S16 (WIDE) 0502 1100fc LW/TP 1202 1K REV C • PRINTED IN USA  LINEAR TECHNOLOGY CORPORATION 1994