LT1168 Low Power, Single Resistor Gain Programmable, Precision Instrumentation Amplifier UFEATURESDESCRIPTIO ■ Supply Current: 530 µ A Max The LT®1168 is a micropower, precision instrumentation am- ■ Meets IEC 1000-4-2 Level 4 ( ± 15kV) ESD Tests plifier that requires only one external resistor to set gains of with Two External 5k Resistors 1 to 10,000. The low voltage noise of 10nV/√Hz (at 1kHz) is ■ Single Gain Set Resistor: G = 1 to 10,000 not compromised by low power dissipation (350µA typical for ■ Gain Error: G = 10, 0.4% Max ±15V supplies). The wide supply range of ±2.3V to ±18V allows ■ Input Offset Voltage Drift: 0.3 µ V/ ° C Max the LT1168 to fit into a wide variety of industrial as well as ■ Gain Nonlinearity: G = 10, 20ppm Max battery-powered applications. ■ Input Offset Voltage: 40µV Max The high accuracy of the LT1168 is due to a 20ppm maximum ■ Input Bias Current: 250pA Max nonlinearity and 0.4% max gain error (G = 10). Previous mono- ■ PSRR at AV =1: 103dB Min lithic instrumentation amps cannot handle a 2k load resistor ■ CMRR at AV = 1: 90dB Min whereas the nonlinearity of the LT1168 is specified for loads ■ Wide Supply Range: ±2.3V to ±18V as low as 2k. The LT1168 is laser trimmed for very low input ■ 1kHz Voltage Noise: 10nV/√Hz offset voltage (40µV max), drift (0.3µV/°C), high CMRR (90dB, ■ 0.1Hz to 10Hz Noise: 0.28µVP-P G = 1) and PSRR (103dB, G = 1). Low input bias currents of ■ Available in 8-Pin PDIP and SO Packages 250pA max are achieved with the use of superbeta process- U ing. The output can handle capacitive loads up to 1000pF in APPLICATIO S any gain configuration while the inputs are ESD protected up to 13kV (human body). The LT1168 with two external 5k ■ Bridge Amplifiers resistors passes the IEC 1000-4-2 level 4 specification. ■ Strain Gauge Amplifiers ■ Thermocouple Amplifiers The LT1168 is a pin-for-pin improved second source for the ■ Differential to Single-Ended Converters AD620 and INA118. The LT1168, offered in 8-pin PDIP and ■ Differential Voltage to Current Converters SO packages, requires significantly less PC board area than ■ Data Acquisition discrete op amp resistor designs. These advantages make ■ Battery-Powered and Portable Equipment the LT1168 the most cost effective solution for precision ■ Medical Instrumentation instrumentation amplifier applications. ■ Scales , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. UTYPICAL APPLICATIOSingle Supply* Pressure MonitorGain Nonlinearity BI TECHNOLOGIES 5V 67-8-3 R40KQ, (0.02% RATIO MATCH) 1 3 40k + 8 7 3.5k 3.5k REF R1 6 G = 200 LT1168 IN DIGITAL 249Ω ADC 3.5k 3.5k 20k DATA 1 5 3 LTC®1286 OUTPUT 2 + – NONLINEARITY (100ppm/DIV) 4 1/2 1 40k LT1112 AGND 2 – G = 1000 OUTPUT VOLTAGE (2V/DIV) 1168 TA01a RL = 2k 1168 TA01 VOUT = ±10V *See Theory of Operation section 1168fa 1