LMP8270

LMP8270,LMP8275 High Common Mode, Gain of 20, Precision Voltage Difference Amplifiers PRELIMINARY January 2005 LMP8270, LMP8275 High Common Mode, Gain of 20, Precision Voltage Difference Amplifiers General Description The LMP™8270, LMP8275 are fixed gain differential amplifiers with a -2V to 27V input common mode voltage range and a supply voltage range of 4.5V to 5.5V. The LMP8270, LMP8275 are precision amplifiers which will detect, amplify and filter small differential signals in the presence of high common mode voltages. The gain is fixed at 20 and is adequate to drive an ADC to full scale in most cases. The LMP8270, LMP8275 have a preamplifier with a fixed gain of 10 and an amplifier with a fixed gain of 2, achieving overall fixed gain of 20. The internal signal path between these two stages is brought out on two pins, A1 and A2, which provide a connection for a filter network. The LMP8270, LMP8275 will function with reduced specifications over the extended common mode input voltage range of -5 to 36 Volts. This feature makes the device suitable for applications with load dump in automotive systems. Features n n n n n n n n n n n n Typical Values, TA = 25˚C Input Offset Voltage 1mV max TCVos (LMP8270) 15µV/˚C max TCVos (LMP8275) 30µV/˚C max CMRR 80dB Min Extended CMVR -5V to 36V Output Voltage Swing Rail to Rail Bandwidth 80KHz Operating Temperature Range (Ambient) -40˚C to 125˚C Operating Temperature Range (bare die) -40˚C to 150˚C Supply Voltage 4.5V to 5.5V Supply C...