LMP8270,LMP8275 High Common Mode, Gain of 20, Precision Voltage Difference Amplifiers
PRELIMINARY
January 2005
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...