LMP8645HV

LMP8645/LMP8645HV Precision High Voltage Current Sense Amplifier July 1, 2010 LMP8645/LMP8645HV Precision High Voltage Current Sense Amplifier General Description The LMP8645 and the LMP8645HV are precision current sense amplifiers that detect small differential voltages across a sense resistor in the presence of high input common mode voltages with a supply voltage range from 2.7V to 12V. The LMP8645 accepts input signals with common mode voltage range from -2V to 42V, while the LMP8645HV accepts input signal with common mode voltage range from -2V to 76V. The LMP8645 and LMP8645HV have adjustable gain for applications where supply current and high common mode voltage are the determining factors. The gain is configured with a single resistor, providing a high level of flexibility, the accuracy could be as low as 2% (max) including the gain setting resistor. The output is buffered in order to provide low output impedance. This high side current sense amplifier is ideal for sensing and monitoring currents in DC or battery powered systems, excellent AC and DC specifications over temperature, and keeps errors in the current sense loop to a minimum. The LMP8645 is an ideal choice for industrial, automotive and consumer applications, and it is available in TSOT-6 package. Features Typical values, TA = 25°C ■ High common-mode voltage range -2V to 42V — LMP8645 -2V to 76V — LMP8645HV 2.7V to 12V ■ Supply voltage range ■ Gain configurable with a single resistor ■ Max variable gain accuracy (with external resistor) 2.0% 200 μA/V ■ Transconductance 1 mV ■ Low offset voltage 12 μA ■ Input bias 90 dB ■ PSRR 95 dB ■ CMRR −40°C to 125°C ■ Temperature range ■ 6-Pin TSOT Package Applications ■ ■ ■ ■ ■ ■ High-side current sense Vehicle current measurement Motor controls Battery monitoring Remote sensing Power management Typical Application 30071632 LMP™ is a trademark of National Semiconductor Corporation. © 2010 National Semiconductor Corporation 300716 www.national.com LMP8645/LMP8645HV Absolute Maximum Ratings (Note 1) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. ESD Tolerance (Note 2) Human Body Model For input pins +IN, -IN For all other pins Machine Model Charge device model Supply Voltage (VS = V+ - V−) Differential voltage +IN- (-IN) Voltage at pins +IN, -IN LMP8645HV ±5000V ±2000V 200V 1250V 13.2V 6V -6V to 80V (Note 4) LMP8645 -6V to 60V Voltage at RG pin 13.2V Voltage at OUT pin V- to V+ Storage Temperature Range -65°C to 150°C Junction Temperature (Note 3) 150°C For soldering specifications, see product folder at www.national.com and www.national.com/ms/MS/MS-SOLDERING.pdf Operating Ratings V+ V−) (Note 1) 2.7V to 12V -40°C to 125°C 96°C/W Supply Voltage (VS = Temperature Range (Note 3) Package Thermal Resistance(Note 3) TSOT-6 2.7V Electrical Characteristics Unless otherwise specified, all limits guaranteed for at TA = 25°C, VS=V+ – V-, V+ = 2.7V, V− = 0V, −2V < VCM < 76V, RG= 25kΩ, RL = 10 MΩ. Boldface limits apply at the temperature extremes. Symbol VOS TCVOS IB eni VSENSE(MAX) Gain AV Gm Parameter Input Offset Voltage Input Offset Voltage Drift(Note 7, Note 9) Input Bias Current(Note 10) Input Voltage Noise (Note 9) VCM = 2.1V VCM = 2.1V VCM = 2.1V f > 10 kHz, RG = 5 kΩ VCM = 12V VCM = 2.1V VCM = 2.1V −40°C to 125°C, VCM=2.1V VCM = 2.1V, 2.7V < V+ < 12V 90 95 dB 60 990 260 135 0.5 380 2000 1.2 20 525 710 2500 2700 V/µs LMP8645HV 2.1V < VCM < 76V LMP8645 2.1V < VCM< 42V -2V 10 kHz, RG = 5 kΩ VCM = 12V VCM = 2.1V VCM = 2.1V −40°C to 125°C, VCM= 2.1V VCM = 2.1V, , 2.7V < V+ < 12V LMP8645HV 2.1V