LMP8278MMEVAL/NOPB

User's Guide SNAA135A – February 2012 – Revised April 2013 AN-2223 LMP8278Q VSSOP Evaluation Board 1 Introduction The LMP8278Q VSSOP Evaluation Board, Figure 1, is designed to evaluate the LMP8278Q current sense amplifier. The LMP8278Q is a 40V Common Mode, Unidirectional Precision Current Sensing amplifier with a gain of 14x. This board has an LMP8278Q part mounted on the PCB together with a de-coupling capacitor, power supply connections, and input and output connectors. 2 General Description The LMP8278Q is a fixed 14x gain precision current sense amplifier. The part amplifies and filters small differential signals in the presence of high common mode voltages. The part operates from a single 5V supply voltage. With an input common mode voltage range from –2V to +28V the gain is very precise (±0.5%). The part can handle common mode voltages in the range –2V to +40V with relaxed specifications. The LMP8278Q is a member of the Linear Monolithic Precision ( LMP™) family and is ideal for unidirectional current sensing applications. The part has a precise gain of 14x, which is adequate in most targeted applications to drive an ADC to its full scale value. The fixed gain is achieved in two separate stages, a preamplifier with a gain of 7x and an output stage buffer amplifier with a gain of 2x. The connection between the two stages of the signal path is brought out on two pins to enable the possibility to create an additional filter network around the output buffer amplifier. These pins can also be used for alternative configurations with different gain as described in the applications section of the datasheet. The LMP8278Q incorporates enhanced manufacturing and support processes for the automotive market, including defect detection methodologies. Reliability qualification is compliant with the requirements and temperature grades defined in the AEC Q100 standard. Figure 1. LMP8278Q Evaluation Board LMP is a trademark of Texas Instruments. All other trademarks are the property of their respective owners. SNAA135A – February 2012 – Revised April 2013 Submit Documentation Feedback AN-2223 LMP8278Q VSSOP Evaluation Board Copyright © 2012–2013, Texas Instruments Incorporated 1 LMP8278Q Operating Conditions 3 LMP8278Q Operating Conditions • • • • 4 www.ti.com Temperature Range −40°C to 125°C Power Supply Voltage 4.5V ≤ VS ≤ 5.5V CMVR for ±1.0% gain accuracy −2V to +40V CMVR for ±0.5% gain accuracy −2V to 28V Description of the LMP8278Q Evaluation Board The LMP8278Q evaluation board requires a power supply with a voltage between 4.5V and 5.5V. The supply current will be