Texas Instruments LMP8278QMME/NOPB

Overview

LMP8278QMME/NOPB from Texas Instruments is an automotive-grade, high common-mode precision current sensing amplifier with fixed 14× gain, −2 V to +40 V input common-mode voltage range, ±2 mV max input offset voltage, and operation from a single 4.5–5.5 V supply. It delivers 90 kHz bandwidth and 80 dB min DC CMRR for unidirectional current monitoring in battery management, transmission control, and power steering systems.

For engineers reviewing the LMP8278QMME/NOPB datasheet, LMP8278QMME/NOPB pinout, LMP8278QMME/NOPB application, or LMP8278QMME/NOPB equivalent, key selection criteria include guaranteed AEC-Q100 Grade 1 qualification, 14× gain accuracy (±0.5% over −2 V to +28 V V_CM), internal 100 kΩ filter resistor, preamplifier output access at A1/A2 pins, and 8-pin VSSOP package compatibility with conformal coating for >25 V applications.

Technical Context

The LMP8278QMME/NOPB implements a two-stage signal path: a proprietary level-shifted preamplifier (7× gain, 100 kΩ internal output resistor) followed by a buffer stage (2× gain), enabling external filtering or gain adjustment between A1 and A2 pins. Its input stage withstands differential fault voltages beyond typical shunt-based sensing conditions due to integrated level-shift resistors.

It achieves ±15 μV/°C max TCV_OS, 285 nV/√Hz input-referred noise at 1 kHz, and maintains 80 dB CMRR up to 10 kHz - critical for accurate current measurement in noisy automotive power domains with fast-switching inductive loads.

Key Specifications

Pinout & Package

Package: 8-pin VSSOP (DGK0008A), 0.65 mm pitch, RoHS-compliant, NIPDAU/SN lead finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar precision current sensing amplifier applications.

Compared with INA240A1QDRQ1 and MAX40056ATA+T, the LMP8278QMME/NOPB uniquely provides accessible A1/A2 nodes for analog filtering/gain tuning, automotive-grade reliability at lower quiescent current (0.55 mA), and tighter gain tolerance (±0.5%) within its −2 V to +40 V CMVR window - making it optimal for cost-sensitive, thermally constrained EPS and transmission control designs.

Availability

LMP8278QMME/NOPB is available at Aetrix Electronics and suitable for automotive transmission control, battery management systems, and electric power steering applications requiring stable component supply, AEC-Q100 compliance, and long-term production continuity.

Supply support for LMP8278QMME/NOPB includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor leader specializing in analog and embedded processing technologies, with decades of automotive IC development expertise and rigorous AEC-Q100 qualification infrastructure.

The LMP8278QMME/NOPB belongs to TI's Linear Monolithic Precision (LMP™) family, designed specifically for high-accuracy, high-CMRR current sensing in safety-critical automotive subsystems where reliability and parametric consistency across temperature are mandatory.

FAQ

What is the guaranteed common-mode voltage range for LMP8278QMME/NOPB with full 80 dB CMRR performance?

The LMP8278QMME/NOPB guarantees 80 dB minimum DC CMRR over a −2 V to +40 V input common-mode voltage range. Within −2 V to +28 V, total gain remains tightly controlled at 14× (±0.5%). Operation above +28 V relaxes gain tolerance but retains functional amplification and CMRR down to 80 dB at DC. For V_CM > 25 V in the VSSOP package, TI strongly recommends conformal coating to prevent leakage currents.

Can LMP8278QMME/NOPB be used for bidirectional current sensing?

No - the LMP8278QMME/NOPB is optimized for unidirectional current sensing only. Its fixed 14× gain architecture, input stage design, and specified common-mode range assume current flow in one direction across the shunt. Bidirectional applications require a zero-drift amplifier with rail-to-rail output swing and symmetric input offset behavior, such as the INA229 or MAX40080.

How does the A1 and A2 pin interface enable external filtering in LMP8278QMME/NOPB?

The A1 pin outputs the 7× preamplified signal; A2 feeds that signal into the 2× output buffer. An external capacitor from A1 to GND forms a first-order low-pass filter with the internal 100 kΩ resistor (f_c = 1/(2π × 100 kΩ × C)). Adding R and C networks between A1 and A2 enables second-order Sallen-Key filters, allowing precise anti-aliasing tailored to specific PWM frequencies without affecting gain accuracy.

Is LMP8278QMME/NOPB pin-compatible with other members of the LMP827x family?

Yes - the LMP8278QMME/NOPB shares identical 8-pin VSSOP (DGK) packaging, pinout, and footprint with LMP8277 and LMP8279. However, gain, bandwidth, and CMVR differ: LMP8277 offers 20× gain, LMP8279 offers 50× gain, and all three maintain the same A1/A2 architecture and AEC-Q100 Grade 1 qualification. PCB layout reuse is possible with only schematic gain-resistor updates.

What is the maximum recommended load capacitance for LMP8278QMME/NOPB's OUT pin when driving an ADC?

TI does not specify an absolute maximum capacitive load, but simulation data shows significant output disturbance (≥100 mV overshoot) with ≥20 pF switched capacitive loads - typical of SAR ADC sample-and-hold inputs. To ensure accuracy, place a series RC filter (e.g., 10 Ω + 1 nF) between LMP8278QMME/NOPB's OUT pin and the ADC input. This isolates the amplifier from abrupt charge injection while preserving signal bandwidth for current-loop control.