Texas Instruments LMP8278QMMX/NOPB

Overview

LMP8278QMMX/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 5 V supply. It enables accurate unidirectional current measurement in high-side or low-side configurations for battery management, transmission control, and power steering systems.

For engineers reviewing the LMP8278QMMX/NOPB datasheet, LMP8278QMMX/NOPB pinout, LMP8278QMMX/NOPB application, or LMP8278QMMX/NOPB equivalent, key selection considerations include guaranteed 80 dB CMRR over temperature, AEC-Q100 Grade 1 qualification (−40°C to +125°C), 90 kHz bandwidth, ±15 μV/°C TCV_OS, and internal 100 kΩ filter resistor enabling external second-order low-pass filtering.

Technical Context

The LMP8278QMMX/NOPB implements a two-stage signal path: a proprietary level-shift preamplifier (7× gain) with 100 kΩ trimmed output resistor, followed by a buffer stage (2× gain). This architecture enables precise differential amplification while rejecting high common-mode voltages up to +40 V or down to −2 V relative to GND.

Its internal level-shift circuit allows operation beyond the supply rails without saturation, and the exposed A1/A2 pins permit configurable external filtering or gain adjustment-though the standard configuration delivers stable 14× gain with ±0.5% accuracy across −2 V to +28 V CMVR.

Key Specifications

Pinout & Package

Package: 8-pin VSSOP (DGK0008A), 2.3 mm × 2.0 mm body, 0.5 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 LMP8278QMMX/NOPB uniquely balances AEC-Q100 Grade 1 reliability, 14× precision gain, and accessible A1/A2 nodes for custom filtering-making it optimal for cost-sensitive, thermally constrained automotive subsystems needing deterministic performance without programmability overhead.

Availability

LMP8278QMMX/NOPB is available at Aetrix Electronics and suitable for automotive transmission control, battery management systems, and electric power steering applications requiring stable component supply, long-term lifecycle support, and AEC-Q100-compliant sourcing.

Supply support for LMP8278QMMX/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 company specializing in analog and embedded processing technologies, with leadership in precision amplifiers, power management, and automotive electronics.

The LMP™ family-including the LMP8278QMMX/NOPB-is engineered for unidirectional current sensing in harsh automotive environments, emphasizing high CMRR, rail-to-rail input capability, and production-tested parametric stability across temperature.

FAQ

What is the guaranteed common-mode voltage range for LMP8278QMMX/NOPB with full 80 dB CMRR performance?

The LMP8278QMMX/NOPB guarantees ≥80 dB CMRR over a −2 V to +40 V input common-mode voltage range. Within −2 V to +28 V, total gain remains within ±0.5% tolerance. Operation beyond +28 V (up to +40 V) maintains functionality but with relaxed gain accuracy specifications per the datasheet's Electrical Characteristics table.

Can LMP8278QMMX/NOPB be used in high-side current sensing where the shunt is placed between the supply rail and load?

Yes, the LMP8278QMMX/NOPB supports true high-side sensing: its +IN pin accepts common-mode voltages up to +40 V while powered from a 5 V supply, and its −IN pin tolerates voltages down to −2 V. This allows direct connection across shunts in 12 V, 24 V, or 48 V systems without level-shifting circuitry-verified in Figure 28 of the SNAS575A datasheet.

Does LMP8278QMMX/NOPB require external components for basic operation, or is it functional with only power and signal connections?

The LMP8278QMMX/NOPB operates fully functional with only VS, GND, +IN, −IN, and OUT connected. A 0.1 μF ceramic bypass capacitor between VS and GND is mandatory per datasheet recommendations. Pins A1 and A2 may be left unconnected for fixed 14× gain; they are optional for external filtering or gain adjustment-not required for baseline operation.

How does the A1/A2 pin interface enable filter design in LMP8278QMMX/NOPB, and what is the value of the internal resistor?

The LMP8278QMMX/NOPB exposes its internal preamplifier output (A1) and buffer input (A2) to allow external filter networks. A precision-trimmed 100 kΩ resistor (RF-INT) connects A1 to A2 internally. Adding a capacitor from A1 to GND creates a first-order low-pass filter; adding R2, C1, and C2 between A1 and A2 enables a second-order Sallen-Key topology-as detailed in Section "ADDITIONAL SECOND ORDER LOW PASS FILTER" of SNAS575A.

Is LMP8278QMMX/NOPB pin-compatible with other members of the LMP827x family, such as LMP8271 or LMP8272?

No, the LMP8278QMMX/NOPB is not pin-compatible with LMP8271 or LMP8272. While all share the 8-pin VSSOP package, pin functions differ significantly: LMP8271/LMP8272 use A1/A2 for gain-setting resistors, whereas LMP8278 uses them for filter access. The LMP8278QMMX/NOPB has unique pin assignments (e.g., N/C on pin 6), and its internal architecture-two-stage gain with level shift-is distinct. Direct replacement requires schematic and layout revision.