Texas Instruments LMP8640MKX-H/NOPB

Overview

LMP8640MKX-H/NOPB from Texas Instruments is a precision high-side current sense amplifier with fixed 100 V/V gain, -2 V to 42 V common-mode input range, 900 µV max input offset voltage, and 0.25% max gain error over temperature - designed for accurate DC/AC current monitoring in industrial power supplies and battery management systems.

For engineers reviewing the LMP8640MKX-H/NOPB datasheet, LMP8640MKX-H/NOPB pinout, LMP8640MKX-H/NOPB application, or LMP8640MKX-H/NOPB equivalent, this page delivers verified specifications, validated pin functions, real-world use cases in motor control and battery monitoring, and two confirmed alternative parts with documented technical and application differences.

Technical Context

The LMP8640MKX-H/NOPB implements a precision current-sense architecture using matched internal resistors (RIN = 5 kΩ) and a high-CMRR error amplifier to reject common-mode transients up to 42 V while amplifying small differential sense voltages. Its fixed-gain topology eliminates external resistor selection errors and ensures stability across supply voltages from 2.7 V to 12 V.

It operates with low input bias current (13 µA typical), delivers 230 kHz bandwidth at 100 V/V gain, and maintains 103 dB CMRR over 2.1 V–42 V common-mode range - enabling accurate sensing in noisy high-voltage DC bus environments without signal conditioning.

Key Specifications

Pinout & Package

Package: 6-pin Thin SOT-23 (2.9 mm × 1.6 mm), surface-mount, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-side current sense amplifier applications.

Compared with INA240A1IDR and MAX4080TASA+, the LMP8640MKX-H/NOPB offers optimal trade-off between gain accuracy (±0.25%), SOT-23 compactness, and industrial-grade temperature range (−40°C to +125°C), making it ideal for space-constrained, cost-sensitive high-side sensing where 100× scaling is required without external components.

Availability

LMP8640MKX-H/NOPB is available at Aetrix Electronics and suitable for industrial power supplies, battery management systems, and motor control designs requiring stable component supply, long-term manufacturability, and automotive-grade reliability validation.

Supply support for LMP8640MKX-H/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 delivering analog and embedded processing solutions, with over 50 years of innovation in precision signal chain components.

The LMP8640 series belongs to TI's precision current-sense amplifier product line, engineered specifically for high-accuracy, high-common-mode industrial and automotive current monitoring with minimal external components.

FAQ

What is the exact gain setting of the LMP8640MKX-H/NOPB?

The LMP8640MKX-H/NOPB has a factory-trimmed fixed gain of 100 V/V, confirmed in TI's SNOSB28G datasheet Section 7.6. This gain is not adjustable and applies across the full operating temperature range (−40°C to +125°C) with ±0.25% maximum error. The "H" suffix in the part number explicitly denotes the 100 V/V variant, distinguishing it from "T" (20 V/V) and "F" (50 V/V) versions.

Does the LMP8640MKX-H/NOPB support high-side sensing on a 48 V rail?

Yes, the LMP8640MKX-H/NOPB supports high-side sensing on 48 V rails. Its specified common-mode input range is −2 V to +42 V, and TI confirms operation up to 42 V in all electrical characteristics tables. While 48 V exceeds the absolute maximum rating for pins +IN and −IN (60 V), sustained operation above 42 V risks violating recommended operating conditions and is not guaranteed. For 48 V systems, consider the LMP8640HV-H/NOPB variant with −2 V to +76 V range.

What is the function of Pin 5 (NC) on the LMP8640MKX-H/NOPB?

Pin 5 on the LMP8640MKX-H/NOPB is labeled NC (Not Connected) and is internally unconnected. As stated in the "Pin Configuration and Functions" section (page 6) of the SNOSB28G datasheet, this pin must remain electrically floating - no trace, pad, or solder connection should be made. Leaving it unconnected prevents unintended coupling or leakage paths that could degrade CMRR or offset performance.

Can the LMP8640MKX-H/NOPB drive a 10 nF capacitive load?

No, the LMP8640MKX-H/NOPB is not rated to drive 10 nF loads. Its maximum specified output capacitance is 30 pF (Section 7.6, "CLOAD"), and driving larger capacitive loads causes instability, overshoot, and degraded settling time. For ADC interfaces requiring higher capacitance, use a series resistor (e.g., 100 Ω) between LMP8640MKX-H/NOPB VOUT and the ADC input capacitor to isolate the load and maintain stability.

How does the supply current of the LMP8640MKX-H/NOPB vary with common-mode voltage?

The supply current (IS) of the LMP8640MKX-H/NOPB increases with rising common-mode voltage (VCM). At VCM = −2 V, IS is 2.0–2.5 mA (typical 2.25 mA); at VCM = 2.1 V, IS drops to 0.72–1.05 mA (typical 0.9 mA); and at VCM = 42 V, IS rises again to ~2.3 mA. This behavior is documented in Figure 2 and Figure 4 of the SNOSB28G datasheet and must be accounted for in low-power designs where VCM varies widely.