LMP8640MK-H/NOPB - 42V Precision Current Sense Amplifier | TI
MPN: LMP8640MK-H/NOPB ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.2 | $3.20 |
| 10 | $2.85 | $28.50 |
| 100 | $2.4 | $240.00 |
| 500 | $2.05 | $1,025.00 |
| 1,000 | $1.75 | $1,750.00 |
LMP8640MK-H/NOPB Overview
A current sense amplifier is an analog IC that amplifies the small differential voltage developed across a shunt resistor carrying the load current, while rejecting the large common-mode voltage present at the resistor terminals. This category sits within the broader hierarchy of operational amplifiers (op-amps) and instrumentation amplifiers, which in turn belong to the signal-conditioning family of analog ICs used in power management, motor control, and battery monitoring. The LMP8640MK-H/NOPB provides fixed internal gain (the "-H" variant specifies the gain version), eliminating the need for external gain-setting resistors and simplifying PCB layout.
Key features include a -2V to +42V common-mode input range that survives load-dump transients in automotive and industrial systems, a fixed gain that improves noise immunity versus discrete op-amp solutions, and a 950 kHz gain-bandwidth product that supports fast transient response for current-mode control loops. The device also delivers 1.8 V/us slew rate, low offset, and integrated EMI filtering. The TSOT-23-6 package offers a compact 2.9 mm x 1.6 mm footprint with thermal performance suitable for industrial temperature ranges (-40C to +125C).
The LMP8640MK-H/NOPB uses a precision chopper-stabilized input stage and thin-film resistor network to achieve low offset and high common-mode rejection ratio (CMRR). Its high PSRR ensures accurate current measurement even when the supply rail is noisy, which is critical in switched-mode power supply (SMPS) and motor-drive applications where large dv/dt events couple into the measurement node.
Typical applications include high-side current sensing in telecom brick modules, battery-pack current monitoring in e-mobility and UPS systems, motor phase-current sensing in industrial drives, and precision load monitoring in solar inverters. The wide common-mode range also suits 48V telecom rails and 24V industrial automation backplanes.
When designing with the LMP8640MK-H/NOPB, select a low-inductance Kelvin-connected sense resistor to avoid errors from PCB trace resistance, and place a 0.1 uF supply bypass capacitor as close to the IC as possible. The internal fixed gain eliminates gain-error calculations but the designer must still budget for sense-resistor tolerance and thermal drift.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for LMP8640MK-H/NOPB — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with LMP8640MK-H/NOPB (same form factor and footprint) — differing in Gain-Bandwidth Product, Manufacturer, Operating Temperature Range, Package / Case, RoHS Status.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
LMP8640MKX-H/NOPB
✅ Drop-In📋 Reference alternative (not in catalog)
LMP8640MK-T/NOPB
✅ Drop-In📋 Reference alternative (not in catalog)
LMP8640HVMK-H/NOPB
✅ Drop-In📋 Reference alternative (not in catalog)
LMP8640QMK-H/NOPB
✅ Drop-In📋 Reference alternative (not in catalog)
LMP8640MK-H
✅ Drop-In✓ In Stock
$2.09 / Unit
View Datasheet →LMP8640MK-H/NOPB Maximum Ratings & Electrical Characteristics
| Manufacturer | Texas Instruments |
| Part Number | LMP8640MK-H/NOPB |
| Amplifier Type | Current Sense Amplifier |
| Number of Circuits | 1 |
| Gain Variant | H (fixed gain version) |
| Supply Voltage Range | 2.7 V to 12 V |
| Common-Mode Input Voltage Range | -2 V to +42 V |
| Gain-Bandwidth Product | 230 kHz (per third-party listing); 950 kHz family value from TI |
| Slew Rate | 1.8 V/us |
| Package / Case | SOT-23-6 Thin (TSOT-23-6, DDC) |
| Number of Pins | 6 |
| Operating Temperature Range | -40C to +125C |
| Mounting Type | Surface Mount |
| Packaging | Tape & Reel (TR) |
| RoHS Status | Compliant |
| Lead-Free | Yes (NOPB suffix) |
LMP8640MK-H/NOPB Pin Configuration
| Pin 1 | IN+ — Positive (high-side) sense input |
| Pin 2 | V- — Negative supply |
| Pin 3 | V+ — Positive supply |
| Pin 4 | IN- — Negative (low-side) sense input |
| Pin 5 | OUT — Amplified current-sense output |
| Pin 6 | GND — Ground |
Typical Applications
LMP8640MK-H/NOPB is suitable for 6 applications: High-Side Current Sensing in 24V Industrial Buses, Battery Pack Current Monitoring in UPS and E-Mobility, Motor Phase Current Sensing in Industrial Drives, Telecom Brick Module Output Current Monitoring, Solar Inverter String Current Measurement, Precision Load Monitoring in Test and Measurement.
High-Side Current Sensing in 24V Industrial Buses
The LMP8640MK-H/NOPB is well-suited for high-side current sensing on 24V industrial automation backplanes because its -2V to +42V common-mode input range covers the full 24V nominal rail plus transient overshoot up to 42V. Placed between the supply rail and the load with a low-inductance Kelvin-connected shunt resistor, the device delivers a fixed-gain output that scales directly to ADC input range. Unlike discrete op-amp circuits, the integrated gain network eliminates four external resistors and improves CMRR consistency across temperature, which is critical when the bus voltage swings 10V or more during load transients.
Recommended
Battery Pack Current Monitoring in UPS and E-Mobility
In UPS battery banks and e-mobility battery packs, the LMP8640MK-H/NOPB monitors charge and discharge current at the pack terminal while withstanding the full battery voltage on its common-mode inputs. The -2V to +42V range covers 12V, 24V, and 36V battery stacks; the 950kHz gain-bandwidth product (family value) tracks fast current transients during cell balancing and inverter switching. The TSOT-23-6 footprint saves PCB area in densely populated battery-management boards, and the fixed internal gain reduces calibration overhead in volume production.
Recommended
Motor Phase Current Sensing in Industrial Drives
Industrial motor drives use the LMP8640MK-H/NOPB to measure phase current through a shunt resistor in the inverter leg. The device's wide common-mode input range tolerates the fast dv/dt transitions of PWM switching up to 42V, while the chopper-stabilized input stage rejects the large common-mode noise injected by the IGBT or MOSFET bridge. Compared to discrete op-amp solutions, the integrated fixed gain reduces PCB area and improves thermal tracking between gain-setting resistors, which is essential for accurate torque control across the -40C to +125C industrial temperature range.
Recommended
Telecom Brick Module Output Current Monitoring
In isolated telecom brick DC-DC converters, the LMP8640MK-H/NOPB senses load current on the 12V or 24V secondary side while the device itself is powered from a local 5V or 3.3V rail. The 42V common-mode tolerance handles ringing and overshoot on the secondary side of the transformer during load transients, and the small TSOT-23-6 footprint fits within the densely packed brick module layout. For true 48V input telecom rails, the LMP8640HV family variant extends the common-mode range beyond 42V.
Recommended
Solar Inverter String Current Measurement
Photovoltaic string inverters use the LMP8640MK-H/NOPB to monitor DC-side current per string, enabling maximum power point tracking (MPPT) and fault detection. The 42V common-mode range covers 24V and 48V PV strings with margin for inverter-side voltage spikes; the fixed gain simplifies per-string calibration during inverter manufacturing. The TSOT-23-6 package allows the sense circuit to be placed close to each string input, minimizing PCB trace resistance error, while the -40C to +125C operating range suits outdoor inverter enclosures.
Recommended
Precision Load Monitoring in Test and Measurement
Bench-top electronic loads and precision test equipment benefit from the LMP8640MK-H/NOPB's low offset and high CMRR when measuring sub-amp currents across a low-value shunt resistor. The fixed gain removes the need for precision external resistors, while the 950kHz bandwidth captures fast current programming steps in pulsed-load testing. The TSOT-23-6 footprint simplifies integration into compact load cards, and the wide supply range (2.7V to 12V) lets the same part serve in 3.3V and 5V instrument architectures.
Recommended
Recommended Products Summary
Engineering reference data for LMP8640MK-H/NOPB — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | LMP8640MKX-H/NOPB | LMP8640MK-T/NOPB | LMP8640HVMK-H/NOPB | LMP8640QMK-H/NOPB | LMP8640MK-H |
|---|---|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Package | SOT-23-6 Thin (TSOT-23-6) | SOT-23-6 Thin (TSOT-23-6) - same | SOT-23-6 Thin (TSOT-23-6) - same | SOT-23-6 Thin (TSOT-23-6) - same | SOT-23-6 Thin (TSOT-23-6) - same | SOT-23-6 Thin (TSOT-23-6) - same |
| Common-Mode Input Range | -2 V to +42 V | -2 V to +42 V | -2 V to +42 V | Beyond +42 V (HV variant) | -2 V to +42 V | -2 V to +42 V |
| Supply Voltage Range | 2.7 V to 12 V | 2.7 V to 12 V | 2.7 V to 12 V | 2.7 V to 12 V | 2.7 V to 12 V | 2.7 V to 12 V |
| Gain Variant | H (fixed) | H (fixed) | T (different fixed gain) | H (fixed, HV input range) | H (fixed, automotive) | H (fixed) |
| Automotive Grade (AEC-Q100) | No | No | No | No | Yes (Q1 suffix) | No |
Key Differentiators
- Wide -2V to +42V common-mode input range (vs INA194AIDBVT)
- Compact TSOT-23-6 package with fixed internal gain (vs INA240A1PW (TSSOP-8))
- Drop-in replacement via same-die LMP8640MKX-H/NOPB (vs LMP8640MK-H/NOPB (obsolete))
Design Notes
Use a Kelvin (4-wire) connection to the sense resistor to eliminate PCB trace resistance from the measurement. Place a 0.1 uF X7R ceramic bypass capacitor as close as possible to the V+ pin (pin 3) of the LMP8640MK-H/NOPB, with the ground return tied directly to the device GND pin (pin 6). Keep sense input traces short and parallel to minimize loop area and reduce susceptibility to dv/dt-induced common-mode noise from switching converters on the same board.
Do not exceed the +42 V common-mode rating on the standard LMP8640MK-H/NOPB; for 48 V telecom rails, choose the LMP8640HV variant per the TI LMP8640 family datasheet. The internal fixed gain eliminates external gain-setting resistors, so verify the H-gain value matches your shunt resistor and full-scale current target before layout. Note that the MK-H part is marked obsolete by TI; migrate new designs to the LMP8640MKX-H/NOPB for production continuity.
The LMP8640MK-H/NOPB output (pin 5) drives the input of an ADC or comparator; place a small RC filter (e.g., 100 ohm + 1 nF) close to the output to limit bandwidth and reduce ADC sampling noise, but verify the filter corner remains well above the current-loop bandwidth requirement. For PWM motor-drive applications, route the sense input traces perpendicular to switching node traces and add a small differential-mode RC filter if common-mode rejection at high frequency is insufficient.
Compliance Information
NOPB suffix indicates lead-free / RoHS-compliant per TI part-number convention. LMP8640MK-H/NOPB itself is not AEC-Q100 qualified; for automotive applications choose the LMP8640QMK-H/NOPB (Q1) variant. Halogen-free status not explicitly stated in the verified data.
