Overview
The LMP8645HV, specifically the LMP8645HVMKE/NOPB, is a precision high-voltage current sense amplifier produced by Texas Instruments. This device is designed to detect small differential voltages across a sense resistor in the presence of high-input common-mode voltages. It operates from a supply voltage range of 2.7 V to 12 V and accepts input signals with a common-mode voltage range of –2 V to 76 V. The LMP8645HV is ideal for applications requiring high accuracy and flexibility in current sensing, particularly in industrial, automotive, and consumer electronics.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Supply Voltage Range | 2.7 to 12 | V |
| Common-Mode Voltage Range | –2 to 76 | V |
| Gain Accuracy (With External Resistor) | ±2% | |
| Transconductance | 200 | µA/V |
| Offset Voltage | 1 | mV |
| Input Bias Current | 12 | µA |
| Power Supply Rejection Ratio (PSRR) | 90 | dB |
| Common-Mode Rejection Ratio (CMRR) | 95 | dB |
| Operating Temperature Range | –40 to 125 | °C |
| Package Type | SOT-6 | |
| Body Size (Nominal) | 1.60 mm × 2.90 mm |
Key Features
- High common-mode voltage range: –2 V to 76 V for LMP8645HV
- Gain configurable with a single external resistor
- Low offset voltage: 1 mV
- High transconductance: 200 µA/V
- Excellent PSRR and CMRR: 90 dB and 95 dB respectively
- Low output impedance due to buffered output
- Operating temperature range: –40°C to 125°C
- Compact SOT-6 package
Applications
- High-side current sensing
- Vehicle current measurement
- Motor controls
- Battery monitoring
- Remote sensing
- Power management in DC or battery-powered systems
Q & A
- What is the common-mode voltage range of the LMP8645HV?
The common-mode voltage range of the LMP8645HV is –2 V to 76 V.
- How is the gain configured in the LMP8645HV?
The gain is configured using a single external resistor.
- What is the typical offset voltage of the LMP8645HV?
The typical offset voltage is 1 mV.
- What is the transconductance of the LMP8645HV?
The transconductance is 200 µA/V.
- What are the PSRR and CMRR values of the LMP8645HV?
The PSRR is 90 dB, and the CMRR is 95 dB.
- What is the operating temperature range of the LMP8645HV?
The operating temperature range is –40°C to 125°C.
- In what package is the LMP8645HV available?
The LMP8645HV is available in a SOT-6 package.
- What are some typical applications of the LMP8645HV?
Typical applications include high-side current sensing, vehicle current measurement, motor controls, battery monitoring, and power management.
- Can the LMP8645HV operate with no supply voltage applied?
- How does the LMP8645HV handle input voltage with no supply voltage?
When powered off, the internal resistors are disconnected by MOSFETs, and leakage currents are very low. Zener clamps protect the inputs from exceeding specified limits.
