Overview
The LMP8645MK/NOPB, produced by Texas Instruments, is a precision high-voltage current sense amplifier. 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 is available in two versions: LMP8645 and LMP8645HV, with common-mode voltage ranges of –2 V to 42 V and –2 V to 76 V, respectively. The amplifier features adjustable gain set by a single external resistor, providing high flexibility and accuracy. It is ideal for sensing and monitoring currents in DC or battery-powered systems, particularly in industrial, automotive, and consumer applications.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Supply Voltage Range | 2.7 to 12 | V |
| Common-Mode Voltage Range | LMP8645: –2 to 42, LMP8645HV: –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: LMP8645 –2 V to 42 V, LMP8645HV –2 V to 76 V
- Adjustable gain set by a single external resistor
- Low offset voltage of 1 mV
- High PSRR and CMRR of 90 dB and 95 dB, respectively
- Transconductance of 200 μA/V
- Low input bias current of 12 μA
- Buffered output with low output impedance
- Operating temperature range of –40°C to 125°C
- Available in SOT-6 package
Applications
- High-side current sensing
- Vehicle current measurement
- Motor controls
- Battery monitoring
- Remote sensing
- Power management
Q & A
- What is the supply voltage range of the LMP8645?
The supply voltage range of the LMP8645 is 2.7 V to 12 V.
- What are the common-mode voltage ranges for the LMP8645 and LMP8645HV?
The LMP8645 has a common-mode voltage range of –2 V to 42 V, while the LMP8645HV has a range of –2 V to 76 V.
- How is the gain of the LMP8645 adjusted?
The gain of the LMP8645 is adjusted using a single external resistor.
- What is the typical offset voltage of the LMP8645?
The typical offset voltage of the LMP8645 is 1 mV.
- What are the PSRR and CMRR values of the LMP8645?
The PSRR is 90 dB, and the CMRR is 95 dB.
- What is the transconductance of the LMP8645?
The transconductance of the LMP8645 is 200 μA/V.
- What is the input bias current of the LMP8645?
The input bias current of the LMP8645 is 12 μA.
- What is the operating temperature range of the LMP8645?
The operating temperature range of the LMP8645 is –40°C to 125°C.
- In what package is the LMP8645 available?
The LMP8645 is available in a SOT-6 package.
- What are some typical applications of the LMP8645?
Typical applications include high-side current sensing, vehicle current measurement, motor controls, battery monitoring, remote sensing, and power management.
