Overview
The INA138NA/3K, produced by Texas Instruments, is a high-side, unipolar current shunt monitor. This device is part of the INA1x8 family, which includes the INA138 and INA168. It is designed for measuring current in high-side configurations, making it ideal for applications where the current to be measured is in a high-voltage part of the circuit. The INA138NA/3K features a wide input common-mode voltage range, low quiescent current, and a compact SOT-23 package, enabling its use in a variety of applications such as current shunt measurement, power management, and precision current sourcing.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Supply Voltage (V+) | 2.7 | 5 | 36 | V |
| Common-Mode Input Range | 2.7 | 36 | V | |
| Quiescent Current | 25 | 45 | 60 | µA |
| Operating Temperature Range | -40 | 125 | °C | |
| Common-Mode Rejection | 100 | 120 | dB | |
| Offset Voltage | ±0.2 | ±1 | ±2 | mV |
| Transconductance | 196 | 200 | 204 | µA/V |
| Bandwidth (ROUT = 5 kΩ) | 800 | kHz |
Key Features
- Complete Unipolar High-Side Current Measurement Circuit: Designed for accurate current measurement in high-side configurations.
- Wide Supply and Common-Mode Range: Input common-mode and power-supply voltages can range from 2.7 V to 36 V for the INA138 and 2.7 V to 60 V for the INA168.
- Independent Supply and Input Common-Mode Voltages: Allows for flexible application in various voltage environments.
- Single Resistor Gain Set: The gain can be set using a single external resistor, allowing for a gain range from 1 to over 100.
- Low Quiescent Current: Only 25 µA typical, minimizing power consumption and error in current measurements.
- Wide Temperature Range: Operates from -40°C to 125°C, making it suitable for a wide range of environmental conditions.
- Compact SOT-23 Package: 5-pin SOT-23 packaging for space-efficient designs.
Applications
- Current Shunt Measurement: Ideal for measuring current in high-side configurations, such as in telephone systems, computers, and battery-backup systems.
- Power Management: Used in battery chargers, power supplies, and other power management circuits.
- Portable and Battery-Backup Systems: Suitable for use in portable devices and systems that require precise current measurement.
- Precision Current Source: Can be used to create precise current sources due to its high accuracy and stability.
- Cell Phones and Other Mobile Devices: Used in the current measurement and power management circuits of mobile devices.
Q & A
- What is the primary function of the INA138NA/3K?
The primary function of the INA138NA/3K is to measure current in high-side configurations using a current shunt monitor.
- What is the operating temperature range of the INA138NA/3K?
The operating temperature range is from -40°C to 125°C.
- What is the typical quiescent current of the INA138NA/3K?
The typical quiescent current is 25 µA.
- How is the gain set in the INA138NA/3K?
The gain can be set using a single external resistor, allowing for a gain range from 1 to over 100.
- What is the common-mode input range for the INA138NA/3K?
The common-mode input range is from 2.7 V to 36 V.
- What type of packaging does the INA138NA/3K use?
The INA138NA/3K is packaged in a 5-pin SOT-23 package.
- Can the INA138NA/3K be used in high-voltage applications?
Yes, it can be used in high-voltage applications due to its wide input common-mode voltage range.
- What are some common applications of the INA138NA/3K?
Common applications include current shunt measurement, power management, battery chargers, and precision current sources.
- How does the INA138NA/3K convert differential input voltage to output voltage?
The device converts a differential input voltage to a current output, which is then converted back to a voltage using an external load resistor.
- What is the bandwidth of the INA138NA/3K when using a 5 kΩ load resistor?
The bandwidth is 800 kHz when using a 5 kΩ load resistor.
