Overview
The LM1085IS-3.3/NOPB, produced by Texas Instruments, is a 3-A low dropout positive voltage regulator. It is part of the LM1085 series, which includes fixed output voltages of 3.3V, 5.0V, and 12V, as well as an adjustable version. This regulator has a maximum dropout voltage of 1.5V at 3A of load current, making it highly efficient for various applications. The LM1085 has the same pin-out as TI's industry standard LM317, ensuring compatibility and ease of use in existing designs. The device features a zener trimmed bandgap reference, current limiting, and thermal shutdown, enhancing its reliability and performance.
Key Specifications
| Parameter | Typical Value | Minimum Value | Maximum Value | Unit |
|---|---|---|---|---|
| Output Voltage | 3.3V (fixed), Adjustable | - | - | V |
| Output Current | 3A | - | - | A |
| Dropout Voltage | 1.5V | - | - | V |
| Line Regulation | 0.015% | - | - | % |
| Load Regulation | 0.1% | - | - | % |
| Maximum Input to Output Voltage Differential | 27V (LM1085-3.3) | - | - | V |
| Junction Temperature | - | -40°C | 150°C | °C |
| Quiescent Current | 5.0-10.0 mA | - | - | mA |
| Ripple Rejection | 60-75 dB | - | - | dB |
Key Features
- Available in 3.3V, 5.0V, 12V, and adjustable output voltage versions.
- Current limiting and thermal protection to ensure device reliability.
- Output current of up to 3A.
- Low dropout voltage of 1.5V at full load current.
- High line and load regulation: 0.015% and 0.1%, respectively.
- Zener trimmed bandgap reference for stable output voltage.
- Same pin-out as TI's industry standard LM317.
Applications
- High efficiency linear regulators.
- Battery chargers: The LM1085 can regulate charging current and maintain the float voltage of the battery.
- Post regulation for switching supplies: Providing a stable output voltage after the switching regulator.
- Constant current regulators: Can be configured to provide a constant current output.
- Microprocessor supply: Reliable power supply for microprocessors and other digital circuits.
- Generating negative supply voltage: Can be used to create a negative output rail for various applications.
Q & A
- What is the maximum output current of the LM1085?
The LM1085 can provide up to 3A of output current.
- What are the available output voltage options for the LM1085?
The LM1085 is available in 3.3V, 5.0V, 12V, and adjustable output voltage versions.
- What is the dropout voltage of the LM1085 at full load current?
The dropout voltage is 1.5V at 3A of load current.
- Does the LM1085 have built-in protection features?
Yes, it includes current limiting and thermal shutdown protection.
- How does the LM1085 compare to the LM317 in terms of pin-out?
The LM1085 has the same pin-out as TI's industry standard LM317.
- What is the typical line regulation of the LM1085?
The typical line regulation is 0.015%.
- Can the LM1085 be used as a battery charger?
Yes, it can be used to regulate the charging current and maintain the float voltage of the battery).
- What is the ripple rejection of the LM1085?
The ripple rejection is typically 60-75 dB, depending on the output voltage setting).
- What is the operating temperature range of the LM1085?
The operating temperature range is -40°C to 125°C).
- How many pins does the LM1085 have in the TO-263 package?
The LM1085 in the TO-263 package has 3 pins).
