Overview
The LM2731, produced by Texas Instruments, is a high-performance switching regulator IC designed as a current-mode boost converter. It operates at fixed frequencies of either 1.6 MHz (X option) or 600 kHz (Y option), making it suitable for applications requiring fast transient response and high power density. The device is packaged in a compact 5-lead SOT-23 package, which minimizes power loss and allows the use of small inductors and capacitors. This design enables the LM2731 to achieve the highest power density in the industry. The internal 22-V DMOS FET switch supports output voltages up to 20 V, and the logic-level shutdown pin helps in reducing quiescent current to extend battery life.
Key Specifications
| Parameter | Min | Max | Unit | |
|---|---|---|---|---|
| Operating Junction Temperature | -40 | 125 | °C | |
| Input Supply Voltage (VIN) | 2.7 | 14 | V | |
| Switching Frequency (X Option) | 1.4 | 1.6 | 1.8 | MHz |
| Switching Frequency (Y Option) | 0.4 | 0.6 | 0.8 | MHz |
| Switch Current | 1.8 | A | ||
| Shutdown Current | <1 µA | |||
| RDS(ON) of DMOS FET | Low | |||
| Package Type | 5-Lead SOT-23 |
Key Features
- 22-V internal DMOS FET switch
- Fixed switching frequencies: 1.6 MHz (X option) and 600 kHz (Y option)
- Low RDS(ON) DMOS FET
- Switch current up to 1.8 A
- Wide input voltage range (2.7 V to 14 V)
- Low shutdown current (<1 µA)
- 5-lead SOT-23 package
- Uses tiny capacitors and inductors
- Cycle-by-cycle current limiting
- Internally compensated
- Logic-level shutdown pin
Applications
The LM2731 is suitable for various applications requiring high power density and efficient voltage boosting. Some common applications include:
- Portable phones and other handheld devices
- Local boost regulators in larger systems
- Battery-powered devices where low quiescent current is crucial for extending battery life
- Systems requiring fast transient response and high efficiency
Q & A
- What are the switching frequencies of the LM2731?
The LM2731 operates at fixed frequencies of either 1.6 MHz (X option) or 600 kHz (Y option).
- What is the maximum switch current of the LM2731?
The maximum switch current of the LM2731 is up to 1.8 A.
- What is the input voltage range of the LM2731?
The input voltage range of the LM2731 is from 2.7 V to 14 V.
- What is the package type of the LM2731?
The LM2731 is packaged in a 5-lead SOT-23 package.
- Does the LM2731 have built-in protection features?
Yes, the LM2731 includes cycle-by-cycle current limiting and thermal shutdown protection.
- How does the shutdown feature work on the LM2731?
The LM2731 has a logic-level shutdown pin that can reduce quiescent current to less than 1 µA when activated.
- What are some typical applications for the LM2731?
The LM2731 is commonly used in portable phones, handheld devices, and as local boost regulators in larger systems.
- What is the thermal performance of the LM2731?
The LM2731 has a junction-to-ambient thermal resistance of 209.9 °C/W in the SOT-23 package.
- Is the LM2731 internally compensated?
Yes, the LM2731 is internally compensated, which simplifies the design and reduces the component count.
- What is the maximum output voltage supported by the LM2731?
The LM2731 can support output voltages up to 20 V due to its 22-V internal DMOS FET switch.
