Overview
The LM2733XMFX/NOPB is a high-frequency switching boost converter produced by Texas Instruments. This device operates in current-mode control, offering fast transient response over a wide input voltage range. It is available in two switching frequency options: 1.6 MHz (X version) and 600 kHz (Y version). The LM2733 is packaged in a 5-pin SOT-23 package, which allows for high power density due to the minimal power loss of the internal 1-A switch and the use of small inductors and capacitors. This converter is ideal for applications requiring high output voltages, including boosting to voltages of 16 V or greater.
Key Specifications
| Parameter | Description |
|---|---|
| Switching Frequency | 1.6 MHz (X version), 600 kHz (Y version) |
| Internal FET Switch | 40-V DMOS FET, low RDS(ON) |
| Switch Current | Up to 1 A |
| Input Voltage Range | 2.7 V to 14 V |
| Shutdown Current | < 1 µA |
| Package | 5-pin SOT-23 |
| Maximum Duty Cycle | 93% (X version), 96% (Y version) |
| Protection Features | Cycle-by-cycle current limiting, thermal shutdown |
Key Features
- High-frequency switching boost converter with 40-V internal DMOS FET switch
- Low RDS(ON) DMOS FET and switch current up to 1 A
- Wide input voltage range of 2.7 V to 14 V
- Low shutdown current of less than 1 µA
- 5-pin SOT-23 package for high power density
- Uses tiny capacitors and inductors
- Cycle-by-cycle current limiting and thermal shutdown for protection
- Internally compensated for simplified design and reduced component count
Applications
- White LED current source
- PDAs and palm-top computers
- Digital cameras
- Portable phones and games
- Local boost regulator
Q & A
- What are the switching frequencies of the LM2733XMFX/NOPB?
The LM2733XMFX/NOPB operates at 1.6 MHz (X version) and 600 kHz (Y version).
- What is the maximum switch current of the LM2733XMFX/NOPB?
The maximum switch current is up to 1 A.
- What is the input voltage range of the LM2733XMFX/NOPB?
The input voltage range is from 2.7 V to 14 V.
- What is the shutdown current of the LM2733XMFX/NOPB?
The shutdown current is less than 1 µA.
- What type of package does the LM2733XMFX/NOPB use?
The device is packaged in a 5-pin SOT-23 package.
- What protection features does the LM2733XMFX/NOPB have?
The device features cycle-by-cycle current limiting and thermal shutdown.
- How is the output voltage set for the LM2733XMFX/NOPB?
The output voltage is set using external resistors R1 and R2 according to the formula: R1 = R2 X (VOUT/1.23 −1).
- What type of capacitors are recommended for use with the LM2733XMFX/NOPB?
Multilayer ceramic capacitors with X5R and X7R dielectric types are recommended.
- What are some typical applications of the LM2733XMFX/NOPB?
Typical applications include white LED current sources, PDAs, digital cameras, portable phones, and local boost regulators.
- How does the shutdown pin function on the LM2733XMFX/NOPB?
The device is turned off by pulling the shutdown pin low. If not used, the pin should be tied directly to VIN with a pullup resistor.
