Overview
The LM2733XMF is a high-frequency boost converter IC designed by Texas Instruments. It operates as a current-mode boost converter with fixed switching frequencies of either 1.6 MHz or 600 kHz, depending on the version. This device is packaged in a compact 5-pin SOT-23 package, making it ideal for applications requiring high power density and small footprint.
The LM2733XMF features a 40-V internal DMOS FET switch, which allows for high output voltages and switch currents up to 1 A. It also includes cycle-by-cycle current limiting and thermal shutdown for protection, and internal compensation to simplify design and reduce component count.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Switching Frequency (X Option) | 1.15 MHz | 1.6 MHz | 1.85 MHz | MHz |
| Switching Frequency (Y Option) | 0.40 MHz | 0.60 MHz | 0.80 MHz | MHz |
| Maximum Duty Cycle (X Option) | 87% | 93% | - | % |
| Maximum Duty Cycle (Y Option) | 93% | 96% | - | % |
| Input Voltage Range | 2.7 V | - | 14 V | V |
| Switch Current | - | 1 A | - | A |
| Shutdown Current | - | < 1 µA | - | µA |
| Package Type | - | SOT-23 (5-pin) | - | - |
Key Features
- 40-V internal DMOS FET switch
- High switching frequencies: 1.6 MHz (X option) and 600 kHz (Y option)
- Low RDS(ON) DMOS FET
- Switch current up to 1 A
- Wide input voltage range: 2.7 V to 14 V
- Low shutdown current (< 1 µA)
- Compact 5-pin SOT-23 package
- 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 in various portable and battery-powered devices
Q & A
- What are the switching frequencies of the LM2733XMF?
The LM2733XMF operates at either 1.6 MHz (X option) or 600 kHz (Y option).
- What is the maximum switch current of the LM2733XMF?
The maximum switch current is up to 1 A.
- What is the input voltage range of the LM2733XMF?
The input voltage range is from 2.7 V to 14 V.
- How does the shutdown function work on the LM2733XMF?
The device is turned off by pulling the shutdown pin low. If this function is not used, the pin should be tied directly to VIN.
- What type of protection does the LM2733XMF offer?
The device includes cycle-by-cycle current limiting and thermal shutdown for protection.
- What package type is the LM2733XMF available in?
The LM2733XMF is available in a 5-pin SOT-23 package.
- What are some typical applications for the LM2733XMF?
Typical applications include white LED current sources, PDAs, digital cameras, portable phones, and games.
- How does the internal compensation of the LM2733XMF simplify design?
The internal compensation reduces the need for external components, simplifying the design and reducing component count.
- What is the recommended type of capacitors for use with the LM2733XMF?
The recommended capacitors are multi-layer ceramic capacitors with X5R and X7R dielectric types.
- How does the LM2733XMF handle thermal considerations?
The device's thermal performance is managed through calculations of switch power dissipation and derating for switching losses.
