LP6235
High-efficiency synchronous buck converter with 2A output and 95% efficiency for battery applications
Product Overview
Description
The LP6235 is a high-efficiency synchronous buck converter designed for battery-powered applications. With up to 95% efficiency, it minimizes power loss and extends battery life compared to linear regulators. The device can deliver up to 2A of continuous output current.
The converter operates from a 2.7V to 5.5V input voltage range, making it suitable for single-cell Li-ion or 3-cell NiMH/NiCd battery applications. The output voltage is adjustable from 0.6V to VIN through an external resistor divider. The fixed 1.5MHz switching frequency allows the use of small external components.
The LP6235 features automatic PFM/PWM mode switching to maintain high efficiency across the entire load range. It includes enable pin, soft-start, current limit, and thermal shutdown protection. Available in a compact SOT-23-5 package, it is ideal for space-constrained portable electronics.
Product Series
LP
Primary Application
Smartphones and tablets
Key Features
- High efficiency up to 95%
- 2A maximum output current
- Synchronous rectification
- Automatic PFM/PWM mode switching
- Low 40μA quiescent current
- 1.5MHz fixed switching frequency
- Enable pin and soft-start
- Current limit and thermal protection
Specifications
| Input Voltage Range | 2.7V - 5.5V |
|---|---|
| Output Voltage Range | 0.6V - VIN (adjustable) |
| Output Current | 2A max |
| Efficiency | Up to 95% |
| Quiescent Current | 40μA (PFM mode) |
| Switching Frequency | 1.5MHz fixed |
| Load Regulation | ±0.5% |
| Line Regulation | ±0.2%/V |
| Operating Temperature | -40°C to +85°C |
| Package | SOT-23-5 |
Applications
Smartphones and tablets
Electronic system design
Portable media players
Electronic system design
Battery-powered instruments
Battery and charging management
Industrial control systems
Industrial automation and control
IoT gateway devices
Electronic system design
FAE Expert Insights
"The LP6235 is an excellent buck converter that I have used in numerous battery-powered designs. The 95% efficiency is genuinely achievable in real applications - I've measured 93-94% at typical loads. The automatic PFM/PWM switching is a key feature that maintains high efficiency across the entire load range. At light loads, the 40μA quiescent current helps extend battery life. The 1.5MHz switching frequency allows the use of small inductors (2.2μH typical) and ceramic capacitors, saving board space. One implementation tip: the feedback resistor divider should be placed close to the FB pin, and the trace should be kept away from the switching node to avoid noise coupling. I've used this converter in designs powering application processors, and it handles load transients very well. The soft-start feature prevents input voltage droop during startup. Overall, a reliable and efficient buck converter at a competitive price point."
High-efficiency synchronous buck converter with 2A output and automatic PFM/PWM switching
— Wang Jian, BeiLuo
Frequently Asked Questions
What is the efficiency of LP6235?
The LP6235 achieves up to 95% efficiency, which is excellent for a synchronous buck converter. The actual efficiency depends on input voltage, output voltage, and load current. Higher efficiency is achieved at moderate to heavy loads with smaller voltage differential between input and output.
95% efficiency excellent for battery applications; actual efficiency varies with operating conditions.
What is the maximum output current of LP6235?
The LP6235 can deliver up to 2A of continuous output current. This high current capability makes it suitable for powering application processors, system-on-chips, and other high-current loads in portable devices.
2A sufficient for most application processors; verify thermal design for continuous high-current operation.
What is the switching frequency of LP6235?
The LP6235 operates at a fixed 1.5MHz switching frequency. This high frequency allows the use of small external inductors (2.2μH typical) and ceramic capacitors, reducing the overall solution size and cost.
1.5MHz allows small external components; verify EMI requirements for your application.
Does LP6235 have PFM mode?
Yes, the LP6235 features automatic PFM/PWM mode switching. At light loads, it operates in PFM (Pulse Frequency Modulation) mode to maintain high efficiency with low quiescent current. At heavier loads, it automatically switches to PWM mode for optimal regulation.
Automatic mode switching maintains efficiency across load range; excellent for variable load applications.
What external components are needed for LP6235?
The LP6235 requires minimal external components: an input capacitor (10μF ceramic), an output capacitor (10μF ceramic), an inductor (2.2μH), and two resistors for output voltage setting. This simple BOM reduces cost and board space.
Minimal external components; use ceramic capacitors and shielded inductor for best performance.
What protection features does LP6235 include?
The LP6235 includes current limit protection, thermal shutdown, and soft-start. The current limit prevents damage during output shorts, while thermal shutdown protects against overheating. Soft-start prevents input voltage droop during startup.
Built-in protections ensure robust operation; implement proper PCB layout for thermal management.
Is LP6235 suitable for Li-ion battery applications?
Yes, the LP6235 is ideal for single-cell Li-ion battery applications. The 2.7V to 5.5V input range covers the full Li-ion battery voltage range (3.0V to 4.2V). The high efficiency extends battery life, and the low dropout allows operation until the battery is nearly depleted.
Excellent for Li-ion applications; verify output voltage setting for your specific requirements.