XB-B3401
High-efficiency synchronous buck converter with integrated MOSFETs and wide input voltage range for industrial
Product Overview
Description
The XB-B3401 is a high-efficiency synchronous buck converter delivering up to 3A output current.
It features integrated high-side and low-side MOSFETs, reducing external component count and cost.
The wide input voltage range and adjustable output make it suitable for diverse applications.
Product Series
XB
Primary Application
Industrial control systems
Key Features
- High efficiency up to 95%
- Wide input voltage range 4.5V to 36V
- Integrated MOSFETs reduce BOM cost
- Adjustable switching frequency
- Low quiescent current for light loads
- Internal compensation simplifies design
- Comprehensive protection features
- Thermal enhanced package
Specifications
| Topology | Synchronous Buck |
|---|---|
| Input Voltage | 4.5V to 36V |
| Output Voltage | 0.8V to 24V (adjustable) |
| Max Current | 3A continuous |
| Switching Frequency | 300kHz to 1MHz |
| Efficiency | Up to 95% |
| Quiescent Current | 50μA typical |
| Package | ESOP-8 |
Applications
Industrial control systems
Industrial automation and control
Battery-powered equipment
Battery and charging management
Distributed power systems
Electronic system design
Automotive electronics
Automotive and EV electronics
LED lighting power supplies
Electronic system design
FAE Expert Insights
"The XB-B3401 is an excellent general-purpose buck converter for industrial and automotive applications. The wide input voltage range handles everything from 5V logic supplies to 24V industrial systems. I particularly like the adjustable frequency feature - lower frequencies improve efficiency while higher frequencies allow smaller inductors. The integrated MOSFETs and internal compensation make this an easy-to-use device that minimizes design time. Efficiency is excellent across the load range, and thermal performance is good with proper PCB layout."
Wide input range with adjustable frequency and integrated MOSFETs
— David Chen, BeiLuo
Frequently Asked Questions
What inductor value should I use with XB-B3401?
Inductor selection depends on switching frequency, input/output voltages, and ripple current requirements. A good starting point is 10-22μH for 500kHz operation with 3A output. Higher inductance reduces ripple current but increases size and DCR. Lower inductance allows smaller size but increases ripple. Calculate ripple current as approximately 30-40% of maximum output current. Use shielded inductors for EMI-sensitive applications.
Start with 10-22μH for 500kHz. Adjust based on ripple and size requirements.
Can XB-B3401 operate at 100% duty cycle?
XB-B3401 supports high duty cycle operation up to 95% typical, but not 100%. At very high duty cycles (low dropout), the high-side MOSFET remains on for extended periods. The minimum off-time ensures bootstrap capacitor refresh for the high-side driver. For dropout operation where input voltage approaches output voltage, the output will track input minus voltage drops. Consider LDO regulators for true dropout applications.
XB-B3401 supports 95% max duty cycle. Use LDO for dropout applications.
How do I calculate power dissipation in XB-B3401?
Power dissipation in XB-B3401 includes conduction losses and switching losses. Conduction loss = Iout² × RDS(on) × D (high-side) + Iout² × RDS(on) × (1-D) (low-side). Switching loss depends on frequency and switching times. For a 3A, 24V to 5V conversion at 500kHz, total dissipation is typically 0.5-1W. Ensure adequate thermal design for the calculated dissipation. Use thermal vias and copper area to keep junction temperature below 125°C.
Calculate both conduction and switching losses. Ensure thermal design adequacy.
What input capacitance is recommended for XB-B3401?
XB-B3401 requires adequate input capacitance to handle switching current ripple and prevent voltage transients. Recommended: 10-22μF ceramic capacitor close to the IC, plus bulk capacitance (100-470μF electrolytic) for higher current applications. Use X5R or X7R ceramic capacitors for temperature stability. Place the ceramic capacitor within 5mm of the input pins. Additional capacitance may be needed for long input leads or high source impedance.
Use 10-22μF ceramic plus bulk capacitance. Place close to IC pins.
Can XB-B3401 be synchronized to an external clock?
Yes, XB-B3401 supports external clock synchronization for applications requiring specific switching frequencies or multi-phase operation. The SYNC pin accepts external clock signals from 300kHz to 1MHz. When synchronized, the converter operates at the external frequency. This feature is useful for EMI management by spreading spectrum or synchronizing multiple converters to avoid beat frequencies. Connect SYNC to ground for free-running operation at the frequency set by the RT resistor.
Use external sync for EMI management or multi-phase systems. Ground SYNC for free-running.