USD3410
High-efficiency 3A synchronous buck converter with 4.5-28V input and 95% peak efficiency for industrial applications.
Product Overview
Description
The USD3410 is a high-efficiency synchronous buck converter delivering up to 3A continuous output current.
With wide input voltage range of 4.5V to 28V and adjustable output from 0.8V to 24V, it serves diverse applications from industrial 24V systems to 12V consumer electronics.
Peak efficiency of 95% and low quiescent current make it ideal for both high-power and battery-powered applications.
Product Series
USD
Primary Application
Industrial control systems
Key Features
- Wide 4.5V to 28V input range
- 3A continuous output current
- 95% peak efficiency
- Adjustable switching frequency
- Low quiescent current (<50µA)
- Internal compensation
Specifications
| Input Voltage | 4.5V - 28V |
|---|---|
| Output Voltage | 0.8V - 24V (Adjustable) |
| Output Current | 3A Continuous |
| Peak Efficiency | 95% |
| Switching Frequency | 300kHz - 2.2MHz |
| Package | SOP-8 EP |
Applications
Industrial control systems
Industrial automation and control
12V and 24V consumer electronics
Consumer electronics
Battery-powered equipment
Battery and charging management
Telecom infrastructure
Electronic system design
Automotive electronics
Automotive and EV electronics
FAE Expert Insights
"The USD3410 is one of our most popular DC-DC converters. I've designed it into dozens of industrial and consumer products. The wide input range handles everything from 5V USB to 24V industrial supplies. Efficiency is excellent - consistently above 90% across most operating conditions. The adjustable frequency is useful for EMI optimization - you can trade off efficiency for smaller magnetics. Thermal performance is good with the exposed pad package. Price is very competitive compared to TI and MPS alternatives. For 3A buck applications, this is my first recommendation."
Versatile 3A buck with excellent efficiency
— Zhang Wei, BeiLuo
Frequently Asked Questions
What is the efficiency curve for USD3410?
USD3410 efficiency characteristics: Peak efficiency: 95% at 50-70% load, Vin=12V, Vout=5V. Light load efficiency: >80% at 10mA with PFM mode. Heavy load efficiency: >90% at 2-3A. Efficiency decreases with larger Vin-Vout differential. 12V to 3.3V: 92-94% typical. 24V to 5V: 90-93% typical. 24V to 3.3V: 88-91% typical. Efficiency improves with higher switching frequency but at cost of higher switching losses.
Expect 90%+ efficiency for most operating points. Higher efficiency with smaller voltage differential.
How do I set the output voltage?
USD3410 output voltage set by resistor divider: Vout = 0.8V × (1 + R1/R2). Recommended R2 = 10kΩ. Calculate R1 = R2 × (Vout/0.8V - 1). Example: For 3.3V output: R1 = 10k × (3.3/0.8 - 1) = 31.25kΩ. Use 1% tolerance resistors for accuracy. Place divider close to FB pin. Add 10-22pF feedforward capacitor across R1 for improved transient response.
Use standard resistor values. Place divider close to IC. Add feedforward cap for stability.
What inductor value should I use?
Inductor selection for USD3410: Recommended range: 4.7µH to 22µH. Lower inductance: Smaller size, faster transient, higher ripple. Higher inductance: Lower ripple, better efficiency at light load, larger size. Typical values: 10µH for 12V to 5V at 3A. 15µH for 24V to 12V at 2A. 22µH for 24V to 5V at 3A. Current rating: Select inductor with saturation current > 1.3 × Iout_max. DCR: Lower is better for efficiency.
Start with 10-15µH. Adjust based on ripple and transient requirements.
How do I optimize EMI performance?
USD3410 EMI optimization techniques: Switching frequency: Lower frequency reduces EMI but increases inductor size. Spread spectrum: Enable if available to spread energy. Input filtering: Add LC filter on input for conducted EMI. Output filtering: Ferrite bead on output for high frequency noise. Layout: Minimize switch node area. Shielding: Use ground plane under inductor. Snubber: Add RC snubber on switch node if needed. Testing: Use near-field probes to identify sources.
Optimize layout first. Add filtering as needed. Test early and often.
Can USD3410 be used for automotive applications?
USD3410 is not AEC-Q100 qualified for automotive. For automotive applications: Consider USD3410Q (automotive grade version). Temperature range: Industrial -40°C to +85°C. Automotive version: -40°C to +125°C. Load dump protection needed for 24V automotive systems. Additional filtering for automotive EMI requirements. Contact Unisplendour for automotive-qualified alternatives and support.
Use USD3410Q for automotive. Add protection for load dump and transients.
What protection features does USD3410 include?
USD3410 protection features: Overcurrent protection: Cycle-by-cycle current limiting. Thermal shutdown: Shutdown at 160°C, hysteresis restart. Overvoltage protection: Output OVP latches off. Undervoltage lockout: Prevents operation below 4V input. Short circuit protection: Current limiting during short. Soft start: Reduces inrush current at startup. These protections make the device robust for industrial and consumer applications.
Built-in protections sufficient for most apps. External fuse recommended for safety-critical.