PSP3406
High-efficiency 3A synchronous buck converter with wide input range, adjustable output, and excellent transient response
Product Overview
Description
The PSP3406 is a high-efficiency synchronous buck converter capable of delivering up to 3A continuous output current.
With a wide input voltage range of 4.5V to 36V and adjustable output from 0.8V to 24V, this converter is ideal for industrial and automotive power applications.
The device features peak current mode control, internal compensation, and protection features including overcurrent, overtemperature, and short-circuit protection.
Product Series
PSP
Primary Application
Industrial control systems
Key Features
- Wide input voltage range: 4.5V to 36V
- 3A continuous output current capability
- High efficiency up to 95%
- Adjustable switching frequency
- Internal soft-start and compensation
- Peak current mode control
- Low quiescent current: 25 uA
- Comprehensive protection features
- Power-good indicator output
Specifications
| Input Voltage | 4.5V - 36V |
|---|---|
| Output Current | 3A continuous |
| Output Voltage | 0.8V - 24V adjustable |
| Switching Frequency | 500 kHz - 2 MHz |
| Efficiency | Up to 95% |
| Quiescent Current | 25 uA |
| Current Limit | 4.5A typical |
| Thermal Shutdown | 165°C with 15°C hysteresis |
| Temperature Range | -40°C to +85°C (Industrial), -40°C to +125°C (Automotive) |
| Package | SOP-8, QFN-12 |
Applications
Industrial control systems
Industrial automation and control
Automotive electronics
Automotive and EV electronics
Battery-powered equipment
Battery and charging management
Distributed power systems
Electronic system design
LED lighting drivers
Motor drive and control systems
Telecom and networking equipment
Communication and interface
Test and measurement systems
Data acquisition and conversion
FAE Expert Insights
"The PSP3406 is an excellent choice for industrial power applications. I particularly like the wide input voltage range that handles both 12V and 24V industrial buses without modification. The efficiency reaches 95% at mid-loads, which significantly reduces thermal management requirements. I've used this converter in battery-powered applications where the 25 uA quiescent current helps extend battery life. The internal compensation simplifies design - just add input and output capacitors and you're good to go. For EMI-sensitive applications, I recommend using the 500 kHz switching frequency and adding a small LC filter on the output."
Wide input range with high efficiency and simple design
— David Wang, BeiLuo
Frequently Asked Questions
What is the maximum output current of the PSP3406?
The PSP3406 can deliver up to 3A continuous output current with adequate thermal management. The device features cycle-by-cycle current limiting at 4.5A typical to protect against overload conditions. For reliable operation, ensure the junction temperature remains below 125°C by providing adequate heatsinking or airflow. The maximum output current may need to be derated at high ambient temperatures or with high input-output voltage differentials.
The 3A rating is suitable for most industrial loads. For higher currents, consider parallel operation or contact our FAE team for alternative solutions.
How do I set the output voltage of the PSP3406?
The PSP3406 output voltage is set using a resistor divider from the output to the FB pin. The formula is: Vout = 0.8V × (1 + R1/R2), where 0.8V is the internal reference voltage. For example, for 3.3V output with R2 = 10kΩ, R1 = 31.25kΩ. Use 1% tolerance resistors for accurate output voltage. The feedback pin is high impedance, so place the divider close to the IC to minimize noise pickup.
Use standard resistor values or our online calculator for precise voltage setting. Contact our FAE team for voltage margining applications.
What input and output capacitors are recommended for the PSP3406?
For input capacitors, use at least 10uF ceramic with X5R or X7R dielectric, rated for the maximum input voltage. Place the capacitor close to the VIN and GND pins to minimize switching noise. For output capacitors, use 22uF to 100uF ceramic depending on load transient requirements. Larger capacitance improves transient response but may affect loop stability. Use capacitors with low ESR for best performance. Additional bulk capacitance may be needed for applications with long input leads.
Start with 22uF output capacitance and adjust based on transient requirements. Our FAE team can help optimize capacitor selection.
How do I optimize the PSP3406 for EMI performance?
To optimize EMI performance: 1) Use the lowest switching frequency that meets your size requirements (500 kHz produces less EMI than 2 MHz); 2) Minimize the switching node area to reduce radiated emissions; 3) Use shielded inductors or toroidal inductors to contain magnetic fields; 4) Add an RC snubber across the switching node if needed; 5) Use proper input filtering with a pi-filter for conducted emissions; 6) Follow good PCB layout practices with proper grounding. These techniques can achieve CISPR 22 Class B compliance with proper implementation.
Follow EMI best practices from the start of design. Our FAE team can provide EMI-optimized reference designs and layout reviews.
What protection features does the PSP3406 include?
The PSP3406 includes comprehensive protection features: Overcurrent Protection (OCP) with cycle-by-cycle current limiting at 4.5A typical; Thermal Shutdown at 165°C junction temperature with 15°C hysteresis to prevent thermal runaway; Short-Circuit Protection that limits current during output short conditions; Undervoltage Lockout (UVLO) that disables the converter when input voltage is too low; and Soft-Start that limits inrush current during startup. These features ensure reliable operation under fault conditions and protect both the converter and the load.
The built-in protections simplify system design. For additional protection needs, contact our FAE team for external protection circuit recommendations.