TC1509
High-efficiency 3A synchronous buck converter with integrated switches for high-current applications
Product Overview
Description
The TC1509 is a high-efficiency synchronous buck converter designed for applications requiring up to 3A output current. It features integrated high-side and low-side MOSFETs, reducing external component count and simplifying PCB layout.
Operating from a 4.5V to 18V input voltage range, the TC1509 delivers excellent efficiency up to 94% thanks to its synchronous rectification architecture. The fixed 1.2MHz switching frequency enables compact designs with small external components.
The device includes soft-start to limit inrush current, power-good indicator for sequencing, and comprehensive protection features. Available in thermally enhanced packages, the TC1509 is ideal for high-current industrial and consumer applications.
Product Series
TC
Primary Application
Industrial power supplies
Key Features
- High efficiency up to 94% with synchronous rectification
- 3A continuous output current capability
- Integrated high-side and low-side switches
- 1.2MHz switching frequency for compact design
- Power-good indicator output
- Soft-start function
- Comprehensive protection features
- Thermally enhanced packages available
Specifications
| Input Voltage | 4.5V - 18V |
|---|---|
| Output Voltage | 0.8V - Vin |
| Output Current | 3A |
| Switching Frequency | 1.2MHz |
| Efficiency | Up to 94% |
| Operating Temperature | -40°C to +85°C |
| Package | ESOP-8, QFN-16 |
Applications
Industrial power supplies
Industrial automation and control
Networking equipment
Communication and interface
Set-top boxes
Electronic system design
LCD TV power
Electronic system design
FPGA and processor power
Electronic system design
FAE Expert Insights
"The TC1509 is my go-to recommendation for 3A applications where cost and performance need to be balanced. The integrated switches are a major advantage - they are well-matched and optimized for this specific converter, resulting in excellent efficiency. I've used this in several industrial power supply designs with great results. The 1.2MHz frequency is a good compromise between component size and efficiency. One design tip: the power-good output is very useful for sequencing multiple rails - I often use it to enable downstream converters after the main rail is stable. Thermal performance is good with the ESOP-8 package, but for continuous 3A operation at high ambient temperatures, I recommend the QFN package with better thermal characteristics. Overall, a solid performer at a competitive price point."
Excellent 3A converter with integrated switches and good thermal performance
— David Liu, BeiLuo
Frequently Asked Questions
What is the difference between TC1508 and TC1509?
TC1508 is a 2A buck converter while TC1509 is a 3A version with higher current capability. TC1509 also features integrated high-side and low-side switches, whereas TC1508 may require external diode. TC1509 has slightly lower switching frequency (1.2MHz vs 1.5MHz) but offers higher efficiency and better thermal performance for high-current applications.
Choose TC1508 for applications up to 2A; select TC1509 for 2-3A applications requiring higher current capability.
What package options are available for TC1509?
TC1509 is available in ESOP-8 and QFN-16 packages. The ESOP-8 is cost-effective and suitable for most applications up to 2.5A. The QFN-16 package offers better thermal performance with exposed thermal pad, recommended for continuous 3A operation or high ambient temperature applications.
Use ESOP-8 for cost-sensitive designs up to 2.5A; select QFN-16 for 3A continuous operation or high ambient temperatures.
How do I use the power-good output?
The power-good (PG) output is an open-drain signal that goes high when the output voltage is within regulation. Connect a 100kΩ pull-up resistor to a logic voltage. PG can be used for power sequencing, reset generation, or monitoring. When input voltage is below UVLO threshold, PG is pulled low.
Use PG for power sequencing in multi-rail systems; connect to enable pins of downstream converters for automatic sequencing.
What is the soft-start time of TC1509?
TC1509 includes internal soft-start with approximately 2ms ramp time. This limits inrush current during startup and prevents output voltage overshoot. The soft-start time is fixed internally and cannot be adjusted. For applications requiring different soft-start timing, consider external soft-start circuits.
Internal 2ms soft-start is suitable for most applications; contact FAE if different timing is required.
Can TC1509 be used for FPGA or processor power?
Yes, TC1509 is suitable for powering FPGAs and processors requiring up to 3A current. The fast transient response and low output ripple meet the requirements of most digital loads. For noise-sensitive applications, add additional output capacitance or use an LDO for post-regulation.
Verify current requirements and transient specifications; add capacitance as needed for your specific FPGA or processor.