Overview
The FSL306LRN, produced by onsemi, is a Green Mode Buck Switch that integrates a Pulse Width Modulator (PWM) and SENSEFET®. This device is specifically designed for high-performance offline buck, buck-boost, and non-isolation flyback Switched Mode Power Supplies (SMPS) with minimal external components. It features an internal high-voltage power regulator, eliminating the need for an auxiliary bias winding. The device includes various protection mechanisms and advanced control features to ensure reliable and efficient operation.
Key Specifications
| Parameter | Unit | Typical | Max | Min |
|---|---|---|---|---|
| Switching Frequency (fOSC) | kHz | 50 | 55 | 45 |
| Frequency Modulation (fM) | kHz | ±3 | ||
| Maximum Turn-On Time (ton.max) | μs | 13.3 | 15.4 | 11.2 |
| UVLO Threshold Voltage (VSTART) | V | 8.0 | 8.8 | 7.2 |
| UVLO Stop Voltage (VSTOP) | V | 7.0 | 7.7 | 6.3 |
| No-Load Power Consumption (at 230 VAC with External Bias) | mW | <25 | ||
| No-Load Power Consumption (at 230 VAC without External Bias) | mW | <120 | ||
| Ultra-Low Operating Current | μA | 250 | ||
| SENSEFET Voltage Rating | V | 650 |
Key Features
- Built-in Avalanche Rugged SENSEFET with 650 V rating
- Fixed Operating Frequency of 50 kHz
- No need for auxiliary bias winding
- Frequency modulation for attenuating EMI
- Pulse-by-pulse current limiting
- Ultra-low operating current of 250 μA
- Built-in soft-start and startup circuit
- Adjustable peak current limit
- Integrated high-voltage startup switch and Burst-Mode operation
- Thermal Shutdown (TSD) and various protection mechanisms including Overload Protection (OLP), Over-Voltage Protection (OVP), Feedback Open Loop Protection (FB_OLP), and Abnormal Over-Current Protection (AOCP)
Applications
The FSL306LRN is suitable for various high-performance offline power supply applications, including:
- Buck converters
- Buck-boost converters
- Non-isolation flyback converters
- General-purpose offline SMPS requiring high efficiency and reliability
Q & A
- What is the primary function of the FSL306LRN?
The FSL306LRN is a Green Mode Buck Switch that integrates a PWM and SENSEFET, designed for high-performance offline SMPS applications.
- What is the typical switching frequency of the FSL306LRN?
The typical switching frequency is 50 kHz.
- Does the FSL306LRN require an auxiliary bias winding?
No, the FSL306LRN does not require an auxiliary bias winding due to its internal high-voltage power regulator.
- What are the key protection mechanisms of the FSL306LRN?
The device includes Overload Protection (OLP), Over-Voltage Protection (OVP), Feedback Open Loop Protection (FB_OLP), Abnormal Over-Current Protection (AOCP), and Thermal Shutdown (TSD).
- How does the FSL306LRN reduce EMI?
The FSL306LRN reduces EMI through frequency modulation, which spreads the energy over a wider frequency range.
- What is the ultra-low operating current of the FSL306LRN?
The ultra-low operating current is 250 μA.
- Does the FSL306LRN have built-in soft-start capabilities?
Yes, the FSL306LRN has built-in soft-start and startup circuits.
- What is the SENSEFET voltage rating of the FSL306LRN?
The SENSEFET voltage rating is 650 V.
- How does the Burst-Mode operation work in the FSL306LRN?
The Burst-Mode operation minimizes power dissipation in Standby Mode by alternately enabling and disabling the switching of the SENSEFET based on the feedback voltage.
- What are the typical no-load power consumption values for the FSL306LRN?
The no-load power consumption is less than 25 mW at 230 VAC with external bias and less than 120 mW at 230 VAC without external bias.
