Key facts
- Brand
- Fairchild
- Model
- SG6742
- Industry
- Industrial
- Documents
- 3
- Languages
- EN
- Last added
- 2012-08-01
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Fairchild Semiconductor FAN6754A Design Guideline to Replace SG6742
The FAN6754A is a highly integrated PWM controller featuring green mode, frequency hopping, constant power limit, and various protection functions. It offers a direct replacement for the SG6742 with the same pin configuration, allowing for PCB layout changes without modification. Functional improvements include reduced operating current for lower standby power and enhanced efficiency through reduced current sensing loss.
The document provides detailed guidance on circuit modifications required for the transition. Key changes involve adjusting the feedback resistor to account for the higher FB impedance, modifying the HV startup circuit for better line surge immunity, and utilizing the two-step UVLO mechanism. It also covers the operation of the internal soft-start, green-mode, and burst-mode functions, along with specific considerations for the output driver and current sensing.
Fairchild SG6742 specifications
| Operating Current | 1.7mA |
|---|---|
| Maximum Duty Cycle | 89% |
| Soft-Start Time | 8ms |
| FB Impedance | 15.5KQ |
| Gate Drive Clamping Voltage | 13V |
Source: Fairchild Semiconductor FAN6754A Design Guideline to Replace SG6742
All Fairchild SG6742 documents by type
How to use the product for one specific task, with worked examples.
Questions answered in these manuals
Can the FAN6754A directly replace the SG6742?
Yes, the two devices have the same pin configuration and direct replacement can be achieved without PCB layout change.
From: Fairchild Semiconductor FAN6754A Design Guideline to Replace SG6742
What is the typical standby power consumption of the FAN6754A?
The operating current is reduced to achieve less than 100mW standby power consumption for most designs.
From: Fairchild Semiconductor FAN6754A Design Guideline to Replace SG6742
Can the FAN6754 replace the SG6742 without PCB changes?
Yes, because these two devices have the same pin configuration and replacement can be achieved without PCB layout changes.
From: Fairchild FAN6754 Design Guideline to Replace SG6742 Application Note
What is the typical standby power consumption of the FAN6754?
The device allows for less than 100mW standby power consumption for most designs due to reduced operating current.
From: Fairchild FAN6754 Design Guideline to Replace SG6742 Application Note
What is the operating current of the SG6742?
The device has a low operating current of 2.7mA.
From: Fairchild SG6742 Highly Integrated Green-Mode PWM Controller Application Note
How does the SG6742 handle open-loop or output short-circuit failures?
It utilizes an internal open-loop protection circuit to ensure safety during these failure conditions.
From: Fairchild SG6742 Highly Integrated Green-Mode PWM Controller Application Note