Key facts
- Brand
- Fairchild
- Model
- FAN7527B
- Category
- Power Management
- Documents
- 2
- Languages
- EN
- Last added
- 2012-07-11
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Fairchild Semiconductor FAN7527B Application Note AN4121
The document describes the FAN7527B, an active power factor correction (PFC) controller designed for boost PFC applications operating in critical conduction mode. It ensures the input current waveform follows the input voltage to achieve a good power factor by turning on the MOSFET when inductor current reaches zero and turning it off based on a reference voltage.
The note details the internal block diagram and functions, including the error amplifier, zero current detection, switch current sensing, input voltage sensing, and switch drive. It also provides design equations and guidelines for the power stage, auxiliary winding, and input capacitor.
Fairchild FAN7527B specifications
| Operating Mode | Critical conduction mode |
|---|---|
| Application Type | Boost PFC application |
| Control Loop Bandwidth | Below 20Hz |
| Soft OVP Threshold | 30uA |
| Dynamic OVP Threshold | 40uA |
| Quiescent Current (OVP) | 2mA |
| Static OVP Threshold | 2.25V |
| Drive Output Peak Current | 500mA |
| Drive Output Rise Time | 130ns |
| Drive Output Fall Time | 50ns |
| Zero Current Detector Threshold | 1.5V |
| Zero Current Detector Hysteresis | 0.5V |
| Watchdog Timer Delay | 150us |
Source: Fairchild Semiconductor FAN7527B Application Note AN4121
All Fairchild FAN7527B documents by type
How to use the product for one specific task, with worked examples.
Ratings, dimensions and ordering codes, for selection and design work.
Questions answered in these manuals
What is the operating mode of the FAN7527B?
The FAN7527B operates in the critical conduction mode.
From: Fairchild Semiconductor FAN7527B Application Note AN4121
How does the device achieve power factor correction?
It turns on the MOSFET when the inductor current reaches zero and turns it off when the current meets the desired input current reference voltage.
From: Fairchild Semiconductor FAN7527B Application Note AN4121
What is the maximum supply voltage for the FAN7527B?
The controller can tolerate up to 30 V supply voltage.
From: Fairchild FAN7527B Power Factor Correction Controller Datasheet
How much peak drive output current can the FAN7527B provide?
It can source up to 500 mA of peak drive output current.
From: Fairchild FAN7527B Power Factor Correction Controller Datasheet