NCP1247:Fixed Frequency Current Mode Controller for Flyback Converters
The NCP1247 is a new fixed-frequency current-mode controller featuring Dynamic Self-Supply. This function greatly simplifies the design of the auxiiary supply and the Vcc capacitor by activating the internal startup current source to supply the controller during start-up, transients, latch, stnad-by etc. This device contains a special HV detector which detects the application unplug from the AC input line and triggers the X2 discharge current. The HV structure also includes brown-out detection circuitry. The NCP1247 features a timer-based fault detection that ensures the detection of overload and an adjustable power compensation to help keep the maximum power independent of the input voltage. Due to frequency foldback, the controller exhibits excellent efficiency in light load condition while still achieving very low standby power consumption. Internal frequency jittering, ramp compensation, and a versatile latch input make this controller an excellent candidate for robust power supply designs. A dedicated off mode allows the SMPS to reach extremely low no load input power consumption when combinded with secondary side contoller NCP4353 or NCP4354. When used together, the SMPS is capable of achieving <10 mW no load input power consumption. The secondary side contoller signals the NCP1247 to enter a sleep mode, minimizing the power consumption of the control circuitry. Similar functionality to NCP1246.
技术特性
- Fixed−Frequency Current−Mode Operation (65 kHz and 100 kHz
frequency options)
- Frequency Foldback then Skip Mode for Maximized Performance in
Light Load and Standby Conditions
- Timer−Based Overload Protection with Latched (Options A/C) or
Auto−Recovery (Options B/D) Operation
- High−voltage Current Source with Brown−Out Detection and
Dynamic Self−Supply, Simplifying the Design of the VCC Circuitry
- Frequency Modulation for Softened EMI Signature
- Adjustable Overpower Protection Dependant on the Bulk Voltage
- Latch−off Input Combined with the Overpower Protection Sensing
Input
- VCC Operation up to 28 V, With Overvoltage Detection
- 500/800 mA Source/Sink Drive Peak Current Capability
- 10 ms Soft−Start
- Internal Thermal Shutdown
- No−Load Standby Power < 30 mW
- X2 Capacitor in EMI Filter Discharging Feature
应用
- AC-DC Adapters
- LCD TV power supplies
|
终端产品
优势
- Optimized efficiency across the entire load range
- Protection against overcurrent and short circuit
- Simplifies the design of the auxiliary supply
- Protects against any drops in line voltage
- Softened EMI signature
- Automatically adjusts the current limit depending on the line input voltage (high line or low line)
- Protection against faults
封装图 PACKAGE DIMENSIONS
|
订购信息 Ordering Information
| 产品 |
状况 |
Compliance |
具体说明 |
封装 |
MSL* |
容器 |
预算价格 (1千个数量的单价） |
| 类型 |
外形 |
类型 |
数量 |
| NCP1247AD065R2G |
Active |
|
Fixed Frequency Current Mode Controller for Flyback Converters |
SOIC-8 |
751U |
1 |
Tape and Reel |
2500 |
$0.5 |
数据资料DataSheet下载
