NCP1234: Fixed Frequency Current Mode Controller for Flyback Converters
The NCP1234 represents a major leap towards achieving low standby power in medium-to-high power Switched-Mode Power Supplies such as notebook adapters, off-line battery chargers and consumer electronics equipment. Housed in a compact 8-pin package (SO-8 or PDIP-7), the NCP1234 contains all needed control functionality to build a rugged and efficient power supply. The NCP1234 is a current mode controller with internal ramp compensation. Among the unique features offered by the NCP1234 is an event management scheme that can disable the front-end PFC circuit during standby, thus reducing the no load power consumption. The NCP1234 itself goes into cycle skipping at light loads while limiting peak current (to 25% of nominal peak) so that no acoustic noise is generated. The NCP1234 has a high-voltage start-up circuit that eliminates external components and reduces power consumption. The NCP1234 also features an internal latching function that can be used for OVP protection. This latch is triggered by pulling the CS pin above 3.0 V and can only be reset by pulling VCC to ground. True overload protection, internal 2.5 ms soft start, internal leading edge blanking, internal frequency dithering for low EMI are some of the other important features offered by the NCP1234.
技术特性
- Fixed−Frequency Current−Mode Operation with Built−In Ramp Compensation
- 65 kHz or 100 kHz Oscillator Frequency version
- Frequency Foldback then Skip Mode for Maximized Performance in
Light Load and Standby Conditions
- Timer−Based Overload Protection with Latched (option A) or
Auto−Recovery (option B) Operation
- High−voltage Current Source with Dynamic Self−Supply,
Simplifying the Design of the VCC Capacitor
- Frequency Modulation for Softened EMI Signature, including during
Frequency Foldback mode
- Adjustable Overpower Compensation
- Latch−off Input for Severe Fault Conditions, Allowing Direct
Connection of an NTC for Overtemperature Protection (OTP)
- VCC Operation up to 28 V, with Overvoltage Detection
- 500 mA Peak Source/Sink Current Drive Capability
- 4.0 ms Soft−Start
- Internal Thermal Shutdown
- Pin−to−Pin Compatible with the Existing NCP12xxSeries
- These Devices are Pb−Free, Halogen Free/BFR Free
and are RoHS Compliant
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终端产品
应用
- Consumer Electronics Power Supplies
- Auxiliary/Housekeeping power supplie
封装图 PACKAGE DIMENSIONS
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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 |
| NCP1234AD100R2G |
Active |
|
Fixed Frequency Current Mode Controller for Flyback Converters |
SOIC-8 |
751U |
1 |
Tape and Reel |
2500 |
$0.32 |
| NCP1234AD65R2G |
Active |
|
Fixed Frequency Current Mode Controller for Flyback Converters |
SOIC-8 |
751U |
1 |
Tape and Reel |
2500 |
$0.32 |
| NCP1234BD100R2G |
Active |
|
Fixed Frequency Current Mode Controller for Flyback Converters |
SOIC-8 |
751U |
1 |
Tape and Reel |
2500 |
$0.32 |
| NCP1234BD65R2G |
Active |
|
Fixed Frequency Current Mode Controller for Flyback Converters |
SOIC-8 |
751U |
1 |
Tape and Reel |
2500 |
$0.32 |
数据资料DataSheet下载
