NCP1251: Current-Mode PWM Controller for Off-line Power Supplies
The NCP1251 is a highly integrated PWM controller capable of delivering a rugged and high performance offline power supply in a tiny TSOP-6 package. With a supply range up to 28 V, the controller hosts a jittered 65 kHz or 100 kHz switching circuitry operated in peak current mode control. When the power on the secondary side starts to decrease, the controller automatically folds back its switching frequency down to a minimum level of 26 kHz. As the power further goes down, the part enters skip cycle while limiting the peak current. Over Power Protection (OPP) is a difficult exercise especially when no-load standby requirements drive the converter specifications. The ON proprietary integrated OPP lets you harness the maximum delivered power without affecting your standby performance simply via two external resistors. A latched Over Voltage Protection (OVP) is combined on the same pin. For ease of implementation, an auto-recovery OVP also monitors the Vcc line. These features offer an efficient protection in case of optocoupler failure or adverse open loop operation. Finally, a timer-based short-circuit protection offers the best protection scheme, letting you precisely select the protection trip point irrespective of a loose coupling between the auxiliary and the power windings.
技术特性
- Fixed−Frequency 65 or 100 kHz Current−Mode Control Operation
- Internal and Adjustable Over Power Protection (OPP) Circuit
- Frequency Foldback Down to 26 kHz and Skip−Cycle in Light Load
Conditions
- Internal Ramp Compensation
- Internal Fixed 4 ms Soft−Start
- 100 ms Timer−Based Auto−Recovery Short−Circuit Protection
- Frequency Jittering in Normal and Frequency Foldback Modes
- Option for Auto−Recovery or Latched Short−Circuit Protection
- OVP Input for Improved Robustness
- Up to 28 V VCC Operation
- Latched OVP Protection on VCC
- +300 mA / −500 mA Source/Sink Drive Capability
- Less than 100 mW Standby Power at High Line
- EPS 2.0 Compliant
- These are Pb−Free Devices
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应用
- Offline Adapters
- AC-DC converters
终端产品
- Set-top Boxes
- Printers
- Notebooks and Netbooks
封装图 PACKAGE DIMENSIONS
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评估板信息
| 评估板 |
状况 |
无铅(Pb-free) |
简短说明 |
| NCP1251GEVB |
Active |
 |
25W POWER SUPPLY DEMO BD |
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 |
| NCP1251ASN100T1G |
Active |
|
Current-Mode PWM Controller for Off-line Power Supplies |
TSOP-6 |
318G-02 |
1 |
Tape and Reel |
3000 |
$0.2 |
| NCP1251ASN65T1G |
Active |
|
Current-Mode PWM Controller for Off-line Power Supplies |
TSOP-6 |
318G-02 |
1 |
Tape and Reel |
3000 |
$0.2 |
| NCP1251BSN100T1G |
Active |
|
Current-Mode PWM Controller for Off-line Power Supplies |
TSOP-6 |
318G-02 |
1 |
Tape and Reel |
3000 |
$0.2 |
| NCP1251BSN65T1G |
Active |
|
Current-Mode PWM Controller for Off-line Power Supplies |
TSOP-6 |
318G-02 |
1 |
Tape and Reel |
3000 |
$0.2 |
数据资料DataSheet下载
