NCP1217:Fixed Frequency Current Mode PWM Controller
Housed in a SOIC-7 or PDIP-7 package, the NCP1217 represents the second generation of NCP1203-based controllers. Thanks to its high drive capability, NCP1217 drives large gate-charge MOSFETs, which together with internal ramp compensation and built-in over voltage protection, ease the design of modern AC/DC adapters. NCP1217 offers a true alternative to UC384X-based designs. With an internal structure operating at different fixed frequencies (65, 100, 133kHz), the controller features a high-voltage start-up FET, which ensures a clean and loss less startup sequence. Its current-mode control topology provides an excellent input audio-susceptibility and inherent pulse-by-pulse control. Internal ramp compensation easily prevents subharmonic oscillations from taking place in continuous conduction mode designs. When the current setpoint falls below a given value, e.g. the output power demand diminishes, the IC automatically enters the so-called skip cycle mode and provides excellent efficiency at light loads. Because this occurs at a user adjustable low peak current, no acoustic noise takes place. The NCP1217 features two efficient protective circuitries: 1) in presence of an over-current condition, the output pulses are disabled and the device enters a safe burst mode, trying to re-start. Once the default has gone, the device auto-recovers. 2) if an external signal (e.g. a temperature sensor) pulls pin1 above 3.2V, output pulses are immediately stopped and the NCP1217 stays latched in this position. Reset occurs when the VCC collapses to ground, e.g. the user un-plugs the power supply.
技术特性
- Current--Mode with Adjustable Skip--Cycle Capability
- Built--in Internal Ramp Compensation
- Auto--Recovery Internal Output Short--Circuit Protection
- Internal 1.0 ms Soft--Start (NCP1217A Only)
- Limited Duty--Cycle to 50% (NCP1217A Only)
- Full Latchoff if Adjustment Pin is Brought High
- Extremely Low No--Load Standby Power
- Internal Temperature Shutdown
- 500 mA Peak Current Capability
- Fixed Frequency Versions at 65 kHz, 100 kHz and 133 kHz
- Direct Optocoupler Connection
- Internal Leading Edge Blanking
- SPICE Models Available for TRANsient and AC Analysis
- These are Pb--Free Devices
应用
- High power AC/DC converters for TVs, set-top boxes etc
- Offline adapters for notebooks
- Telecom DC-DC converters
- All power supplies
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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 |
| NCP1217D100R2G |
Active |
|
Fixed Frequency Current Mode PWM Controller |
SOIC-8 |
751-07 |
1 |
Tape and Reel |
2500 |
$0.35 |
| NCP1217D133R2G |
Active |
|
Fixed Frequency Current Mode PWM Controller |
SOIC-8 |
751-07 |
1 |
Tape and Reel |
2500 |
$0.35 |
| NCP1217D65R2G |
Active |
|
Fixed Frequency Current Mode PWM Controller |
SOIC-8 |
751-07 |
1 |
Tape and Reel |
2500 |
$0.35 |
| NCP1217P100G |
Active |
|
Fixed Frequency Current Mode PWM Controller |
PDIP-8 |
626B |
|
Tube |
50 |
$0.35 |
| NCP1217P133G |
Active |
|
Fixed Frequency Current Mode PWM Controller |
PDIP-8 |
626B |
|
Tube |
50 |
$0.35 |
| NCP1217P65G |
Active |
|
Fixed Frequency Current Mode PWM Controller |
PDIP-8 |
626B |
|
Tube |
50 |
$0.35 |
数据资料DataSheet下载
