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NCP1251: PWM Controller, Current Mode, for Offline Power Supplies

Datasheet: Controller, Current Mode PWM, for Offline Power Supplies
Rev. 14 (261kB)
Product Overview
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»View Material Composition
» Product Change Notification
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.
Features   Benefits
     
  • Non-dissipative internal and adjustable Over Power Protection (OPP)
 
  • Limits maximum delivered power without affecting standby performance
  • Frequency Foldback down to 26 kHz and Skip-Cycle in light load conditions
 
  • High efficiency in light load conditions
  • Internal Ramp Compensation
 
  • Reduces the number of external components
  • Frequency jittering from full load to skip-cycle
 
  • Improved EMI performance
  • Latch input for OVP and OTP implementations
 
  • Simple implementation of required protection functions
  • Over Voltage Protection (OVP) monitoring on the Vcc pin
 
  • Protects against output over voltage conditions without any added components
  • See NCP1250 for no Over Voltage Protection (OVP) on the Vcc pin
   
Applications   End Products
  • Offline Adapters
  • AC-DC converters
  • 45W Adapter
 
  • Set-top Boxes
  • Printers
  • Notebooks and Netbooks
Availability & Samples
Specifications
Case Outlines
Application Diagram
Product
Status
Compliance
Description
Package
MSL
Container
Budgetary Price/Unit
Type
Case Outline
Type
Temperature
Type
Qty.
NCP1251ASN100T1G Last Shipments
Pb-free
Halide free
NCP1251 TSOP-6 318G-02 1 260 Tape and Reel 3000  
NCP1251ASN65T1G Active
Pb-free
Halide free
NCP1251 TSOP-6 318G-02 1 260 Tape and Reel 3000 $0.1872
NCP1251BSN100T1G Active
Pb-free
Halide free
NCP1251 TSOP-6 318G-02 1 260 Tape and Reel 3000 $0.1872
NCP1251BSN65T1G Active
Pb-free
Halide free
NCP1251 TSOP-6 318G-02 1 260 Tape and Reel 3000 $0.1872
NCP1251CSN65T1G Active
Pb-free
Halide free
NCP1251 TSOP-6 318G-02 1 260 Tape and Reel 3000 $0.1872
NCP1251FSN65T1G Last Shipments
Pb-free
Halide free
NCP1251 TSOP-6 318G-02 1 260 Tape and Reel 3000  
Market Leadtime (weeks) : Contact Factory
Market Leadtime (weeks) : 4 to 8
PandS   (2020-09-14 00:00) : >1K
Market Leadtime (weeks) : 4 to 8
Market Leadtime (weeks) : 4 to 8
PandS   (2020-09-14 00:00) : >1K
Market Leadtime (weeks) : 13 to 16
ON Semiconductor   (2020-09-02 00:00) : 66,000
Market Leadtime (weeks) : Contact Factory

Product
Description
Pricing ($/Unit)
Compliance
Status
Topology
Control Mode
fsw Typ (kHz)
Stand-by Mode
UVLO (V)
Short Circuit Protection
Latch
Soft Start
VCC Max (V)
Drive Cap. (mA)
Package Type
NCP1251ASN65T1G  
 $0.1872 
Pb
H
 Active   
Flyback
Current Mode
65
Yes
8.8
Yes
Yes
Yes
28
300 / 500
TSOP-6
NCP1251BSN100T1G  
 $0.1872 
Pb
H
 Active   
Flyback
Current Mode
100
Yes
8.8
Yes
OVP
Yes
28
300 / 500
TSOP-6
NCP1251BSN65T1G  
 $0.1872 
Pb
H
 Active   
Flyback
Current Mode
65
Yes
8.8
Yes
OVP
Yes
28
300 / 500
TSOP-6
NCP1251CSN65T1G  
 $0.1872 
Pb
H
 Active   
Flyback
Current Mode
65
Yes
8.8
Yes
NO
Yes
28
300 / 500
TSOP-6
Case Outlines
318G-02   
Packages
NCP1251: PWM Controller, Current Mode, for Offline Power Supplies
NCP1251: PWM Controller, Current Mode, for Offline Power Supplies
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