NCP1207A,NCP1207B PWM Current--Mode Controller for Free Running Quasi--Resonant Operation

2022-07-27

The NCP1207AB combines a true current mode modulator and a demagnetization detector to ensure full borderline/critical Conduction Mode in any load/line conditions and minimum drain voltage switching (Quasi-Resonant operation). Due to its inherent skip cycle capability', the controller enters burst mode as soon as the power demand falls below a predetermined level. As this happens at low peak current, no audible noise can be heard. For the NCP1207A, an internal 8.0 ps timer prevents the free-run frequency to exceed 125 kHz (therefore below the 150 kHz CISPR-22 EMI starting limit), while the skip adjustment capability lets the user select the frequency at which the burst foldback takes place. For the NCP1207B, the internal tinier duration is reduced to 4.5 ps to allow operation at higher frequencies (up to 200 kHz).
The Dynamic Self-Supply (DSS) drastically simplifies the transformer design in avoiding the use of an auxiliary winding to supply the NCP1207A/B. This feature is particularly useful in applications where the output voltage varies during operation (e.g. battery chargers). Due to its high-voltage technology, the IC is directly connected to the high-voltage DC rail. As a result, the short-circuit trip point is not dependent upon any Vcc auxiliary level.
The transformer core reset detection is done through an auxiliary winding which, brought via a dedicated pin, also enables fast Overvoltage Protection (OVP). Once an OVP has been detected, the IC permanently latches off.
Finally, the continuous feedback signal monitoring implemented with an overcurrent fault protection circuitry (OCP) makes the final design rugged and reliable.
●Free-Running Borderline/Critical Mode Quasi-Resonant Operation
●Current-Mode with Adjustable Skip-Cycle Capability
●No Auxiliary Winding Vcc Operation
●Auto-Recovery Overcurrent Protection
●Latching Overvoltage Protection
●External Latch Triggering, e.g. Via Overtemperature Signal
●500 mA Peak Current Source/Sink Capability
●Undervoltage Lockout for Vcc Below 10 V
●Internal 1.0 ms Soft-Start
●Internal 8.0 ps Minimum Toff for NCP1207A,4.5 its Minimum Toff for NCP1207B
●Adjustable Skip Level
●Internal Temperature Shutdown
●Direct Optocoupler Connection
●SPICE Models Available for TRANsient Analysis
●These are Pb-Free and Halide-Free Devices

ON Semiconductor

NCP1207ANCP1207BNCP1207ADR2GNCP1207APGNCP1207BDR2G

More

Part#

PWM Current--Mode Controller

More

AC/DC Adapters ]Notebooks ]Offline Battery Chargers ]Consumer Electronics ]DVD Players ]Set--Top Boxes ]TVs ]Auxiliary Power Supplies ](USB ]Appliances ]

More

Datasheet

More

More

Please see the document for details

More

More

SOIC-8;SOIC-7;PDIP-8

English Chinese Chinese and English Japanese

December, 2010

Rev. 11

NCP1207A/D

648 KB

- The full preview is over. If you want to read the whole 17 page document,please Sign in/Register -
  • +1 Like
  • Add to Favorites

Recommend

All reproduced articles on this site are for the purpose of conveying more information and clearly indicate the source. If media or individuals who do not want to be reproduced can contact us, which will be deleted.

Contact Us

Email: