Electronic Components Datasheet Search |
|
NCP1012AP100 Datasheet(PDF) 8 Page - ON Semiconductor |
|
NCP1012AP100 Datasheet(HTML) 8 Page - ON Semiconductor |
8 / 24 page NCP1010, NCP1011, NCP1012, NCP1013, NCP1014 http://onsemi.com 8 APPLICATION INFORMATION Introduction The NCP101X offers a complete current--mode control solution (actually an enhanced NCP1200 controller section) together with a high--voltage power MOSFET in a monolithic structure. The component integrates everything needed to build a rugged and low--cost Switch--Mode Power Supply (SMPS) featuring low standby power. The Quick Selection Table on Page 2, details the differences between references, mainly peak current setpoints and operating frequency. No need for an auxiliary winding: ON Semiconductor Very High Voltage Integrated Circuit technology lets you supply the IC directly from the high--voltage DC rail. We call it Dynamic Self--Supply (DSS). This solution simplifies the transformer design and ensures a better control of the SMPS in difficult output conditions, e.g. constant current operations. However, for improved standby performance, an auxiliary winding can be connected to the VCC pin to disable the DSS operation. Short--circuit protection: By permanently monitoring the feedback line activity, the IC is able to detect the presence of a short--circuit, immediately reducing the output power for a total system protection. Once the short has disappeared, the controller resumes and goes back to normal operation. Fail--safe optocoupler and OVP: When an auxiliary winding is connected to the VCC pin, the device stops its internal Dynamic Self--Supply and takes its operating power from the auxiliary winding. A 8.7 V active clamp is connected between VCC and ground. In case the current injected in this clamp exceeds a level of 7.4 mA (typical), the controller immediately latches off and stays in this position until VCC cycles downto 3.0 V(e.g. unpluggingthe converter from the wall). By adjusting a limiting resistor in series with the VCC terminal, it becomes possible to implement an overvoltage protection function, latching off the circuit in case of broken optocoupler or feedback loop problems. Low standby--power: If SMPS naturally exhibits a good efficiency at nominal load, it begins to be less efficient when the output power demand diminishes. By skippingunneeded switching cycles, the NCP101X drastically reduces the power wasted during light load conditions. An auxiliary winding can further help decreasing the standby power to extremely low levels by invalidating the DSS operation. Typical measurements show results below 80 mW @ 230 Vac for a typical 7.0 W universal power supply. No acoustic noise while operating: Instead of skipping cycles at high peak currents, the NCP101X waits until the peak current demand falls below a fixed 1/4 of the maximum limit. As a result, cycle skipping can take place without having a singing transformer You can thus select cheap magnetic components free of noise problems. SPICE model: A dedicated model to run transient cycle--by--cycle simulations is available but also an averaged version to help close the loop. Ready--to--use templates can be downloaded in OrCAD’s PSpice, and INTUSOFT’s IsSpice4 from ON Semiconductor web site, NCP101X related section. Dynamic Self--Supply When the power supply is first powered from the mains outlet, the internal current source (typically 8.0 mA) is biased and charges up the VCC capacitor from the drain pin. Once the voltage on this VCC capacitor reaches the VCCOFF level (typically 8.5 V), the current source turns off and pulses are delivered by the output stage: the circuit is awake and activates the power MOSFET. Figure 13 details the internal circuitry. Figure 13. The Current Source Regulates VCC by Introducing a Ripple Vref OFF = 8.5 V Vref ON = 7.5 V Vref Latch = 4.7 V* -- + Internal Supply + Vref VCCOFF +200 mV (8.7 V Typ.) VCC + CVCC Startup Source Drain *In fault condition |
Similar Part No. - NCP1012AP100 |
|
Similar Description - NCP1012AP100 |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.NET |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |