Datenblatt-Suchmaschine für elektronische Bauteile |
|
LM25183 Datenblatt(PDF) 14 Page - Texas Instruments |
|
|
LM25183 Datenblatt(HTML) 14 Page - Texas Instruments |
14 / 39 page ª º ˜ « » ¬ ¼ SW-PEAK OUT(max) OUT D IN PS I I V V 1 2 V N 14 LM25183 SNVSBJ3 – APRIL 2020 www.ti.com Product Folder Links: LM25183 Submit Documentation Feedback Copyright © 2020, Texas Instruments Incorporated Feature Description (continued) When using a transformer auxiliary winding for bias power, the total leakage current related to diodes DBIAS1 and DBIAS2 in Figure 18 must be less than 1 µA across the full operating temperature range. 7.3.8 Minimum On-Time and Off-Time When the internal power MOSFET is turned off, the leakage inductance of the transformer resonates with the SW node parasitic capacitance. The resultant ringing behavior can be excessive with large transformer leakage inductance and can corrupt the secondary zero-current detection. To prevent such a situation, a minimum switch off-time, designated as tOFF-MIN, of a maximum of 375 ns is set internally to ensure proper functionality. This sets a lower limit for the transformer magnetizing inductance as discussed in the Detailed Design Procedure. Furthermore, noise effects as a result of power MOSFET turnon can impact the internal current sense circuit measurement. To mitigate this effect, the LM25183 provides a blanking time after the MOSFET turns on. This blanking time forces a minimum on-time, tON-MIN, of 140 ns. 7.3.9 Overcurrent Protection In case of an overcurrent condition on the isolated output or outputs, the output voltage drops lower than the regulation level since the maximum power delivered is limited by the peak current capability on the primary side. The peak primary current is maintained at 2.5 A (plus an amount related to the 100-ns propagation delay of the current limit comparator) until the output decreases to the secondary diode voltage drop to impact the reflected signal on the primary side. At this point, the LM25183 assumes the output cannot be recovered and re-calibrates its switching frequency to 9 kHz until the overload condition is removed. The LM25183 responds with similar behavior to an output short circuit condition. For a given input voltage, Equation 13 gives the maximum output current prior to the engagement of overcurrent protection. The typical threshold value for ISW-PEAK from the Electrical Characteristics is 2.5 A. (13) 7.3.10 Thermal Shutdown Thermal shutdown is an integrated self-protection to limit junction temperature and prevent damage related to overheating. Thermal shutdown turns off the device when the junction temperature exceeds 175°C to prevent further power dissipation and temperature rise. Junction temperature decreases after shutdown, and the LM25183 restarts when the junction temperature falls to 165°C. |
Ähnliche Teilenummer - LM25183 |
|
Ähnliche Beschreibung - LM25183 |
|
|
Link URL |
Privatsphäre und Datenschutz |
ALLDATASHEETDE.COM |
War ALLDATASHEET hilfreich? [ DONATE ] |
Über Alldatasheet | Werbung | Kontakt | Privatsphäre und Datenschutz | Linktausch | Hersteller 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 |