Electronic Components Datasheet Search |
|
TOP264-271 Datasheet(PDF) 10 Page - Power Integrations, Inc. |
|
TOP264-271 Datasheet(HTML) 10 Page - Power Integrations, Inc. |
10 / 40 page Rev. E 08/12 10 TOP264-271 www.powerint.com the clamp circuit and the output rectifier during start-up. This feature also helps minimize output overshoot and prevents saturation of the transformer during start-up. Shutdown/Auto-Restart (for OCP, SCP, OPP) To minimize TOP264-271 power dissipation under fault conditions such as over current (OC), short-circuit (SC) or over power (OP), the shutdown/auto-restart circuit turns the power supply on and off at an auto-restart duty cycle of typically 2% if an out of regulation condition persists. Loss of regulation interrupts the external current into the CONTROL pin. V C regulation changes from shunt mode to the hysteretic auto- restart mode as described in CONTROL pin operation section. When the fault condition is removed, the power supply output becomes regulated, V C regulation returns to shunt mode, and normal operation of the power supply resumes. Hysteretic Over-Temperature Protection (OTP) Temperature protection is provided by a precision analog circuit that turns the output MOSFET off when the junction temperature exceeds the thermal shutdown temperature (142 °C typical). When the junction temperature cools to below the lower hysteretic temperature point, normal operation resumes, thus providing automatic recovery. A large hysteresis of 75 °C (typical) is provided to prevent overheating of the PC board due to a continuous fault condition. V C is regulated in hysteretic mode, and a 4.8 V to 5.8 V (typical) triangular waveform is present on the CONTROL pin while in thermal shutdown. Bandgap Reference All critical TOP264-271 internal voltages are derived from a temperature-compensated bandgap reference. This voltage reference is used to generate all other internal current references, which are trimmed to accurately set the switching frequency, MOSFET gate drive current, current limit, and the line OV/UV/ OVP thresholds. TOP264-271 has improved circuitry to maintain all of the above critical parameters within very tight absolute and temperature tolerances. High-Voltage Bias Current Source This high-voltage current source biases TOP264-271 from the DRAIN pin and charges the CONTROL pin external capacitance during start-up or hysteretic operation. Hysteretic operation occurs during auto-restart, remote-off and over-temperature shutdown. In this mode of operation, the current source is switched on and off, with an effective duty cycle of approxi- mately 35%. This duty cycle is determined by the ratio of CONTROL pin charge (I C) and discharge currents (ICD1 and ICD2). This current source is turned off during normal operation when the output MOSFET is switching. The effect of the current source switching will be seen on the DRAIN voltage waveform as small disturbances and is normal. |
Similar Part No. - TOP264-271 |
|
Similar Description - TOP264-271 |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.COM |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Datasheet Upload | 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 |