 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
LNK6XX4E Datasheet(PDF) 4 Page - Power Integrations, Inc. |
|
||||||||||||||||||||||||||||||
LNK6XX4E Datasheet(HTML) 4 Page - Power Integrations, Inc. |
|
|
4 / 24 page  Rev. C 03/14 4 LinkSwitch-HP www.powerint.com www.powerint.com Auto-Restart In the event of an open-loop fault (no connection between the feedback winding and the feedback divider network or the FEEDBACK pin to the feedback network), the sensed current out of FEEDBACK pin will be zero during MOSFET on-time, the device enters into line brown-out protection (line UV). In the event of output short-circuit or overload condition, the device enters into auto-restart mode. Auto-restart minimizes the power dissipation under fault conditions, the device will turn on and off at duty cycle of typically 3% as long as the fault condition persists. In auto-restart switching is disabled for t AR(OFF)1 (typ. 150 ms) when the FEEDBACK pin voltage has dropped below the auto-restart threshold V FB(AR) for the shutdown default delay time t AR(ON) (typ. 35 ms). After this period switching is enabled again with the device entering soft-start (typ. 15 ms). For the first auto-restart off-period switching is disabled for a reduced time t AR(OFF)2 (typ. 1500 ms) to reduce the power supply restart time during line cycling. Optionally the default shutdown delay time can be extended by adding a capacitor to the PROGRAM pin. Hysteretic Thermal Shutdown The thermal shutdown circuitry senses the controller die temperature. The threshold is set at 142 °C with a 75 °C hysteresis (both typical). Once the device temperature rises above 142 °C, the power MOSFET is disabled and remains disabled until the die temperature falls by 75 °C, at which point the device is re-enabled. The large hysteresis maintain the average temperature below the temperature rating of low cost CEM type PCB material in most cases. Safe Operating Area (SOA) Protection The device features a safe operating area (SOA) protection mode which disables MOSFET switching for 4 consecutive cycles in the event the peak switching current reaches the current limit in less than time t ON(SOA). This prevents excessive drain currents during start-up and output short-circuit conditions by providing additional time for the primary inductance to reset. The SOA protection is disabled when the output voltage is within 7.5% of regulation voltage. Sample and Hold (S/H) The sample and hold block senses the output voltage at auxiliary winding during secondary rectifier on-time. The FEEDBACK pin voltage is sampled after the turn-off of the internal switch to compensate for diode conduction time differences. Sampling time increases monotonically from 1.2 ms at no or light load to 2.5 ms at full load. Sampled voltage is held until the next clock cycle. The output of S/H is fed to the error amplifier, once in regulation the sampled voltage is 2 V. BYPASS (BP) Programming This feature selects either hysteretic or latching OVP/OCP and OTP protection based on capacitor loading on the BYPASS pin. The shutdown type is determined at the device power-up as shown in Table 3. Current Limit Setting During power-up the cycle-by-cycle current limit is determined by measuring the resistor value connected to the PROGRAM pin by the measurement is performed by applying 1.25 V (see Figure 10). The current limit can be set between 40% to 100% in steps of 10% as shown in Table 4. After the current limit is set the PROGRAM pin voltage is reduced to ~0 in order to minimize power dissipation. Programmable Shutdown Delay The default auto-restart shutdown delay time t SD(AR) (typ. 35 ms) can optionally be extended by connecting a capacitor to the PROGRAM pin. Once a lost regulation fault is detected the PROGRAM pin voltage is cycled 128 times between V PD(DL) (typ. 0.5 V) and V PD(DU) (typ. 1.2 V) as shown in Figure 10. Figure 6 depicts the relationship between extended shutdown delay time, added PROGRAM pin capacitor and current limit programming resistor. Figure 5. Compensation Pin Characteristics (Multi-Mode Operation). fSW(LF) VC(MAX) VC(MIN) VC(MCM) 32 132 100% 50% 25% PI-6722-111212 Compensation Voltage ( ∝ POUT) Compensation Voltage ( ∝ POUT) I PD R PD I LIMIT(NORM) I PD R PD I LIMIT(NORM) mA k W % mA k W % 10 124 100 54 23.2 60 16 78.7 90 83 15.0 50 24 52.3 80 125 10.0 40 36 34.8 70 Table 4. Current Limit Selection vs. Program Pin Resistor Value. C BP 0.47 mF 4.7 mF 47 mF OVP Latching Auto-Restart Latching Lost Regulation (SC, OC) Auto-Restart Auto-Restart Latching OTP Latching Hysteretic Latching Table 3. Shutdown Type vs. Value of BYPASS Pin Capacitance. |
Similar Part No. - LNK6XX4E |
|
Similar Description - LNK6XX4E |
|
|
|
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 |
English ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
