Datasheet InnoSwitch3-CP (Power Integrations) - 5

InnoSwitch3-CP
The auto-restart is reset as soon as an AC reset occurs.
SOA Protection
In the event that there are two consecutive cycles where the I is P: Primary Chip LIM S: Secondary Chip reached within ~500 ns (the blanking time + current limit delay time), Start P: Powered Up, Switching the control er will skip 2.5 cycles or ~25 ms (based on full frequency S: Powering Up of 100 kHz). This provides sufficient time for the transformer to reset with large capacitive loads without extending the start-up time.
Secondary Rectifier/SR Switch Short Protection (SRS)
P: Auto-Restart In the event that the output diode or SR FET is short-circuited before S: Powering Up or during the primary conduction cycle, the drain current (prior to the end of the leading edge blanking time) can be much higher than the t maximum current limit threshold. If the control er turns the high- AR(OFF) voltage power switch off, the resulting peak drain voltage could exceed the rated BV of the device, resulting in catastrophic failure S: Has powered No P: Goes to Auto-Restart Off DSS up within t S: Bypass Discharging even with minimum on-time. AR To address this issue, the control er features a circuit that reacts Yes when the drain current exceeds the maximum current limit threshold tAR prior to the end of leading-edge blanking time. If the leading-edge P: Switching current exceeds current limit within a cycle (200 ns), the primary S: Sends Handshaking Pulses control er will trigger a 30 ms off-time event. SOA mode is triggered if there are two consecutive cycles above current limit within t LES (~500 ns). SRS mode also triggers ~200 ms off-time, if the current limit is reached within 200 ns after a 30 ms off-time. P: Has Received No P: Continuous Switching Handshaking S: Doesn’t Take Control SRS Protetction is not available in INN3279C and INN3270C. Pulses
Input Line Voltage Monitoring
Yes The UNDER/OVER INPUT VOLTAGE pin is used for input undervoltage and overvoltage sensing and protection. P: Stops Switching, Hands Over Control to Secondary A sense resistor is tied between the high-voltage DC bulk capacitor after the bridge (or to the AC side of the bridge rectifier for fast AC reset) and the UNDER/OVER INPUT VOLTAGE pin to enable this functionality. This function can be disabled by shorting the UNDER/ S: Has Taken No OVER INPUT VOLTAGE pin to SOURCE pin. P: Not Switching Control? S: Doesn’t Take Control At power-up, after the primary bypass capacitor is charged and the ILIM state is latched, and prior to switching, the state of the UNDER/ Yes OVER INPUT VOLTAGE pin is checked to confirm that it is above the brown-in and below the overvoltage shutdown thresholds. End of Handshaking, Secondary Control Mode In normal operation, if the UNDER/OVER INPUT VOLTAGE pin current fal s below the brown-out threshold and remains below brown-in for PI-7416a-102116 longer than t , the control er enters auto-restart. Switching will only UV- resume once the UNDER/OVER INPUT VOLTAGE pin current is above Figure 8. Primary-Secondary Handshake Flowchart. the brown-in threshold. In the event that the UNDER/OVER INPUT VOLTAGE pin current is
Primary-Secondary Handshake
above the overvoltage threshold, the control er will also enter At start-up, the primary-side initial y switches without any feedback auto-restart. Again, switching will only resume once the UNDER/ information (this is very similar to the operation of a standard OVER INPUT VOLTAGE pin current has returned to within its normal TOPSwitch™, TinySwitch™ or LinkSwitch™ control ers). operating range. If no feedback signals are received during the auto-restart on-time The input line UV/OV function makes use of an internal high-voltage (t ), the primary goes into auto-restart mode. Under normal AR Switch on the UNDER/OVER INPUT VOLTAGE pin to reduce power conditions, the secondary control er will power-up via the FORWARD consumption. If the cycle off-time t is greater than 50 ms, the pin or from the OUTPUT VOLTAGE pin and take over control. From OFF internal high-voltage Switch will disconnect the external sense this point onwards the secondary controls switching. resistor from the internal IC to eliminate current drawn through the sense resistor. The line sensing function will activate again at the If the primary control er stops switching or does not respond to cycle beginning of the next switching cycle. requests from the secondary during normal operation (when the secondary has control), the handshake protocol is initiated to ensure that the secondary is ready to assume control once the primary begins to switch again. An additional handshake is also triggered if the secondary detects that the primary is providing more cycles than were requested.
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Rev. E 07/19 www.power.com Document Outline Product Highlights Description Output Power Table Pin Functional Description InnoSwitch3-CP Functional Description Primary Controller Secondary Controller Applications Example Key Application Considerations Selection of Components Recommendations for Circuit Board Layout Layout Example Quick Design Checklist Absolute Maximum Ratings Thermal Resistance Typical Performance Curves InSOP-24D Package Drawing InSOP-24D Package Marking Part Ordering Table MSL Table ESD and Latch-Up Table Part Ordering Information