InnoSwitch3-EPPin Functional DescriptionISENSE (IS) Pin (Pin 1) Connection to the power supply output terminals. An external current sense resistor should be connected between this and the GND pin. If current regulation is not required, this pin should be tied V 1312 NC to the GND pin. BPP 1411 NCNC 1510 NCSECONDARY GROUND (GND) (Pin 2)9 NC GND for the secondary IC. Note this is not the power supply output 8 NCS 16-19 GND due to the presence of the sense resistor between this and the 7 FWD6 VOUT ISENSE pin. 5 SRFEEDBACK (FB) Pin (Pin 3)4 BPS3 FB Connection to an external resistor divider to set the power supply 2 GND output voltage. D 241 ISSECONDARY BYPASS (BPS) Pin (Pin 4) Connection point for an external bypass capacitor for the secondary IC supply. PI-7877-022216 SYNCHRONOUS RECTIFIER DRIVE (SR) Pin (Pin 5) Gate driver for external SR FET. If no SR FET is used connect this pin Figure 5. Pin Configuration. to GND. OUTPUT VOLTAGE (VOUT) Pin (Pin 6)InnoSwitch3-EP Functional Description Connected directly to the output voltage, to provide current for the The InnoSwitch3-EP combines a high-voltage power switch, along control er on the secondary-side and provide secondary protection. with both primary-side and secondary-side control ers in one device. FORWARD (FWD) Pin (Pin 7) The connection point to the switching node of the transformer output The architecture incorporates a novel inductive coupling feedback winding providing information on primary switch timing. Provides power scheme (FluxLink) using the package lead frame and bond wires to for the secondary-side control er when V is below threshold. provide a safe, reliable, and cost-effective means to transmit OUT accurate, output voltage and current information from the secondary NC Pin (Pin 8-12) control er to the primary control er. Leave open. Should not be connected to any other pins. The primary control er on InnoSwitch3-EP is a Quasi-Resonant (QR) UNDER/OVER INPUT VOLTAGE (V) Pin (Pin 13) flyback control er that has the ability to operate in continuous A high-voltage pin connected to the AC or DC side of the input bridge conduction mode (CCM), boundary mode (CrM) and discontinuous for detecting undervoltage and overvoltage conditions at the power conduction mode (DCM). The control er uses both variable frequency supply input. This pin should be tied to SOURCE pin to disable UV/OV and variable current control schemes. The primary control er consists protection. of a frequency jitter oscillator, a receiver circuit magnetical y coupled to PRIMARY BYPASS (BPP) Pin (Pin 14) the secondary control er, a current limit control er, 5 V regulator on The connection point for an external bypass capacitor for the the PRIMARY BYPASS pin, audible noise reduction engine for light primary-side supply. This is also the ILIM selection pin for choosing load operation, bypass overvoltage detection circuit, a lossless input standard ILIM or ILIM+1. line sensing circuit, current limit selection circuitry, over-temperature protection, leading edge blanking, secondary output diode / SR FET NC Pin (Pin 15) short protection circuit and a 725 V power switch. Leave open. Should not be connected to any other pins. The InnoSwitch3-EP secondary control er consists of a transmitter SOURCE (S) Pin (Pin 16-19) circuit that is magnetical y coupled to the primary receiver, a constant These pins are the power switch source connection. Also ground voltage (CV) and a constant current (CC) control circuit, a 4.4 V reference for primary BYPASS pin. regulator on the SECONDARY BYPASS pin, synchronous rectifier FET DRAIN (D) Pin (Pin 24) driver, QR mode circuit, oscillator and timing circuit, and numerous Power switch drain connection. integrated protection features. Figure 3 and Figure 4 show the functional block diagrams of the primary and secondary control er, highlighting the most important features. 3 Rev. G 07/19 www.power.com Document Outline Product Highlights Description Output Power Table Pin Functional Description InnoSwitch3-EP Functional Description Primary Controller Secondary Controller Applications Example Key Application Considerations Selection of Components Components for InnoSwitch3-EP Primary-Side Circuit Components for InnoSwitch3-EP Secondary-Side Circuit 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