LYTSwitch-6Pin 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 NCBPP 1411 NC to the GND pin. NC 1510 NCSECONDARY GROUND (GND) (Pin 2)9 NC8 NC GND for the secondary IC. Note this is not the power supply output S 16-197 FWD GND due to the presence of the sense resistor between this and the 6 VOUT ISENSE pin. 5 SR4 BPSFEEDBACK (FB) Pin (Pin 3)3 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) Figure 5. Pin Configuration. Gate driver for external SR FET. OUTPUT VOLTAGE (VOUT) Pin (Pin 6)LYTSwitch-6 Functional Description Connected directly to the output voltage to provide current for the control er on the secondary-side. The LYTSwitch-6 combines a high-voltage power switch, along with FORWARD (FWD) Pin (Pin 7) both primary-side and secondary-side control ers in one device. The connection point to the switching node of the transformer output The architecture incorporates a novel inductive coupling feedback winding providing information on the primary switch timing. Provides scheme using the package lead frame and bond wires to provide a power for the secondary-side control er when V is below a threshold. OUT safe, reliable, and low-cost means to communicate accurate direct NC Pin (Pin 8-12) sensing of the output voltage and output current on the secondary Leave open. Should not be connected to any other pins. control er to the primary control er. Input Overvoltage (V) Pin (Pin 13) LYTSwitch-6 is a Quasi-Resonant (QR) flyback control er that has the A high-voltage pin connected to the AC or DC side of the input bridge ability to operate in continuous conduction mode (CCM). The for detecting overvoltage conditions at the power supply input. This control er uses both variable frequency and variable current control pin should be tied to Source to disable OV protection. schemes. The primary control er consists of a frequency jitter oscillator; a receiver circuit magnetical y coupled to the secondary PRIMARY BYPASS (BPP) Pin (Pin 14) control er, a current limit control er, 5 V regulator on the PRIMARY The connection point for an external bypass capacitor for the BYPASS pin, audible noise reduction engine for light load operation, primary-side supply. This is also the ILIM selection pin for choosing bypass overvoltage detection circuit, a lossless input line sensing standard ILIM or ILIM+1. circuit, current limit selection circuitry, over-temperature protection, NC Pin (Pin 15) leading edge blanking, and a 650 V, 725 V or 750 V power switch. Leave open. Should not be connected to any other pins. The LYTSwitch-6 secondary control er consists of a transmitter circuit SOURCE (S) Pin (Pin 16-19) that is magnetical y coupled to the primary receiver, a constant These pins are the power switch source connection. It is also ground voltage (CV) and a constant current (CC) control circuit, a 4.4 V reference for primary BYPASS pin. regulator on the secondary SECONDARY BYPASS
pin, synchronous DRAIN (D) Pin (Pin 24) rectifier MOSFET driver, QR mode circuit, oscillator and timing Power switch drain connection. functions, thermal foldback control and a host of integrated protection features. Figure 3 and Figure 4 show the functional block diagrams of the primary and secondary control er with the most important features. 3 Rev. G 08/19 www.power.com Document Outline Product Highlights Description Output Power Table LYTSwitch-6 Functional Description Primary Controller Secondary Controller Absolute Maximum Ratings Thermal Resistance Key Electrical Characteristics Typical Performance Curves InSOP-24D Package Drawing MSL Table ESD and Latch-Up Table Part Ordering Information
