Datasheet LYTSwitch-6 (Power Integrations) - 3

LYTSwitch-6 Pin Functional Description ISENSE (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 13 12 NC BPP 14 11 NC
to the GND pin.
NC 15 10 NC SECONDARY GROUND (GND) (Pin 2) 9 NC 8 NC
GND for the secondary IC. Note this is not the power supply output
S 16-19 7 FWD
GND due to the presence of the sense resistor between this and the
6 VOUT
ISENSE pin.
5 SR 4 BPS FEEDBACK (FB) Pin (Pin 3) 3 FB
Connection to an external resistor divider to set the power supply
2 GND
output voltage.
D 24 1 IS SECONDARY 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)
Connected directly to the output voltage to provide current for the
LYTSwitch-6 Functional Description
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 winding providing information on the primary switch timing. Provides The architecture incorporates a novel inductive coupling feedback power for the secondary-side control er when V is below a threshold. scheme using the package lead frame and bond wires to provide a 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
PRIMARY BYPASS (BPP) Pin (Pin 14)
oscillator; a receiver circuit magnetical y coupled to the secondary The connection point for an external bypass capacitor for the control er, a current limit control er, 5 V regulator on the PRIMARY primary-side supply. This is also the ILIM selection pin for choosing BYPASS pin, audible noise reduction engine for light load operation, standard ILIM or ILIM+1. bypass overvoltage detection circuit, a lossless input line sensing 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 or connect to SOURCE pin or BPP pin.
SOURCE (S) Pin (Pin 16-19)
The LYTSwitch-6 secondary control er consists of a transmitter circuit These pins are the power switch source connection. It is also ground that is magnetical y coupled to the primary receiver, a constant reference for primary BYPASS pin. voltage (CV) and a constant current (CC) control circuit, a 4.4 V 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.
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Rev. K 06/20 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