POWER INTEGRATIONS TOP245YN TOPSwitch-GX Off-Line Switcher, TO220-6

The POWER INTEGRATIONS TOP245YN is an integrated off-line switcher from the advanced TOPSwitch-GX EcoSmart series, housed in a 6-pin TO-220 package. This highly efficient component utilises a proven topology, cost-effectively integrating a high-voltage power MOSFET, PWM control, comprehensive fault protection, and other essential control circuitry onto a single CMOS chip. It incorporates numerous innovative functions designed to reduce overall system cost while enhancing design flexibility, performance, and energy efficiency.

Key features of the TOP245YN include soft start for controlled power-up, frequency jittering to minimise electromagnetic interference (EMI), a wider maximum duty cycle (DC_MAX), and hysteretic thermal shutdown for robust fault protection. The device also boasts larger creepage packages for improved safety and reliability. All critical parameters, such as current limit, frequency, and PWM gain, benefit from tighter temperature and absolute tolerances, which simplifies the design process and helps optimise system costs.

This switcher offers impressive output power capabilities, delivering up to 85W at 230VAC and 60W across a wide input range of 85VAC to 265VAC in an open-frame design. For enclosed, non-ventilated adapter applications, it provides 40W at 230VAC and 26W over the same input range. Its extended power range makes it suitable for higher-power applications, while the wider duty cycle allows for more power delivery from a smaller input capacitor. A significant advantage is its ability to regulate down to zero load without the need for dummy loading.

Operating at a 132kHz switching frequency (when the frequency pin is connected to source), the TOP245YN enables the use of smaller transformers and power supplies, contributing to more compact end-product designs. The hysteretic thermal shutdown feature ensures automatic recovery from fault conditions, and its large thermal hysteresis helps to PC