TOP270KG

TOP270KG is a high performance, high efficiency, off-line quasiresonance power IC, specifically designed to meet the need for cost effective, reliable low power and low noise power supplies. The device consists of an AC/DC converter, OFFLINE switcher and secondary regulator in an integrated circuit. The device works in two modes, DC/DC and OFFLINE, to provide power to the load from a wide range of input–voltage sources.

In DC/DC mode, the TOP270KG converts an AC input voltage (or DC) to a regulated DC output voltage. It is usually used for step-down applications where the input voltage is greater than the output voltage and for step-up applications when the output voltage is greater than the input voltage. In both cases, the output voltage is regulated, being constant regardless of load variations.

When operating in OFFLINE mode, the TOP270KG switches the input voltage according to its pulse-width-modulated (PWM) converting technique. The main features of the OFFLINE mode are high efficiency at light loads, small output-voltage ripple and low noise operation. This mode of operation is suitable for low-cost applications where an AC/DC supply is not considered a necessity.

The TOP270KG utilizes an advanced self-oscillating architecture which automatically adjusts pulse-widths and modulation frequencies as needed to deliver regulated output power with high efficiency at light loads. The device is capable of supplying output currents up to 270mA, hence the name TOP270KG.

The device incorporates integrated switches for the AC/DC converter and OFFLINE switcher, which allow the device to work with a wide range of input–voltage sources. This makes it a perfect candidate for applications such as LED drivers, cell-phone chargers, laptop adapters and consumer electronics. The device also supports over-voltage protection, thermal shut-down and under-voltage lockout (UVLO) protection.

The internal components of the TOP270KG include a low noise operational amplifier, a voltage comparator and a transitor. The operational amplifier is used to detect the peak of an AC waveform and compare it to a reference voltage to generate the signals for the OFFLINE converter. The voltage comparator is used to detect the peak of the waveform and compare it to a reference voltage in order to generate the gate drive signal for the integrated AC/DC converter switch. The transistor is used to switch between the two operating modes, AC/DC and OFFLINE, in order to control the output voltage.

The TOP270KG is an integrated power semiconductor device which offers a cost-effective, reliable solution for low-power and low-noise power supplies. Its internal components, including an AC/DC converter, OFFLINE switcher and secondary regulator, make it ideal for applications such as LED drivers, cell-phone chargers, laptop adapters and consumer electronics. The device is capable of supplying output currents up to 270mA, and its self-oscillating architecture ensures a constant output voltage with high efficiency and low noise operation.