The S-8355Q50MC-OXJT2G is a DC DC switching controller IC from SeikoSangyo designed specifically for off-line converter applications such as LED lighting and home appliances, and is suitable for applications with an input voltage (VCC) range of 4.5 - 48V and an output voltage of 0.5 - 50V. This device is an adjustable and integrated step-down DC converter, which offers a high efficiency of up to 96% when implemented correctly. It comes with a built-in desaturation current limit and short circuit protection, as well as an adjustable soft start and an adjustable PWM frequency of up to 600kHz, making it an ideal choice for high-speed load driven applications.

Features:

• Input voltage range: 4.5 V to 48 V
• Output voltage range: 0.5 V to 50 V
• Max Input Current: 3.2 A
• Max Output Current: 2 A
• Integrated desaturation current limit and short circuit protection
• Internal PWM frequency adjustable up to 600kHz
• Adjustable soft start

Working Principle

The S-8355Q50MC-OXJT2G is designed according to the discontinuous conduction mode (DCM) topology, which features automatic load current sensing and lower standby current consumption. When the output voltage falls below its nominal value, the IC enters the “DCM” state, where its load is forcibly switched off. This is because the output voltage will be ripple free, even when the load current is greater than the average value. When the output voltage rises to its nominal value, the load is switched on again. The DCM operation ensures high efficiency and fast dynamic response. The IC incorporates an integrated desaturation current limit and soft start function for further optimization of performance.

Applications

The wide input voltage range makes the S-8355Q50MC-OXJT2G suitable for a wide range of applications, including:

• LED Lighting Drivers
• Home Appliance Drivers
• AC-DC Adapter Drivers
• Battery Chargers