ST8115 18W Flyback Controller
Specifications
Product details
Overview
The ST8115 is a high-performance, current-mode PWM controller designed for cost-effective AC/DC converter applications. It delivers up to 12W/18W of continuous output power across a wide 85-265V AC input range, with peak output power reaching 15W/20W; an optimized circuit architecture combined with a cost-effective bipolar process minimizes total system cost. Operating in a typical flyback topology, the internal startup circuit uses a unique current-sinking scheme that leverages the current gain of the external power transistor to complete startup, significantly reducing startup-resistor dissipation; under light loads the IC automatically reduces its operating frequency for extremely low standby power. When VCC reaches 9.9V/12V/22.5V the internal OVP clamps the output to prevent excessive voltage rise from opto-coupler or feedback-loop failures; comprehensive overload and transformer-saturation protection plus hysteretic thermal protection are built in, and the current limit is externally programmable via Rs for different power requirements.
Features
- Integrated 700V high-voltage power switch
- Internal high-voltage startup current source for fast startup
- Built-in energy-efficiency control; standby power below 0.1W
- Integrated over-voltage, under-voltage and short-circuit protection
- Integrated overload and over-temperature protection
- Precision temperature compensation with accurate cycle-by-cycle current control
- Low startup current and low operating current
- Adaptive frequency foldback design for low EMI
- High conversion efficiency, compliant with ENERGY STAR 2.0
- Wide-range output power 12W/18W; high-line output 15W/20W
- Minimal external component count for low total system cost
Typical Applications
- Power adapters
- Portable device chargers
- DVD / DVB power supplies
- Battery chargers
- ATX standby power supplies
