The AP61402 is a 2.3V to 5.5V input, 4A synchronous buck converter intended for point-of-load regulation where board area and EMI must be carefully managed. Integrating both high-side and low-side MOSFETs, the converter reduces external component count while supporting efficient step-down conversion in space-constrained designs.
To reduce ringing through controlling switching-node behavior without extending MOSFET transition times the AP61402 uses a proprietary gate driver design. This approach reduces high-frequency radiated EMI typically associated with fast switching edges, helping designers to meet strict electromagnetic noise emission requirements.
The converter uses constant on-time control to provide fast transient response and straightforward loop behavior, avoiding the need for external compensation. Operating at a nominal 2MHz switching frequency, the AP61402 supports both pulse-frequency modulation and forced PWM modes, allowing optimization for light-load efficiency or predictable switching behavior depending on system requirements.
