MP155 Energy Efficient Off-line Regulator TSOT23

MP155 Energy Efficient Off-line Regulator TSOT23

The MP155 is a primary-side regulator that provides accurate constant voltage regulation without the opto-coupler, and supports Buck, Buck-boost, Boost and Flyback topologies.

Key Specifications

Features

• Primary-side constant voltage (CV) control, supporting Buck, Buck-boost, Boost and Flyback topologies
• Integrated 500V/20Ω MOSFET
• < 100mW No-load power consumption
• Up to 4W output power
• Maximum DCM output current of 130mA
• Maximum CCM output current of 220mA
• Low VCC operating current
• Frequency foldback
• Maximum frequency limit
• Peak current compression

Typical Application Circuit

Applications

• Home Appliances, white goods and consumer electronics
• Industrial Controls

Design Notes

• The PFC inductor must support the maximum duty cycle at the lowest line voltage, which is where saturation risk peaks.
• High-voltage startup and X-capacitor discharge paths dominate no-load standby loss; verify them against the efficiency target.
• Leakage inductance and the RCD clamp set the turn-off loss — snubber values are a thermal trade-off, not a fixed recipe.
• Synchronous rectification timing must track the primary switching; a mistimed SR FET conducts through its body diode and fails hot.

Common Questions