MICROCHIP MCP1661T Adjustable DC-DC Boost Regulator, 2.4-5.5V in, 200mA, SOT-23

The MICROCHIP MCP1661T-E/OT is a compact, high-efficiency, fixed-frequency DC-DC switching boost regulator designed to step up lower input voltages to a higher output level. Integrating a robust 36V, 800mΩ NMOS switch, it provides a space-efficient and reliable power supply solution for a wide range of portable and battery-powered applications. The device achieves an impressive efficiency of up to 92%, maximising battery life by minimising power loss during conversion.

Key Features & Protections

• High-Voltage Integrated Switch: Features a 36V, 800mΩ integrated NMOS switch for robust performance.
• Comprehensive Protection: Includes cycle-by-cycle inductor peak current limiting (1.3A), output overvoltage protection (OVP) that disables switching if the feedback path is compromised, and under-voltage lockout (UVLO).
• Low Quiescent Current: Consumes only 250µA typical input current under no load and features a sleep mode with a remarkably low 200nA typical quiescent current, ideal for power-sensitive designs.
• Internal Compensation & Soft Start: Simplifies design with internal compensation and includes inrush current limiting with an internal soft start for stable, reliable power-up.
• Adjustable Output: The feedback voltage reference (VFB = 1.227V) allows for an adjustable output voltage, configurable via external resistors.
• Versatile Topology Support: Easily configurable for SEPIC or Flyback converter topologies, offering design flexibility beyond standard boost applications.

Technical Specifications

This surface-mount regulator is supplied in a space-saving SOT-23-5 package. It operates from a 2.4V to 5.5V input range, making it compatible with two or three-cell alkaline, ultimate lithium, NiCd, NiMH, or single-cell Li-ion/Li-polymer batteries. It delivers a maximum output current of 200mA with a switching frequency of 500kHz and