Microchip MCP1661

Description

The MCP1661 device is a compact, high-efficiency,fixed-frequency, non-synchronous step-up DC-DC converter which integrates a 36V, 800 m NMOS switch. It provides a space-efficient high-voltage step-up power supply solution for applications powered by either two-cell or three-cell alkaline, Ultimate Lithium,NiCd, NiMH, one-cell Li-Ion or Li-Polymer batteries.

The integrated switch is protected by the 1.3A cycle-by-cycle inductor peak current limit operation. There is an output overvoltage protection which turns off switching in case the feedback resistors are accidentally disconnected or the feedback pin is short-circuited to GND.

Low-voltage technology allows the regulator to start-up without high inrush current or output voltage overshoot from a low-voltage input. The device features a UVLO which avoids start-up and operation with low inputs or discharged batteries for two cell-powered applications.

For standby applications (EN = GND), the device stops switching, enters Sleep mode and consumes 200 nA (typical) of input current.

MCP1661 is easy to use and allows creating classic boost, SEPIC or flyback DC-DC converters within a small Printed Circuit Board (PCB) area. Allcompensation and protection circuitry is integrated to minimize the number of external components. Ceramic input and output capacitors are used.

Features

• 36V, 800m Integrated Switch
• Up to 92% Efficiency
• High Output Voltage Range: up to 32V
• 1.3A Peak Input Current Limit:
• IOUT > 200 mA @ 5.0V VIN, 12V VOUT
• IOUT > 125 mA @ 3.3V VIN, 12V VOUT
• IOUT > 100 mA @ 4.2V VIN, 24V VOUT
• Input Voltage Range: 2.4V to 5.5V
• Undervoltage Lockout (UVLO):
• UVLO@VIN Rising: 2.3V, typical
• UVLO@VIN Falling: 1.85V, typical
• No Load Input Current: 250 μA, typical
• Sleep mode with 200 nA Typical Quiescent Current
• PWM Operation with Skip mode: 500 kHz
• Feedback Voltage Reference: VFB = 1.227V
• Cycle-by-Cycle Current Limiting
• Internal Compensation
• Inrush Current Limiting and Internal Soft Start
• Output Overvoltage Protection (OVP) in the event of:
• Feedback pin shorted to GND
• Disconnected feedback divider
• Overtemperature Protection
• Easily Configurable for SEPIC or Flyback Topologies
• Available Packages:
• 5-Lead SOT-23
• 8-Lead 2x3 TDFN

Typical applications

• Single-Cell Li-Ion to 5V, 12V or 24V Converters
• Hand-Held Instruments
• Two and Three-Cell Alkaline, Lithium Ultimate and NiMH/NiCd Portable Products
• Single-Cell Li-Ion to 3.0V or 3.3V SEPIC Applications
• Camera Phone Flash
• Portable Medical Equipment
• LCD Bias Supply for Portable Applications

More information

• Datasheet
• IC product information