Features: • Input Range of 2.7V to 5.5V
• 3 Operating Modes: PWM, PFM and LDO
• Integrated BUCK and Synchronous Switches
• Ceramic or Electrolytic Input/Output Filtering Capacitors
• 750 kHz Fixed Switching Frequency
• Oscillator Synchronization to 1 MHz PWM Mode
• Auto-Switching from PWM/PFM Operation
• 100% Duty Cycle Capable for Low Input Voltage
• 500 mA Continuous Output Current Capability
• Integrated Under-Voltage Lock-Out Protection
• Integrated Over-Temperature Protection
• Integrated Soft Start Circuitry
• Low Output Voltage Capability to 0.9V
• Temperature Range: -40°C to +85ºC
• Small 8-Pin MSOP Package
Application• Low Power Handheld CPUs and DSPs
• Cellular Phones
• Organizers and PDAs
• Digital Cameras
• +5V or +3.3V Distributed Voltages
• USB Powered DevicesPinout
Specifications| Device Description | Synchronous Buck Regulator |
| SW Reg Output | Adjustable |
| Typical Active Supply (A) | 119 |
| Switching Frequency (kHz) | 750 |
| Output Current (mA) | 500 |
| Output Voltage (V) | 0.9 to Vin |
| Input Voltage Range (V) | 2.7 to 5.5 |
| Device Description |
Synchronous Buck Regulator |
| SW Reg Output |
Adjustable |
| Typical Active Supply (A) |
119 |
| Switching Frequency (kHz) |
750 |
| Output Current (mA) |
500 |
| Output Voltage (V) |
0.9 to Vin |
| Input Voltage Range (V) |
2.7 to 5.5 |
VIN - AGND......................................................................6.0V
SHDN, FB, SYNC/PWM, VOUT ......... (AGND-0.3V) to (VIN+0.3V)
LX to PGND................................................ -0.3V to (VIN+0.3V)
PGND to AGND ................................................. -0.3V to +0.3V
Output Short Circuit Current .................................continuous
Storage temperature ...................................-65°C to +150°C
Ambient Temp. with Power Applied ................-40°C to +85°C
Operating Junction Temperature...................-40°C to +125°C
ESD protection on all pins ............................................. 4 kV
DescriptionThe MCP1601 is a fully integrated synchronous BUCK (step down) DC/DC converter for battery powered systems. With an input operating range of 2.7V to 5.5V, the MCP1601 is ideal for applications being powered by one single cell Li-Ion, 2 to 3 cell NiMH, NiCd or alkaline sources. Output voltages can range from 0.9V to VIN to
accommodate a wide range of applications. Efficiency can exceed 92% while operating at 750 kHz with load current capability up to 500 mA. The MCP1601 is used to minimize space, cost and wasted energy.
The PWM mode switching frequency is internally set to a fixed 750 kHz allowing the use of low profile, surface mount inductors and ceramic capacitors while maintaining a typical efficiency of 92%.
The MCP1601 is capable of three distinct operating modes: PWM, PFM and Low Drop Out.
When operating in PWM (pulse width modulation) mode, the DC/DC converter switches at a single high frequency determined by either the internal 750 kHz oscillator or external synchronization frequency.
For applications that operate at very light to no load for extended periods of time, the MCP1601 is capable of operating in PFM (pulse frequency modulation mode) to reduce the number of switching cycles/sec and consume less energy.
The third mode of operation (LDO mode) occurs when the input voltage approaches the output voltage and the BUCK duty cycle approaches 100%. The MCP1601 will enter a low drop out mode and the high-side P-Channel BUCK switch will saturate, providing the output with the maximum voltage possible.
The MCP1601 has integrated over-current protection, over-temperature protection and UVLO (Under Voltage Lockout) to provide for a fail safe solution with no external components.
The MCP1601 is available in the 8-pin MSOP package, with an operating temperature range of -40°C to +85°C.
The MCP1601 is a synchronous Buck (step-down) switching regulator that can continuously supply 500mA of load current. This DC/DC converter can provide output voltages of 0.9V to Vin with an operating efficiency that can exceed 92%. Although ideally suited for a single Li-Ion, or 2 to 3 cell NiCd, NiMH, or alkaline battery operation, the input range of 2.7V to 5.5V is also useful for converting bus voltages to standard system requirements.
MCP1601 Data Sheet
