General Description
The MCP16311/2 is a compact, high-efficiency, fixed
frequency, synchronous step-down DC-DC converter in
an 8-pin MSOP, or 2 x 3 mm TDFN package that
operates from input voltage sources up to 30V.
Integrated features include a high-side and a low-side
switch, fixed frequency peak current mode control,
internal compensation, peak current limit and
overtemperature protection. The MCP16311/2 provides
all the active functions for local DC-DC conversion, with
fast transient response and accurate regulation.
High converter efficiency is achieved by integrating the
current-limited, low-resistance, high-speed high-side
and low-side switches and associated drive circuitry.
The MCP16311 is capable of running in PWM/PFM
mode. It switches in PFM mode for light load
conditions and for large buck conversion ratios. This
results in a higher efficiency over all load ranges. The
MCP16312 runs in PWM-only mode, and is
recommended for noise-sensitive applications.
The MCP16311/2 can supply up to 1A of continuous
current while regulating the output voltage from 2V to
12V. An integrated, high-performance peak current
mode architecture keeps the output voltage tightly
regulated, even during input voltage steps and output
current transient conditions common in power systems.
The EN input is used to turn the device on and off.
While off, only a few micro amps of current are
consumed from the input.
Output voltage is set with an external resistor divider.
The MCP16311/2 is offered in small MSOP-8 and
2 x 3 mm TDFN surface mount packages.

Features
• Up to 95% Efficiency
• Input Voltage Range: 4.4V to 30V
• 1A Output Current Capability
• Output Voltage Range: 2.0V to 24V
• Qualification: AEC-Q100 Rev. G, Grade 1
(-40°C to +125°C)
• Integrated N-Channel High-Side and Low-Side
Switches:
- 170m, Low Side
- 300m, High Side
• Stable Reference Voltage: 0.8V
• Automatic Pulse Frequency Modulation/Pulse-
Width Modulation (PFM/PWM) Operation
(MCP16311):
- PFM Operation Disabled (MCP16312)
- PWM Operation: 500 kHz
• Low Device Shutdown Current: 3 μA Typical
• Low Device Quiescent Current:
- 44 μA (Non-switching, PFM Mode)
• Internal Compensation
• Internal Soft-Start: 300 μs (EN Low-to-High)
• Peak Current Mode Control
• Cycle-by-Cycle Peak Current Limit
• Undervoltage Lockout (UVLO):
- 4.1V typical to start
- 3.6V typical to stop
• Overtemperature Protection
• Thermal Shutdown:
- +150°C
- +25°C Hysteresis

Applications
• PIC® /dsPIC® Microcontroller Bias Supply
• 24V Industrial Input DC-DC Conversion
• General Purpose DC-DC Conversion
• Local Point of Load Regulation
• Automotive Battery Regulation
• Set-Top Boxes
• Cable Modems
• Wall Transformer Regulation
• Laptop Computers
• Networking Systems
• AC-DC Digital Control Bias
• Distributed Power Supplies