Microchip Technology ADM00414 Data Sheet

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© 2011 Microchip Technology Inc.
DS22285A-page 1
MCP16321/2
Features
• Up to 95% Typical Efficiency
• Input Voltage Range: 6.0V to 24V
• 1A Output Current (MCP16321)
• 2A Output Current (MCP16322)
• Fixed Output Voltages: 0.9V, 1.5V, 1.8V, 2.5V, 
3.3V, 5V with 2% Output Voltage Accuracy
• Adjustable Version Output Voltage Range: 
0.9V to 5V with 1.5% Reference Voltage Accuracy
• Integrated N-Channel High-Side Switch: 180 mΩ
• Integrated N-Channel Low-Side Switch: 120 mΩ
• 1 MHz Fixed Frequency
• Low Device Shutdown Current
• Peak Current Mode Control
• Internal Compensation
• Stable with Ceramic Capacitors
• Internal Soft-Start
• Cycle-by-Cycle Peak Current Limit
• Undervoltage Lockout (UVLO): 5.75V
• Overtemperature Protection
• V
OUT
 Overvoltage Protection
• V
OUT 
Voltage Supervisor Reported at the PG Pin
• Available Package: QFN-16 (3x3 mm)
Applications
• PIC
®
/dsPIC
®
 Microcontroller Bias Supply
• 12V Industrial Input DC-DC Conversion
• Set-Top Boxes
• DSL Cable Modems
• Automotive
• Wall Cube Regulation
• SLA Battery Powered Devices
• AC-DC Digital Control Power Source
• Power Meters
• Consumer
• Medical and Health Care
• Distributed Power Supplies
Description
The MCP16321/2 is a highly integrated, high-efficiency,
fixed frequency, synchronous step-down DC-DC
converter in a 16-pin QFN package that operates from
input voltages up to 24V. Integrated features include a
high-side and low-side N-Channel switch, fixed
frequency Peak Current Mode Control, internal
compensation, peak current limit, V
OUT
 overvoltage
protection and overtemperature protection. Minimal
external components are necessary to develop a
complete synchronous step-down DC-DC converter
power supply.
High converter efficiency is achieved by integrating a
high-speed, current limited, low resistance, high-side
N-Channel MOSFET, as well as a high-speed, low
resistance, low-side N-Channel MOSFET and
associated drive circuitry. High switching frequency
minimizes the size of the inductor and output capacitor,
resulting in a small solution size.
The MCP16321/2 device can supply 1A/2A of
continuous current while regulating the output voltage
from 0.9V to 5V. A high-performance peak current
mode architecture keeps the output voltage tightly
regulated, even during input voltage steps and output
current transient conditions that are common in power
supplies.
The regulator can be turned on and off with a logic level
signal applied to the EN input. The EN input is internally
pulled up to a 4.2V reference and is rated for a
maximum of 6V. With EN low, typically 5 µA of current
is consumed from the input, making the part ideal for
power shedding and load distribution applications. The
PG output is an open drain output pin used to interface
with other components of the system, and can be
pulled up to a maximum of 6V.
The output voltage can either be fixed at output
voltages of 0.9V, 1.5V, 1.8V, 2.5V, 3.3V, 5V or
adjustable using an external resistor divider. The
MCP16321/2 is offered in a 3x3 QFN-16 surface mount
package.
24V Input, 1A/2A Output, High Efficiency Synchronous Buck Regulator
with Power Good Indication