General Description

The MCP1633 High Speed PWM Controller is a pulsewidth

modulator developed for standalone power

supply applications. The MCP1633 design is based on

the MCP1632 PWM Controller but includes specific

blocks for PWM LED dimming. It is suitable for use in

topologies requiring a low-side MOSFET, such as

Boost, Flyback, SEPIC, CUK, etc.

The MCP1633 uses Current Mode Control to provide

superior bandwidth and transient response, and also

cycle-by-cycle current limiting with adjustable peak

offset. The MCP1633 is also capable of operating in

Voltage Mode Control if required.

The switching frequency of the MCP1633 can be set by

an external resistor between 200 kHz and 2.2 MHz.

The MCP1633 reference voltage is adjustable by using

only one external resistor.

The MCP1633 integrates a current sense amplifier with

programmable gain using external resistors.

The MCP1633 can achieve high performance LED

dimming by “freezing” the compensation network and

load disconnect capability.

The MCP1633 integrates a high speed comparator with

a high performance error amplifier with a PWM latch to

perform the high speed analog Power Supply PWM

function.

Integrated Undervoltage Lockout, Overvoltage

protection and Overtemperature Protection make

designs using the MCP1633 robust over a range of

external conditions.

Features

• High Speed Current Mode Pulse-Width Modulator

(PWM) Controller

• Easy to Interface with PIC® Microcontroller for

Implementing High-Performance LED Drivers

• Integrated General Purpose Operational Amplifier

that can be Used for Current Sensing

• Internal Oscillator with Adjustable Frequency via

External Resistor

• External Synchronization Option for the Oscillator

• Internal Slope Compensation Circuit

• Current Sense to VEXT Response <120 ns Typical

• Internal Leading Edge Blanking Circuit for Current

Sense Input

• Programmable Current Sense Offset

• Internal Reference Voltage Generator

• Soft Start Capability

• Internal Push-Pull MOSFET Driver with 1A Peak

Current Capability

• Internal MOSFET Driver for Dimming/Load

Disconnect

• Input Voltage Range: 3V to 5.5V

• Undervoltage Lockout Circuit

• Output Overvoltage Protection

• Output Short Circuit Protection

• Overtemperature Protection

• Small 16-Pin QFN 3 x 3 mm Package

• Passes automotive AEC-Q100 reliability testing

Applications

• LED Drivers

• Switch Mode Power Supplies

• Brick DC-DC Converters