MIC38C43YN

MIC38C43YN DC DC Switching Controllers

The MIC38C43YN is a monolithic DC/DC switching regulator control integrated circuit. The circuit provides all the active functions for a step-up (boost), flyback, forward, or inverting switching regulator. The part incorporates all the necessary circuitry for driving an external MOSFET and for low voltage logic operation as referenced to a low voltage common terminal, Vss. The MIC38C43YN circuit also has internal temperature compensation and soft-start circuitry. Additional features include undervoltage lockout and cycle-by-cycle current limiting.

Overview

The MIC38C43YN provides the control functions for step-up (boost), flyback, forward, or inverting switching regulator circuits that employ a suitably-rated MOSFET switch and at least one other linear or switched-mode auxiliary circuit. It has all of the functions necessary to provide a complete switching regulator system, including a reference, a 5-bit digital-to-analog converter, an oscillator, a startup circuit, a current limit circuit, an enable circuit, an undervoltage lockout circuit and feedback voltage control.

Applications

The MIC38C43YN is ideal for a variety of DC/DC switching regulator applications including telecom, automotive, computing, networking, industrial and consumer. It provides the necessary circuitry for switching regulator designs using a variety of topologies, diode or synchronous rectified output and step-up, boost, positive to negative polarity, and negative to positive polarity.

Features

• Integrated MOSFET gate driver
• Output voltage adjustable from 0.8V to 5V
• 5-bit DAC with voltage adjust pin
• High switching frequency and efficiency
• Programmable soft start
• Undervoltage lockout with foldback
• Low external component count
• High side current sensing
• Programmable clock frequency
• Thermal Shutdown
• Cost-effective integrated solution

Working Principle

The MIC38C43YN is designed to operate as a constant-frequency, current-mode, pulse width modulated (PWM) controller. The output voltage is adjusted by varying the duty cycle of the externally provided MOSFET switch. The current-mode control offers excellent line and load regulation characteristics. The device includes a 5-bit digital-to-analog converter (DAC) which enables the user to fine tune the output voltage using the voltage adjust (VADJ) pin. The output voltage of the converter is adjusted by the duty cycle of the pulse width modulated (PWM) signal. The maximum duty cycle of the PWM signal is determined by the voltage at the Vcc pin.

Conclusion

The MIC38C43YN is a high performance integrated DC/DC switching regulator controller designed to operate as a constant-frequency, current-mode, pulse width modulated (PWM) controller. The device includes a 5-bit digital-to-analog converter (DAC) which enables the user to fine tune the output voltage using the voltage adjust (VADJ) pin. Additionally, the device features a variety of features such as integrated MOSFET gate driver, undervoltage lockout with foldback, thermal shutdown, low external component count, cost-effective integrated solution, high side current sensing, and programmable clock frequency.