Variable Frequency Micropower Step-up DC-DC Converter
The MC33468 is a micropower step–up switching voltage regulator, specifically designed for handheld and pager applications, to provide a regulated output voltage using a minimum of external parts. This device features a quiescent bias current of 3.0 µA typical.
The MC33468 features a highly accurate voltage reference, an error amplifier, an oscillator, a variable frequency modulation (VFM) controller, a drive pin (EXT) for an external transistor, and feedback resistors.
The Vout pin is fixed at 2V in the IC. The output of the converter with an inductor, a diode, a capacitor, a drive transistor, and feed–back resistors can have an output of 30V.
MC33468 Features:
• Low Quiescent Bias Current of 3.0 µA
• High Output Voltage Accuracy of ±2.5%
• Low Startup Voltage of 0.8 V at No Load
• Output Voltage Set With External Resistors
• Operating Temperature Range: –40°C to +85°C
• Surface Mount Package