The MAX1771ESA+ is an adjustable, high-efficiency, low IQ, Step-up DC-DC Controller. The MAX1771 step-up switching controller provides 90% efficiency over a 30mA to 2A load. A unique current-limited pulse-frequency-modulation (PFM) control scheme gives this device the benefits of pulse-width modulation (PWM) converters (high efficiency at heavy loads), while using less than 110µA of supply current (vs.2 to 10mA for PWM converters). This controller uses miniature external components. Its high switching frequency (up to 300kHz) allows surface-mount magnetic of 5mm height and 9mm diameter. It accepts input voltages from 2 to 16.5V. The output voltage is preset at 12V or can be adjusted using two resistors. The MAX1771 optimizes efficiency at low input voltages and reduces noise by using a single 100mV current-limit threshold under all load conditions.
