MAX1771ESA-T

The MAX1771ESA-T is one member of the MAX1771 series.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 110A of supply current (vs.2mA to 10mA for PWM converters).The MAX1771 uses a proprietary current-limited PFM control scheme to provide high efficiency over a wide range of load currents. This control scheme combines the ultra-low supply current of PFM converters (or pulse skippers) with the high full-load efficiency of PWM converters.

Features of the MAX1771ESA-T are:(1)90% efficiency for 30mA to 2A load currents; (2)up to 24W output power; (3)110A max supply current; (4)5A max shutdown current; (5)2V to 16.5V input range; (6)preset 12V or adjustable output voltage; (7)current-limited PFM control scheme; (8)up to 300kHz switching frequency; (9)evaluation kit available.This controller uses miniature external components. Its high switching frequency (up to 300kHz) allows surface-mount magnetics of 5mm height and 9mm diameter.It accepts input voltages from 2V to 16.5V. The output voltage is preset at 12V, or can be adjusted using two resistors.

The absolute maximum ratings of the MAX1771ESA-T can be summarized as:(1)supply voltage V+ to GND:-0.3 to 17V;(2)storage temperature range:-65 to 160;(3)junction temperature:150;(4)continuous power dissipation:727mW;(5)operating temperature ranges:0 to 70.Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.The MAX1771 is a BiCMOS, step-up, switch-mode power-supply controller that provides a preset 12V output in addition to adjustable-output operation. Its unique control scheme combines the advantages of pulse-frequency modulation (low supply current) and pulsewidth modulation (high efficiency with heavy loads), providing high efficiency over a wide output current range, as well as increased output current capability over previous PFM devices.