High-Voltage, Step-Down DC-DC Controller in µMAX

The MAX1744/MAX1745 are step-down DC-DC controllers capable of handling up to 36V inputs. These parts use a proprietary current-limited control scheme for excellent light- and full-load efficiency, while their 330kHz (max) switching frequency permits small external components for space-critical applications. Operation to 100% duty cycle permits the lowest possible dropout voltage.

The MAX1744 contains an internal feedback network that provides a pin-selectable output voltage of either 3.3V or 5V. The MAX1745 uses an external feedback network to generate an adjustable output voltage between 1.25V and 18V.

The MAX1744/MAX1745 are available in a space-saving 10-pin µMAX® package.

Applications

* Automotive Electronics * FireWire®/IEEE® 1394 * Industrial Control Systems * Telecom Systems * Wall-Cube-Powered Devices

* High-Voltage Operation (up to 36VIN)

* Efficiency > 90%

* Output Power Capability Exceeds 50W

* 10-Pin µMax Package

* Low-Dropout Voltage

* 100% (max) Duty Cycle

* 90µA Quiescent Current

* 4µA Shutdown Current

* Up to 330kHz Switching Frequency

* Output Voltage

* 5V or 3.3V (MAX1744)

* Adjustable 1.25V to 18V (MAX1745)

* Current-Limited Control Scheme