Power IC with Integrated MOSFETs for Isolated IEEE 802.3af PD and Telecom Power-Supply Applications

The MAX5074A isolated PWM power IC features integrated switching power MOSFETs connected in a voltage-clamped, two-transistor, power-circuit configuration. This device can be used in both forward and flyback configurations with a wide input voltage range from 11V to 76V and up to 15W of output power.

The voltage-clamped power topology enables full recovery of stored magnetizing and leakage inductive energy for enhanced efficiency and reliability. A look-ahead signal for driving secondary-side synchronous rectifiers can be used to increase efficiency.

A wide array of protection features includes UVLO, overtemperature shutdown, and short-circuit protection with hiccup current limit for enhanced performance and reliability. Operation up to 500kHz allows smaller external magnetics and capacitors.

The MAX5074A is rated for operation over the -40°C to +125°C temperature range and is available in a 20-pin TSSOP package.

Warning: The MAX5074A is designed to work with high voltages. Exercise caution.

Applications

* 48V Input, Isolated Power-Supply Modules * ADSL Line Cards * ADSL Line-Driver Power Supplies * Distributed Power Systems with 48V Bus * High-Efficiency Telecom/Datacom Power Supplies * IEEE 802.3af PD Power Supplies * Isolated IP Phone Power Supplies * WLAN Access-Point Power Supplies

* Clamped, Two-Switch Power IC for High Efficiency

* No Reset Winding Required

* Up to 15W Output Power

* Bias Voltage Regulator with Automatic High-Voltage Supply Turn-Off

* 11V to 76V Wide Input Voltage Range

* Integrated High-Voltage 0.4Ω Power MOSFETs

* Feed-Forward Voltage-Mode Control for Fast Input Transient Rejection

* Programmable Brownout Undervoltage Lockout

* Internal Overtemperature Shutdown

* Indefinite Short-Circuit Protection with Programmable Fault Integration

* Integrated Look-Ahead Signal for Secondary-Side Synchronous Rectification

* > 90% Efficiency with Synchronous Rectification

* Up to 500kHz Switching Frequency

* High-Power (1.74W), Small-Footprint 20-Pin Thermally Enhanced TSSOP Package