High-Voltage PWM Power-Supply Controller

The MAX5003 high-voltage switching power-supply controller has all the features and building blocks needed for a cost-effective flyback and forward voltage-mode control converter. This device can be used to design both isolated and nonisolated power supplies with multiple output voltages that operate from a wide range of voltage sources. It includes a high-voltage internal start-up circuit that operates from a wide 11V to 110V input range. The MAX5003 drives an external N-channel power MOSFET and has a current-sense pin that detects overcurrent conditions and turns off the power switch when the current-limit threshold is exceeded. The choice of external power MOSFET and other external components determines output voltage and power.

The MAX5003 offers some distinctive advantages: soft-start, undervoltage lockout, external frequency synchronization, and fast input voltage feed-forward. The device is designed to operate at up to 300kHz switching frequency. This allows use of miniature magnetic components and low-profile capacitors. Undervoltage lockout, soft-start, switching frequency, maximum duty cycle, and overcurrent protection limit are all adjustable using a minimum number of external components. In systems with multiple controllers, the MAX5003 can be externally synchronized to operate from a common system clock.

Warning: The MAX5003 is designed to operate with high voltages. Exercise caution.

The MAX5003 is available in 16-pin SO and QSOP packages. An evaluation kit (MAX5003EVKIT) is also available.

Applications

* +42V Automobile Systems * High-Voltage Power Supply Modules * Industrial Power Supplies * ISDN Power Supplies * Telecommunication Power Supplies

* Wide Input Range: 11V to 110V

* Internal High-Voltage Startup Circuit

* Externally Adjustable Settings

* Output Switch Current Limit

* Oscillator Frequency

* Soft-Start

* Undervoltage Lockout

* Maximum Duty Cycle

* Low External Component Count

* External Frequency Synchronization

* Primary or Secondary Regulation

* Input Feed-Forward for Fast Line-Transient Response

* Precision ±2.5% Reference over Rated Temperature Range

* Thermal Shutdown