Dual, 2.2MHz, Buck or Boost Converter with 80V Load-Dump Protection

The MAX5098A is a dual-output, high-switching-frequency DC-DC converter with integrated n-channel switches that can be used either in high-side or low-side configuration. Each output can be configured either as a buck converter or a boost converter. In the buck configuration, this device delivers up to 2A from converter 1 and 1A from converter 2. The MAX5098A also integrates a load-dump protection circuitry that is capable of handling load-dump transients up to 80V for industrial applications. The load-dump protection circuit utilizes an internal charge-pump to drive the gate of an external n-channel MOSFET. When an overvoltage or load-dump condition occurs, the series protection MOSFET absorbs the high voltage transient to prevent damage to lower voltage components.

The DC-DC converters operate over a wide operating voltage range from 4.5V to 19V. The MAX5098A operates 180° out-of-phase with an adjustable switching frequency to minimize external components while allowing the ability to make trade-offs between the size, efficiency, and cost.

This device utilizes voltage-mode control for stable operation and external compensation, thus the loop gain is tailored to optimize component selection and transient response. This device can be synchronized to an external clock fed at the SYNC input. Also, a clock output (CKO) allows a master-slave connection of two devices with a four-phase synchronized switching sequence. Additional features include internal digital soft-start, individual enable for each DC-DC regulator (EN1 and EN2), open-drain power-good outputs (PGOOD1 and PGOOD2), and a shutdown input (ON/OFF).

Other features of the MAX5098A include overvoltage protection, short-circuit (hiccup current limit) and thermal protection. The MAX5098A is available in a thermally enhanced, exposed pad, 5mm x 5mm, 32-pin TQFN package and is fully specified over the -40°C to +125°C temperature range.

Applications

* Industrial

* Wide 4.5V to 5.5V or 5.2V to 19V Input Voltage Range (with Up to 80V Load-Dump Protection)

* Dual-Output DC-DC Converter with Integrated Power MOSFETs

* Each Output Configurable in Buck or Boost Mode

* Adjustable Outputs from 0.8V to 0.85VIN Buck Configuration) and from VIN to 28V (Boost Configuration)

* IOUT1 and IOUT2 of 2A and 1A (Respectively) in Buck Configuration

* Switching Frequency Programmable from 200kHz to 2.2MHz

* Synchronization Input (SYNC)

* Clock Output (CKO) for Four-Phase Master-Slave Operation

* Individual Converter Enable Input and Power-Good Output

* Low-IQ (7µA) Standby Current (ON/OFF)

* Internal Digital Soft-Start and Soft-Stop

* Short-Circuit Protection on Outputs and Maximum Duty-Cycle Limit

* Overvoltage Protection on Outputs with Auto Restart

* Thermal Shutdown

* Thermally Enhanced 32-Pin TQFN Package Dissipates up to 2.7W at +70°C