30V 2A DC-DC converter for demanding industrial applications

Incorporating Over Current and Short circuit protection circuits, the XC9250 / XC9251 series feature a maximum output current of 2A. They also include the option for the designer to select either a Latch or Auto-restart (Hiccup) configuration, dependant on specific application requirements. Readily available with a 300KHz or 500kHz switching frequency, designers can opt to synchronize the switching frequency of the DC-DC with an external CLK signal (within ±25% of the nominal frequency).

Using the internal 0.8V reference voltage, the output voltage can be set using two external resistors within a range of 1.2V to 12V.  The designer can select fixed frequency PWM mode using the MODE/SYNC pin, ensuring maximum efficiency at higher output loads. Alternatively, PFM/PWM automatic switching can be used for improved efficiency during light loads.

A thermal shutdown circuit will force stop the operation of the XC9250 / XC9251 series, when the chip’s temperature reaches 150°C. An Under Voltage Lock Out circuit will also force stop operation when the input voltage decreases below 4.6V (TYP). Implemented using hysteresis, these functions allow the XC9250 / XC9251 to resume normal operation when the chip’s temperature drops below 125˚C and when the input voltage increases to 5.3V respectively.

The XC9250 / XC9251 series also feature a chip enable pin to turn the IC on and off and an integral soft-start circuit to help limit rush current and output voltage overshoot during start-up. The new DC-DC converters feature a fixed soft start time of 0.7ms or 1.3ms, at 300KHz and 500KHz respectively. An external CR can be connected to extend the time as desired and inexpensive ceramic capacitors can also be used for the output load capacitor.

Key features:

• Input Voltage: 7.0V - 30V,
• FB Voltage: 0.8V (±2%),
• Output Current: 2A,
• Switching Frequency: 300kHz, 500kHz,
• Quiescent Current: 200uA,
• Soft Start (externally set),
• Thermal Shutdown,
• Current Limit (with optional latch),
• Operating Ambient Temperature: -40°C - 105°C.

The XC9250 / XC9251 is readily available in a SOP-8FD package measuring 6.0mm x 4.9mm x 1.55mm and the package incorporates an exposed GND tab to maximise heat dissipation. A fully populated EVB can be provided upon request.