What is the point of the VCC2 pin on the MC33883?

[matthew_k_mcdon]

Hello. Maybe I missed it in the datasheet, but what is the point of the VCC2 pin on the MC33883. Assuming the voltage is less than 35 Volts, can we connect VCC2 and VCC? 

Also, because of the integral charge pump, can this chip drive the high-side MOSfets at 100% Duty Cycle?

Thanks, 

Matt

[TomasVaverka]

Hello Matthew,

From datasheet:

The VCC and VCC2 pins are the power supply inputs to the device. VCC is used for the output high-side drivers and the charge pump. VCC2 is used for the linear regulation. They can be connected together or independent with different voltage values. The device can operate with VCC up to 55 V and VCC2 up to 28 V.

VCC2 Overvoltage Shutdown:

As for the 100% Duty Cycle, we ran an experiment with the MC33883 EVB and there was no issue with running the charge pump for >30 seconds. Using the EVB and the default MOSFETs and 49 Ohm gate resistance it sourced about 1 mA to the HS gate with no issue.

Best regards,

Tomas

[matthew_k_mcdon]

Thank you very much,

So as long as my input voltage range is less than 28V I can tie VCC and

VCC2 together.

And thanks for testing the 100% duty cycle.

On Wed, Aug 1, 2018 at 6:22 AM, TomasVaverka <admin@community.nxp.com>