DRV103: Driving a proportional valve

Part Number:DRV103

Hi,

For a new project I will use some proportional valve (SMC PVQ31 - 12V).

All the logic will be handled by an ATMEGA328 and as a proportional valve driver I’ll use the DRV103.

I need to drive the proportional valve in a two step way. 

When a certain output on the uP is high the valve should be driven at about 20% duty cycle. After a certain period of time (about 0,5 sec.) it will be driven at 90% to 100% duty cycle.

I’m planning to use a digital pot to set the duty cycle control pin (1) on the DRV103 and a Voltage reference  IC as a voltage source for this input.

The digital pot value and timing will be handled by the uP.

This is my first time with a driver like DRV103 and I have some question.

1.- Is the digital pot a correct solution to handle different duty cycle ? 

2.- Is there any latency when increasing the duty cycle changing the voltage applied to the duty cycle adj. pin?

3.- how many mA duty cycle adj. input sink ? Is it enough for the voltage reference IC (LM4050AIM3-5.0) to work properly ?

4.- The proportional valve PVQ31 have a working voltage of 12V. Is it ok to supply 12V to the DRV 103 or is better to increase the supply voltage to say 14/15 volt ?

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