Hi,
See page 8 and 9 of the manual.
It requires a 0 to 5V control voltage as the graph, shows.
It advises against PWM but a PWM of 500Hz can be used or 1 to 20kHz can be used, depending on the model.
Which is yours?
I don't know anything about these Micro Diaphram Pumps to advise anymore, you may need to chat with a distributor or seller.
Tom..... 