Need a modem wiring diagram on the board

Question

Do it yourself

Hello!
I'm making a usb modem on Sim900.
I want to make it turn on automatically as soon as the power comes on.
To turn on this modem, you need to keep one of its legs (PWKEY) pressed to the ground for at least 1s.
It would be possible to take ATtiny, but for me it is somehow cumbersome.
Datasheet (17-19str)

Answer 1

Here is a thread on the subject. At the very end, advice is given to connect PWRKEY through a diode to VBAT and put a 470uF capacitor between PWRKEY and ground. True, the advice is not tested.

Answer 2

Solution in the forehead.
PNP transistor. a larger resistor from the power supply to the base, a capacitor from the base to ground.
Emitter on PWKEY.
ground collector.