Power for 2 motors

Hi, I've been recently at work trying to build an autonomous tank with an Arduino. I am using an Sn754410 motor driver IC to control two motors, each 1.5-3V. As a power source for both motors, should I have a voltage of 3v which is good for one motor) or a voltage of 6v(since there are two motors)?

How many volts does the Sn754410 drop?

Currents up to 1 A at voltages from 4.5 V to 36 V

How many volts does the Sn754410 drop?

Can you clear up your question, I am having a bit of a hard time understanding what"volts does it drop" means.

The switch will drop some volts.
If you supply it with x volts, the motor will only see x - y volts.
I’m guessing y is roughly 1.3 volts, so if you’ve got a motor expecting 3.5 volts, you need to supply the switch with more like 4.8 volts.
It’ll be in the data sheet.

okay, but what I meant to ask was that is it necessary to double my power source(double the voltage) to control two motors?

If they are in series, you need to double the motors rated voltage AND add the switch voltage drop to get the supply voltage.