Dual VNH5019 Motor Driver - Power on problem

i have a “VNH5019 Motor Driver”.

i connect the vdd(5v) to driver from my micro controller(stm32f0).
i connect the 12v from ext PS.

the only oparation that the SW do is :
in_a = 1;
pwm = 1;
in_b = 0; and the result of this 2 commands -> out_a and out _b have a 12v.

my problem is that if i reset the micro -> out_a = 10V and out _b = 2v.

maybe the problem is in the EN, CS pins?

(i dont set any value to this 2 pin’s).


Hello David,

Could you clarify whether you have the EN pin floating or connected to anything, like an IO line from the microcontroller? The current sense (CS) pin should not have an effect on the driver outputs. The EN pins are pulled high by default, so there is no need to connect them to anything.

It is not clear to me whether your measurements of the driver outputs were taken between the two outputs or between each output and ground. Could you clarify? Do you have a motor connected to the driver? If so, could you post a datasheet or some specifications for the motors you are using. Could you also post pictures of your setup that show all connections.


Hi Joshd,

i attach my circuit schema.

i do not connected CS and EN pin’s.

the problem even happens without the motor.

if i set to IN_A ‘1’ and to IN_B ‘0’ the OUT_A have 10[v] and OUT_B 12[v]. (in PWM pin i set ‘1’).

about the motor its a simple DC motor (Maxon).

thanks of the help,

i see that the problem calls when I hang up and continue connect the pwm pin.
mayby the driver goes into a fault process?

thanks of the help,

By connecting 5V from the microcontroller to “VIN” on the driver, did you mean “VDD” instead? VIN is the connection point for the positive side of the motor power supply, while VDD is meant to power the driver’s internal logic.

It is unclear what you mean by “the problem calls when I hang up and continue connect the pwm pin”; could you restate that in another way? Giving a step by step process for how you are able to recreate the problem might help. It is possible to detect faults via the “EN” pin, which doubles as a fault indicator and is pulled low in the event of a fault condition. What is the voltage level on the “EN” pin after resetting?