MP6601 – 35V, 2.5A, STEPPER MOTOR DRIVER W/ INTERNAL CURRENT SENSE

MP6601 Rev. 1.01

www.MonolithicPower.com

12

9/4/2018

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APPLICATIONS INFORMATION

Driving DC Brush Motors

The MP6601 can be used to drive two DC

brush motors. The connections are shown in

Figure 4 below:

Figure 4: DC Brush Motor Connection

When driving DC motors with the MP6601,

there are some limitations that must be taken

into account.

Since both H-bridges use the same current

regulation threshold, both motors will current

limit at the same current.

Often, current

regulation is not used with DC brush motors; in

this case, it is recommended to select a 28kΩ

ISET resistor to set the current limit at 2.5A. If it

is desired to limit the stall current of the motors

to a lower value, select an appropriate value for

the ISET resistor as described in Equation (2)

above.

The MP6601 does not support the short brake

function, where both outputs are connected

together. The enable signal shown above drives

the motor when low, and the motor coasts when

high. Speed control can be implemented by

applying a PWM signal to the enable signals.

Bidirectional control can be accomplished by

applying a PWM signal to the direction inputs –

duty cycles above 50% will cause rotation in

one direction, and less than 50% will cause

rotation in the other direction.

PCB Layout

The power dissipated in the output MOSFETs

must be removed from the IC package to keep

the device temperature within limits.

The

exposed pad under the device is used to

conduct heat out of the die.

The pad should be connected to a large copper

area or ground plane, using thermal vias to

transmit heat to other layers as needed.

External components, including the ISET and

ROSC resistors and a supply bypass capacitors,

should be placed as close as possible to the

device.