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STSPIN240

Functional description

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6.3

PWM current control

The device implements two independent current controllers, one for each full-bridge.

the decay sequence is performed.

The decay sequence starts turning on both low sides of the full-bridge.

value (peak value) and sense resistors value.

Equation 1

In choosing the sense resistor value, two main issues must be taken into account:



The sensing resistor dissipates energy and provides dangerous negative voltages on

the SENSE pins during the current recirculation. For this reason the resistance of this

component should be kept low (using multiple resistors in parallel will help to obtain the

required power rating with standard resistors).



Table 9. ON and slow decay states

PHx

PWMx

ON

Decay

00

HSx1 = OFF

LSx1 = ON

HSx2 = OFF

LSx2 = ON

1. During decays the inputs values are ignored until the system returns to ON condition (decay time expired).

01

HSx1 = OFF

LSx1 = ON

HSx2 = ON

LSx2 = OFF

HSx1 = OFF

LSx1 = ON

HSx2 = OFF

LSx2 = ON

10

HSx1 = OFF

LSx1 = ON

HSx2 = OFF

LSx2 = ON

N.A.(1)

11

HSx1 = ON

LSx1 = OFF

HSx2 = OFF

LSx2 = ON

HSx1 = OFF

LSx1 = ON

HSx2 = OFF

LSx2 = ON