5

Functional description

5.1

Inputs and outputs

The devices are controlled through the following logic inputs:

•

EN: Enable input, active high;

•

LIN: low-side driver inputs, active low;

•

HIN: high-side driver inputs, active low.

Table 6. Inputs truth table

Note:

Applicable when device is not in UVLO or SmartSD protection

Input pins

Output pins

EN

LIN

HIN

LVG

HVG

L

X

X

Low

Low

H

H

H

Low

Low

H

L

H

High

Low

H

H

L

Low

High

Interlocking

H

L

L

Low

Low

The FAULT and OD pins are open-drain outputs.

The FAULT signal is set low in case VCC UVLO is detected, or in case the SmartShutDown comparator

triggers an event. It is only used to signal a UVLO or SmartSD activation to external circuits, and its state

does not affect the behavior of other functions or circuits inside the driver. The OD behavior is explained in

Section 5.5 Comparator and smart shutdown.

When EN is set low, gate driver outputs are forced low and assure low impedance.

5.2

Deadtime

The deadtime feature, in companion with interlocking feature, guarantees that driver outputs of the same channel

are not high simultaneously and at least a DT time passes between the turn-off of one driver's output and the

turn-on of the companion output of the same channel. If a deadtime longer than the internal DT is applied to

LIN and HIN inputs by the external controller, the internal DT is ignored, and the outputs follow the deadtime

determined by the inputs.

Refer to Figure 4. Deadtime timing definitions for the dead time and interlocking waveforms.

5.3

VCC UVLO protection

Undervoltage protection is available on VCC and BOOT supply pins. In order to avoid intermittent operation, a

hysteresis set the turn-off threshold with respect to the turn-on threshold.

When VCC voltage goes below VCCTHOFF threshold all the outputs are switched off, both LVG and HVG. When

VCC voltage reaches VCCTHON threshold the driver returns to normal operation and sets the LVG outputs

according to actual input pins status; HVG is also set according to input pin status if the corresponding VBO

section is not in UVLO condition.

The FAULT output is kept low when VCC is in UVLO condition. The following figures show some examples of

typical operation conditions.

STDRIVE601

Functional description

DS12949 - Rev 2

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