Rev. C 12/22

4

SIC1181KQ / SIC1182KQ

www.power.com

Safe Power-Up and Power-Down

It is recommended during power-up and power-down that the IN

pin stays at logic low. Any supply voltage related to VCC, VISO, VEE

and VGXX pins should be stabilized using ceramic capacitors C

1, C2,

C

S1, CS2, and CGXX respectively as shown in Figure 5, 6, 7 and 8. After

supply voltages reach their nominal values, the driver will begin to

function after a time delay t

START.

Short-Pulse Operation

If command signals applied to IN are shorter than the minimum

specified by t

GE(MIN), then SIC118xKQ output signals at GH and GL will

extend to a value of t

GE(MIN). The duration of pulses longer than tGE(MIN)

will not be changed.

Short-Circuit Protection

The SIC118xKQ uses the semiconductor device drain to source voltage

to detect a short-circuit utilizing a sensing resistor network. With

the help of a well stabilized V

VISO and a Schottky diode connected

between semiconductor device gate and VISO the V

GS is clamped to

the regulated VISO and the short-circuit current as well related SiC

semiconductor energy will be limited.

During the off-state, SNS is internally connected to the COM pin. In

case an optional filter-capacitor is applied between SNS pin and COM

this capacitor is discharged.

When the driver is in turn-on transition or in on-state, the short-circuit

detection algorithm through SNS is activated after an ASIC internally

blanking time has elapsed. If now a voltage drop of about 0.4 V

(typically) is detected at SNS referenced to VEE, this is interpreted

as a detected short-circuit. The driver initiates a short-circuit turn-

off without receiving a primary-side command. A fault command is

sent to the primary side and SO is pulled to GND for typically 10 µs.

During this time the driver ignores any command signal at the IN pin.

In parallel to the short-circuit turn-off transition phase, the SCALE-

iDriver’s internal Advanced Active Clamping overvoltage limitation

scheme is activated.

V

DS Overvoltage Limitation (Advanced Active Clamping)

If the driver is in turn-off transition or in off-state the overvoltage

limitation algorithm is activated at SNS and the internal reference is

COM. In case a current of typically 440 µA (turn-off transition) to

520 µA (off-state) is feed to SNS, the driver will regulate the gate

current to limit the turn-off di/dt and therefore the overvoltage at

drain to source during turn-off.

Over-Current Detection

In case the semiconductor device offers a so called current-sense

terminal, this signal can be fed into SNS with reference to VEE. As

described in the short-circuit protection section, a voltage of about

0.4 V at SNS with reference to VEE will now be handled as an

over-current. That leads to an over-current turn-off, following the

same scheme as for a short-circuit condition.