MSK4422D datasheet(4/6 Pages) MSK

4 / 6 page

PROTECTION

All logic inputs use a 300nS filter.

A pulse width

below this will get ignored.

VCC voltage below the cutoff level of 8.65 volts will

reset all switch outputs off and ignore subsequent

logic inputs until VCC is restored.

Undervoltage lockout of the internal drivers for the

high-side switches also occurs at 8.65 volts, but will

not flag with the FAULT output. This may occur if the

high-side output gets switched without switching the

low-side. The internal boot strap powersupply for the

high-side switch will sag too low for adequate switch-

ing.

The boot strap supply depends on PWMing of

the low-side switches for proper operation.

Switching a low-side logic input while the correspond-

ing phase high-side logic input is activated will turn

off both switches. The opposite condition is also true.

This is cross-conduction lockout and will occur any

time low and high-side inputs for a phase are acti-

vated at the same time.

A 2µS deadtime is automatically inserted between

high and low-side output switching to allow complete

turn-off of each switch so no overlap will occur.

An overcurrent condition detected by the ITRIP pin

will shut down all output switches until the overcurrent

condition is removed and all three low-side logic in-

puts are held high for 10µS, then normal operation

will resume.

ITRIP has a 100nS leading edge blanking time after

switching to ignore any switching current transients.

TYPICAL OPERATION

APPLICATION NOTES

MSK 4422 PIN DESCRIPTION

VCC - Is the low voltage supply for all the internal logic

and drivers. A 0.1 µF ceramic capacitor in parallel with

a 10µF tantalum capacitor is recommended bypassing

for the VCC-VSS pins.

VSS - Is the low voltage supply return pin and the input

logic return reference. All logic input and logic output

is referenced to this pin. This pin can vary ±5V from

the COM power return pin without affecting any of the

logic functions.

AØHIN, BØHIN, CØHIN - Are low active logic inputs for

signalling the corresponding phase high-side switch to

turn on. The input levels are 5V CMOS or TTL compat-

ible.

AØLIN, BØLIN, CØLIN - Are low active inputs for sig-

nalling the corresponding phase low-side switch to turn

on. The input levels are 5V CMOS or TTL compatible.

FAULT - Is an open drain logic output pin that gets

enabled any time the VCC level goes below the cutoff

point, or an overcurrent condition occurs. Bringing VCC

back to normal levels will reset FAULT. Removing the

overcurrent condition and allowing the low-side logic

inputs to remain high(off) for 10µS will restore opera-

tion.

ITRIP - Is an analog input pin for sensing current flow-

ing from the COM pin through a sense resistor to the

high power ground. A 0.5 volt level at this pin with

respect to VSS will signal an overcurrent condition,

enable the FAULT pin and shut down all output switch-

ing.

Bringing the voltage below this point (100 mV

hysteresis) will remove the FAULT output and leaving

the low-side logic inputs simultaneously high (de-acti-

vated) for 10µS will restore normal operation.

V+ - Is the high voltage positive rail for the bridge.

Proper bypassing to VSS with sufficient capacitance

to suppress any voltage transients and to ensure re-

moving any drooping during switching, should be done

as close to the pins on the hybrid as possible.

COM - Is the return side of the bridge. A sense resistor

can be connected between this point and VSS, which

is the high voltage negative rail. COM can float above

and below the VSS pin up to 5 volts and proper opera-

tion will be maintained. Precautions should be taken

so as to not allow this voltage to get over ±5 volts

under any conditions.

AØ, BØ, CØ - Are the pins connecting the 3 phase

bridge switch outputs.

Rev. B 4/05

MSK4422D Datasheet(PDF) 4 Page - M.S. Kennedy Corporation

MSK4422D Datasheet(HTML) 4 Page - M.S. Kennedy Corporation

Html Pages

1 2 3 4 5 6

Datasheet Download

Link URL