MIC4607 datasheet(19/42 Pages) MICROCHIP

Part #	MIC4607

Description	85V, Three-Phase MOSFET Driver with Adaptive Dead-Time, Anti-Shoot-Through and Overcurrent Protection

PDF	42 Pages

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Manufacturer	MICROCHIP [Microchip Technology]

Direct Link	http://www.microchip.com

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 2016 Microchip Technology Inc.

DS20005610A-page 19

MIC4607

4.4

Overcurrent Timing Diagram

The motor current is sensed in an external resistor that

is connected between the low-side MOSFET’s source

pins and ground. If the sense resistor voltage exceeds

the rising overcurrent threshold (typically 0.2V), all LO

and HO outputs are latched off and the FLT/ pin is

pulled low. Once the outputs are latched off, an internal

current source (typically 0.44 μA) begins to charge up

the external CDLY capacitor. The outputs remain

latched off and all xLI/xHI (or xPWM) input signals are

ignored until the voltage on the CDLY capacitor rises

above the VDLY+ threshold (typically 1.5V), which

resets the latch on the first rising edge of any LI input of

the MIC4607-1 (or falling edge on any PWM input for

the MIC4607-2).

Once this occurs, the CDLY capacitor is discharged, the

FLT/ pin returns to a high impedance state and all out-

puts will respond to their respective input signals.

On startup, the current limit latch is reset during a rising

VDD or a rising EN pin voltage to assure normal opera-

tion.

FIGURE 4-4:

Overcurrent Timing Diagram.

MIC4607 Datasheet(PDF) 19 Page - Microchip Technology