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INT202

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INT202 Functional Description

5 V Regulator

The 5 V linear regulator circuit provides

the supply voltage for the control logic

and high-voltage level shift circuit. This

allows the logic section to be directly

compatible with 5 V CMOS logic

without the need of an external 5 V

supply.

Undervoltage Lockout

The undervoltage lockout circuit disables

the LS OUT pin and both HSD pins

whenever the V

below typically 9.0 V, and maintains

this condition until the V

rises above typically 9.35 V.

This

guarantees that both MOSFETs will

remain off during power-up or fault

conditions.

HSD1/HSD2

The HSD1 and HSD2 outputs are

connected to integrated high-voltage N-

channel MOSFET transistors which

perform the level-shifting function for

communication to the high-side driver.

Controlled current capability allows the

drain voltage to float with the high-side

driver. Two individual channels produce

a true differential communication

channel for accurately controlling the

high-side driver in the presence of fast

moving high-voltage waveforms.

Pulse Circuit

The pulse circuit provides the two high-

voltage level shifters with precise timing

signals. Two pulses are sent over HSD1

to signal the high-side driver to turn on.

One pulse is sent over HSD2 to signal

the high-side driver to turn off. The

combination

of

differential

communication with the precise timing

provides maximum immunity to noise.

Driver

The CMOS drive circuit provides drive

power to the gate of the MOSFET used

on the low side of the half bridge circuit.

The driver consists of a CMOS buffer

capable of driving an external transistor

gate at up to 15 V.

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Figure 4. Using the INT202 and INT201 to Drive a Switched Reluctance Motor.

PI-1473-042695

HV+

VDD

CONTROL

HV-

12

34

87

65

12

34

87

65

INT201

INT202

PHASE 1

PHASE 2

PHASE 3

3-PHASE

SRM

D1

C2

C1

R1

R2

D2

D3

Q2

Q1