3940

FULL-BRIDGE POWER

MOSFET CONTROLLER

115 Northeast Cutoff, Box 15036

Worcester, Massachusetts 01615-0036 (508) 853-5000

10

Functional Description (cont’d)

Control Logic

PHASE ENABLE MODE SR

GLA

GLB GHA GHB SA SB

Mode of Operation

0

1

X

X

1

0

0

1

Lo

Hi

Reverse

0

0

0

1

0

1

1

0

Hi

Lo

Fast decay, SR enabled

0

0

1

1

1

1

0

0

Lo

Lo

Slow decay, braking mode

0

0

0

0

0

0

0

0

Z

Z

Fast decay, coast

0

0

1

0

1

0

0

0

Lo

Z

Slow decay, SR disabled

1

1

X

X

0

1

1

0

Hi

Lo

Forward

1

0

0

1

1

0

0

1

Lo

Hi

Fast decay, SR enabled

1

0

1

1

1

1

0

0

Lo

Lo

Slow decay, braking mode

1

0

0

0

0

0

0

0

Z

Z

Fast decay, coast

1

0

1

0

0

1

0

0

Z

Lo

Slow decay, SR disabled

NOTES: All faults will coast the motor, i.e., GHA = GHB = GLA = GLB = 0 to switch off all bridge MOSFETs.

X = Indicates a “don’t care”.

Z = Indicates a high-impedance state.

Fault Responses

Fault Mode

RESET FAULT CP Reg.

VREG13

VREG5

GHx

GLx

No Fault

1

0

ON

ON

ON

–

–

Short-to-Battery"#

1

1

ON

ON

ON

0

0

Short-to-Ground"$

1

1

ON

ON

ON

0

0

Open Bridge (V

1

1

ON

ON

ON

0

0

V

1

1

ON

ON&

ON

0'

0'

V

1

1

ON

ON

ON

0

0

V

1

1

OFF

OFF

ON&

0'

0'

Thermal Shutdown

1

1

OFF

OFF

ON&

0'

0'

Sleep

0

1

OFF

OFF

OFF

Z

Z

NOTES:

Other faults will not clear except when their cause is removed.

low = 0; however, with V