Motorola M68HC08 Reference Manual page 138

User Guide
6.5.4.2 Maximal and Minimal Current Limits Setting
Designer Reference Manual
138
Freescale Semiconductor, Inc.
VOLT_MIN_FAULT_V determines the minimal voltage when the
drive fault state should be entered. So the constants
VOLT_MIN_FAULT_V must be set according to minimal voltage
limits of the motor application. It should be changed when there are
problems with under-voltage.
Dc-bus voltage threshold mains 120V/230V [V]:
/* CAN_CHANGE_10: */
#define VOLT_120_THRESHOLD_V 150
Range: <0,VOLT_RANGE_MAX>
120 V voltage threshold setting should only be used for high-voltage
hardware. It determines if 120 or 230 V mains voltage will be detected
by software. But the VOLT_120_THRESHOLD_V detection has no
importance for the software functionality! For low-voltage hardware
the VOLT_120_THRESHOLD_V should be set to 0.
Most of current limits settings do not necessarily need to be done.
Current offset limit for fault during calibration (initialization) [V]:
/* CAN_CHANGE_4: */
#define OFFSET_MAX_CURR_V (1.65+0.225)
Range: <0,5>
When PWM is off, the default hardware determined offset should be 1.65
V.The actual offset is checked during current calibration. The fault offset
limit should be:
OFFSET_MAX_CURR_V = Default h/w offset
+ minimal allowed offset error
OFFSET_MAX_CURR_V should only be changed if there are
over-current problems during current offset calibration (at MCU
initialization).
Maximal limit of dc-bus current [A]:
/* CAN_CHANGE_3: */
#define CURR_MAX_FAULT_A 1.5
Range: <0,CURRENT_RANGE_MAX_A>
User Guide
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(EQ 6-3.)
DRM028 — Rev 0
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