Motorola M68HC08 manual Maximal and Minimal Current Limits Setting, Range 0,CURRENTRANGEMAXA

Freescale Semiconductor, Inc.

Freescale Semiconductor, Inc.

User Guide

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.

6.5.4.2 Maximal and Minimal Current Limits Setting

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	(EQ 6-3.)

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>

Designer Reference Manual		DRM028 — Rev 0
138	User Guide	MOTOROLA
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