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Motorola M68HC08 User Manual

Page 136

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User Guide

Designer Reference Manual

DRM028 — Rev 0

136

User Guide

MOTOROLA

Minimal measurable current determined by hardware current sensing
[A]:

/* MUST_IF_HW_CHANGE_5: */

#define CURR_HW_MIN_A (-2.93)

Range: (-infinity,0>

CURR_HW_MAX_A and CURR_HW_MIN_A

must be changed

when current sensing range is different from default hardware.

Maximal limit of dc-bus current allowable for the hardware [A]:

/* MUST_IF_HW_CHANGE_6: */

#define CURR_MAX_FAULT_A 1.5

Range: <0,CURRENT_RANGE_MAX_A>

CURR_MAX_FAULT_A determines the maximal current when the
drive fault state should be entered. So, it must be set to the maximum
current allowed for the power stage or the motor (see also

Maximal

and Minimal Current Limits Setting

)

6.5.3.5 Example of Software Customizing to Hardware

Let’s have low-voltage power stage ECLOVACBLDC modified to 42 V
(from 12 V) as described in its documentation. So, software must be
customized for hardware changes. Because of low-voltage set, the
const_cust_lv.h must be modified

1. Maximal PWM duty cycle remains the same:

#define DUTY_PWM_MAX 0.942

2. Modified maximal measurable voltage is 55 V, so set:

#define VOLT_HW_MAX 55.0

3. Maximum limit of dc-bus voltage should be set according to motor

or application requirements, but VOLT_MAX_FAULT_V

> 42V

#define VOLT_MAX_FAULT_V 63.0

4. Board modified to 42 V has maximal measurable current

unchanged

#define CURR_HW_MAX_A 2.93

#define CURR_HW_MIN_A (-2.93)

5. Maximum limit of dc-bus current should remain unchanged or set

according to motor or application requirements:

#define CURR_MAX_FAULT_A 45.0

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Freescale Semiconductor, Inc.

For More Information On This Product,

Go to: www.freescale.com

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