DG-IRMCK203 Datasheet, PDF (31/67 Pages) International Rectifier – Application Developer’s Guide

IRMCK203 Application Developer’s Guide
ParkTmRet - During motor start-up, dc current is injected to the motor for maximization of startup torque per ampere
rating. ParkTm controls the duration of dc current injection. However, users are able to use a longer duration after two
or more restarts by setting this parameter (ParkTmRet scaling 255 = 4 secs.). This is done to increase the chance of a
successful start-up.
RetryTm - This parameter provides the adjustment to the sampling instant for determination of start failure. The
sampling instant starts when Closed_Loop = 1. Scaling 1 count = 1.966 msec. Please do not modify this parameter
without consulting a motor drive FAE.
3.2 Standalone Operation and Register Initialization via Serial EEPROM
This section describes the register-controlled configuration and operation for an example system that uses the
IRMCK203 system in standalone mode, which requires no initialization by a host microprocessor. In standalone
mode, the IRMCK203 initializes the host write registers from an I²C serial EEPROM at power up and receives control
commands from the external hardware user interface signals during motor operation. The system described in this
example is shown in Figure 20.
IRMCx203 Motion
Control Processor
Start/Stop
DIR
FltClr
ESTOP
Fault
nSync
Motor Control
Functions
Clk
Data
Atmel
ATC24C01
128 byte
Serial
EEPROM
SCL
SDA
Host
Write
registers
Host read
Registers
IGBT gate
control (6)
GATEKILL
Intelligent IGBT
module
(IR2136 + IGBT)
20m Ohm
shunt resistors
Phase U
Phase V
Phase W
BRAKE
V-IFB
W-IFB
BRAKE
IGBT
PM
Motor
Figure 20. IRMCK203 Standalone System
3.2.1 Register Initialization via EEPROM
Each time the IRMCK203 powers up, it checks for valid EEPROM data by reading a single byte from EEPROM
address 0x5D, which represents the IRMCK203 register map version code. If this value matches the IRMCK203
internal register map version, the IRMCK203 EEPROM initialization sequencer reads 128 sequential bytes from the
EEPROM and stores them in host write registers 0 - 0x7F.
If the user sets the location in the EEPROM that corresponds to the SystemConfig register group’s ExtCtrl field to “1”,
motor operation can be controlled directly using the external user interface immediately after power-on host write
register initialization.
This document is the property of International Rectifier and may not be copied or distributed without expressed consent.
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