TMC428-I TRINAMIC, TMC428-I Datasheet - Page 33

• Manufacturer Part Number: TMC428-I
• Description: IC, MOTOR CTRL/DRVR, STEPPER, SSOP-16
• Manufacturer: TRINAMIC

Specifications of TMC428-I

• Motor Type: Stepper
• No. Of Outputs: 6
• Output Voltage: 5.5V
• Supply Voltage Range: 4.5V To 5.5V
• Driver Case Style: SSOP
• No. Of Pins: 16
• Operating Temperature Range: -40°C To +85°C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

TMC428 DATASHEET (v. 2.02 / April 26
Table 9-3: Association of reference inputs depending on configuration bits refmux & mot1r
If continuous_update is ‘1’, internal reference switch bits are updated periodically, even if all stepper
motors are at rest. Additionally, the chip select signal nSCS_S for the stepper motor driver chain is
also the control signal for a multiplexer in case of using the reference switch multiplexing option (see
Figure 9-5). So, the continuous_update must be set to ‘1’ if automatic stop by reference switches is
enabled, if six multiplexed reference switches are used, and to get the states of reference switches
while all stepper motors are at rest.
The bit named refmux must be set to ‘1’ to enable reference switch multiplexing (see Figure 9-5). For
the two variants TMC428-PI24 and TMC428-DI20, the reference switch multiplexing also works for
csCommonIndividual=’1’ using three separate driver selection signals (nSCS_S, nSCS2, nSCS3) if
the signal nSCS_S is connected to the multiplexer 74HC157 according to Figure 9-8.
If reference switch multiplexing is enabled, mot1r is ignored. With refmux set to ‘0’, the association of
the reference switch inputs REF1, REF2, REF3 depends on the setting of the configuration bit mot1r.
The power-on default value of mot1r is ‘0’. With that default value, REF1 is associated to the left
reference switch of stepper motor #1, REF2 is associated to the left reference switch of stepper motor
#2, and REF3 is associated to the left reference switch of stepper motor #3.
If mot1r is set to ‘1’ the input REF1 is also associated with the left reference switch of stepper motor
#1. REF2 is also associated to the left reference switch of stepper motor #2. But, the input REF3 is
associated to the right reference switch of stepper motor #1 and no reference switch input is
associated to stepper motor number#3 (see Figure 9-4). After power-on-reset, per default refmux=0
and mot1r=0 selects the single reference switch configuration outlined in Figure 9-3, where each
reference switch input (REF1, REF2, REF3) is assigned individually to one each stepper motor as the
left reference switch.
9.8 Triple Switch Configuration
The programmable tolerance range around the reference switch position is useful for a triple switch
configuration, as outlined in Figure 9-6. In that configuration two switches are used as automatic stop
switches, and one additional switch is used as the reference switch between the left stop switch and
the right stop switch. The left stop switch and the reference switch are wired or. After successful
reference search, programming a tolerance range into the register dx_ref_tolerance allows to disable
automatic stop within the range of the reference switch only.
Figure 9-6: Triple switch configuration 'left stop switch - reference switch - right stop switch'
Copyright © 2004-2006, TRINAMIC Motion Control GmbH & Co. KG
refmux
negative direction
0
0
1
1
mot1r
0
1
0
1
left stop
switch
x'
1
x'
left
REF1_LEFT
RE1_LEFT
left switch
x'
2
REF1
REF1
traveller
motor
x
traveler
motor 1
REF1_RIGHT
REF1_RIGHT
right switch
REF3
%
reference switch
th
, 2006)
x
1
REF2_LEFT
REF2_LEFT
left switch
x
0
REF2
REF2
x
2
motor 2
REF2_RIGHT
REF2_RIGHT
dx_ref_tolerance
right switch
%
%
REF3_LEFT
REF3_LEFT
left switch
x
REF3
3
%
x
right
right stop
switch
x
motor 3
4
REF3_RIGHT
REF3_RIGHT
right switch
positive direction
%
%
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