TMC5031 DATASHEET (Rev. 1.07 / 2013-APR-30)
11
3.1.1 VCC_IO Requirements
For a reliable start-up it is essential that VCC_IO comes up to a minimum of 1.5V before the TMC5031
leaves the reset condition. The reset condition ends earliest 50µs after the time when VSA exceeds its
undervoltage threshold of typically 4.2V, or when 5VOUT exceeds its undervoltage threshold of
typically 3.5V, whichever comes last.
THERE ARE THREE WAYS TO COME UP TO VCC_IO REQUIREMENTS
-
5VOUT can be used directly to supply VCC_IO. In this case there are no further requirements.
-
An external low drop regulator can be used in a 3.3V environment as shown in Figure 3.1.
Note, that most voltage regulators are not suitable for this application because they show a
delayed boot up. The following external regulators are proved by TRINAMIC:
This regulator can be used within the full supply voltage range when tied
to the motor supply voltage.
TS3480CX33
This regulator can be used to supply VCC_IO from 5VOUT, or from a supply
LD1117-3.3
voltage of up to 15V.
-
VCC_IO can be supplied externally as shown in Figure 3.2 . In this case it is mandatory to
connect the Schottky diode to the logic supply of the external circuitry. Please note, that the
2K resistor is not to be used with 5V I/O voltage.
22n
+VM
VCP
charge pump
100n
VSA
5V Voltage
regulator
5VOUT
100n
4.7µ
2R2
VCC
+VCC_IO
1K
VCC_IO
MSS1P3
22n
470n
2K
3.3V, only
Figure 3.2 External supply of VCC_IO (showing optional filtering for VCC)
Refer to application note no. 028 Supply Voltage Considerations: VCC_IO in TMC50xx Designs
(www.trinamic.com). Here you will find complete information about connecting VCC_IO.
www.trinamic.com
TRINAMIC [ TRINAMIC MOTION CONTROL GMBH & CO. KG. ]
