TMC248-LA DATASHEET (Rev. 1.01 / 2013-MAR-26)
12
Voltage VIN for reference
3V
2V
2V
1V
Typical trip voltage of the current sense comparator
1.5x340mV
340mV
0.5x340mV
t
-0.5x340mV
-340mV
-1.5x340mV
Figure 4.1 Relation between VIN and trip voltage of current sense comparator
IN CASE A VARIABLE INPUT VOLTAGE VIN IS USED THE TYPICAL TRIP VOLTAGE IS CALCULATED:
VTRIP,A = 0.17 VINA percentage SPI current setting A
VTRIP,B = 0.17 VINB percentage SPI current setting B
GENERATING INPUT VOLTAGE VIN
A maximum of 3.0V VIN is possible. Multiply the percentage of base current setting and the DAC table
to get the overall coil current. It is advised to operate at a high base current setting, to reduce the
effects of noise voltages. This feature allows a high resolution setting of the required motor current
using an external DAC or PWM-DAC (see schematic for examples).
using PWM signal
8 level via R2R-DAC
2 level control
INA
INB
µC-
PWM
µC-Port .2
47K
100K
100K
100K
R1
100nF
10nF
µC-Port .1
µC-Port .0
AGND
ANN
µC-Port
Figure 4.2 External DAC and PWM-DAC
www.trinamic.com
TRINAMIC [ TRINAMIC MOTION CONTROL GMBH & CO. KG. ]
